,,dry-,,farming ,a ,,system ,,of ,,agriculture ,,for ,,countries ,,under ,,low ,,rainfall ,,by ,,john ,a4 ,,widtsoe1 ,a4,m41 ,ph4 ,d ,,president ,,of ,,the ,,agricultural ,,college ,,of ,,utah ,,new ,,york #aibj ,,to ,,leah ,,this ,,book ,,is ,,inscribed ,,june #a1 #aiaj ,,preface ,nearly six tenths of the earth's land surface receive an annual rainfall of less than twenty inches1 and can be reclaimed for agricultural purposes only by irrigation and dry-farming4 ,a perfected world-system of irrigation will convert about one tenth of this vast area into an incomparably fruitful garden1 leaving about one half of the earth's land surface to be reclaimed1 if at all1 by the methods of dry-farming4 ,the noble system of modern agriculture has been constructed almost wholly in countries of abundant rainfall1 and its applications are those demanded for the agricultural development of humid regions4 ,until recently irrigation was given scant attention1 and dry-farming1 with its world problem of conquering one half of the earth1 was not considered4 ,these facts furnish the apology for the writing of this book4 ,one volume1 only1 in this world of many books1 and that less than a year old1 is devoted to the exposition of the accepted dry-farm practices of to-day4 ,the book now offered is the first attempt to assemble and organize the known facts of science in their relation to the production of plants1 without irrigation1 in regions of limited rainfall4 ,the needs of the actual farmer1 who must understand the principles before his practices can be wholly satisfactory1 have been kept in view primarily2 but it is hoped that the enlarging group of dry-farm investigators will also be helped by this presentation of the principles of dry-farming4 ,the subject is now growing so rapidly that there will soon be room for two classes of treatment3 one for the farmer1 and one for the technical student4 ,this book has been written far from large libraries1 and the material has been drawn from the available sources4 ,specific references are not given in the text1 but the names of investigators or institutions are found with nearly all statements of fact4 ,the files of the ,experiment ,station ,record and ,der ,jahresbericht der ,agrikultur ,chemie have taken the place of the more desirable original publications4 ,free use has been made of the publications of the experiment stations and the ,united ,states ,department of ,agriculture4 ,inspiration and suggestions have been sought and found constantly in the works of the princes of ,american soil investigation1 ,hilgard of ,california and ,king of ,wisconsin4 ,i am under deep obligation1 for assistance rendered1 to numerous friends in all parts of the country1 especially to ,professor ,l4 ,a4 ,merrill1 with whom ,i have collaborated for many years in the study of the possibilities of dry-farming in ,western ,america4 ,the possibilities of dry-farming are stupendous4 ,in the strength of youth we may have felt envious of the great ones of old2 of ,columbus looking upon the shadow of the greatest continent2 of ,balboa shouting greetings to the resting ,pacific2 of ,father ,escalante1 pondering upon the mystery of the world1 alone1 near the shores of ,america's ,dead ,sea4 ,we need harbor no such envyings1 for in the conquest of the nonirrigated and nonirrigable desert are offered as fine opportunities as the world has known to the makers and shakers of empires4 ,we stand before an undiscovered land2 through the restless1 ascending currents of heated desert air the vision comes and goes4 ,with striving eyes the desert is seen covered with blossoming fields1 with churches and homes and schools1 and1 in the distance1 with the vision is heard the laughter of happy children4 ,the desert will be conquered4 ,,john ,a4 ,,widtsoe4 ,june #a1 #aiaj4 ,,chapter ,i ,,introduction ,,dry-,,farming ,,defined ,dry-farming1 as at present understood1 is the profitable production of useful crops1 without irrigation1 on lands that receive annually a rainfall of #bj inches or less4 ,in districts of torrential rains1 high winds1 unfavorable distribution of the rainfall1 or other water-dissipating factors1 the term dry-farming is also properly applied to farming without irrigation under an annual precipitation of #be or even #cj inches4 ,there is no sharp demarcation between dry-and humid-farming4 ,when the annual precipitation is under #bj inches1 the methods of dry-farming are usually indispensable4 ,when it is over #cj inches1 the methods of humid-farming are employed2 in places where the annual precipitation is between #bj and #cj inches1 the methods to be used depend chiefly on local conditions affecting the conservation of soil moisture4 ,dry-farming1 however1 always implies farming under a comparatively small annual rainfall4 ,the term dry-farming is1 of course1 a misnomer4 ,in reality it is farming under drier conditions than those prevailing in the countries in which scientific agriculture originated4 ,many suggestions for a better name have been made4 ,scientific agriculture has-been proposed1 but all agriculture should be scientific1 and agriculture without irrigation in an arid country has no right to lay sole claim to so general a title4 ,dry-land agriculture1 which has also been suggested1 is no improvement over dry-farming1 as it is longer and also carries with it the idea of dryness4 ,instead of the name dry-farming it would1 perhaps1 be better to use the names1 arid-farming4 semiarid-farming1 humid-farming1 and irrigation-farming1 according to the climatic conditions prevailing in various parts of the world4 ,however1 at the present time the name dry-farming is in such general use that it would seem unwise to suggest any change4 ,it should be used with the distinct understanding that as far as the word dry is concerned it is a misnomer4 ,when the two words are hyphenated1 however1 a compound technical term--dry-farming--is secured which has a meaning of its own1 such as we have just defined it to be2 and dry-farming1 therefore1 becomes an addition to the lexicon4 ,dry-versus humid-farming ,dry-farming1 as a distinct branch of agriculture1 has for its purpose the reclamation1 for the use of man1 of the vast unirrigable desert or semi-desert areas of the world1 which until recently were considered hopelessly barren4 ,the great underlying principles of agriculture are the same the world over1 yet the emphasis to be placed on the different agricultural theories and practices must be shifted in accordance with regional conditions4 ,the agricultural problem of first importance in humid regions is the maintenance of soil fertility2 and since modern agriculture was developed almost wholly under humid conditions1 the system of scientific agriculture has for its central idea the maintenance of soil fertility4 ,in arid regions1 on the other hand1 the conservation of the natural water precipitation for crop production is the important problem2 and a new system of agriculture must therefore be constructed1 on the basis of the old principles1 but with the conservation of the natural precipitation as the central idea4 ,the system of dry-farming must marshal and organize all the established facts of science for the better utilization1 in plant growth1 of a limited rainfall4 ,the excellent teachings of humid agriculture respecting the maintenance of soil fertility will be of high value in the development of dry-farming1 and the firm establishment of right methods of conserving and using the natural precipitation will undoubtedly have a beneficial effect upon the practice of humid agriculture4 ,the problems of dry-farming ,the dry-farmer1 at the outset1 should know with comparative accuracy the annual rainfall over the area that he intends to cultivate4 ,he must also have a good acquaintance with the nature of the soil1 not only as regards its plant-food content1 but as to its power to receive and retain the water from rain and snow4 ,in fact1 a knowledge of the soil is indispensable in successful dry-farming4 ,only by such knowledge of the rainfall and the soil is he able to adapt the principles outlined in this volume to his special needs4 ,since1 under dry-farm conditions1 water is the limiting factor of production1 the primary problem of dry-farming is the most effective storage in the soil of the natural precipitation4 ,only the water1 safely stored in the soil within reach of the roots1 can be used in crop production4 ,of nearly equal importance is the problem of keeping the water in the soil until it is needed by plants4 ,during the growing season1 water may be lost from the soil by downward drainage or by evaporation from the surface4 ,it becomes necessary1 therefore1 to determine under what conditions the natural precipitation stored in the soil moves downward and by what means surface evaporation may be prevented or regulated4 ,the soil-water1 of real use to plants1 is that taken up by the roots and finally evaporated from the leaves4 ,a large part of the water stored in the soil is thus used4 ,the methods whereby this direct draft of plants on the soil-moisture may be regulated are1 naturally1 of the utmost importance to the dry-farmer1 and they constitute another vital problem of the science of dry-farming4 ,the relation of crops to the prevailing conditions of arid lands offers another group of important dry-farm problems4 ,some plants use much less water than others4 ,some attain maturity quickly1 and in that way become desirable for dry-farming4 ,still other crops1 grown under humid conditions1 may easily be adapted to dry-farming conditions1 if the correct methods are employed1 and in a few seasons may be made valuable dry-farm crops4 ,the individual characteristics of each crop should be known as they relate themselves to a low rainfall and arid soils4 ,after a crop has been chosen1 skill and knowledge are needed in the proper seeding1 tillage1 and harvesting of the crop4 ,failures frequently result from the want of adapting the crop treatment to arid conditions4 ,after the crop has been gathered and stored1 its proper use is another problem for the dry-farmer4 ,the composition of dry-farm crops is different from that of crops grown with an abundance of water4 ,usually1 dry-farm crops are much more nutritious and therefore should command a higher price in the markets1 or should be fed to stock in corresponding proportions and combinations4 ,the fundamental problems of dry-farming are1 then1 the storage in the soil of a small annual rainfall2 the retention in the soil of the moisture until it is needed by plants2 the prevention of the direct evaporation of soil-moisture during2 the growing season2 the regulation of the amount of water drawn from the soil by plants2 the choice of crops suitable for growth under arid conditions2 the application of suitable crop treatments1 and the disposal of dry-farm products1 based upon the superior composition of plants grown with small amounts of water4 ,around these fundamental problems cluster a host of minor1 though also important1 problems4 ,when the methods of dry-farming are understood and practiced1 the practice is always successful2 but it requires more intelligence1 more implicit obedience to nature's laws1 and greater vigilance1 than farming in countries of abundant rainfall4 ,the chapters that follow will deal almost wholly with the problems above outlined as they present themselves in the construction of a rational system of farming without irrigation in countries of limited rainfall4 ,,chapter ,,ii ,,the ,,theoretical ,,basis ,,of ,,dry-,,farming ,the confidence with which scientific investigators1 familiar with the arid regions1 have attacked the problems of dry-farming rests largely on the known relationship of the water requirements of plants to the natural precipitation of rain and snow4 ,it is a most elementary fact of plant physiology that no plant can live and grow unless it has at its disposal a sufficient amount of water4 ,the water used by plants is almost entirely taken from the soil by the minute root-hairs radiating from the roots4 ,the water thus taken into the plants is passed upward through the stem to the leaves1 where it is finally evaporated4 ,there is1 therefore1 a more or less constant stream of water passing through the plant from the roots to the leaves4 ,by various methods it is possible to measure the water thus taken from the soil4 ,while this process of taking water from the soil is going on within the plant1 a certain amount of soil-moisture is also lost by direct evaporation from the soil surface4 ,in dry-farm sections1 soil-moisture is lost only by these two methods2 for wherever the rainfall is sufficient to cause drainage from deep soils1 humid conditions prevail4 ,water for one pound dry matter ,many experiments have been conducted to determine the amount of water used in the production of one pound of dry plant substance4 ,generally1 the method of the experiments has been to grow plants in large pots containing weighed quantities of soil4 ,as needed1 weighed amounts of water were added to the pots4 ,to determine the loss of water1 the pots were weighed at regular intervals of three days to one week4 ,at harvest time1 the weight of dry matter was carefully determined for each pot4 ,since the water lost by the pots was also known1 the pounds of water used for the production of every pound of dry matter were readily calculated4 ,the first reliable experiments of the kind were undertaken under humid conditions in ,germany and other ,european countries4 ,from the mass of results1 some have been selected and presented in the following table4 ,the work was done by the famous ,german investigators1 ,wollny1 ,hellriegel1 and ,sorauer1 in the early eighties of the last century4 ,in every case1 the numbers in the table represent the number of pounds of water used for the production of one pound of ripened dry substance3 ,pounds ,of ,water ,for ,one ,pound ,of ,dry ,matter ,wollny ,hellreigel ,sorauer ,wheat #cch #dei ,oats #ffe #cgf #efi ,barley #caj #dca ,rye #ggd #cec #bcf ,corn #bcc ,buckwheat #fdf #cfc ,peas #daf #bgc ,horsebeans #bhb ,red clover #caj ,sunflowers #dij ,millet #ddg ,it is clear from the above results1 obtained in ,germany1 that the amount of water required to produce a pound of dry matter is not the same for all plants1 nor is it the same under all conditions for the same plant4 ,in fact1 as will be shown in a later chapter1 the water requirements of any crop depend upon numerous factors1 more or less controllable4 ,the range of the above ,german results is from #bcc to #ggd pounds1 with an average of about #dai pounds of water for each pound of dry matter produced4 ,during the late eighties and early nineties1 ,king conducted experiments similar to the earlier ,german experiments1 to determine the water requirements of crops under ,wisconsin conditions4 ,a summary of the results of these extensive and carefully conducted experiments is as follows3-- ,oats #che ,barley #dfd ,corn #bga ,peas #dgg ,clover #egf ,potatoes #che ,the figures in the above table1 averaging about #ddf pounds1 indicate that very nearly the same quantity of water is required for the production of crops in ,wisconsin as in ,germany4 ,the ,wisconsin results tend to be somewhat higher than those obtained in ,europe1 but the difference is small4 ,it is a settled principle of science1 as will be more fully discussed later1 that the amount of water evaporated from the soil and transpired by plant leaves increases materially with an increase in the average temperature during the growing season1 and is much higher under a clear sky and in districts where the atmosphere is dry4 ,wherever dry-farming is likely to be practiced1 a moderately high temperature1 a cloudless sky1 and a dry atmosphere are the prevailing conditions4 ,it appeared probable therefore1 that in arid countries the amount of water required for the production of one pound of dry matter would be higher than in the humid regions of ,germany and ,wisconsin4 ,to secure information on this subject1 ,widtsoe and ,merrill undertook1 in #aijj1 a series of experiments in ,utah1 which were conducted upon the plan of the earlier experimenters4 ,an average statement of the results of six years' experimentation is given in the subjoined table1 showing the number of pounds of water required for one pound of dry matter on fertile soils3-- ,wheat #ajdh ,corn #ehi ,peas #aaah ,sugar ,beets #fcj ,these ,utah findings support strongly the doctrine that the amount of water required for the production of each pound of dry matter is very much larger under arid conditions1 as in ,utah1 than under humid conditions1 as in ,germany or ,wisconsin4 ,it must be observed1 however1 that in all of these experiments the plants were supplied with water in a somewhat wasteful manner2 that is1 they were given an abundance of water1 and used the largest quantity possible under the prevailing conditions4 ,no attempt of any kind was made to economize water4 ,the results1 therefore1 represent maximum results and can be safely used as such4 ,moreover1 the methods of dry-farming1 involving the storage of water in deep soils and systematic cultivation1 were not employed4 ,the experiments1 both in ,europe and ,america1 rather represent irrigated conditions4 ,there are good reasons for believing that in ,germany1 ,wisconsin1 and ,utah the amounts above given can be materially reduced by the employment of proper cultural methods4 ,the water in the large bottle would be required to produce the grain in the small bottle4 ,in view of these findings concerning the water requirements of crops1 it cannot be far from the truth to say that1 under average cultural conditions1 approximately #gej pounds of water are required in an arid district for the production of one pound of dry matter4 ,where the aridity is intense1 this figure may be somewhat low1 and in localities of sub-humid conditions1 it will undoubtedly be too high4 ,as a maximum average1 however1 for districts interested in dry-farming1 it can be used with safety4 ,crop-producing power of rainfall ,if this conclusion1 that not more than #gej pounds of water are required under ordinary dry-farm conditions for the production of one pound of dry matter1 be accepted1 certain interesting calculations can be made respecting the possibilities of dry-farming4 ,for example1 the production of one bushel of wheat will require #fj times #gej1 or #de1jjj pounds of water4 ,the wheat kernels1 however1 cannot be produced without a certain amount of straw1 which under conditions of dry-farming seldom forms quite one half of the weight of the whole plant4 ,let us say1 however1 that the weights of straw and kernels are equal4 ,then1 to produce one bushel of wheat1 with the corresponding quantity of straw1 would require #b times #de1jjj1 or #ij1jjj pounds of water4 ,this is equal to #de tons of water for each bushel of wheat4 ,while this is a large figure1 yet1 in many localities1 it is undoubtedly well within the truth4 ,in comparison with the amounts of water that fall upon the land as rain1 it does not seem extraordinarily large4 ,one inch of water over one acre of land weighs approximately #bbf1hge pounds4 or over #aac tons4 ,if this quantity of water could be stored in the soil and used wholly for plant production1 it would produce1 at the rate of #de tons of water for each bushel1 about #b-a_/b bushels of wheat4 ,with #aj inches of rainfall1 which up to the present seems to be the lower limit of successful dry-farming1 there is a maximum possibility of producing #be bushels of wheat annually4 ,in the subjoined table1 constructed on the basis of the discussion of this chapter1 the wheat-producing powers of various degrees of annual precipitation are shown3-- ,one acre inch of water will produce #b-a_/b bushels of wheat4 ,ten acre inches of water will produce #be bushels of wheat4 ,fifteen acre inches of water will produce #cg-a_/b bushels of wheat4 ,twenty acre inches of water will produce #ej bushels of wheat4 ,it must be distinctly remembered1 however1 that under no known system of tillage can all the water that falls upon a soil be brought into the soil and stored there for plant use4 ,neither is it possible to treat a soil so that all the stored soil-moisture may be used for plant production4 ,some moisture1 of necessity1 will evaporate directly from the soil1 and some may be lost in many other ways4 ,yet1 even under a rainfall of #ab inches1 if only one half of the water can be conserved1 which experiments have shown to be very feasible1 there is a possibility of producing #cj bushels of wheat per acre every other year1 which insures an excellent interest on the money and labor invested in the production of the crop4 ,it is on the grounds outlined in this chapter that students of the subject believe that ultimately large areas of the desert may be reclaimed by means of dry-farming4 ,the real question before the dry-farmer is not1 ,is the rainfall sufficient8 but rather1 ,is it possible so to conserve and use the rainfall as to make it available for the production of profitable crops8 ,,chapter ,,iii ,,dry-,,farm ,,areas--,,rainfall ,the annual precipitation of rain and snow determines primarily the location of dry-farm areas4 ,as the rainfall varies1 the methods of dry-farming must be varied accordingly4 ,rainfall1 alone1 does not1 however1 furnish a complete index of the crop-producing possibilities of a country4 ,the distribution of the rainfall1 the amount of snow1 the water-holding power of the soil1 and the various moisture-dissipating causes1 such as winds1 high temperature1 abundant sunshine1 and low humidity frequently combine to offset the benefits of a large annual precipitation4 ,nevertheless1 no one climatic feature represents1 on the average1 so correctly dry-farming possibilities as does the annual rainfall4 ,experience has already demonstrated that wherever the annual precipitation is above #ae inches1 there is no need of crop failures1 if the soils are suitable and the methods of dry-farming are correctly employed4 ,with an annual precipitation of #aj to #ae inches1 there need be very few failures1 if proper cultural precautions are taken4 ,with our present methods1 the areas that receive less than #aj inches of atmospheric precipitation per year are not safe for dry-farm purposes4 ,what the future will show in the reclamation of these deserts1 without irrigation1 is yet conjectural4 ,arid1 semiarid1 and sub-humid ,before proceeding to an examination of the areas in the ,united ,states subject to the methods of dry-farming it may be well to define somewhat more clearly the terms ordinarily used in the description of the great territory involved in the discussion4 ,the states lying west of the #ajjth meridian are loosely spoken of as arid1 semiarid1 or sub-humid states4 ,for commercial purposes no state wants to be classed as arid and to suffer under the handicap of advertised aridity4 ,the annual rainfall of these states ranges from about #c to over #cj inches4 ,in order to arrive at greater definiteness1 it may be well to assign definite rainfall values to the ordinarily used descriptive terms of the region in question4 ,it is proposed1 therefore1 that districts receiving less than #aj inches of atmospheric precipitation annually1 be designated arid2 those receiving between #aj and #bj inches1 semiarid2 those receiving between #bj and #cj inches1 sub-humid1 and those receiving over #cj inches1 humid4 ,it is admitted that even such a classification is arbitrary1 since aridity does not alone depend upon the rainfall1 and even under such a classification there is an unavoidable overlapping4 ,however1 no one factor so fully represents varying degrees of aridity as the annual precipitation1 and there is a great need for concise definitions of the terms used in describing the parts of the country that come under dry-farming discussions4 ,in this volume1 the terms arid1 semiarid1 sub-humid and humid are used as above defined4 ,precipitation over the dry-farm territory ,nearly one half of the ,united ,states receives #bj inches or less rainfall annually2 and that when the strip receiving between #bj and #cj inches is added1 the whole area directly subject to reclamation by irrigation or dry-farming is considerably more than one half 7#fc per cent7 of the whole area of the ,united ,states4 ,eighteen states are included in this area of low rainfall4 ,the areas of these1 as given by the ,census of #aijj1 grouped according to the annual precipitation received1 are shown below3-- ,arid to ,semi-arid ,group ,total ,area ,land ,surface 7,sq4 ,miles7 ,arizona #aab1ibj ,california #aef1agb ,colorado #ajc1fde ,idaho #hd1bij ,nevada #aji1gdj ,utah #hb1aij ,wyoming #ig1ede ,,total #gdf1ecb ,semiarid to ,sub-,humid ,group ,montana #ade1caj ,nebraska #gf1hdj ,new ,mexico #aab1dfj ,north ,dakota #gj1aie ,oregon #id1efj ,south ,dakota #gf1hej ,washington #ff1hhj ,,total #fec1jie ,sub-,humid to ,humid ,group ,kansas #ha1gjj ,minnesota #gi1bje ,oklahoma #ch1hcj ,texas #bfb1bij ,,total #dfb1jbe ,,grand ,,total #a1hfa1feb ,the territory directly interested in the development of the methods of dry-farming forms #fc per cent of the whole of the continental ,united ,states1 not including ,alaska1 and covers an area of #a1hfa1feb square miles1 or #a1aia1deg1bhj acres4 ,if any excuse were needed for the lively interest taken in the subject of dry-farming1 it is amply furnished by these figures showing the vast extent of the country interested in the reclamation of land by the methods of dry-farming4 ,as will be shown below1 nearly every other large country possesses similar immense areas under limited rainfall4 ,of the one billion1 one hundred and ninety-one million1 four hundred and fifty-seven thousand1 two hundred and eighty acres 7#a1aia1deg1bhj7 representing the dry-farm territory of the ,united ,states1 about #bb per cent1 or a little more than one fifth1 is sub-humid and receives between #bj and #cj inches of rainfall1 annually2 #fa per cent1 or a little more than three fifths1 is semiarid and receives between #aj and #bj inches1 annually1 and about #ag per cent1 or a little less than one fifth1 is arid and receives less than #aj inches of rainfall1 annually4 ,these calculations are based upon the published average rainfall maps of the ,united ,states ,weather ,bureau4 ,in the far ,west1 and especially over the so-called desert regions1 with their sparse population1 meteorological stations are not numerous1 nor is it easy to secure accurate data from them4 ,it is strongly probable that as more stations are established1 it will be found that the area receiving less than #aj inches of rainfall annually is considerably smaller than above estimated4 ,in fact1 the ,united ,states ,reclamation ,service states that there are only #gj1jjj1jjj acres of desert-like land2 that is1 land which does not naturally support plants suitable for forage4 ,this area is about one third of the lands which1 so far as known1 at present receive less than #aj inches of rainfall1 or only about #f per cent of the total dry-farming territory4 ,in any case1 the semiarid area is at present most vitally interested in dry-farming4 ,the sub-humid area need seldom suffer from drouth1 if ordinary well-known methods are employed2 the arid area1 receiving less than #aj inches of rainfall1 in all probability1 can be reclaimed without irrigation only by the development of more suitable4 methods than are known to-day4 ,the semiarid area1 which is the special consideration of present-day dry-farming represents an area of over #gbe1jjj1jjj acres of land4 ,moreover1 it must be remarked that the full certainty of crops in the sub-humid regions will come only with the adoption of dry-farming methods2 and that results already obtained on the edge of the deserts lead to the belief that a large portion of the area receiving less than #aj inches of rainfall1 annually1 will ultimately be reclaimed without irrigation4 ,naturally1 not the whole of the vast area just discussed could be brought under cultivation1 even under the most favorable conditions of rainfall4 ,a very large portion of the territory in question is mountainous and often of so rugged a nature that to farm it would be an impossibility4 ,it must not be forgotten1 however1 that some of the best dry-farm lands of the ,west are found in the small mountain valleys1 which usually are pockets of most fertile soil1 under a good supply of rainfall4 ,the foothills of the mountains are almost invariably excellent dry-farm lands4 ,newell estimates that #aie1jjj1jjj acres of land in the arid to sub-humid sections are covered with a more or less dense growth of timber4 ,this timbered area roughly represents the mountainous and therefore the nonarable portions of land4 ,the same authority estimates that the desert-like lands cover an area of #gj1jjj1jjj acres4 ,making the most liberal estimates for mountainous and desert-like lands1 at least one half of the whole area1 or about #fjj1jjj1jjj acres1 is arable land which by proper methods may be reclaimed for agricultural purposes4 ,irrigation when fully developed may reclaim not to exceed #e per cent of this area4 ,from any point of view1 therefore1 the possibilities involved in dry-farming in the ,united ,states are immense4 ,dry-farm area of the world ,dry-farming is a world problem4 ,aridity is a condition met and to be overcome upon every continent4 ,mc,coll estimates that in ,australia1 which is somewhat larger than the continental ,united ,states of ,america1 only one third of the whole surface receives above #bj inches of rainfall annually2 one third receives from #aj to #bj inches1 and one third receives less than l,o inches4 ,that is1 about #a1bfg1jjj1jjj acres in ,australia are subject to reclamation by dry-farming methods4 ,this condition is not far from that which prevails in the ,united ,states1 and is representative of every continent of the world4 ,the following table gives the proportions of the earth's land surface under various degrees of annual precipitations3-- ,annual ,precipitation ,proportion of ,earth's ,land ,surface ,under #aj inches #be4j per cent ,from #aj to #bj inches #cj4j per cent ,from #bj to #dj inches #bj4j per cent ,from #dj to #fj inches #aa4j per cent ,from #fj to #hj inches #i4j per cent ,from #ajj to #abj inches #d4j per cent ,from #abj to #afj inches #j4e per cent ,above #afj inches #j4e per cent ,total #ajj per cent ,fifty-five per cent1 or more than one half of the total land surface of the earth1 receives an annual precipitation of less than #bj inches1 and must be reclaimed1 if at all1 by dry-farming4 ,at least #aj per cent more receives from #bj to #cj inches under conditions that make dry-farming methods necessary4 ,a total of about #fe per cent of the earth's land surface is1 therefore1 directly interested in dry-farming4 ,with the future perfected development of irrigation systems and practices1 not more than #aj per cent will be reclaimed by irrigation4 ,dry-farming is truly a problem to challenge the attention of the race4 ,,chapter ,,iv ,,dry-,,farm ,,areas4--,,general ,,climatic ,,features ,the dry-farm territory of the ,united ,states stretches from the ,pacific seaboard to the #ifth parallel of longitude1 and from the ,canadian to the ,mexican boundary1 making a total area of nearly #a1hjj1jjj square miles4 ,this immense territory is far from being a vast level plain4 ,on the extreme east is the ,great ,plains region of the ,mississippi ,valley which is a comparatively uniform country of rolling hills1 but no mountains4 ,at a point about one third of the whole distance westward the whole land is lifted skyward by the ,rocky ,mountains1 which cross the country from south to northwest4 ,here are innumerable peaks1 canons1 high table-lands1 roaring torrents1 and quiet mountain valleys4 ,west of the ,rockies is the great depression known as the ,great ,basin1 which has no outlet to the ocean4 ,it is essentially a gigantic level lake floor traversed in many directions by mountain ranges that are offshoots from the backbone of the ,rockies4 ,south of the ,great ,basin are the high plateaus1 into which many great chasms are cut1 the best known and largest of which is the great ,canon of the ,colorado4 ,north and east of the ,great ,basin is the ,columbia ,river ,basin characterized by basaltic rolling plains and broken mountain country4 ,to the west1 the floor of the ,great ,basin is lifted up into the region of eternal snow by the ,sierra ,nevada ,mountains1 which north of ,nevada are known as the ,cascades4 ,on the west1 the ,sierra ,nevadas slope gently1 through intervening valleys and minor mountain ranges1 into the ,pacific ,ocean4 ,it would be difficult to imagine a more diversified topography than is possessed by the dry-farm territory of the ,united ,states4 ,uniform climatic conditions are not to be expected over such a broken country4 ,the chief determining factors of climate--latitude1 relative distribution of land and water1 elevation1 prevailing winds--swing between such large extremes that of necessity the climatic conditions of different sections are widely divergent4 ,dry-farming is so intimately related to climate that the typical climatic variations must be pointed out4 ,the total annual precipitation is directly influenced by the land topography1 especially by the great mountain ranges4 ,on the east of the ,rocky ,mountains is the sub-humid district1 which receives from #bj to #cj inches of rainfall annually2 over the ,rockies themselves1 semiarid conditions prevail2 in the ,great ,basin1 hemmed in by the ,rockies on the east and the ,sierra ,nevadas on the west1 more arid conditions predominate2 to the west1 over the ,sierras and down to the seacoast1 semiarid to sub-humid conditions are again found4 ,seasonal distribution of rainfall ,it is doubtless true that the total annual precipitation is the chief factor in determining the success of dry-farming4 ,however1 the distribution of the rainfall throughout the year is also of great importance1 and should be known by the farmer4 ,a small rainfall1 coming at the most desirable season1 will have greater crop-producing power than a very much larger rainfall poorly distributed4 ,moreover1 the methods of tillage to be employed where most of the precipitation comes in winter must be considerably different from those used where the bulk of the precipitation comes in the summer4 ,the successful dry-farmer must know the average annual precipitation1 and also the average seasonal distribution of the rainfall1 over the land which he intends to dry-farm before he can safely choose his cultural methods4 ,with reference to the monthly distribution of the precipitation over the dry-farm territory of the ,united ,states1 ,henry of the ,united ,states ,weather ,bureau recognizes five distinct types2 namely3 7#a7 ,pacific1 7#b7 ,sub-,pacific1 7#c7 ,arizona1 7#d7 the ,northern ,rocky ,mountain and ,eastern ,foothills1 and 7#e7 the ,plains ,type3-- ,the ,pacific ,type4--,this type is found in all of the territory west of the ,cascade and ,sierra ,nevada ranges1 and also obtains in a fringe of country to the eastward of the mountain summits4 ,the distinguishing characteristic of the ,pacific type is a wet season1 extending from ,october to ,march1 and a practically rainless summer1 except in northern ,california and parts of ,oregon and ,washington4 ,about half of the yearly precipitation comes in the months of ,december1 ,january1 and ,february1 the remaining half being distributed throughout the seven months--,september1 ,october1 ,november1 ,march1 ,april1 ,may1 and ,june4 ,sub-,pacific ,type4--,the term ',sub-,pacific' has been given to that type of rainfall which obtains over eastern ,washington1 ,nevada1 and ,utah4 ,the influences that control the precipitation of this region are much similar to those that prevail west of the ,sierra ,nevada and ,cascade ranges4 ,there is not1 however1 as in the eastern type1 a steady diminution in the precipitation with the approach of spring1 but rather a culmination in the precipitation4 ,arizona ,type4--,the ,arizona ,type1 so called because it is more fully developed in that territory than elsewhere1 prevails over ,arizona1 ,new ,mexico1 and a small portion of eastern ,utah and ,nevada4 ,this type differs from all others in the fact that about #ce per cent of the rain falls in ,july and ,august4 ,may and ,june are generally the months of least rainfall4 ,the ,northern ,rocky ,mountain and ,eastern ,foothills ,type4--,this type is closely allied to that of the plains to the eastward1 and the bulk of the rain falls in the foothills of the region in ,april and ,may2 in ,montana1 in ,may and ,june4 ,the ,plains ,type4--,this type embraces the greater part of the ,dakotas1 ,nebraska1 ,kansas2 ,oklahoma1 the ,panhandle of ,texas1 and all the great corn and wheat states of the interior valleys4 ,this region is characterized by a scant winter precipitation over the northern states and moderately heavy rains during the growing season4 ,the4 bulk of the rains comes in ,may1 ,june1 and ,july4 ,this classification emphasizes the great variation in distribution of rainfall over the dry-farm territory of the country4 ,west of the ,rocky ,mountains the precipitation comes chiefly in winter and spring1 leaving the summers rainless2 while east of the ,rockies1 the winters are somewhat rainless and the precipitation comes chiefly in spring and summer4 ,the ,arizona type stands midway between these types4 ,this variation in the distribution of the rainfall requires that different methods be employed in storing and conserving the rainfall for crop production4 ,the adaptation of cultural methods to the seasonal distribution of rainfall will be discussed hereafter4 ,snowfall ,closely related to the distribution of the rainfall and the average annual temperature is the snowfall4 ,wherever a relatively large winter precipitation occurs1 the dry-farmer is benefited if it comes in the form of snow4 ,the fall-planted seeds are better protected by the snow2 the evaporation is lower and it appears that the soil is improved by the annual covering of snow4 ,in any case1 the methods of culture are in a measure dependent upon the amount of snowfall and the length of time that it lies upon the ground4 ,snow falls over most of the dry-farm territory1 excepting the lowlands of ,california1 the immediate ,pacific coast1 and other districts where the average annual temperature is high4 ,the heaviest snowfall is in the intermountain district1 from the west slope of the ,sierra ,nevadas to the east slope of the ,rockies4 ,the degree of snowfall on the agricultural lands is very variable and dependent upon local conditions4 ,snow falls upon all the high mountain ranges4 ,temperature ,with the exceptions of portions of ,california1 ,arizona1 and ,texas the average annual surface temperature of the dry-farm territory of the ,united ,states ranges from #dj deg to #ee deg ,f4 ,the average is not far from #de deg ,f4 ,this places most of the dry-farm territory in the class of cold regions1 though a small area on the extreme east border may be classed as temperate1 and parts of ,california and ,arizona as warm4 ,the range in temperature from the highest in summer to the lowest in winter is considerable1 but not widely different from other similar parts of the ,united ,states4 ,the range is greatest in the interior mountainous districts1 and lowest along the seacoast4 ,the daily range of the highest and lowest temperatures for any one day is generally higher over dry-farm sections than over humid districts4 ,in the ,plateau regions of the semiarid country the average daily variation is from #cj to #ce deg ,f41 while east of the ,mississippi it is only about #bj deg ,f4 ,this greater daily range is chiefly due to the clear skies and scant vegetation which facilitate excessive warming by day and cooling by night4 ,the important temperature question for the dry-farmer is whether the growing season is sufficiently warm and long to permit the maturing of crops4 ,there are few places1 even at high altitudes in the region considered1 where the summer temperature is so low as to retard the growth of plants4 ,likewise1 the first and last killing frosts are ordinarily so far apart as to allow an ample growing season4 ,it must be remembered that frosts are governed very largely by local topographic features1 and must be known from a local point of view4 ,it is a general law that frosts are more likely to occur in valleys than on hillsides1 owing to the downward drainage of the cooled air4 ,further1 the danger of frost increases with the altitude4 ,in general1 the last killing frost in spring over the dry-farm territory varies from ,march #ae to ,may #bi1 and the first killing frost in autumn from ,september #ae to ,november #ae4 ,these limits permit of the maturing of all ordinary farm crops1 especially the grain crops4 ,relative humidity ,at a definite temperature1 the atmosphere can hold only a certain amount of water vapor4 ,when the air can hold no more1 it is said to be saturated4 ,when it is not saturated1 the amount of water vapor actually held by the air is expressed in percentages of the quantity required for saturation4 ,a relative humidity of #ajj per cent means that the air is saturated2 of #ej per cent1 that it is only one half saturated4 ,the drier the air is1 the more rapidly does the water evaporate into it4 ,to the dry-farmer1 therefore1 the relative humidity or degree of dryness of the air is of very great importance4 ,according to ,professor ,henry1 the chief characteristics of the geographic distribution of relative humidity in the ,united ,states are as follows3-- 7#a7 ,along the coasts there is a belt of high humidity at all seasons1 the percentage of saturation ranging from #ge to #hj per cent4 7#b7 ,inland1 from about the #gjth meridian eastward to the ,atlantic coast1 the amount varies between #gj and #ge per cent4 7#c7 ,the dry region is in the ,southwest1 where the average annual value is not over #ej per cent4 ,in this region are included ,arizona1 ,new ,mexico1 western ,colorado1 and the greater portion of both ,utah and ,nevada4 ,the amount of annual relative humidity in the remaining portion of the elevated district1 between the #ajjth meridian on the east to the ,sierra ,nevada and the ,cascades on the west1 varies between #ee and #fe per cent4 ,in ,july1 ,august1 and ,september1 the mean values in the ,southwest sink as low as #bj to #cj per cent1 while along the ,pacific coast districts they continue about #hj per cent the year round4 ,in the ,atlantic coast districts1 and generally east from the ,mississippi ,river1 the variation from month to month is not great4 ,april is probably the driest month of the year4 ,the air of the dry-farm territory1 therefore1 on the whole1 contains considerably less than two thirds the amount of moisture carried by the air of the humid states4 ,this means that evaporation from plant leaves and soil surfaces will go on more rapidly in semiarid than in humid regions4 ,against this danger1 which cannot he controlled1 the dry-farmer must take special precautions4 ,sunshine ,the amount of sunshine in a dry-farm section is also of importance4 ,direct sunshine promotes plant growth1 but at the same time it accelerates the evaporation of water from the soil4 ,the whole dry-farm territory receives more sunshine than do the humid sections4 ,in fact1 the amount of sunshine may roughly be said to increase as the annual rainfall decreases4 ,over the larger part of the arid and semiarid sections the sun shines over #gj per cent of the time4 ,winds ,the winds of any locality1 owing to their moisture-dissipating power play an important part in the success of dry-farming4 ,a persistent wind will offset much of the benefit of a heavy rainfall and careful cultivation4 ,while great general laws have been formulated regarding the movements of the atmosphere1 they are of minor value in judging the effect of wind on any farming district4 ,local observations1 however1 may enable the farmer to estimate the probable effect of the winds and thus to formulate proper cultural means of protection4 ,in general1 those living in a district are able to describe it without special observations as windy or quiet4 ,in the dry-farm territory of the ,united ,states the one great region of relatively high and persistent winds is the ,great ,plains region east of the ,rocky ,mountains4 ,dry-farmers in that section will of necessity be obliged to adopt cultural methods that will prevent the excessive evaporation naturally induced by the unhindered wind1 and the possible blowing of well-tilled fallow land4 ,summary ,the dry-farm territory is characterized by a low rainfall1 averaging between #aj and #bj inches1 the distribution of which falls into two distinct types3 a heavy winter and spring with a light summer precipitation1 and a heavy spring and summer with a light winter precipitation4 ,snow falls over most of the territory1 but does not lie long outside of the mountain states4 ,the whole dry-farm territory may be classed as temperate to cold2 relatively high and persistent winds blow only over the ,great ,plains1 though local conditions cause strong regular winds in many other places2 the air is dry and the sunshine is very abundant4 ,in brief1 little water falls upon the dry-farm territory1 and the climatic factors are of a nature to cause rapid evaporation4 ,in view of this knowledge1 it is not surprising that thousands of farmers1 employing1 often carelessly agricultural methods developed in humid sections1 have found only hardships and poverty on the present dry-farm empire of the ,united ,states4 ,drouth ,drouth is said to be the arch enemy of the dry-farmer1 but few agree upon its meaning4 ,for the purposes of this volume1 drouth may be defined as a condition under which crops fail to mature because of an insufficient supply of water4 ,providence has generally been charged with causing drouths1 but under the above definition1 man is usually the cause4 ,occasionally1 relatively dry years occur1 but they are seldom dry enough to cause crop failures if proper methods of farming have been practiced4 ,there are four chief causes of drouth3 7#a7 ,improper or careless preparation of the soil2 7#b7 failure to store the natural precipitation in the soil2 7#c7 failure to apply proper cultural methods for keeping the moisture in the soil until needed by plants1 and 7#d7 sowing too much seed for the available soil-moisture4 ,crop failures due to untimely frosts1 blizzards1 cyclones1 tornadoes1 or hail may perhaps be charged to ,providence1 but the dry-farmer must accept the responsibility for any crop injury resulting from drouth4 ,a fairly accurate knowledge of the climatic conditions of the district1 a good understanding of the principles of agriculture without irrigation under a low rainfall1 and a vigorous application of these principles as adapted to the local climatic conditions will make dry-farm failures a rarity4 ,,chapter ,v ,,dry-,,farm ,,soils ,important as is the rainfall in making dry-farming successful1 it is not more so than the soils of the dry-farms4 ,on a shallow soil1 or on one penetrated with gravel streaks1 crop failures are probable even under a large rainfall2 but a deep soil of uniform texture1 unbroken by gravel or hardpan1 in which much water may be stored1 and which furnishes also an abundance of feeding space for the roots1 will yield large crops even under a very small rainfall4 ,likewise1 an infertile soil1 though it be deep1 and under a large precipitation1 cannot be depended on for good crops2 but a fertile soil1 though not quite so deep1 nor under so large a rainfall1 will almost invariably bring large crops to maturity4 ,a correct understanding of the soil1 from the surface to a depth of ten feet1 is almost indispensable before a safe ,judgment can be pronounced upon the full dry-farm possibilities of a district4 ,especially is it necessary to know 7a7 the depth1 7b7 the uniformity of structure1 and 7c7 the relative fertility of the soil1 in order to plan an intelligent system of farming that will be rationally adapted to the rainfall and other climatic factors4 ,it is a matter of regret that so much of our information concerning the soils of the dry-farm territory of the ,united ,states and other countries has been obtained according to the methods and for the needs of humid countries1 and that1 therefore1 the special knowledge of our arid and semiarid soils needed for the development of dry-farming is small and fragmentary4 ,what is known to-day concerning the nature of arid soils and their relation to cultural processes under a scanty rainfall is due very largely to the extensive researches and voluminous writings of ,dr4 ,e4 ,w4 ,hilgard1 who for a generation was in charge of the agricultural work of the state of ,california4 ,future students of arid soils must of necessity rest their investigations upon the pioneer work done by ,dr4 ,hilgard4 ,the contents of this chapter are in a large part gathered from ,hilgard's writings4 ,the formation of soils ,soil is the more or less loose and friable material in which1 by means of their roots1 plants may or do find a foothold and nourishment1 as well as other conditions of growth4 ,soil is formed by a complex process1 broadly known as weathering1 from the rocks which constitute the earth's crust4 ,soil is in fact only pulverized and altered rock4 ,the forces that produce soil from rocks are of two distinct classes1 physical and chemical4 ,the physical agencies of soil production merely cause a pulverization of the rock2 the chemical agencies1 on the other hand1 so thoroughly change the essential nature of the soil particles that they are no longer like the rock from which they were formed4 ,of the physical agencies1 temperature changes are first in order of time1 and perhaps of first importance4 ,as the heat of the day increases1 the rock expands1 and as the cold night approaches1 contracts4 ,this alternate expansion and contraction1 in time1 cracks the surfaces of the rocks4 ,into the tiny crevices thus formed water enters from the falling snow or rain4 ,when winter comes1 the water in these cracks freezes to ice1 and in so doing expands and widens each of the cracks4 ,as these processes are repeated from day to day1 from year to year1 and from generation to generation1 the surfaces of the rocks crumble4 ,the smaller rocks so formed are acted upon by the same agencies1 in the same manner1 and thus the process of pulverization goes on4 ,it is clear1 then1 that the second great agency of soil formation1 which always acts in conjunction with temperature changes1 is freezing water4 ,the rock particles formed in this manner are often washed down into the mountain valleys1 there caught by great rivers1 ground into finer dust1 and at length deposited in the lower valleys4 ,moving water thus becomes another physical agency of soil production4 ,most of the soils covering the great dry-farm territory of the ,united ,states and other countries have been formed in this way4 ,in places1 glaciers moving slowly down the canons crush and grind into powder the rock over which they pass and deposit it lower down as soils4 ,in other places1 where strong winds blow with frequent regularity1 sharp soil grains are picked up by the air and hurled against the rocks1 which1 under this action1 are carved into fantastic forms4 ,in still other places1 the strong winds carry soil over long distances to be mixed with other soils4 ,finally1 on the seashore the great waves dashing against the rocks of the coast line1 and rolling the mass of pebbles back and forth1 break and pulverize the rock until soil is formed4 ,glaciers1 winds1 and waves are also1 therefore1 physical agencies of soil formation4 ,it may be noted that the result of the action of all these agencies is to form a rock powder1 each particle of which preserves the composition that it had while it was a constituent part of the rock4 ,it may further be noted that the chief of these soil-forming agencies act more vigorously in arid than in humid sections4 ,under the cloudless sky and dry atmosphere of regions of limited rainfall1 the daily and seasonal temperature changes are much greater than in sections of greater rainfall4 ,consequently the pulverization of rocks goes on most rapidly in dry-farm districts4 ,constant heavy winds1 which as soil formers are second only to temperature changes and freezing water1 are also usually more common in arid than in humid countries4 ,this is strikingly shown1 for instance1 on the ,colorado desert and the ,great ,plains4 ,the rock powder formed by the processes above described is continually being acted upon by agencies1 the effect of which is to change its chemical composition4 ,chief of these agencies is water1 which exerts a solvent action on all known substances4 ,pure water exerts a strong solvent action1 but when it has been rendered impure by a variety of substances1 naturally occurring1 its solvent action is greatly increased4 ,the most effective water impurity1 considering soil formation1 is the gas1 carbon dioxid4 ,this gas is formed whenever plant or animal substances decay1 and is therefore found1 normally1 in the atmosphere and in soils4 ,rains or flowing water gather the carbon dioxid from the atmosphere and the soil2 few natural waters are free from it4 ,the hardest rock particles are disintegrated by carbonated water1 while limestones1 or rocks containing lime1 are readily dissolved4 ,the result of the action of carbonated water upon soil particles is to render soluble1 and therefore more available to plants1 many of the important plant-foods4 ,in this way the action of water1 holding in solution carbon dioxid and other substances1 tends to make the soil more fertile4 ,the second great chemical agency of soil formation is the oxygen of the air4 ,oxidation is a process of more or less rapid burning1 which tends to accelerate the disintegration of rocks4 ,finally1 the plants growing in soils are powerful agents of soil formation4 ,first1 the roots forcing their way into the soil exert a strong pressure which helps to pulverize the soil grains2 secondly1 the acids of the plant roots actually dissolve the soil1 and third1 in the mass of decaying plants1 substances are formed1 among them carbon dioxid1 that have the power of making soils more soluble4 ,it may be noted that moisture1 carbon dioxid1 and vegetation1 the three chief agents inducing chemical changes in soils1 are most active in humid districts4 ,while1 therefore1 the physical agencies of soil formation are most active in arid climates1 the same cannot be said of the chemical agencies4 ,however1 whether in arid or humid climates1 the processes of soil formation1 above outlined1 are essentially those of the fallow or resting-period given to dry-farm lands4 ,the fallow lasts for a few months or a year1 while the process of soil formation is always going on and has gone on for ages2 the result1 in quality though not in quantity1 is the same--the rock particles are pulverized and the plant-foods are liberated4 ,it must be remembered in this connection that climatic differences may and usually do influence materially the character of soils formed from one and the same kind of rock4 ,characteristics of arid soils ,the net result of the processes above described ,is a rock powder containing a great variety of sizes of soil grains intermingled with clay4 ,the larger soil grains are called sand2 the smaller1 silt1 and those that are so small that they do not settle from quiet water after #bd hours are known as clay4 ,clay differs materially from sand and silt1 not only in size of particles1 but also in properties and formation4 ,it is said that clay particles reach a degree of fineness equal to #a_/bejj of an inch4 ,clay itself1 when wet and kneaded1 becomes plastic and adhesive and is thus easily distinguished from sand4 ,because of these properties1 clay is of great value in holding together the larger soil grains in relatively large aggregates which give soils the desired degree of filth4 ,moreover1 clay is very retentive of water1 gases1 and soluble plant-foods1 which are important factors in successful agriculture4 ,soils1 in fact1 are classified according to the amount of clay that they contain4 ,hilgard suggests the following classification3-- ,very sandy soils #j4e to #c per cent clay ,ordinary sandy soils #c4j to #aj per cent clay ,sandy loams #aj4j to #ae per cent clay ,clay loams #ae4j to #be per cent clay ,clay soils #be4j to #ce per cent clay ,heavy clay soils #ce4j per cent and over ,clay may be formed from any rock containing some form of combined silica 7quartz74 ,thus1 granites and crystalline rocks generally1 volcanic rocks1 and shales will produce clay if subjected to the proper climatic conditions4 ,in the formation of clay1 the extremely fine soil particles are attacked by the soil water and subjected to deep-going chemical changes4 ,in fact1 clay represents the most finely pulverized and most highly decomposed and hence in a measure the most valuable portion of the soil4 ,in the formation of clay1 water is the most active agent1 and under humid conditions its formation is most rapid4 ,it follows that dry-farm soils formed under a more or less rainless climate contain less clay than do humid soils4 ,this difference is characteristic1 and accounts for the statement frequently made that heavy clay soils are not the best for dry-farm purposes4 ,the fact is1 that heavy clay soils are very rare in arid regions2 if found at all1 they have probably been formed under abnormal conditions1 as in high mountain valleys1 or under prehistoric humid climates4 ,sand4--,the sand-forming rocks that are not capable of clay production usually consist of uncombined silica or quartz1 which when pulverized by the soil-forming agencies give a comparatively barren soil4 ,thus it has come about that ordinarily a clayey soil is considered strong and a sandy soil weak4 ,though this distinction is true in humid climates where clay formation is rapid1 it is not true in arid climates1 where true clay is formed very slowly4 ,under conditions of deficient rainfall1 soils are naturally less clayey1 but as the sand and silt particles are produced from rocks which under humid conditions would yield clay1 arid soils are not necessarily less fertile4 ,experiment has shown that the fertility in the sandy soils of arid sections is as large and as available to plants as in the clayey soils of humid regions4 ,experience in the arid section of ,america1 in ,egypt1 ,india1 and other desert-like regions has further proved that the sands of the deserts produce excellent crops whenever water is applied to them4 ,the prospective dry-farmer1 therefore1 need not be afraid of a somewhat sandy soil1 provided it has been formed under arid conditions4 ,in truth1 a degree of sandiness is characteristic of dry-farm soils4 ,the humus content forms another characteristic difference between arid and humid soils4 ,in humid regions plants cover the soil thickly2 in arid regions they are bunched scantily over the surface2 in the former case the decayed remnants of generations of plants form a large percentage of humus in the upper soil2 in the latter1 the scarcity of plant life makes the humus content low4 ,further1 under an abundant rainfall the organic matter in the soil rots slowly2 whereas in dry warm climates the decay is very complete4 ,the prevailing forces in all countries of deficient rainfall therefore tend to yield soils low in humus4 ,while the total amount of humus in arid soils is very much lower than in humid soils1 repeated investigation has shown that it contains about #c-a_/b times more nitrogen than is found in humus formed under an abundant rainfall4 ,owing to the prevailing sandiness of dry-farm soils1 humus is not needed so much to give the proper filth to the soil as in the humid countries where the content of clay is so much higher4 ,since1 for dry-farm purposes1 the nitrogen content is the most important quality of the humus1 the difference between arid and humid soils1 based upon the humus content1 is not so great as would appear at first sight4 ,soil and subsoil4--,in countries of abundant rainfall1 a great distinction exists between the soil and the subsoil4 ,the soil is represented by the upper few inches which are filled with the remnants of decayed vegetable matter and modified by plowing1 harrowing1 and other cultural operations4 ,the subsoil has been profoundly modified by the action of the heavy rainfall1 which1 in soaking through the soil1 has carried with it the finest soil grains1 especially the clay1 into the lower soil layers4 ,in time1 the subsoil has become more distinctly clayey than the topsoil4 ,lime and other soil ingredients have likewise been carried down by the rains and deposited at different depths in the soil or wholly washed away4 ,ultimately1 this results in the removal from the topsoil of the necessary plant-foods and the accumulation in the subsoil of the fine clay particles which so compact the subsoil as to make it difficult for roots and even air to penetrate it4 ,the normal process of weathering or soil disintegration will then go on most actively in the topsoil and the subsoil will remain unweathered and raw4 ,this accounts for the well-known fact that in humid countries any subsoil that may have been plowed up is reduced to a normal state of fertility and crop production only after several years of exposure to the elements4 ,the humid farmer1 knowing this1 is usually very careful not to let his plow enter the subsoil to any great depth4 ,in the arid regions or wherever a deficient rainfall prevails1 these conditions are entirely reversed4 ,the light rainfall seldom completely fills the soil pores to any considerable depth1 but it rather moves down slowly as a him1 enveloping the soil grains4 ,the soluble materials of the soil are1 in part at least1 dissolved and carried down to the lower limit of the rain penetration1 but the clay and other fine soil particles are not moved downward to any great extent4 ,these conditions leave the soil and subsoil of approximately equal porosity4 ,plant roots can then penetrate the soil deeply1 and the air can move up and down through the soil mass freely and to considerable depths4 ,as a result1 arid soils are weathered and made suitable for plant nutrition to very great depths4 ,in fact1 in dry-farm regions there need be little talk about soil and subsoil1 since the soil is uniform in texture and usually nearly so in composition1 from the top down to a distance of many feet4 ,many soil sections #ej or more feet in depth are exposed in the dry-farming territory of the ,united ,states1 and it has often been demonstrated that the subsoil to any depth is capable of producing1 without further weathering1 excellent yields of crops4 ,this granular1 permeable structure1 characteristic of arid soils1 is perhaps the most important single quality resulting from rock disintegration under arid conditions4 ,as ,hilgard remarks1 it would seem that the farmer in the arid region owns from three to four farms1 one above the other1 as compared with the same acreage in the eastern states4 ,this condition is of the greatest importance in developing the principles upon which successful dry-farming rests4 ,further1 it may be said that while in the humid ,east the farmer must be extremely careful not to turn up with his plow too much of the inert subsoil1 no such fear need possess the western farmer4 ,on the contrary1 he should use his utmost endeavor to plow as deeply as possible in order to prepare the very best reservoir for the falling waters and a place for the development of plant roots4 ,gravel seams4--,it need be said1 however1 that in a number of localities in the dry-farm territory the soils have been deposited by the action of running water in such a way that the otherwise uniform structure of the soil is broken by occasional layers of loose gravel4 ,while this is not a very serious obstacle to the downward penetration of roots1 it is very serious in dry-farming1 since any break in the continuity of the soil mass prevents the upward movement of water stored in the lower soil depths4 ,the dry-farmer should investigate the soil which he intends to use to a depth of at least #h to #aj feet to make sure1 first of all1 that he has a continuous soil mass1 not too clayey in the lower depths1 nor broken by deposits of gravel4 ,hardpan4--,instead of the heavy clay subsoil of humid regions1 the so-called hardpan occurs in regions of limited rainfall4 ,the annual rainfall1 which is approximately constant1 penetrates from year to year very nearly to the same depth4 ,some of the lime found so abundantly in arid soils is dissolved and worked down yearly to the lower limit of the rainfall and left there to enter into combination with other soil ingredients4 ,continued through long periods of time this results in the formation of a layer of calcareous material at the average depth to which the rainfall has penetrated the soil4 ,not only is the lime thus carried down1 but the finer particles are carried down in like manner4 ,especially where the soil is poor in lime is the clay worked down to form a somewhat clayey hardpan4 ,a hardpan formed in such a manner is frequently a serious obstacle to the downward movement of the roots1 and also prevents the annual precipitation from moving down far enough to be beyond the influence of the sunshine and winds4 ,it is fortunate1 however1 that in the great majority of instances this hardpan gradually disappears under the influence of proper methods of dry-farm tillage4 ,deep plowing and proper tillage1 which allow the rain waters to penetrate the soil1 gradually break up and destroy the hardpan1 even when it is #aj feet below the surface4 ,nevertheless1 the farmer should make sure whether or not the hardpan does exist in the soil and plan his methods accordingly4 ,if a hardpan is present1 the land must be fallowed more carefully every other year1 so that a large quantity of water may be stored in the soil to open and destroy the hardpan4 ,of course1 in arid as in humid countries1 it often happens that a soil is underlaid1 more or less near the surface1 by layers of rock1 marl deposits1 and similar impervious or hurtful substances4 ,such deposits are not to be classed with the hardpans that occur normally wherever the rainfall is small4 ,leaching4--,fully as important as any of the differences above outlined are those which depend definitely upon the leaching power of a heavy rainfall4 ,in countries where the rainfall is #cj inches or over1 and in many places where the rainfall is considerably less1 the water drains through the soil into the standing ground water4 ,there is1 therefore1 in humid countries1 a continuous drainage through the soil after every rain1 and in general there is a steady downward movement of soil-water throughout the year4 ,as is clearly shown by the appearance1 taste1 and chemical composition of drainage waters1 this process leaches out considerable quantities of the soluble constituents of the soil4 ,when the soil contains decomposing organic matter1 such as roots1 leaves1 stalks1 the gas carbon dioxid is formed1 which1 when dissolved in water1 forms a solution of great solvent power4 ,water passing through well-cultivated soils containing much humus leaches out very much more material than pure water could do4 ,a study of the composition of the drainage waters from soils and the waters of the great rivers shows that immense quantities of soluble soil constituents are taken out of the soil in countries of abundant rainfall4 ,these materials ultimately reach the ocean1 where they are and have been concentrated throughout the ages4 ,in short1 the saltiness of the ocean is due to the substances that have been washed from the soils in countries of abundant rainfall4 ,in arid regions1 on the other hand1 the rainfall penetrates the soil only a few feet4 ,in time1 it is returned to the surface by the action of plants or sunshine and evaporated into the air4 ,it is true that under proper methods of tillage even the light rainfall of arid and semiarid regions may he made to pass to considerable soil depths1 yet there is little if any drainage of water through the soil into the standing ground water4 ,the arid regions of the world1 therefore1 contribute proportionately a small amount of the substances which make up the salt of the sea4 ,alkali soils4--,under favorable conditions it sometimes happens that the soluble materials1 which would normally be washed out of humid soils1 accumulate to so large a degree in arid soils as to make the lands unfitted for agricultural purposes4 ,such lands are called alkali lands4 ,unwise irrigation in arid climates frequently produces alkali spots1 but many occur naturally4 ,such soils should not be chosen for dry-farm purposes1 for they are likely to give trouble4 ,plant-food content4--,this condition necessarily leads at once to the suggestion that the soils from the two regions must differ greatly in their fertility or power to produce and sustain plant life4 ,it cannot be believed that the water-washed soils of the ,east retain as much fertility as the dry soils of the ,west4 ,hilgard has made a long and elaborate study of this somewhat difficult question and has constructed a table showing the composition of typical soils of representative states in the arid and humid regions4 ,the following table shows a few of the average results obtained by him3-- ,partial ,percentage ,composition ,source of soil ,humid ,arid ,number of samples analyzed #fif #egc ,insoluble residue #hd4ag #fi4af ,soluble silica #d4jd #f4ga ,alumina #c4ff #g4fa ,lime #j4ac #a4dc ,potash #j4ba #j4fg ,phos4 ,acid #j4ab #j4af ,humus #a4bb #a4ac ,soil chemists have generally attempted to arrive at a determination of the fertility of soil by treating a carefully selected and prepared sample with a certain amount of acid of definite strength4 ,the portion which dissolves under the influence of acids has been looked upon as a rough measure of the possible fertility of the soil4 ,the column headed ,insoluble ,residue shows the average proportions of arid and humid soils which remain undissolved by acids4 ,it is evident at once that the humid soils are much less soluble in acids than arid soils1 the difference being #hd to #fi4 ,since the only plant-food in soils that may be used for plant production is that which is soluble1 it follows that it is safe to assume that arid soils are generally more fertile than humid soils4 ,this is borne out by a study of the constituents of the soil4 ,for instance1 potash1 one of the essential plant foods ordinarily present in sufficient amount1 is found in humid soils to the extent of #j4ba per cent1 while in arid soils the quantity present is #j4fg per cent1 or over three times as much4 ,phosphoric acid1 another of the very important plant-foods1 is present in arid soils in only slightly higher quantities than in humid soils4 ,this explains the somewhat well-known fact that the first fertilizer ordinarily required by arid soils is some form of phosphorus3 ,the difference in the chemical composition of arid and humid soils is perhaps shown nowhere better than in the lime content4 ,there is nearly eleven times more lime in arid than in humid soils4 ,conditions of aridity favor strongly the formation of lime1 and since there is very little leaching of the soil by rainfall1 the lime accumulates in the soil4 ,the presence of large quantities of lime in arid soils has a number of distinct advantages1 among which the following are most important3 7#a7 ,it prevents the sour condition frequently present in humid climates1 where much organic material is incorporated with the soil4 7#b7 ,when other conditions are favorable1 it encourages bacterial life which1 as is now a well-known fact1 is an important factor in developing and maintaining soil fertility4 7#c7 ,by somewhat subtle chemical changes it makes the relatively small percentages of other plant-foods notably phosphoric acid and potash1 more available for plant growth4 7#d7 ,it aids to convert rapidly organic matter into humus which represents the main portion of the nitrogen content of the soil4 ,of course1 an excess of lime in the soil may be hurtful1 though less so in arid than in humid regions4 ,some authors state that from #h to #bj per cent of calcium carbonate makes a soil unfitted for plant growth4 ,there are1 however1 a great many agricultural soils covering large areas and yielding very abundant crops which contain very much larger quantities of calcium carbonate4 ,for instance1 in the ,sanpete ,valley of ,utah1 one of the most fertile sections of the ,great ,basin1 agricultural soils often contain as high as #dj per cent of calcium carbonate1 without injury to their crop-producing power4 ,in the table are two columns headed ,soluble ,silica and ,alumina1 in both of which it is evident that a very much larger per cent is found in the arid than in the humid soils4 ,these soil constituents indicate the condition of the soil with reference to the availability of its fertility for plant use4 ,the higher the percentage of soluble silica and alumina1 the more thoroughly decomposed1 in all probability1 is the soil as a whole and the more readily can plants secure their nutriment from the soil4 ,it will be observed from the table1 as previously stated1 that more humus is found in humid than in arid soils1 though the difference is not so large as might be expected4 ,it should be recalled1 however1 that the nitrogen content of humus formed under rainless conditions is many times larger than that of humus formed in rainy countries1 and that the smaller per cent of humus in dry-farming countries is thereby offset4 ,all in all1 the composition of arid soils is very much more favorable to plant growth than that of humid soils4 ,as will be shown in ,chapter ,,ix1 the greater fertility of arid soils is one of the chief reasons for dry-farming success4 ,depth of the soil alone does not suffice4 ,there must be a large amount of high fertility available for plants in order that the small amount of water can be fully utilized in plant growth4 ,summary of characteristics4--,arid soils differ from humid soils in that they contain3 less clay2 more sand1 but of fertile nature because it is derived from rocks that in humid countries would produce clay2 less humus1 but that of a kind which contains about #c-a_/b times more nitrogen than the humus of humid soils2 more lime1 which helps in a variety of ways to improve the agricultural value of soils2 more of all the essential plant-foods1 because the leaching by downward drainage is very small in countries of limited rainfall4 ,further1 arid soils show no real difference between soil and subsoil2 they are deeper and more permeable2 they are more uniform in structure2 they have hardpans instead of clay subsoil1 which1 however1 disappear under the influence of cultivation2 their subsoils to a depth of ten feet or more are as fertile as the topsoil1 and the availability of the fertility is greater4 ,the failure to recognize these characteristic differences between arid and humid soils has been the chief cause for many crop failures in the more or less rainless regions of the world4 ,this brief review shows that1 everything considered1 arid soils are superior to humid soils4 ,in ease of handling1 productivity1 certainty of crop-lasting quality1 they far surpass the soils of the countries in which scientific agriculture was founded4 ,as ,hilgard has suggested1 the historical datum that the majority of the most populous and powerful historical peoples of the world have been located on soils that thirst for water1 may find its explanation in the intrinsic value of arid soils4 ,from ,babylon to the ,united ,states is a far cry2 but it is one that shouts to the world the superlative merits of the soil that begs for water4 ,to learn how to use the desert is to make it blossom like the rose4 ,soil divisions ,the dry-farm territory of the ,united ,states may be divided roughly into five great soil districts1 each of which includes a great variety of soil types1 most of which are poorly known and mapped4 ,these districts are3-- #a4 ,great ,plains district4 #b4 ,columbia ,river district #c4 ,great ,basin district4 #d4 ,colorado ,river district4 #e4 ,california district4 ,great ,plains district4--,on the eastern slope of the ,rocky ,mountains1 extending eastward to the extreme boundary of the dry-farm territory1 are the soils of the ,high ,plains and the ,great ,plains4 ,this vast soil district belongs to the drainage basin of the ,missouri1 and includes ,north and ,south ,dakota1 ,nebraska1 ,kansas1 ,oklahoma1 and parts of ,montana1 ,wyoming1 ,colorado1 ,new ,mexico1 ,texas1 and ,minnesota4 ,the soils of this district are usually of high fertility4 ,they have good lasting power1 though the effect of the higher rainfall is evident in their composition4 ,many of the distinct types of the plains soils have been determined with considerable care by ,snyder and ,lyon1 and may be found described in ,bailey's ,cyclopedia of ,american ,agriculture1 ,vol4 ,i4 ,columbia ,river district4--,the second great soil district of the dry-farming territory is located in the drainage basin of the ,columbia ,river1 and includes ,idaho and the eastern two thirds of ,washington and ,oregon4 ,the high plains of this soil district are often spoken of as the ,palouse country4 ,the soils of the western part of this district are of basaltic origin2 over the southern part of ,idaho the soils have been made from a somewhat recent lava flow which in many places is only a few feet below the surface4 ,the soils of this district are generally of volcanic origin and very much alike4 ,they are characterized by the properties which normally belong to volcanic soils2 somewhat poor in lime1 but rich in potash and phosphoric acid4 ,they last well under ordinary methods of tillage4 ,the ,great ,basin4--,the third great soil district is included in the ,great ,basin1 which covers nearly all of ,nevada1 half of ,utah1 and takes small portions out of ,idaho1 ,oregon1 and southern ,california4 ,this basin has no outlet to the sea4 ,its rivers empty into great saline inland lakes1 the chief of which is the ,great ,salt ,lake4 ,the sizes of these interior lakes are determined by the amounts of water flowing into them and the rates of evaporation of the water into the dry air of the region4 ,in recent geological times1 the ,great ,basin was filled with water1 forming a vast fresh-water lake known as ,lake ,bonneville1 which drained into the ,columbia ,river4 ,during the existence of this lake1 soil materials were washed from the mountains into the lake and deposited on the lake bottom4 ,when at length1 the lake disappeared1 the lake bottom was exposed and is now the farming lands of the ,great ,basin district4 ,the soils of this district are characterized by great depth and uniformity1 an abundance of lime1 and all the essential plant-foods with the exception of phosphoric acid1 which1 while present in normal quantities1 is not unusually abundant4 ,the ,great ,basin soils are among the most fertile on the ,american ,continent4 ,colorado ,river district4--,the fourth soil district lies in the drainage basin of the ,colorado ,river ,it includes much of the southern part of ,utah1 the eastern part of ,colorado1 part of ,new ,mexico1 nearly all of ,arizona1 and part of southern ,california4 ,this district1 in its northern part1 is often spoken of as the ,high ,plateaus4 ,the soils are formed from the easily disintegrated rocks of comparatively recent geological origin1 which themselves are said to have been formed from deposits in a shallow interior sea which covered a large part of the ,west4 ,the rivers running through this district have cut immense canons with perpendicular walls which make much of this country difficult to traverse4 ,some of the soils are of an extremely fine nature1 settling firmly and requiring considerable tillage before they are brought to a proper condition of tilth4 ,in many places the soils are heavily charged with calcium sulfate1 or crystals of the ordinary land plaster4 ,the fertility of the soils1 however1 is high1 and when they are properly cultivated1 they yield large and excellent crops4 ,california district4--,the fifth soil district lies in ,california in the basin of the ,sacramento and ,san ,joaquin rivers4 ,the soils are of the typical arid kind of high fertility and great lasting powers4 ,they represent some of the most valuable dry-farm districts of the ,west4 ,these soils have been studied in detail by ,hilgard4 ,dry-farming in the five districts4--,it is interesting to note that in all of these five great soil districts dry-farming has been tried with great success4 ,even in the ,great ,basin and the ,colorado ,river districts1 where extreme desert conditions often prevail and where the rainfall is slight1 it has been found possible to produce profitable crops without irrigation4 ,it is unfortunate that the study of the dry-farming territory of the ,united ,states has not progressed far enough to permit a comprehensive and correct mapping of its soils4 ,our knowledge of this subject is1 at the best1 fragmentary4 ,we know1 however1 with certainty that the properties which characterize arid soils1 as described in this chapter' are possessed by the soils of the dry-farming territory1 including the five great districts just enumerated4 ,the characteristics of arid id soils increase as the rainfall decreases and other conditions of aridity increase4 ,they are less marked as we go eastward or westward toward the regions of more abundant rainfall2 that is to say1 the most highly developed arid soils are found in the ,great ,basin and ,colorado ,river districts4 ,the least developed are on the eastern edge of the ,great ,plains4 ,the judging of soils ,a chemical analysis of a soil1 unless accompanied by a large amount of other information1 is of little value to the farmer4 ,the main points in judging a prospective dry-farm are3 the depth of the soil1 the uniformity of the soil to a depth of at least #aj feet1 the native vegetation1 the climatic conditions as relating to early and late frosts1 the total annual rainfall and its distribution1 and the kinds and yields of crops that have been grown in the neighborhood4 ,the depth of the soil is best determined by the use of an auger4 ,a simple soil auger is made from the ordinary carpenter's auger1 #a-a_/b to #b inches in diameter1 by lengthening its shaft to #c feet or more4 ,where it is not desirable to carry sectional augers1 it is often advisable to have three augers made3 one #c feet1 the other #f1 and the third #i or #aj feet in length4 ,the short auger is used first and the others afterwards as the depth of the boring increases4 ,the boring should he made in a large number of average places--preferably one boring or more on each acre if time and circumstances permit--and the results entered on a map of the farm4 ,the uniformity of the soil is observed as the boring progresses4 ,if gravel layers exist1 they will necessarily stop the progress of the boring4 ,hardpans of any kind will also be revealed by such an examination4 ,the climatic information must be gathered from the local weather bureau and from older residents of the section4 ,the native vegetation is always an excellent index of dry-farm possibilities4 ,if a good stand of native grasses exists1 there can scarcely be any doubt about the ultimate success of dry-farming under proper cultural methods4 ,a healthy crop of sagebrush is an almost absolutely certain indication that farming without irrigation is feasible4 ,the rabbit brush of the drier regions is also usually a good indication1 though it frequently indicates a soil not easily handled4 ,greasewood1 shadscale1 and other related plants ordinarily indicate heavy clay soils frequently charged with alkali4 ,such soils should be the last choice for dry-farming purposes1 though they usually give good satisfaction under systems of irrigation4 ,if the native cedar or other native trees grow in profusion1 it is another indication of good dry-farm possibilities4 ,,chapter ,,vi ,,the ,,root ,,systems ,,of ,,plants ,the great depth and high fertility of the soils of arid and semiarid regions have made possible the profitable production of agricultural plants under a rainfall very much lower than that of humid regions4 ,to make the principles of this system fully understood1 it is necessary to review briefly our knowledge of the root systems of plants growing under arid conditions4 ,functions of roots ,the roots serve at least three distinct uses or purposes3 ,first1 they give the plant a foothold in the earth2 secondly1 they enable the plant to secure from the soil the large amount of water needed in plant growth1 and1 thirdly1 they enable the plant to secure the indispensable mineral foods which can be obtained only from the soil4 ,so important is the proper supply of water and food in the growth of a plant that1 in a given soil1 the crop yield is usually in direct proportion to the development of the root system4 ,whenever the roots are hindered in their development1 the growth of the plant above ground is likewise retarded1 and crop failure may result4 ,the importance of roots is not fully appreciated because they are hidden from direct view4 ,successful dry-farming consists1 largely in the adoption of practices that facilitate a full and free development-of plant roots4 ,were it not that the nature of arid soils1 as explained in preceding chapters1 is such that full root development is comparatively easy1 it would probably be useless to attempt to establish a system of dry-farming4 ,kinds of roots ,the root is the part of the plant that is found underground4 ,it has numerous branches1 twigs1 and filaments4 ,the root which first forms when the seed bursts is known as the primary root4 ,from this primary root other roots develop1 which are known as secondary roots4 ,when the primary root grows more rapidly than the secondary roots1 the so-called taproot1 characteristic of lucerne1 clover1 and similar plants1 is formed4 ,when1 on the other hand1 the taproot grows slowly or ceases its growth1 and the numerous secondary roots grow long1 a fibrous root system results1 which is characteristic of the cereals1 grasses1 corn1 and other similar plants4 ,with any type of root1 the tendency of growth is downward2 though under conditions that are not favorable for the downward penetration of the roots the lateral extensions may be very large and near the surface ,extent of roots ,a number of investigators have attempted to determine the weight of the roots as compared with the weight of the plant above ground1 hut the subject1 because of its great experimental difficulties1 has not been very accurately explained4 ,schumacher1 experimenting about #ahfg1 found that the roots of a well-established field of clover weighed as much as the total weight of the stems and leaves of the year's crop1 and that the weight of roots of an oat crop was #dc per cent of the total weight of seed and straw4 ,nobbe1 a few years later1 found in one of his experiments that the roots of timothy weighed #ca per cent of the weight of the hay4 ,hosaeus1 investigating the same subject about the same time1 found that the weight of roots of one of the brome grasses was as great as the weight of the part above ground2 of serradella1 #gg per cent2 of flax1 #cd per cent2 of oats1 #ad per cent2 of barley1 #ac per cent1 and of peas1 #i per cent4 ,sanborn1 working at the ,utah ,station in #ahic1 found results very much the same ,although these results are not concordant1 they show that the weight of the roots is considerable1 in many cases far beyond the belief of those who have given the subject little or no attention4 ,it may be noted that on the basis of the figures above obtained1 it is very probable that the roots in one acre of an average wheat crop would weigh in the neighborhood of a thousand pounds--possibly considerably more4 ,it should be remembered that the investigations which yielded the preceding results were all conducted in humid climates and at a time when the methods for the study of the root systems were poorly developed4 ,the data obtained1 therefore1 represent1 in all probability1 minimum results which would be materially increased should the work be repeated now4 ,the relative weights of the roots and the stems and the leaves do not alone show the large quantity of roots2 the total lengths of the roots are even more striking4 ,the ,german investigator1 ,nobbe1 in a laborious experiment conducted about #ahfg1 added the lengths of all the fine roots from each of various plants4 ,he found that the total length of roots1 that is1 the sum of the lengths of all the roots1 of one wheat plant was about #bfh feet1 and that the total length of the roots of one plant of rye was about #che feet4 ,king1 of ,wisconsin1 estimates that in one of his experiments1 one corn plant produced in the upper #c feet of soil #adeb feet of roots4 ,these surprisingly large numbers indicate with emphasis the thoroughness with which the roots invade the soil4 ,depth of root penetration ,the earlier root studies did not pretend to determine the depth to which roots actually penetrate the earth4 ,in recent years1 however1 a number of carefully conducted experiments were made by the ,new ,york1 ,wisconsin1 ,minnesota1 ,kansas1 ,colorado1 and especially the ,north ,dakota stations to obtain accurate information concerning the depth to which agricultural plants penetrate soils4 ,it is somewhat regrettable1 for the purpose of dry-farming1 that these states1 with the exception of ,colorado1 are all in the humid or sub-humid area of the ,united ,states4 ,nevertheless1 the conclusions drawn from the work are such that they may be safely applied in the development of the principles of dry-farming4 ,there is a general belief among farmers that the roots of all cultivated crops are very near the surface and that few reach a greater depth than one or two feet4 ,the first striking result of the ,american investigations was that every crop1 without exception1 penetrates the soil deeper than was thought possible in earlier days4 ,for example1 it was found that corn roots penetrated fully four feet into the ground and that they fully occupied all of the soil to that depth4 ,on deeper and somewhat drier soils1 corn roots went down as far as eight feet4 ,the roots of the small grains1--wheat1 oats1 barley1--penetrated the soil from four to eight or ten feet4 ,various perennial grasses rooted to a depth of four feet the first year2 the next year1 five and one half feet2 no determinations were made of the depth of the roots in later years1 though it had undoubtedly increased4 ,alfalfa was the deepest rooted of all the crops studied by the ,american stations4 ,potato roots filled the soil fully to a depth of three feet2 sugar beets to a depth of nearly four feet4 ,sugar ,beet ,roots ,in every case1 under conditions prevailing in the experiments1 and which did not have in mind the forcing of the roots down to extraordinary depths1 it seemed that the normal depth of the roots of ordinary field crops was from three to eight feet4 ,sub-soiling and deep plowing enable the roots to go deeper into the soil4 ,this work has been confirmed in ordinary experience until there can be little question about the accuracy of the results4 ,almost all of these results were obtained in humid climates on humid soils1 somewhat shallow1 and underlain by a more or less infertile subsoil4 ,in fact1 they were obtained under conditions really unfavorable to plant growth4 ,it has been explained in ,chapter ,v that soils formed under arid or semiarid conditions are uniformly deep and porous and that the fertility of the subsoil is1 in most cases1 practically as great as of the topsoil4 ,there is1 therefore1 in arid soils1 an excellent opportunity for a comparatively easy penetration of the roots to great depths and1 because of the available fertility1 a chance throughout the whole of the subsoil for ample root development4 ,moreover1 the porous condition of the soil permits the entrance of air1 which helps to purify the soil atmosphere and thereby to make the conditions more favorable for root development4 ,consequently it is to be expected that1 in arid regions1 roots will ordinarily go to a much greater depth than in humid regions4 ,it is further to be remembered that roots are in constant search of food and water and are likely to develop in the directions where there is the greatest abundance of these materials4 ,under systems of dry-farming the soil water is stored more or less uniformly to considerable depths--ten feet or more--and in most cases the percentage of moisture in the spring and summer is as large or larger some feet below the surface than in the upper two feet4 ,the tendency of the root is1 then1 to move downward to depths where there is a larger supply of water4 ,especially is this tendency increased by the available soil fertility found throughout the whole depth of the soil mass4 ,it has been argued that in many of the irrigated sections the roots do not penetrate the soil to great depths4 ,this is true1 because by the present wasteful methods of irrigation the plant receives so much water at such untimely seasons that the roots acquire the habit of feeding very near the surface where the water is so lavishly applied4 ,this means not only that the plant suffers more greatly in times of drouth1 but that1 since the feeding ground of the roots is smaller1 the crop is likely to be small4 ,these deductions as to the depth to which plant roots will penetrate the soil in arid regions are fully corroborated by experiments and general observation4 ,the workers of the ,utah ,station have repeatedly observed plant roots on dry-farms to a depth of ten feet4 ,lucerne roots from thirty to fifty feet in length are frequently exposed in the gullies formed by the mountain torrents4 ,roots of trees1 similarly1 go down to great depths4 ,hilgard observes that he has found roots of grapevines at a depth of twenty-two feet below the surface1 and quotes ,aughey as having found roots of the native ,shepherdia in ,nebraska to a depth of fifty feet4 ,hilgard further declares that in ,california fibrous-rooted plants1 such as wheat and barley1 may descend in sandy soils from four to seven feet4 ,orchard trees in the arid ,west1 grown properly1 are similarly observed to send their roots down to great depths4 ,in fact1 it has become a custom in many arid regions where the soils are easily penetrable to say that the root system of a tree corresponds in extent and branching to the part of the tree above ground4 ,now1 it is to be observed that1 generally1 plants grown in dry climates send their roots straight down into the soil2 whereas in humid climates1 where the topsoil is quite moist and the subsoil is hard1 roots branch out laterally and fill the upper foot or two of the soil4 ,a great deal has been said and written about the danger of deep cultivation1 because it tends to injure the roots that feed near the surface4 ,however true this may be in humid countries1 it is not vital in the districts primarily interested in dry-farming2 and it is doubtful if the objection is as valid in humid countries as is often declared4 ,true1 deep cultivation1 especially when performed near the plant or tree1 destroys the surface-feeding roots1 but this only tends to compel the deeper lying roots to make better use of the subsoil4 ,when1 as in arid regions1 the subsoil is fertile and furnishes a sufficient amount of water1 destroying the surface roots is no handicap whatever4 ,on the contrary1 in times of drouth1 the deep-lying roots feed and drink at their leisure far from the hot sun or withering winds1 and the plants survive and arrive at rich maturity1 while the plants with shallow roots wither and die or are so seriously injured as to produce an inferior crop4 ,therefore1 in the system of dry-farming as developed in this volume1 it must be understood that so far as the farmer has power1 the roots must be driven downward into the soil1 and that no injury needs to be apprehended from deep and vigorous cultivation4 ,one of the chief attempts of the dry-farmer must be to see to it that the plants root deeply4 ,this can be done only by preparing the right kind of seed-bed and by having the soil in its lower depths well-stored with moisture1 so that the plants may be invited to descend4 ,for that reason1 an excess of moisture in the upper soil when the young plants are rooting is really an injury to them4 ,,chapter ,,vii ,,storing ,,water ,,in ,,the ,,soil ,the large amount of water required for the production of plant substance is taken from the soil by the roots4 ,leaves and stems do not absorb appreciable quantities of water4 ,the scanty rainfall of dry-farm districts or the more abundant precipitation of humid regions must1 therefore1 be made to enter the soil in such a manner as to be readily available as soil-moisture to the roots at the right periods of plant growth4 ,in humid countries1 the rain that falls during the growing season is looked upon1 and very properly1 as the really effective factor in the production of large crops4 ,the root systems of plants grown under such humid conditions are near the surface1 ready to absorb immediately the rains that fall1 even if they do not soak deeply into the soil4 ,as has been shown in ,chapter ,,iv1 it is only over a small portion of the dry-farm territory that the bulk of the scanty precipitation occurs during the growing season4 ,over a large portion of the arid and semiarid region the summers are almost rainless and the bulk of the precipitation comes in the winter1 late fall1 or early spring when plants are not growing4 ,if the rains that fall during the growing season are indispensable in crop production1 the possible area to be reclaimed by dry-farming will be greatly limited4 ,even when much of the total precipitation comes in summer1 the amount in dry-farm districts is seldom sufficient for the proper maturing of crops4 ,in fact1 successful dry-farming depends chiefly upon the success with which the rains that fall during any season of the year may be stored and kept in the soil until needed by plants in their growth4 ,the fundamental operations of dry-farming include a soil treatment which enables the largest possible proportion of the annual precipitation to be stored in the soil4 ,for this purpose1 the deep1 somewhat porous soils1 characteristic of arid regions1 are unusually well adapted4 ,alway's demonstration ,an important and unique demonstration of the possibility of bringing crops to maturity on the moisture stored in the soil at the time of planting has been made by ,alway4 ,cylinders of galvanized iron1 #f feet long1 were filled with soil as nearly as possible in its natural position and condition ,water was added until seepage began1 after which the excess was allowed to drain away4 ,when the seepage had closed1 the cylinders were entirely closed except at the surface4 ,sprouted grains of spring wheat were placed in the moist surface soil1 and #a inch of dry soil added to the surface to prevent evaporation4 ,no more water was added2 the air of the greenhouse was kept as dry as possible4 ,the wheat developed normally4 ,the first ear was ripe in #acb days after planting and the last in #adc days4 ,the three cylinders of soil from semiarid western ,nebraska produced #cg4h grams of straw and #bi ears1 containing #dae kernels weighing #aa4ahh grams4 ,the three cylinders of soil from humid eastern ,nebraska produced only #aa4b grams of straw and #ac ears containing #aad kernels1 weighing #c grams4 ,this experiment shows conclusively that rains are not needed during the growing season1 if the soil is well filled with moisture at seedtime1 to bring crops to maturity4 ,what becomes of the rainfall8 ,the water that falls on the land is disposed of in three ways3 ,first1 under ordinary conditions1 a large portion runs off without entering the soil2 secondly1 a portion enters the soil1 but remains near the surface1 and is rapidly evaporated back into the air2 and1 thirdly1 a portion enters the lower soil layers1 from which it is removed at later periods by several distinct processes4 ,the run-off is usually large and is a serious loss1 especially in dry-farming regions1 where the absence of luxuriant vegetation1 the somewhat hard1 sun-baked soils1 and the numerous drainage channels1 formed by successive torrents1 combine to furnish the rains with an easy escape into the torrential rivers4 ,persons familiar with arid conditions know how quickly the narrow box canyons1 which often drain thousands of square miles1 are filled with roaring water after a comparatively light rainfall4 ,the run-off ,the proper cultivation of the soil diminishes very greatly the loss due to run-off1 but even on such soils the proportion may often be very great4 ,farrel observed at one of the ,utah stations that during a torrential rain--#b4f inches in #d hours--the surface of the summer fallowed plats was packed so solid that only one fourth inch1 or less than one tenth of the whole amount1 soaked into the soil1 while on a neighboring stubble field1 which offered greater hindrance to the run-off1 #a-a_/b inches or about #fj per cent were absorbed4 ,it is not possible under any condition to prevent the run-off altogether1 although it can usually be reduced exceedingly4 ,it is a common dry-farm custom to plow along the slopes of the farm instead of plowing up and down them4 ,when this is done1 the water which runs down the slopes is caught by the succession of furrows and in that way the runoff is diminished4 ,during the fallow season the disk and smoothing harrows are run along the hillsides for the same purpose and with results that are nearly always advantageous to the dry-farmer4 ,of necessity1 each man must study his own farm in order to devise methods that will prevent the run-off4 ,the structure of soils ,before examining more closely the possibility of storing water in soils a brief review of the structure of soils is desirable4 ,as previously explained1 soil is essentially a mixture of disintegrated rock and the decomposing remains of plants4 ,the rock particles which constitute the major portion of soils vary greatly in size4 ,the largest ones are often #ejj times the sizes of the smallest4 ,it would take #ej of the coarsest sand particles1 and #be1jjj of the finest silt particles1 to form one lineal inch4 ,the clay particles are often smaller and of such a nature that they cannot be accurately measured4 ,the total number of soil particles in even a small quantity of cultivated soil is far beyond the ordinary limits of thought1 ranging from #abe1jjj particles of coarse sand to #ae1fbe1jjj1jjj1jjj particles of the finest silt in one cubic inch4 ,in other words1 if all the particles in one cubic inch of soil consisting of fine silt were placed side by side1 they would form a continuous chain over a thousand miles long4 ,the farmer1 when he tills the soil1 deals with countless numbers of individual soil grains1 far surpassing the understanding of the human mind4 ,it is the immense number of constituent soil particles that gives to the soil many of its most valuable properties4 ,it must be remembered that no natural soil is made up of particles all of which are of the same size2 all sizes1 from the coarsest sand to the finest clay1 are usually present4 ,these particles of all sizes are not arranged in the soil in a regular1 orderly way2 they are not placed side by side with geometrical regularity2 they are rather jumbled together in every possible way4 ,the larger sand grains touch and form comparatively large interstitial spaces into which the finer silt and clay grains filter4 ,then1 again1 the clay particles1 which have cementing properties1 bind1 as it were1 one particle to another4 ,a sand grain may have attached to it hundreds1 or it may be thousands1 of the smaller silt grains2 or a regiment of smaller soil grains may themselves be clustered into one large grain by cementing power of the clay4 ,further1 in the presence of lime and similar substances1 these complex soil grains are grouped into yet larger and more complex groups4 ,the beneficial effect of lime is usually due to this power of grouping untold numbers of soil particles into larger groups4 ,when by correct soil culture the individual soil grains are thus grouped into large clusters1 the soil is said to be in good tilth4 ,anything that tends to destroy these complex soil grains1 as1 for instance1 plowing the soil when it is too wet1 weakens the crop-producing power of the soil4 ,this complexity of structure is one of the chief reasons for the difficulty of understanding clearly the physical laws governing soils4 ,pore-space of soils ,it follows from this description of soil structure that the soil grains do not fill the whole of the soil space4 ,the tendency is rather to form clusters of soil grains which1 though touching at many points1 leave comparatively large empty spaces4 ,this pore space in soils varies greatly1 but with a maximum of about #ee per cent4 ,in soils formed under arid conditions the percentage of pore-space is somewhere in the neighborhood of #ej per cent4 ,there are some arid soils1 notably gypsum soils1 the particles of which are so uniform size that the pore-space is exceedingly small4 ,such soils are always difficult to prepare for agricultural purposes4 ,it is the pore-space in soils that permits the storage of soil-moisture2 and it is always important for the farmer so to maintain his soil that the pore-space is large enough to give him the best results1 not only for the storage of moisture1 but for the growth and development of roots1 and for the entrance into the soil of air1 germ life1 and other forces that aid in making the soil fit for the habitation of plants4 ,this can always be best accomplished1 as will be shown hereafter1 by deep plowing1 when the soil is not too wet1 the exposure of the plowed soil to the elements1 the frequent cultivation of the soil through the growing season1 and the admixture of organic matter4 ,the natural soil structure at depths not reached by the plow evidently cannot be vitally changed by the farmer4 ,hygroscopic soil-water ,under normal conditions1 a certain amount of water is always found in all things occurring naturally1 soils included4 ,clinging to every tree1 stone1 or animal tissue is a small quantity of moisture varying with the temperature1 the amount of water in the air1 and with other well-known factors4 ,it is impossible to rid any natural substance wholly of water without heating it to a high temperature4 ,this water which1 apparently1 belongs to all natural objects is commonly called hygroscopic water4 ,hilgard states that the soils of the arid regions contain1 under a temperature of #ae deg ,c4 and an atmosphere saturated with water1 approximately #e-a_/b per cent of hygroscopic water4 ,in fact1 however1 the air over the arid region is far from being saturated with water and the temperature is even higher than #ae deg ,c41 and the hygroscopic moisture actually found in the soils of the dry-farm territory is considerably smaller than the average above given4 ,under the conditions prevailing in the ,great ,basin the hygroscopic water of soils varies from 4#ge per cent to #c-a_/b per cent2 the average amount is not far from #ab per cent4 ,whether or not the hygroscopic water of soils is of value in plant growth is a disputed question4 ,hilgard believes that the hygroscopic moisture can be of considerable help in carrying plants through rainless summers1 and further1 that its presence prevents the heating of the soil particles to a point dangerous to plant roots4 ,other authorities maintain earnestly that the hygroscopic soil-water is practically useless to plants4 ,considering the fact that wilting occurs long before the hygroscopic water contained in the soil is reached1 it is very unlikely that water so held is of any real benefit to plant growth4 ,gravitational water ,it often happens that a portion of the water in the soil is under the immediate influence of gravitation4 ,for instance1 a stone which1 normally1 is covered with hygroscopic water is dipped into water ,the hydroscopic water is not thereby affected1 but as the stone is drawn out of the water a good part of the water runs off4 ,this is gravitational water ,that is1 the gravitational water of soils is that portion of the soil-water which filling the soil pores1 flows downward through the soil under the influence of gravity4 ,when the soil pores are completely filled1 the maximum amount of gravitational water is found there4 ,in ordinary dry-farm soils this total water capacity is between #ce and #dj per cent of the dry weight of soil4 ,the gravitational soil-water cannot long remain in that condition2 for1 necessarily1 the pull of gravity moves it downward through the soil pores and if conditions are favorable1 it finally reaches the standing water-table1 whence it is carried to the great rivers1 and finally to the ocean4 ,in humid soils1 under a large precipitation1 gravitational water moves down to the standing water-table after every rain4 ,in dry-farm soils the gravitational water seldom reaches the standing water-table2 for1 as it moves downward1 it wets the soil grains and remains in the capillary condition as a thin film around the soil grains4 ,to the dry-farmer1 the full water capacity is of importance only as it pertains to the upper foot of soil4 ,if1 by proper plowing and cultivation1 the upper soil be loose and porous1 the precipitation is allowed to soak quickly into the soil1 away from the action of the wind and sun4 ,from this temporary reservoir1 the water1 in obedience to the pull of gravity1 will move slowly downward to the greater soil depths1 where it will be stored permanently until needed by plants4 ,it is for this reason that dry-farmers find it profitable to plow in the fall1 as soon as possible after harvesting4 ,in fact1 ,campbell advocates that the harvester be followed immediately by the disk1 later to be followed by the plow ,the essential thing is to keep the topsoil open and receptive to a rain4 ,capillary soil-water ,the so-called capillary soil-water is of greatest importance to the dry-farmer4 ,this is the water that clings as a film around a marble that has been dipped into water4 ,there is a natural attraction between water and nearly all known substances1 as is witnessed by the fact that nearly all things may be moistened4 ,the water is held around the marble because the attraction between the marble and the water is greater than the pull of gravity upon the water4 ,the greater the attraction1 the thicker the film2 the smaller the attraction1 the thinner the film will be4 ,the water that rises in a capillary glass tube when placed in water does so by virtue of the attraction between water and glass4 ,frequently1 the force that makes capillary water possible is called surface tension4 ,whenever there is a sufficient amount of water available1 a thin film of water is found around every soil grain2 and where the soil grains touch1 or where they are very near together1 water is held pretty much as in capillary tubes4 ,not only are the soil particles enveloped by such a film1 but the plant roots foraging in the soil are likewise covered2 that is1 the whole system of soil grains and roots is covered1 under favorable conditions1 with a thin film of capillary water4 ,it is the water in this form upon which plants draw during their periods of growth4 ,the hygroscopic water and the gravitational water are of comparatively little value in plant growth4 ,field capacity of soils for capillary water ,the tremendously large number of soil grains found in even a small amount of soil makes it possible for the soil to hold very large quantities of capillary water4 ,to illustrate3 ,in one cubic inch of sand soil the total surface exposed by the soil grains varies from #db square inches to #bg square feet2 in one cubic inch of silt soil1 from #bg square feet to #gb square feet1 and in one cubic inch of an ordinary soil the total surface exposed by the soil grains is about #be square feet4 ,this means that the total surface of the soil grains contained in a column of soil #a square foot at the top and #aj feet deep is approximately #aj acres4 ,when even a thin film of water is spread over such a large area1 it is clear that the total amount of water involved must be large ,it is to be noticed1 therefore1 that the fineness of the soil particles previously discussed has a direct bearing upon the amount of water that soils may retain for the use of plant growth4 ,as the fineness of the soil grains increases1 the total surface increases' and the water-holding capacity also increases4 ,naturally1 the thickness of a water film held around the soil grains is very minute4 ,king has calculated that a film #bge millionths of an inch thick1 clinging around the soil particles1 is equivalent to #ad4bd per cent of water in a heavy clay2 #g4b per cent in a loam2 #e4ba per cent in a sandy loam1 and #a4da per cent in a sandy soil4 ,it is important to know the largest amount of water that soils can hold in a capillary condition1 for upon it depend1 in a measure1 the possibilities of crop production under dry-farming conditions4 ,king states that the largest amount of capillary water that can be held in sandy loams varies from #ag4fe per cent to #aj4fg per cent2 in clay loams from #bb4fg per cent to #ah4af per cent1 and in humus soils 7which are practically unknown in dry-farm sections7 from #dd4gb per cent to #ba4bi per cent4 ,these results were not obtained under dry-farm conditions and must be confirmed by investigations of arid soils4 ,the water that falls upon dry-farms is very seldom sufficient in quantity to reach the standing water-table1 and it is necessary1 therefore1 to determine the largest percentage of water that a soil can hold under the influence of gravity down to a depth of #h or #aj feet--the depth to which the roots penetrate and in which root action is distinctly felt4 ,this is somewhat difficult to determine because the many conflicting factors acting upon the soil-water are seldom in equilibrium4 ,moreover1 a considerable time must usually elapse before the rain-water is thoroughly distributed throughout the soil4 ,for instance1 in sandy soils1 the downward descent of water is very rapid2 in clay soils1 where the preponderance of fine particles makes minute soil pores1 there is considerable hindrance to the descent of water1 and it may take weeks or months for equilibrium to be established4 ,it is believed that in a dry-farm district1 where the major part of the precipitation comes during winter1 the early springtime1 before the spring rains come1 is the best time for determining the maximum water capacity of a soil4 ,at that season the water-dissipating influences1 such as sunshine and high temperature1 are at a minimum1 and a sufficient time has elapsed to permit the rains of fall and winter to distribute themselves uniformly throughout the soil4 ,in districts of high summer precipitation1 the late fall after a fallow season will probably be the best time for the determination of the field-water capacity4 ,experiments on this subject have been conducted at the ,utah ,station4 ,as a result of several thousand trials it was found that1 in the spring1 a uniform1 sandy loam soil of true arid properties contained1 from year to year1 an average of nearly #af-a_/b per cent of water to a depth of #h feet4 ,this appeared to be practically the maximum water capacity of that soil under field conditions1 and it may be called the field capacity of that soil for capillary water4 ,other experiments on dry-farms showed the field capacity of a clay soil to a depth of #h feet to be #ai per cent2 of a clay loam1 to be #ah per cent2 of a loam1 #ag per cent2 of another loam somewhat more sandy1 #af per cent2 of a sandy loam1 #ad-a_/b per cent2 and of a very sandy loam1 #ad per cent4 ,leather found that in the calcareous arid soil of ,india the upper #e feet contained #ah per cent of water at the close of the wet season4 ,it may be concluded1 therefore1 that the field-water capacities of ordinary dry-farm soils are not very high1 ranging from #ae to #bj per cent1 with an average for ordinary dry-farm soils in the neighborhood of #af or #ag per cent4 ,expressed in another way this means that a layer of water from #b to #c inches deep can be stored in the soil to a depth of #ab inches4 ,sandy soils will hold less water than clayey ones4 ,it must not be forgotten that in the dry-farm region are numerous types of soils1 among them some consisting chiefly of very fine soil grains and which would2 consequently1 possess field-water capacities above the average here stated4 ,the first endeavor of the dry-farmer should be to have the soil filled to its full field-water capacity before a crop is planted4 ,downward movement of soil-moisture ,one of the chief considerations in a discussion of the storing of water in soils is the depth to which water may move under ordinary dry-farm conditions4 ,in humid regions1 where the water table is near the surface and where the rainfall is very abundant1 no question has been raised concerning the possibility of the descent of water through the soil to the standing water4 ,considerable objection1 however1 has been offered to the doctrine that the rainfall of arid districts penetrates the soil to any great extent4 ,numerous writers on the subject intimate that the rainfall under dry-farm conditions reaches at the best the upper #c or #d feet of soil4 ,this cannot be true1 for the deep rich soils of the arid region1 which never have been disturbed by the husbandman1 are moist to very great depths4 ,in the deserts of the ,great ,basin1 where vegetation is very scanty1 soil borings made almost anywhere will reveal the fact that moisture exists in considerable quantities to the full depth of the ordinary soil auger1 usually #aj feet4 ,the same is true for practically every district of the arid region4 ,such water has not come from below1 for in the majority of cases the standing water is #ej to #ejj feet below the surface4 ,whitney made this observation many years ago and reported it as a striking feature of agriculture in arid regions1 worthy of serious consideration4 ,investigations made at the ,utah ,station have shown that undisturbed soils within the ,great ,basin frequently contain1 to a depth of #aj feet1 an amount of water equivalent to #b or #c years of the rainfall which normally occurs in that locality4 ,these quantities of water could not be found in such soils1 unless1 under arid conditions1 water has the power to move downward to considerably greater depths than is usually believed by dry-farmers4 ,in a series of irrigation experiments conducted at the ,utah ,station it was demonstrated that on a loam soil1 within a few hours after an irrigation1 some of the water applied had reached the eighth foot1 or at least had increased the percentage of water in the eighth foot4 ,in soil that was already well filled with water1 the addition of water was felt distinctly to the full depth of #h feet4 ,moreover1 it was observed in these experiments that even very small rains caused moisture changes to considerable depths a few hours after the rain was over4 ,for instance1 #j4ad of an inch of rainfall was felt to a depth of #b feet within #c hours2 #j4ic of an inch was felt to a depth of #c feet within the same period4 ,to determine whether or not the natural winter precipitation1 upon which the crops of a large portion of the dry-farm territory depend1 penetrates the soil to any great depth a series of tests were undertaken4 ,at the close of the harvest in ,august or ,september the soil was carefully sampled to a depth of #h feet1 and in the following spring similar samples were taken on the same soils to the same depth4 ,in every case1 it was found that the winter precipitation had caused moisture changes to the full depth reached by the soil auger4 ,moreover1 these changes were so great as to lead the investigators to believe that moisture changes had occurred to greater depths4 ,in districts where the major part of the precipitation occurs during the summer the same law is undoubtedly in operation2 but1 since evaporation is most active in the summer1 it is probable that a smaller proportion reaches the greater soil depths4 ,in the ,great ,plains district1 therefore1 greater care will have to be exercised during the summer in securing proper water storage than in the ,great ,basin1 for instance4 ,the principle is1 nevertheless1 the same4 ,burr1 working under ,great ,plains conditions in ,nebraska1 has shown that the spring and summer rains penetrate the soil to the depth of #f feet1 the average depth of the borings1 and that it undoubtedly affects the soil-moisture to the depth of #aj feet4 ,in general1 the dry-farmer may safely accept the doctrine that the water that falls upon his land penetrates the soil far beyond the immediate reach of the sun1 though not so far away that plant roots cannot make use of it4 ,importance of a moist subsoil ,in the consideration of the downward movement of soil-water it is to be noted that it is only when the soil is tolerably moist that the natural precipitation moves rapidly and freely to the deeper soil layers4 ,when the soil is dry1 the downward movement of the water is much slower and the bulk of the water is then stored near the surface where the loss of moisture goes on most rapidly4 ,it has been observed repeatedly in the investigations at the ,utah ,station that when desert land is broken for dry-farm purposes and then properly cultivated1 the precipitation penetrates farther and farther into the soil with every year of cultivation4 ,for example1 on a dry-farm1 the soil of which is clay loam1 and which was plowed in the fall of #aijd and farmed annually thereafter1 the eighth foot contained in the spring of #aije1 #f4ei per cent of moisture2 in the spring of #aijf1 #ac4aa per cent1 and in the spring of #aijg1 #ad4ge per cent of moisture4 ,on another farm1 with a very sandy soil and also plowed in the fall of #aijd1 there was found in the eighth foot in the spring of #aije1 #e4fc per cent of moisture1 in the spring of #aijf1 #aa4da per cent of moisture1 and in the spring of #aijg1 #ae4di per cent of moisture4 ,in both of these typical cases it is evident that as the topsoil was loosened1 the full field water capacity of the soil was more nearly approached to a greater depth4 ,it would seem that1 as the lower soil layers are moistened1 the water is enabled1 so to speak1 to slide down more easily into the depths of the soil4 ,this is a very important principle for the dry farmer to understand4 ,it is always dangerous to permit the soil of a dry-farm to become very dry1 especially below the first foot4 ,dry-farms should be so manipulated that even at the harvesting season a comparatively large quantity of water remains in the soil to a depth of #h feet or more4 ,the larger the quantity of water in the soil in the fall1 the more readily and quickly will the water that falls on the land during the resting period of fall1 winter1 and early spring sink into the soil and move away from the topsoil4 ,the top or first foot will always contain the largest percentage of water because it is the chief receptacle of the water that falls as rain or snow but when the subsoil is properly moist1 the water will more completely leave the topsoil4 ,further1 crops planted on a soil saturated with water to a depth of #h feet are almost certain to mature and yield well4 ,if the field-water capacity has not been filled1 there is always the danger that an unusually dry season or a series of hot winds or other like circumstances may either seriously injure the crop or cause a complete failure4 ,the dry-farmer should keep a surplus of moisture in the soil to be carried over from year to year1 just as the wise business man maintains a sufficient working capital for the needs of his business4 ,in fact1 it is often safe to advise the prospective dry-farmer to plow his newly cleared or broken land carefully and then to grow no crop on it the first year1 so that1 when crop production begins1 the soil will have stored in it an amount of water sufficient to carry a crop over periods of drouth4 ,especially in districts of very low rainfall is this practice to be recommended4 ,in the ,great ,plains area1 where the summer rains tempt the farmer to give less attention to the soil-moisture problem than in the dry districts with winter precipitation farther ,west1 it is important that a fallow season be occasionally given the land to prevent the store of soil moisture from becoming dangerously low4 ,to what extent is the rainfall stored in soils8 ,what proportion of the actual amount of water falling upon the soil can be stored in the soil and carried over from season to season8 ,this question naturally arises in view of the conclusion that water penetrates the soil to considerable depths4 ,there is comparatively little available information with which to answer this question1 because the great majority of students of soil moisture have concerned themselves wholly with the upper two1 three1 or four feet of soil4 ,the results of such investigations are practically useless in answering this question4 ,in humid regions it may be very satisfactory to confine soil-moisture investigations to the upper few feet2 but in arid regions1 where dry-farming is a living question1 such a method leads to erroneous or incomplete conclusions4 ,since the average field capacity of soils for water is about #b4e inches per foot1 it follows that it is possible to store #be inches of water in #aj feet of soil4 ,this is from two to one and a half times one year's rainfall over the better dry-farming sections4 ,theoretically1 therefore1 there is no reason why the rainfall of one season or more could not be stored in the soil4 ,careful investigations have borne out this theory4 ,atkinson found1 for example1 at the ,montana ,station1 that soil1 which to a depth of #i feet contained #g4g per cent of moisture in the fall contained #aa4e per cent in the spring and1 after carrying it through the summer by proper methods of cultivation1 #aa per cent4 ,it may certainly be concluded from this experiment that it is possible to carry over the soil moisture from season to season4 ,the elaborate investigations at the ,utah ,station have demonstrated that the winter precipitation1 that is1 the precipitation that comes during the wettest period of the year1 may be retained in a large measure in the soil4 ,naturally1 the amount of the natural precipitation accounted for in the upper eight feet will depend upon the dryness of the soil at the time the investigation commenced4 ,if at the beginning of the wet season the upper eight feet of soil are fairly well stored with moisture1 the precipitation will move down to even greater depths1 beyond the reach of the soil auger4 ,if1 on the other hand1 the soil is comparatively dry at the beginning of the season1 the natural precipitation will distribute itself through the upper few feet1 and thus be readily measured by the soil auger4 ,in the ,utah investigations it was found that of the water which fell as rain and snow during the winter1 as high as #ie-a_/b per cent was found stored in the first eight feet of soil at the beginning of the growing season4 ,naturally1 much smaller percentages were also found1 but on an average1 in soils somewhat dry at the beginning of the dry season1 more than three fourths of the natural precipitation was found stored in the soil in the spring4 ,the results were all obtained in a locality where the bulk of the precipitation comes in the winter1 yet similar results would undoubtedly be obtained where the precipitation occurs mainly in the summer4 ,the storage of water in the soil cannot be a whit less important on the ,great ,plains than in the ,great ,basin4 ,in fact1 ,burr has clearly demonstrated for western ,nebraska that over #ej per cent of the rainfall of the spring and summer may be stored in the soil to the depth of six feet4 ,without question1 some is stored also at greater depths4 ,all the evidence at hand shows that a large portion of the precipitation falling upon properly prepared soil1 whether it be summer or winter1 is stored in the soil until evaporation is allowed to withdraw it ,whether or not water so stored may be made to remain in the soil throughout the season or the year will be discussed in the next chapter4 ,it must be said1 however1 that the possibility of storing water in the soil1 that is1 making the water descend to relatively great soil depths away from the immediate and direct action of the sunshine and winds1 is the most fundamental principle in successful dry-farming4 ,the fallow ,it may be safely concluded that a large portion of the water that falls as rain or snow may be stored in the soil to considerable depths 7eight feet or more74 ,however1 the question remains1 ,is it possible to store the rainfall of successive years in the soil for the use of one crop8 ,in short1 ,does the practice of clean fallowing or resting the ground with proper cultivation for one season enable the farmer to store in the soil the larger portion of the rainfall of two years1 to be used for one crop8 ,it is unquestionably true1 as will be shown later1 that clean fallowing or summer tillage is one of the oldest and safest practices of dry-farming as practiced in the ,west1 but it is not generally understood why fallowing is desirable4 ,considerable doubt has recently been cast upon the doctrine that one of the beneficial effects of fallowing in dry-farming is to store the rainfall of successive seasons in the soil for the use of one crop4 ,since it has been shown that a large proportion of the winter precipitation can be stored in the soil during the wet season1 it merely becomes a question of the possibility of preventing the evaporation of this water during the drier season4 ,as will be shown in the next chapter1 this can well be effected by proper cultivation4 ,there is no good reason1 therefore1 for believing that the precipitation of successive seasons may not be added to water already stored in the soil4 ,king has shown that fallowing the soil one year carried over per square foot1 in the upper four feet1 #i4ch pounds of water more than was found in a cropped soil in a parallel experiment2 and1 moreover1 the beneficial effect of this4 water advantage was felt for a whole succeeding season4 ,king concludes1 therefore1 that one of the advantages of fallowing is to increase the moisture content of the soil4 ,the ,utah experiments show that the tendency of fallowing is always to increase the soil-moisture content4 ,in dry-farming1 water is the critical factor1 and any practice that helps to conserve water should be adopted4 ,for that reason1 fallowing1 which gathers soil-moisture1 should be strongly advocated4 ,in ,chapter ,,ix another important value of the fallow will be discussed4 ,in view of the discussion in this chapter it is easily understood why students of soil-moisture have not found a material increase in soil-moisture due to fallowing4 ,usually such investigations have been made to shallow depths which already were fairly well filled with moisture4 ,water falling upon such soils would sink beyond the depth reached by the soil augers1 and it became impossible to judge accurately of the moisture-storing advantage of the fallow4 ,a critical analysis of the literature on this subject will reveal the weakness of most experiments in this respect4 ,it may be mentioned here that the only fallow that should be practiced by the dry-farmer is the clean fallow4 ,water storage is manifestly impossible when crops are growing upon a soil4 ,a healthy crop of sagebrush1 sunflowers1 or other weeds consumes as much water as a first-class stand of corn1 wheat1 or potatoes4 ,weeds should be abhorred by the farmer4 ,a weedy fallow is a sure forerunner of a crop failure4 ,how to maintain a good fallow is discussed in ,chapter ,,viii1 under the head of ,cultivation4 ,moreover1 the practice of fallowing should be varied with the climatic conditions4 ,in districts of low rainfall1 #aj-ae inches1 the land should be clean summer-fallowed every other year2 under very low rainfall perhaps even two out of three years2 in districts of more abundant rainfall1 #ae-bj inches1 perhaps one year out of every three or four is sufficient4 ,where the precipitation comes during the growing season1 as in the ,great ,plains area1 fallowing for the storage of water is less important than where the major part of the rainfall comes during the fall and winter4 ,however1 any system of dry-farming that omits fallowing wholly from its practices is in danger of failure in dry years4 ,deep plowing for water storage ,it has been attempted in this chapter to demonstrate that water falling upon a soil may descend to great depths1 and may be stored in the soil from year to year1 subject to the needs of the crop that may be planted4 ,by what cultural treatment may this downward descent of the water be accelerated by the farmer8 ,first and foremost1 by plowing at the right time and to the right depth4 ,plowing should be done deeply and thoroughly so that the falling water may immediately be drawn down to the full depth of the loose1 spongy1 plowed soil1 away from the action of the sunshine or winds4 ,the moisture thus caught will slowly work its way down into the lower layers of the soil4 ,deep plowing is always to be recommended for successful dry-farming4 ,in humid districts where there is a great difference between the soil and the subsoil1 it is often dangerous to turn up the lifeless subsoil1 but in arid districts where there is no real differentiation between the soil and the subsoil1 deep plowing may safely be recommended4 ,true1 occasionally1 soils are found in the dry-farm territory which are underlaid near the surface by an inert clay or infertile layer of lime or gypsum which forbids the farmer putting the plow too deeply into the soil4 ,such soils1 however' are seldom worth while trying for dry-farm purposes4 ,deep plowing must be practiced for the best dry-farming results4 ,it naturally follows that subsoiling should be a beneficial practice on dry-farms4 ,whether or not the great cost of subsoiling is offset by the resulting increased yields is an open question2 it is1 in fact1 quite doubtful4 ,deep plowing done at the right time and frequently enough is possibly sufficient4 ,by deep plowing is meant stirring or turning the soil to a depth of six to ten inches below the surface of the land4 ,fall plowing far water storage ,it is not alone sufficient to plow and to plow deeply2 it is also necessary that the plowing be done at the right time4 ,in the very great majority of cases over the whole dry-farm territory1 plowing should be done in the fall4 ,there are three reasons for this3 ,first1 after the crop is harvested1 the soil should be stirred immediately1 so that it can be exposed to the full action of the weathering agencies1 whether the winters be open or closed4 ,if for any reason plowing cannot be done early it is often advantageous to follow the harvester with a disk and to plow later when convenient4 ,the chemical effect on the soil resulting from the weathering1 made possible by fall plowing1 as will be shown in ,chapter ,,ix1 is of itself so great as to warrant the teaching of the general practice of fall plowing4 ,secondly1 the early stirring of the soil prevents evaporation of the moisture in the soil during late summer and the fall4 ,thirdly1 in the parts of the dry-farm territory where much precipitation occurs in the fall1 winter1 or early spring1 fall plowing permits much of this precipitation to enter the soil and be stored there until needed by plants4 ,a number of experiment stations have compared plowing done in the early fall with plowing done late in the fall or in the spring1 and with almost no exception it has been found that early fall plowing is water-conserving and in other ways advantageous4 ,it was observed on a ,utah dry-farm that the fall-plowed land contained1 to a depth of #aj feet1 #g4dg acre-inches more water than the adjoining spring-plowed land--a saving of nearly one half of a year's precipitation4 ,the ground should be plowed in the early fall as soon as possible after the crop is harvested4 ,it should then be left in the rough throughout the winter1 so that it may be mellowed and broken down by the elements4 ,the rough lend further has a tendency to catch and hold the snow that may be blown by the wind1 thus insuring a more even distribution of the water from the melting snow4 ,a common objection to fall plowing is that the ground is so dry in the fall that it does not plow up well1 and that the great dry clods of earth do much to injure the physical condition of the soil4 ,it is very doubtful if such an objection is generally valid1 especially if the soil is so cropped as to leave a fair margin of moisture in the soil at harvest time4 ,the atmospheric agencies will usually break down the clods1 and the physical result of the treatment will be beneficial4 ,undoubtedly1 the fall plowing of dry land is somewhat difficult1 but the good results more than pay the farmer for his trouble4 ,late fall plowing1 after the fall rains have softened the land1 is preferable to spring plowing4 ,if for any reason the farmer feels that he must practice spring plowing1 he should do it as early as possible in the spring4 ,of course1 it is inadvisable to plow the soil when it is so wet as to injure its tilth seriously1 but as soon as that danger period has passed1 the plow should be placed in the ground4 ,the moisture in the soil will thereby be conserved1 and whatever water may fall during the spring months will be conserved also4 ,this is of especial importance in the ,great ,plains region and in any district where the precipitation comes in the spring and winter months4 ,likewise1 after fall plowing1 the land must be well stirred in the early spring with the disk harrow or a similar implement1 to enable the spring rains to enter the soil easily and to prevent the evaporation of the water already stored4 ,where the rainfall is quite abundant and the plowed land has been beaten down by the frequent rains1 the land should be plowed again in the spring4 ,where such conditions do not exist1 the treatment of the soil with the disk and harrow in the spring is usually sufficient4 ,in recent dry-farm experience it has been fairly completely demonstrated that1 providing the soil is well stored with water1 crops will mature even if no rain falls during the growing season4 ,naturally1 under most circumstances1 any rains that may fall on a well-prepared soil during the season of crop growth will tend to increase the crop yield1 but some profitable yield is assured1 in spite of the season1 if the soil is well stored with water at seed time4 ,this is an important principle in the system of dry-farming4 ,,chapter ,,viii ,,regulating ,,the ,,evaporation ,the demonstration in the last chapter that the water which falls as rain or snow may be stored in the soil for the use of plants is of first importance in dry-farming1 for it makes the farmer independent1 in a large measure1 of the distribution of the rainfall4 ,the dry-farmer who goes into the summer with a soil well stored with water cares little whether summer rains come or not1 for he knows that his crops will mature in spite of external drouth4 ,in fact1 as will be shown later1 in many dry-farm sections where the summer rains are light they are a positive detriment to the farmer who by careful farming has stored his deep soil with an abundance of water4 ,storing the soil with water is1 however1 only the first step in making the rains of fall1 winter1 or the preceding year available for plant growth4 ,as soon as warm growing weather comes1 water-dissipating forces come into play1 and water is lost by evaporation4 ,the farmer must1 therefore1 use all precautions to keep the moisture in the soil until such time as the roots of the crop may draw it into the plants to be used in plant production4 ,that is1 as far as possible1 direct evaporation of water from the soil must be prevented4 ,few farmers really realize the immense possible annual evaporation in the dry-farm territory4 ,it is always much larger than the total annual rainfall4 ,in fact1 an arid region may be defined as one in which under natural conditions several times more water evaporates annually from a free water surface than falls as rain and snow4 ,for that reason many students of aridity pay little attention to temperature1 relative humidity1 or winds1 and simply measure the evaporation from a free water surface in the locality in question4 ,in order to obtain a measure of the aridity1 ,mac,dougal has constructed the following table1 showing the annual precipitation and the annual evaporation at several well-known localities in the dry-farm territory4 ,true1 the localities included in the following table are extreme1 but they illustrate the large possible evaporation1 ranging from about six to thirty-five times the precipitation4 ,at the same time it must be borne in mind that while such rates of evaporation may occur from free water surfaces1 the evaporation from agricultural soils under like conditions is very much smaller4 ,place ,annual ,precipitation ,annual ,evaporation ,ratio 7,in ,inches7 7,in ,inches7 ,el ,paso1 ,texas #i4bc #hj #h4g ,fort ,wingate1 ,new ,mexico #ad4jj #hj #e4g ,fort ,yuma1 ,arizona #b4hd #ajj #ce4b ,tucson1 ,,az #aa4gd #ij #g4g ,mohave1 ,,ca #d4ig #ie #ai4a ,hawthorne1 ,nevada #d4ej #hj #ag4e ,winnemucca1 ,nevada #i4ea #hj #i4f ,st4 ,george1 ,utah #f4df #ij #ac4i ,fort ,duchesne1 ,utah #f4di #ge #aa4f ,pineville1 ,oregon #i4ja #gj #g4h ,lost ,river1 ,idaho #h4dg #gj #h4c ,laramie1 ,wyoming #i4ha #gj #g4a ,torres1 ,mexico #af4ig #ajj #f4j ,to understand the methods employed for checking evaporation from the soil1 it is necessary to review briefly the conditions that determine the evaporation of water into the air1 and the manner in which water moves in the soil4 ,the formation of water vapor ,whenever water is left freely exposed to the air1 it evaporates2 that is1 it passes into the gaseous state and mixes with the gases of the air4 ,even snow and ice give off water vapor1 though in very small quantities4 ,the quantity of water vapor which can enter a given volume of air is definitely limited4 ,for instance1 at the temperature of freezing water #b4abf grains of water vapor can enter one cubic foot of air1 but no more4 ,when air contains all the water possible1 it is said to be saturated1 and evaporation then ceases4 ,the practical effect of this is the well-known experience that on the seashore1 where the air is often very nearly fully saturated with water vapor1 the drying of clothes goes on very slowly1 whereas in the interior1 like the dry-farming territory1 away from the ocean1 where the air is far from being saturated1 drying goes on very rapidly4 ,the amount of water necessary to saturate air varies greatly with the temperature4 ,it is to be noted that as the temperature increases1 the amount of water that may be held by the air also increases2 and proportionately more rapidly than the increase in temperature4 ,this is generally well understood in common experience1 as in drying clothes rapidly by hanging them before a hot fire4 ,at a temperature of #ajj deg ,f41 which is often reached in portions of the dry-farm territory during the growing season1 a given volume of air can hold more than nine times as much water vapor as at the temperature of freezing water4 ,this is an exceedingly important principle in dry-farm practices1 for it explains the relatively easy possibility of storing water during the fall and winter when the temperature is low and the moisture usually abundant1 and the greater difficulty of storing the rain that falls largely1 as in the ,great ,plains area1 in the summer when water-dissipating forces are very active4 ,this law also emphasizes the truth that it is in times of warm weather that every precaution must be taken to prevent the evaporation of water from the soil surface4 ,temperature ,grains of ,water held in in ,degrees ,f4 ,one ,cubic ,foot of ,air #cb #b4abf #dj #b4hfb #ej #d4jhi #fj #e4gef #gj #g4iib #hj #aj4idi #ij #ad4haj #ajj #ai4gij ,it is of course well understood that the atmosphere as a whole is never saturated with water vapor4 ,such saturation is at the best only local1 as1 for instance1 on the seashore during quiet days1 when the layer of air over the water may be fully saturated1 or in a field containing much water from which1 on quiet warm days1 enough water may evaporate to saturate the layer of air immediately upon the soil and around the plants4 ,whenever1 in such cases1 the air begins to move and the wind blows1 the saturated air is mixed with the larger portion of unsaturated air1 and evaporation is again increased4 ,meanwhile1 it must be borne in mind that into a layer of saturated air resting upon a field of growing plants very little water evaporates1 and that the chief water-dissipating power of winds lies in the removal of this saturated layer4 ,winds or air movements of any kind1 therefore1 become enemies of the farmer who depends upon a limited rainfall4 ,the amount of water actually found in a given volume of air at a certain temperature1 compared with the largest amount it can hold1 is called the relative humidity of the air4 ,as shown in ,chapter ,,iv1 the relative humidity becomes smaller as the rainfall decreases4 ,the lower the relative humidity is at a given temperature1 the more rapidly will water evaporate into the air4 ,there is no more striking confirmation of this law than the fact that at a temperature of #ij deg sunstrokes and similar ailments are reported in great number from ,new ,york1 while the people of ,salt ,lake ,city are perfectly comfortable4 ,in ,new ,york the relative humidity in summer is about #gc per cent2 in ,salt ,lake ,city1 about #ce per cent4 ,at a high summer temperature evaporation from the skin goes on slowly in ,new ,york and rapidly in ,salt ,lake ,city1 with the resulting discomfort or comfort4 ,similarly1 evaporation from soils goes on rapidly under a low and slowly under a high percentage of relative humidity4 ,evaporation from water surfaces is hastened1 therefore1 by 7#a7 an increase in the temperature1 7#b7 an increase in the air movements or winds1 and 7#c7 a decrease in the relative humidity4 ,the temperature is higher2 the relative humidity lower1 and the winds usually more abundant in arid than in humid regions4 ,the dry-farmer must consequently use all possible precautions to prevent evaporation from the soil4 ,conditions of evaporation from from soils ,evaporation does not alone occur from a surface of free water4 ,all wet or moist substances lose by evaporation most of the water that they hold1 providing the conditions of temperature and relative humidity are favorable4 ,thus1 from a wet soil1 evaporation is continually removing water4 ,yet1 under ordinary conditions1 it is impossible to remove all the water1 for a small quantity is attracted so strongly by the soil particles that only a temperature above the boiling point of water will drive it out4 ,this part of the soil is the hygroscopic moisture spoken of in the last chapter4 ,moreover1 it must be kept in mind that evaporation does not occur as rapidly from wet soil as from a water surface1 unless all the soil pores are so completely filled with water that the soil surface is practically a water surface4 ,the reason for this reduced evaporation from a wet soil is almost self-evident4 ,there is a comparatively strong attraction between soil and water1 which enables the moisture to cling as a thin capillary film around the soil particles1 against the force of gravity4 ,ordinarily1 only capillary water is found in well-tilled soil1 and the force causing evaporation must be strong enough to overcome this attraction besides changing the water into vapor4 ,the less water there is in a soil1 the thinner the water film1 and the more firmly is the water held4 ,hence1 the rate of evaporation decreases with the decrease in soil-moisture4 ,this law is confirmed by actual field tests4 ,for instance1 as an average of #bgd trials made at the ,utah ,station1 it was found that three soils1 otherwise alike1 that contained1 respectively1 #bb4fc per cent1 #ag4ad per cent1 and #ab4ge per cent of water lost in two weeks1 to a depth of eight feet1 respectively #ba4j1 #ag4 #a1 and #aj4j pounds of water per square foot4 ,similar experiments conducted elsewhere also furnish proof of the correctness of this principle4 ,from this point of view the dry-farmer does not want his soils to be unnecessarily moist4 ,the dry-farmer can reduce the per cent of water in the soil without diminishing the total amount of water by so treating the soil that the water will distribute itself to considerable depths4 ,this brings into prominence again the practices of fall plowing1 deep plowing1 subsoiling1 and the choice of deep soils for dry-farming4 ,very much for the same reasons1 evaporation goes on more slowly from water in which salt or other substances have been dissolved4 ,the attraction between the water and the dissolved salt seems to be strong enough to resist partially the force causing evaporation4 ,soil-water always contains some of the soil ingredients in solution1 and consequently under the given conditions evaporation occurs more slowly from soil-water than from pure water4 ,now1 the more fertile a soil is1 that is1 the more soluble plant-food it contains1 the more material will be dissolved in the soil-water1 and as a result the more slowly will evaporation take place4 ,fallowing1 cultivation1 thorough plowing and manuring1 which increase the store of soluble plant-food1 all tend to diminish evaporation4 ,while these conditions may have little value in the eyes of the farmer who is under an abundant rainfall1 they are of great importance to the dry-farmer4 ,it is only by utilizing every possibility of conserving water and fertility that dry-farming may be made a perfectly safe practice4 ,loss by evaporation chiefly at the surface ,evaporation goes on from every wet substance4 ,water evaporates therefore from the wet soil grains under the surface as well as from those at the surface4 ,in developing a system of practice which will reduce evaporation to a minimum it must be learned whether the water which evaporates from the soil particles far below the surface is carried in large quantities into the atmosphere and thus lost to plant use4 ,over forty years ago1 ,nessler subjected this question to experiment and found that the loss by evaporation occurs almost wholly at the soil surface1 and that very little if any is lost directly by evaporation from the lower soil layers4 ,other experimenters have confirmed this conclusion1 and very recently ,buckingham1 examining the same subject1 found that while there is a very slow upward movement of the soil gases into the atmosphere1 the total quantity of the water thus lost by direct evaporation from soil1 a foot below the surface1 amounted at most to one inch of rainfall in six years4 ,this is insignificant even under semiarid and arid conditions4 ,however1 the rate of loss of water by direct evaporation from the lower soil layers increases with the porosity of the soil1 that is1 with the space not filled with soil particles or water4 ,fine-grained soils1 therefore1 lose the least water in this manner4 ,nevertheless1 if coarse-grained soils are well filled with water1 by deep fall plowing and by proper summer fallowing for the conservation of moisture1 the loss of moisture by direct evaporation from the lower soil layers need not be larger than from finer grained soils ,thus again are emphasized the principles previously laid down that1 for the most successful dry-farming1 the soil should always be kept well filled with moisture1 even if it means that the land1 after being broken1 must lie fallow for one or two seasons1 until a sufficient amount of moisture has accumulated4 ,further1 the correlative principle is emphasized that the moisture in dry-farm lands should be stored deeply1 away from the immediate action of the sun's rays upon the land surface4 ,the necessity for deep soils is thus again brought out4 ,the great loss of soil moisture due to an accumulation of water in the upper twelve inches is well brought out in the experiments conducted by the ,utah ,station4 ,the following is selected from the numerous data on the subject4 ,two soils1 almost identical in character1 contained respectively #ag4eg per cent and #af4ee per cent of water on an average to a depth of eight feet2 that is1 the total amount of water held by the two soils was practically identical4 ,owing to varying cultural treatment1 the distribution of the water in the soil was not uniform2 one contained #bc4bb per cent and the other #af4fd per cent of water in the first twelve inches4 ,during the first seven days the soil that contained the highest percentage of water in the first foot lost #ac4cj pounds of water1 while the other lost only #h4dh pounds per square foot4 ,this great difference was due no doubt to the fact that direct evaporation takes place in considerable quantity only in the upper twelve inches of soil1 where the sun's heat has a full chance to act4 ,any practice which enables the rains to sink quickly to considerable depths should be adopted by the dry-farmer4 ,this is perhaps one of the great reasons for advocating the expensive but usually effective subsoil plowing on dry-farms4 ,it is a very common experience1 in the arid region1 that great1 deep cracks form during hot weather4 ,from the walls of these cracks evaporation goes on1 as from the topsoil1 and the passing winds renew the air so that the evaporation may go on rapidly4 ,the dry-farmer must go over the land as often as needs be with some implement that will destroy and fill up the cracks that may have been formed4 ,in a field of growing crops this is often difficult to do2 but it is not impossible that hand hoeing1 expensive as it is1 would pay well in the saving of soil moisture and the consequent increase in crop yield4 ,how soil water reaches the surface ,it may be accepted as an established truth that the direct evaporation of water from wet soils occurs almost wholly at the surface4 ,yet it is well known that evaporation from the soil surface may continue until the soil-moisture to a depth of eight or ten feet or more is depleted4 ,this is shown by the following analyses of dry-farm soil in early spring and midsummer4 ,no attempt was made to conserve the moisture in the soil3-- ,per cent of water in ,early spring ,midsummer #ast foot #bj4hd #h4hc #bnd foot #bj4jf #h4hg #crd foot #ai4fb #aa4jc #dth foot #ah4bh #i4ei #eth foot #ah4gj #aa4bg #fth foot #ad4bi #aa4jc #gth foot #ad4dh #h4ie #hth foot #ac4hc #i4dg ,avg #ag4ea #i4hh ,in this case water had undoubtedly passed by capillary movement from the depth of eight feet to a point near the surface where direct evaporation could occur4 ,as explained in the last chapter1 water which is held as a film around the soil particles is called capillary water2 and it is in the capillary form that water may be stored in dry-farm soils4 ,moreover1 it is the capillary soil-moisture alone which is of real value in crop production4 ,this capillary water tends to distribute itself uniformly throughout the soil1 in accordance with the prevailing conditions and forces4 ,if no water is removed from the soil1 in course of time the distribution of the soil-water will be such that the thickness of the film at any point in the soil mass is a direct resultant of the various forces acting at that particular point4 ,there will then be no appreciable movement of the soil-moisture4 ,such a condition is approximated in late winter or early spring before planting begins4 ,during the greater part of the year1 however1 no such quiescent state can occur1 for there are numerous disturbing elements that normally are active1 among which the three most effective are 7l7 the addition of water to the soil by rains2 7#b7 the evaporation of water from the topsoil1 due to the more active meteorological factors during spring1 summer1 and fall2 and 7#c7 the abstraction of water from the soil by plant roots4 ,water1 entering the soil1 moves downward under the influence of gravity as gravitational water1 until under the attractive influence of the soil it has been converted into capillary water and adheres to the soil particles as a film4 ,if the soil were dry1 and the film therefore thin1 the rain water would move downward only a short distance as gravitational water2 if the soil were wet1 and the film therefore thick1 the water would move down to a greater distance before being exhausted4 ,if1 as is often the case in humid districts1 the soil is saturated1 that is1 the film is as thick as the particles can hold1 the water would pass right through the soil and connect with the standing water below4 ,this1 of course1 is seldom the case in dry-farm districts4 ,in any soil1 excepting one already saturated1 the addition of water will produce a thickening of the soil-water film to the full descent of the water4 ,this immediately destroys the conditions of equilibrium formerly existing1 for the moisture is not now uniformly distributed4 ,consequently a process of redistribution begins which continues until the nearest approach to equilibrium is restored4 ,in this process water will pass in every direction from the wet portion of the soil to the drier2 it does not necessarily mean that water will actually pass from the wet portion to the drier portion2 usually1 at the driest point a little water is drawn from the adjoining point1 which in turn draws from the next1 and that from the next1 until the redistribution is complete4 ,the process is very much like stuffing wool into a sack which already is loosely filled4 ,the new wool does not reach the bottom of the sack1 yet there is more wool in the bottom than there was before4 ,if a plant-root is actively feeding some distance under the soil surface1 the reverse process occurs4 ,at the feeding point the root continually abstracts water from the soil grains and thus makes the film thinner in that locality4 ,this causes a movement of moisture similar to the one above described1 from the wetter portions of the soil to the portion being dried out by the action of the plant-root4 ,soil many feet or even rods distant may assist in supplying such an active root with moisture4 ,when the thousands of tiny roots sent out by each plant are recalled4 it may well be understood what a confusion of pulls and counter-pulls upon the soil-moisture exists in any cultivated soil4 ,in fact1 the soil-water film may be viewed as being in a state of trembling activity1 tending to place itself in full equilibrium with the surrounding contending forces which1 themselves1 constantly change4 ,were it not that the water film held closely around the soil particles is possessed of extreme mobility1 it would not be possible to meet the demands of the plants upon the water at comparatively great distances4 ,even as it is1 it frequently happens that when crops are planted too thickly on dry-farms1 the soil-moisture cannot move quickly enough to the absorbing roots to maintain plant growth1 and crop failure results4 ,incidentally1 this points to planting that shall be proportional to the moisture contained by the soil4 ,see ,chapter ,,xi4 ,as the temperature rises in spring1 with a decrease in the relative humidity1 and an increase in direct sunshine1 evaporation from the soil surface increases greatly4 ,however1 as the topsoil becomes drier1 that is1 as the water fihn becomes thinner1 there is an attempt at readjustment1 and water moves upward to take the place of that lost by evaporation4 ,as this continues throughout the season1 the moisture stored eight or ten feet or more below the surface is gradually brought to the top and evaporated1 and thus lost to plant use4 ,the effect of rapid top drying of soils ,as the water held by soils diminishes1 and the water film around the soil grains becomes thinner1 the capillary movement of the soil-water is retarded4 ,this is easily understood by recalling that the soil particles have an attraction for water1 which is of definite value1 and may be measured by the thickest film that may be held against gravity4 ,when the film is thinned1 it does not diminish the attraction of the soil for water2 it simply results in a stronger pull upon the water and a firmer holding of the film against the surfaces of the soil grains4 ,to move soil-water under such conditions requires the expenditure of more energy than is necessary for moving water in a saturated or nearly saturated soil4 ,under like conditions1 therefore1 the thinner the soil-water film the more difficult will be the upward movement of the soil-water and the slower the evaporation from the topsoil4 ,as drying goes on1 a point is reached at which the capillary movement of the water wholly ceases4 ,this is probably when little more than the hygroscopic moisture remains4 ,in fact1 very dry soil and water repel each other4 ,this is shown in the common experience of driving along a road in summer1 immediately after a light shower4 ,the masses of dust are wetted only on the outside1 and as the wheels pass through them the dry dust is revealed4 ,it is an important fact that very dry soil furnishes a very effective protection against the capillary movement of water4 ,in accordance with the principle above established if the surface soil could be dried to the point where capillarity is very slow1 the evaporation would be diminished or almost wholly stopped4 ,more than a quarter of a century ago1 ,eser showed experimentally that soil-water may be saved by drying the surface soil rapidly4 ,under dry-farm conditions it frequently occurs that the draft upon the water of the soil is so great that nearly all the water is quickly and so completely abstracted from the upper few inches of soil that they are left as an effective protection against further evaporation4 ,for instance1 in localities where hot dry winds are of common occurrence1 the upper layer of soil is sometimes completely dried before the water in the lower layers can by slow capillary movement reach the top4 ,the dry soil layer then prevents further loss of water1 and the wind because of its intensity has helped to conserve the soil-moisture4 ,similarly in localities where the relative humidity is low1 the sunshine abundant1 and the temperature high1 evaporation may go on so rapidly that the lower soil layers cannot supply the demands made1 and the topsoil then dries out so completely as to form a protective covering against further evaporation4 ,it is on this principle that the native desert soils of the ,united ,states1 untouched by the plow1 and the surfaces of which are sun-baked1 are often found to possess large percentages of water at lower depths4 ,whitney recorded this observation with considerable surprise1 many years ago1 and other observers have found the same conditions at nearly all points of the arid region4 ,this matter has been subjected to further study by ,buckingham1 who placed a variety of soils under artificially arid and humid conditions4 ,it was found in every case that1 the initial evaporation was greater under arid conditions1 but as the process went on and the topsoil of the arid soil became dry1 more water was lost under humid conditions4 ,for the whole experimental period1 also1 more water was lost under humid conditions4 ,it was notable that the dry protective layer was formed more slowly on alkali soils1 which would point to the inadvisability of using alkali lands for dry-farm purposes4 ,all in all1 however1 it appears that under very arid conditions a soil automatically protects itself from drying by the formation of a natural mulch on the surface4 ,naturally1 dry-farm soils differ greatly in their power of forming such a mulch4 ,a heavy clay or a light sandy soil appears to have less power of such automatic protection than a loamy soil4 ,an admixture of limestone seems to favor the formation of such a natural protective mulch4 ,ordinarily1 the farmer can further the formation of a dry topsoil layer by stirring the soil thoroughly4 ,this assists the sunshine and the air to evaporate the water very quickly4 ,such cultivation is very desirable for other reasons also1 as will soon be discussed4 ,meanwhile1 the water-dissipating forces of the dry-farm section are not wholly objectionable1 for whether the land be cultivated or not1 they tend to hasten the formation of dry surface layers of soil which guard against excessive evaporation4 ,it is in moist cloudy weather1 when the drying process is slow1 that evaporation causes the greatest losses of soil-moisture4 ,the effect of shading ,direct sunshine is1 next to temperature1 the most active cause of rapid evaporation from moist soil surfaces4 ,whenever1 therefore1 evaporation is not rapid enough to form a dry protective layer of topsoil1 shading helps materially in reducing surface losses of soil-water4 ,under very arid conditions1 however1 it is questionable whether in all cases shading has a really beneficial effect1 though under semiarid or sub-humid conditions the benefits derived from shading are increased largely4 ,ebermayer showed in #ahgc that the shading due to the forest cover reduced evaporation #fb per cent1 and many experiments since that day have confirmed this conclusion4 ,at the ,utah ,station1 under arid conditions1 it was found that shading a pot of soil1 which otherwise was subjected to water-dissipating influences1 saved #bi per cent of the loss due to evaporation from a pot which was not shaded4 ,this principle cannot be applied very greatly in practice1 but it points to a somewhat thick planting1 proportioned to the water held by the soil4 ,it also shows a possible benefit to be derived from the high header straw which is allowed to stand for several weeks in dry-farm sections where the harvest comes early and the fall plowing is done late1 as in the mountain states4 ,the high header stubble shades the ground very thoroughly4 ,thus the stubble may be made to conserve the soil-moisture in dry-farm sections1 where grain is harvested by the header method4 ,a special case of shading is the mulching of land with straw or other barnyard litter1 or with leaves1 as in the forest4 ,such mulching reduces evaporation1 but only in part1 because of its shading action1 since it acts also as a loose top layer of soil matter breaking communication with the lower soil layers4 ,whenever the soil is carefully stirred1 as will be described1 the value of shading as a means or checking evaporation disappears almost entirely4 ,it is only with soils which are tolerably moist at the surface that shading acts beneficially4 ,alfalfa in cultivated rows4 ,this practice is employed to make possible the growth of alfalfa and other perennial crops on arid lands without irrigation4 ,the effect of tillage ,capillary soil-moisture moves from particle to particle until the surface is reached4 ,the closer the soil grains are packed together1 the greater the number of points or contact1 and the more easily will the movement of the soil-moisture proceed4 ,if by any means a layer of the soil is so loosened as to reduce the number of points of contact1 the movement of the soil-moisture is correspondingly hindered4 ,the process is somewhat similar to the experience in large r airway stations4 ,just before train time a great crowd of people is gathered outside or the gates ready to show their tickets4 ,if one gate is opened1 a certain number of passengers can pass through each minute2 if two are opened1 nearly twice as many may be admitted in the same time2 if more gates are opened1 the passengers will be able to enter the train more rapidly4 ,the water in the lower layers of the soil is ready to move upward whenever a call is made upon it4 ,to reach the surface it must pass from soil grain to soil grain1 and the larger the number of grains that touch1 the more quickly and easily will the water reach the surface1 for the points of contact of the soil particles may be likened to the gates of the railway station4 ,now if1 by a thorough stirring and loosening of the topsoil1 the number of points of contact between the top and subsoil is greatly reduced1 the upward flow of water is thereby largely checked4 ,such a loosening of the topsoil for the purpose of reducing evaporation from the topsoil has come to be called cultivation1 and includes plowing1 harrowing1 disking1 hoeing1 and other cultural operations by which the topsoil is stirred4 ,the breaking of the points of contact between the top and subsoil is undoubtedly the main reason for the efficiency of cultivation1 but it is also to be remembered that such stirring helps to dry the top soil very thoroughly1 and as has been explained a layer of dry soil of itself is a very effective check upon surface evaporation4 ,that the stirring or cultivation of the topsoil really does diminish evaporation of water from the soil has been shown by numerous investigations4 ,in #ahfh1 ,nessler found that during six weeks of an ordinary ,german summer a stirred soil lost #eaj grams of water per square foot1 while the adjoining compacted soil lost #afhj grams1--a saving due to cultivation of nearly #fj per cent4 ,wagner1 testing the correctness of ,nessler's work1 found1 in #ahgd1 that cultivation reduced the evaporation a little more than #fj per cent2 ,johnson1 in #ahgh1 confirmed the truth of the principle on ,american soils1 and ,levi ,stockbridge1 working about the same time1 also on ,american soils1 found that cultivation diminished evaporation on a clay soil about #bc per cent1 on a sandy loam #ee per cent1 and on a heavy loam nearly #ac per cent4 ,all the early work done on this subject was done under humid conditions1 and it is only in recent years that confirmation of this important principle has been obtained for the soils of the dry-farm region4 ,fortier1 working under ,california conditions1 determined that cultivation reduced the evaporation from the soil surface over #ee per cent4 ,at the ,utah ,station similar experiments have shown that the saving of soil-moisture by cultivation was #fc per cent for a clay soil1 #cd per cent for a coarse sand1 and #ac per cent for a clay loam4 ,further1 practical experience has demonstrated time and time again that in cultivation the dry-farmer has a powerful means of preventing evaporation from agricultural soils4 ,closely connected with cultivation is the practice of scattering straw or other litter over the ground4 ,such artificial mulches are very effective in reducing evaporation4 ,ebermayer found that by spreading straw on the land1 the evaporation was reduced #bb per cent2 ,wagner found under similar conditions a saving of #ch per cent1 and these results have been confirmed by many other investigators4 ,on the modern dry-farms1 which are large in area1 the artificial mulching of soils cannot become a very extensive practice1 yet it is well to bear the principle in mind4 ,the practice of harvesting dry-farm grain with the header and plowing under the high stubble in the fall is a phase of cultivation for water conservation that deserves special notice4 ,the straw1 thus incorporated into the soil1 decomposes quite readily in spite of the popular notion to the contrary1 and makes the soil more porous1 and1 therefore1 more effectively worked for the prevention of evaporation4 ,when this practice is continued for considerable periods1 the topsoil becomes rich in organic matter1 which assists in retarding evaporation1 besides increasing the fertility of the land4 ,when straw cannot be fed to advantage1 as is yet the case on many of the western dry-farms1 it would be better to scatter it over the land than to burn it1 as is often done4 ,anything that covers the ground or loosens the topsoil prevents in a measure the evaporation of the water stored in lower soil depths for the use of crops4 ,depth of cultivation ,the all-important practice for the dry-farmer who is entering upon the growing season is cultivation4 ,the soil must be covered continually with a deep layer of dry loose soil1 which because of its looseness and dryness makes evaporation difficult4 ,a leading question in connection with cultivation is the depth to which the soil should be stirred for the best results4 ,many of the early students of the subject found that a soil mulch only one half inch in depth was effective in retaining a large part of the soil-moisture which noncultivated soils would lose by evaporation4 ,soils differ greatly in the rate of evaporation from their surfaces4 ,some form a natural mulch when dried1 which prevents further water loss4 ,others form only a thin hard crust1 below which lies an active evaporating surface of wet soil4 ,soils which dry out readily and crumble on top into a natural mulch should be cultivated deeply1 for a shallow cultivation does not extend beyond the naturally formed mulch4 ,in fact1 on certain calcareous soils1 the surfaces of which dry out quickly and form a good protection against evaporation1 shallow cultivations often cause a greater evaporation by disturbing the almost perfect natural mulch4 ,clay or sand soils1 which do not so well form a natural mulch1 will respond much better to shallow cultivations4 ,in general1 however1 the deeper the cultivation1 the more effective it is in reducing evaporation4 ,fortier1 in the experiments in ,california to which allusion has already been made1 showed the greater value of deep cultivation4 ,during a period of fifteen days1 beginning immediately after an irrigation1 the soil which had not been mulched lost by evaporation nearly one fourth of the total amount of water that had been added4 ,a mulch #d inches deep saved about #gb per cent of the evaporation2 a mulch #h inches deep saved about #hh per cent1 and a mulch #aj inches deep stopped evaporation almost wholly4 ,it is a most serious mistake for the dry-farmer1 who attempts cultivation for soil-moisture conservation1 to fail to get the best results simply to save a few cents per acre in added labor4 ,when to cultivate or till ,it has already been shown that the rate of evaporation is greater from a wet than from a dry surface4 ,it follows1 therefore1 that the critical time for preventing evaporation is when the soil is wettest4 ,after the soil is tolerably dry1 a very large portion of the soil-moisture has been lost1 which possibly might have been saved by earlier cultivation4 ,the truth of this statement is well shown by experiments conducted by the ,utah ,station4 ,in one case on a soil well filled with water1 during a three weeks' period1 nearly one half of the total loss occurred the first1 while only one fifth fell on the third week4 ,of the amount lost during the first week1 over #fj per cent occurred during the first three days4 ,cultivation should1 therefore1 be practiced as soon as possible after conditions favorable for evaporation have been established4 ,this means1 first1 that in early spring1 just as soon as the land is dry enough to be worked without causing puddling1 the soil should be deeply and thoroughly stirred4 ,spring plowing1 done as early as possible1 is an excellent practice for forming a mulch against evaporation4 ,even when the land has been fall-plowed1 spring plowing is very beneficial1 though on fall-plowed land the disk harrow is usually used in early spring1 and if it is set at rather a sharp angle1 and properly weighted1 so that it cuts deeply into the ground1 it is practically as effective as spring plowing4 ,the chief danger to the dry-farmer is that he will permit the early spring days to slip by until1 when at last he begins spring cultivation1 a large portion of the stored soil-water has been evaporated4 ,it may be said that deep fall plowing1 by permitting the moisture to sink quickly into the lower layers of soil1 makes it possible to get upon the ground earlier in the spring4 ,in fact1 unplowed land cannot be cultivated as early as that which has gone through the winter in a plowed condition ,if the land carries a fall-sown crop1 early spring cultivation is doubly important4 ,as soon as the plants are well up in spring the land should be gone over thoroughly several times if necessary1 with an iron tooth harrow1 the teeth of which are set to slant backward in order not to tear up the plants4 ,the loose earth mulch thus formed is very effective in conserving moisture2 and the few plants torn up are more than paid for by the increased water supply for the remaining plants4 ,the wise dry-fanner cultivates his land1 whether fallow or cropped1 as early as possible in the spring4 ,following the first spring plowing1 disking1 or cultivation1 must come more cultivation4 ,soon after the spring plowing1 the land should be disked and4 then harrowed4 ,every device should be used to secure the formation of a layer of loose drying soil over the land surface4 ,the season's crop will depend largely upon the effectiveness of this spring treatment4 ,as the season advances1 three causes combine to permit the evaporation of soil-moisture4 ,first1 there is a natural tendency1 under the somewhat moist conditions of spring1 for the soil to settle compactly and thus to restore the numerous capillary connections with the lower soil layers through which water escapes4 ,careful watch should therefore be kept upon the soil surface1 and whenever the mulch is not loose1 the disk or harrow should be run over the land4 ,secondly1 every rain of spring or summer tends to establish connections with the store of moisture in the soil4 ,in fact1 late spring and summer rains are often a disadvantage on dry-farms1 which by cultural treatment have been made to contain a large store of moisture4 ,it has been shown repeatedly that light rains draw moisture very quickly from soil layers many feet below the surface4 ,the rainless summer is not feared by the dry-farmer whose soils are fertile and rich in moisture4 ,it is imperative that at the very earliest moment after a spring or summer rain the topsoil be well stirred to prevent evaporation4 ,it thus happens that in sections of frequent summer rains1 as in the ,great ,plains area1 the farmer has to harrow his land many times in succession1 but the increased crop yields invariably justify the added expenditure of effort4 ,thirdly1 on the summer-fallowed ground weeds start vigorously in the spring and draw upon the soil-moisture1 if allowed to grow1 fully as heavily as a crop of wheat or corn4 ,the dry-farmer must not allow a weed upon his land4 ,cultivation must he so continuous as to make weeds an impossibility4 ,the belief that the elements added to the soil by weeds offset the loss of soil-moisture is wholly erroneous4 ,the growth of weeds on a fallow dry-farm is more dangerous than the packed uncared-for topsoil4 ,many implements have been devised for the easy killing of weeds1 but none appear to be better than the plow and the disk which are found on every farm4 7,see ,chapter ,,xv47 ,when crops are growing on the land1 thorough summer cultivation is somewhat more difficult1 but must be practiced for the greatest certainty of crop yields4 ,potatoes1 corn1 and similar crops may be cultivated with comparative ease1 by the use of ordinary cultivators4 ,with wheat and the other small grains1 generally1 the damage done to the crop by harrowing late in the season is too great1 and reliance is therefore placed on the shading power of the plants to prevent undue evaporation4 ,however1 until the wheat and other grains are ten to twelve inches high1 it is perfectly safe to harrow them4 ,the teeth should be set backward to diminish the tearing up of the plants1 and the implement weighted enough to break the soil crust thoroughly4 ,this practice has been fully tried out over the larger part of the dry-farm territory and found satisfactory4 ,so vitally important is a permanent soil mulch for the conservation for plant use of the water stored in the soil that many attempts have been made to devise means for the effective cultivation of land on which small grains and grasses are growing4 ,in many places plants have been grown in rows so far apart that a man with a hoe could pass between them4 ,scofield has described this method as practiced successfully in ,tunis4 ,campbell and others in ,america have proposed that a drill hole be closed every three feet to form a path wide enough for a horse to travel in and to pull a large spring tooth cultivator' with teeth so spaced as to strike between the rows of wheat4 ,it is yet doubtful whether1 under average conditions1 such careful cultivation1 at least of grain crops1 is justified by the returns4 ,under conditions of high aridity1 or where the store of soil-moisture is low1 such treatment frequently stands between crop success and failure1 and it is not unlikely that methods will be devised which will permit of the cheap and rapid cultivation between the rows of growing wheat4 ,meanwhile1 the dry-farmer must always remember that the margin under which he works is small1 and that his success depends upon the degree to which he prevents small wastes4 ,dry-farm potatoes1 ,rosebud ,co41 ,montana1 #aiji4 ,yield1 #bhb bushels per acre4 ,the conservation of soil-moisture depends upon the vigorous1 unremitting1 continuous stirring of the topsoil4 ,cultivation6 cultivation6 and more cultivation6 must be the war-cry of the dry-farmer who battles against the water thieves of an arid climate4 ,,chapter ,,ix ,,regulating ,,the ,,transpiration ,water that has entered the soil may be lost in three ways4 ,first1 it may escape by downward seepage1 whereby it passes beyond the reach of plant roots and often reaches the standing water4 ,in dry-farm districts such loss is a rare occurrence1 for the natural precipitation is not sufficiently large to connect with the country drainage1 and it may1 therefore1 be eliminated from consideration4 ,second1 soil-water may be lost by direct evaporation from the surface soil4 ,the conditions prevailing in arid districts favor strongly this manner of loss of soil-moisture4 ,it has been shown1 however1 in the preceding chapter that the farmer1 by proper and persistent cultivation of the topsoil1 has it in his power to reduce this loss enough to be almost negligible in the farmer's consideration4 ,third1 soil-water may be lost by evaporation from the plants themselves4 ,while it is not generally understood1 this source of loss is1 in districts where dry-farming is properly carried on1 very much larger than that resulting either from seepage or from direct evaporation4 ,while plants are growing1 evaporation from plants1 ordinarily called transpiration1 continues4 ,experiments performed in various arid districts have shown that one and a half to three times more water evaporates from the plant than directly from well-tilled soil4 ,to the present very little has been learned concerning the most effective methods of checking or controlling this continual loss of water4 ,transpiration1 or the evaporation of water from the plants themselves and the means of controlling this loss1 are subjects of the deepest importance to the dry-farmer4 ,absorption ,to understand the methods for reducing transpiration1 as proposed in this chapter1 it is necessary to review briefly the manner in which plants take water from the soil4 ,the roots are the organs of water absorption4 ,practically no water is taken into the plants by the stems or leaves1 even under conditions of heavy rainfall4 ,such small quantities as may enter the plant through the stems and leaves are of very little value in furthering the life and growth of the plant4 ,the roots alone are of real consequence in water absorption4 ,all parts of the roots do not possess equal power of taking up soil-water4 ,in the process of water absorption the younger roots are most active and effective4 ,even of the young roots1 however1 only certain parts are actively engaged in water absorption4 ,at the very tips of the young growing roots are numerous fine hairs4 ,these root-hairs1 which cluster about the growing point of the young roots1 are the organs of the plant that absorb soil-water4 ,they are of value only for limited periods of time1 for as they grow older1 they lose their power of water absorption4 ,in fact1 they are active only when they are in actual process of growth4 ,it follows1 therefore1 that water absorption occurs near the tips of the growing roots1 and whenever a plant ceases to grow the water absorption ceases also4 ,the root-hairs are filled with a dilute solution of various substances1 as yet poorly understood1 which plays an important tent part in the ab sorption of water and plant-food from the soil4 ,owing to their minuteness1 the root-hairs are in most cases immersed in the water film that surrounds the soil particles1 and the soil-water is taken directly into the roots from the soil-water film by the process known as osmosis4 ,the explanation of this inward movement is complicated and need not be discussed here4 ,it is sufficient to say that the concentration or strength of the solution within the root-hair is of different degree from the soil-water solution4 ,the water tends1 therefore1 to move from the soil into the root1 in order to make the solutions inside and outside of the root of the same concentration4 ,if it should ever occur that the soil-water and the water within the root-hair became the same concentration1 that is to say1 contained the same substances in the same proportional amounts1 there would be no further inward movement of water4 ,moreover1 if it should happen that the soil-water is stronger than the water within the root-hair1 the water would tend to pass from the plant into the soil4 ,this is the condition that prevails in many alkali lands of the ,west1 and is the cause of the death of plants growing on such lands4 ,it is clear that under these circumstances not only water enters the root-hairs1 but many of the substances found in solution in the soil-water enter the plant also4 ,among these are the mineral substances which are indispensable for the proper life and growth of plants4 ,these plant nutrients are so indispensable that if any one of them is absent1 it is absolutely impossible for the plant to continue its life functions4 ,the indispensable plant-foods gathered from the soil by the root-hairs1 in addition to water1 are3 potassium1 calcium1 magnesium1 iron1 nitrogen1 and phosphorus1--all in their proper combinations4 ,how the plant uses these substances is yet poorly understood1 but we are fairly certain that each one has some particular function in the life of the plant4 ,for instance1 nitrogen and phosphorus are probably necessary in the formation of the protein or the flesh-forming portions of the plant1 while potash is especially valuable in the formation of starch4 ,there is a constant movement of the indispensable plant nutrients after they have entered the root-hairs1 through the stems and into the leaves4 ,this constant movement of the plant-foods depends upon the fact that the plant consumes in its growth considerable quantities of these substances1 and as the plant juices are diminished in their content of particular plant-foods1 more enters from the soil solution4 ,the necessary plant-foods do not alone enter the plant but whatever may be in solution in the soil-water enters the plant in variable quantities4 ,nevertheless1 since the plant uses only a few definite substances and leaves the unnecessary ones in solution1 there is soon a cessation of the inward movement of the unimportant constituents of the soil solution4 ,this process is often spoken of as selective absorption2 that is1 the plant1 because of its vital activity1 appears to have the power of selecting from the soil certain substances and rejecting others4 ,movement of water through plant ,the soil-water1 holding in solution a great variety of plant nutrients1 passes from the root-hairs into the adjoining cells and gradually moves from cell to cell throughout the whole plant4 ,in many plants this stream of water does not simply pass from cell to cell1 but moves through tubes that apparently have been formed for the specific purpose of aiding the movement of water through the plant4 ,the rapidity of this current is often considerable4 ,ordinarily1 it varies from one foot to six feet per hour1 though observations are on record showing that the movement often reaches the rate of eighteen feet per hour4 ,it is evident1 then1 that in an actively growing plant it does not take long for the water which is in the soil to find its way to the uppermost parts of the plant4 ,the work of leaves ,whether water passes upward from cell to cell or through especially provided tubes1 it reaches at last the leaves1 where evaporation takes place4 ,it is necessary to consider in greater detail what takes place in leaves in order that we may more clearly understand the loss due to transpiration4 ,one half or more of every plant is made up of the element carbon4 ,the remainder of the plant consists of the mineral substances taken from the soil 7not more than two to #aj per cent of the dry plant7 and water which has been combined with the carbon and these mineral substances to form the characteristic products of plant life4 ,the carbon which forms over half of the plant substance is gathered from the air by the leaves and it is evident that the leaves are very active agents of plant growth4 ,the atmosphere consists chiefly of the gases oxygen and nitrogen in the proportion of one to four1 but associated with them are small quantities of various other substances4 ,chief among the secondary constituents of the atmosphere is the gas carbon dioxid1 which is formed when carbon burns1 that is1 when carbon unites with the oxygen of the air4 ,whenever coal or wood or any carbonaceous substance burns1 carbon dioxid is formed4 ,leaves have the power of absorbing the gas carbon dioxid from the air and separating the carbon from the oxygen4 ,the oxygen is returned to the atmosphere while the carbon is retained to be used as the fundamental substance in the construction by the plant of oils1 fats1 starches1 sugars1 protein1 and all the other products of plant growth4 ,this important process known as carbon assimilation is made possible by the aid of countless small openings which exist chicfly on the surfaces of leaves and known as stomata4 ,the stomata are delicately balanced valves1 exceedingly sensitive to external influences4 ,they are more numerous on the lower side than on the upper side of plants4 ,in fact1 there is often five times more on the under side than on the upper side of a leaf4 ,it has been estimated that #aej1jjj stomata or more are often found per square inch on the under side of the leaves of ordinary cultivated plants4 ,the stomata or breathing-pores are so constructed that they may open and close very readily4 ,in wilted leaves they are practically closed2 often they also close immediately after a rain2 but in strong sunlight they are usually wide open4 ,it is through the stomata that the gases of the air enter the plant through which the discarded oxygen returns to the atmosphere4 ,it is also through the stomata that the water which is drawn from the soil by the roots through the stems is evaporated into the air4 ,there is some evaporation of water from the stems and branches of plants1 but it is seldom more than a thirtieth or a fortieth of the total transpiration4 ,the evaporation of water from the leaves through the breathing-pores is the so-called transpiration1 which is the greatest cause of the loss of soil-water under dry-farm conditions4 ,it is to the prevention of this transpiration that much investigation must be given by future students of dry-farming4 ,transpiration ,as water evaporates through the breathing-pores from the leaves it necessarily follows that a demand is made upon the lower portions of the plant for more water4 ,the effect of the loss of water is felt throughout the whole plant and is1 undoubtedly1 one of the chief causes of the absorption of water from the soil4 ,as evaporation is diminished the amount of water that enters the plants is also diminished4 ,yet transpiration appears to be a process wholly necessary for plant life4 ,the question is1 simply1 to what extent it may be diminished without injuring plant growth4 ,many students believe that the carbon assimilation of the plant1 which is fundamentally important in plant growth1 cannot be continued unless there is a steady stream of water passing through the plant and then evaporating from the leaves4 ,of one thing we are fairly sure3 if the upward stream of water is wholly stopped for even a few hours1 the plant is likely to be so severely injured as to be greatly handicapped in its future growth4 ,botanical authorities agree that transpiration is of value to plant growth1 first1 because it helps to distribute the mineral nutrients necessary for plant growth uniformly throughout the plant2 secondly1 because it permits an active assimilation of the carbon by the leaves2 thirdly1 because it is not unlikely that the heat required to evaporate water1 in large part taken from the plant itself1 prevents the plant from being overheated4 ,this last mentioned value of transpiration is especially important in dry-farm districts1 where1 during the summer1 the heat is often intense4 ,fourthly1 transpiration apparently influences plant growth and development in a number of ways not yet clearly understood4 ,conditions influencing transpiration ,in general1 the conditions that determine the evaporation of water from the leaves are the same as those that favor the direct evaporation of water from soils1 although there seems to be something in the life process of the plant1 a physiological factor1 which permits or prevents the ordinary water-dissipating factors from exercising their full powers4 ,that the evaporation of water from the soil or from a free water surface is not the same as that from plant leaves may be shown in a general way from the fact that the amount of water transpired from a given area of leaf surface may be very much larger or very much smaller than that evaporated from an equal surface of free water exposed to the same conditions4 ,it is further shown by the fact that whereas evaporation from a free water surface goes on with little or no interruption throughout the twenty-four hours of the day1 transpiration is virtually at a standstill at night even though the conditions for the rapid evaporation from a free water surface are present4 ,some of the conditions influencing the transpiration may be enumerated as follows3-- ,first1 transpiration is influenced by the relative humidity4 ,in dry air1 under otherwise similar conditions1 plants transpire more water than in moist air though it is to be noted that even when the atmosphere is fully saturated1 so that no water evaporates from a free water surface1 the transpiration of plants still continues in a small degree4 ,this is explained by the observation that since the life process of a plant produces a certain amount of heat1 the plant is always warmer than the surrounding air and that transpiration into an atmosphere fully charged with water vapor is consequently made possible4 ,the fact that transpiration is greater under a low relative humidity is of greatest importance to the dry-farmer who has to contend with the dry atmosphere4 ,second1 transpiration increases with the increase in temperature2 that is1 under conditions otherwise the same1 transpiration is more rapid on a warm day than on a cold one4 ,the temperature increase of itself1 however1 is not sufficient to cause transpiration4 ,third1 transpiration increases with the increase of air currents1 which is to say1 that on a windy day transpiration is much more rapid than on a quiet day4 ,fourth1 transpiration increases with the increase of direct sunlight4 ,it is an interesting observation that even with the same relative humidity1 temperature1 and wind1 transpiration is reduced to a minimum during the night and increases manyfold during the day when direct sunlight is available4 ,this condition is again to be noted by the dry-farmer1 for the dry-farm districts are characterized by an abundance of sunshine4 ,fifth1 transpiration is decreased by the presence in the soil-water of large quantities of the substances which the plant needs for its food material4 ,this will be discussed more fully in the next section4 ,sixth1 any mechanical vibration of the plant seems to have some effect upon the transpiration4 ,at times it is increased and at times it is decreased by such mechanical disturbance4 ,seventh1 transpiration varies also with the age of the plant4 ,in the young plant it is comparatively small4 ,just before blooming it is very much larger and in time of bloom it is the largest in the history of the plant4 ,as the plant grows older transpiration diminishes1 and finally at the ripening stage it almost ceases4 ,eighth1 transpiration varies greatly with the crop4 ,not all plants take water from the soil at the same rate4 ,very little is as yet known about the relative water requirements of crops on the basis of transpiration4 ,as an illustration1 ,mac,dougall has reported that sagebrush uses about one fourth as much water as a tomato plant4 ,even greater differences exist between other plants4 ,this is one of the interesting subjects yet to be investigated by those who are engaged in the reclamation of dry-farm districts4 ,moreover1 the same crop grown under different conditions varies in its rate of transpiration4 ,for instance1 plants grown for some time under arid conditions greatly modify their rate of transpiration1 as shown by ,spalding1 who reports that a plant reared under humid conditions gave off #c4g times as much water as the same plant reared under arid conditions4 ,this very interesting observation tends to confirm the view commonly held that plants grown under arid conditions will gradually adapt themselves to the prevailing conditions1 and in spite of the greater water dissipating conditions will live with the expenditure of less water than would be the case under humid conditions4 ,further1 ,sorauer found1 many years ago1 that different varieties of the same crop possess very different rates of transpiration4 ,this also is an interesting subject that should be more fully investigated in the future4 ,ninth1 the vigor of growth of a crop appears to have a strong influence on transpiration4 ,it does not follow1 however1 that the more vigorously a crop grows1 the more rapidly does it transpire water1 for it is well known that the most luxuriant plant growth occurs in the tropics1 where the transpiration is exceedingly low4 ,it seems to be true that under the same conditions1 plants that grow most vigorously tend to use proportionately the smallest amount of water4 ,tenth1 the root system--its depth and manner of growth--influences the rate of transpiration4 ,the more vigorous and extensive the root system1 the more rapidly can water be secured from the soil by the plant4 ,the conditions above enumerated as influencing transpiration are nearly all of a physical character1 and it must not be forgotten that they may all be annulled or changed by a physiological regulation4 ,it must be admitted that the subject of transpiration is yet poorly understood1 though it is one of the most important subjects in its applications to plant production in localities where water is scaree4 ,it should also be noted that nearly all of the above conditions influencing transpiration are beyond the control of the farmer4 ,the one that seems most readily controlled in ordinary agricultural practice will be discussed in the following section4 ,plant-food and transpiration ,it has been observed repeatedly by students of transpiration that the amount of water which actually evaporates from the leaves is varied materially by the substances held in solution by the soil-water4 ,that is1 transpiration depends upon the nature and concentration of soil solution4 ,this fact1 though not commonly applied even at the present time1 has really been known for a very long time4 ,woodward1 in #afii1 observed that the amount of water transpired by a plant growing in rain water was #aib4c grams2 in spring water1 #afc4f grams1 and in water from the ,river ,thames1 #aei4e grams2 that is1 the amount of water transpired by the plant in the comparatively pure rain water was nearly #bj per cent higher than that used by the plant growing in the notoriously impure water of the ,river ,thames4 ,sachs1 in #ahei1 carried on an elaborate series of experiments on transpiration in which he showed that the addition of potassium nitrate1 ammonium sulphate or common salt to the solution in which plants grew reduced the transpiration2 in fact1 the reduction was large1 varying from #aj to #ge per cent4 ,this was confirmed by a number of later workers1 among them1 for instance1 ,buergerstein1 who1 in #ahge1 showed that whenever acids were added to a soil or to water in which plants are growing1 the transpiration is increased greatly2 but when alkalies of any kind are added1 transpiration decreases4 ,this is of special interest in the development of dry-farming1 since dry-farm soils1 as a rule1 contain more substances that may be classed as alkalies than do soils maintained under humid conditions4 ,sour soils are very characteristic of districts where the rainfall is abundant2 the vegetation growing on such soils transpires excessively and the crops are consequently more subject to drouth4 ,the investigators of almost a generation ago also determined beyond question that whenever a complete nutrient solution is presented to plants1 that is1 a solution containing all the necessary plant-foods in the proper proportions1 the transpiration is reduced immensely4 ,it is not necessary that the plant-foods should be presented in a water solution in order to effect this reduction in transpiration2 if they are added to the soil on which plants are growing1 the same effect will result4 ,the addition of commercial fertilizers to the soil will therefore diminish transpiration4 ,it was further discovered nearly half a century ago that similar plants growing on different soils evaporate different amounts of water from their leaves2 this difference1 undoubtedly1 is due to the conditions in the fertility of the soils1 for the more fertile a soil is1 the richer will the soil-water be in the necessary plant-foods4 ,the principle that transpiration or the evaporation of water from the plants depends on the nature and concentration of the soil solution is of far-reaching importance in the development of a rational practice of dry-farming4 ,transpiration for a pound of dry matter ,is plant growth proportional to transpiration8 ,do plants that evaporate much water grow more rapidly than those that evaporate less8 ,these questions arose very early in the period characterized by an active study of transpiration4 ,if varying the transpiration varies the growth1 there would be no special advantage in reducing the transpiration4 ,from an economic point of view the important question is this3 ,does the plant when its rate of transpiration is reduced still grow with the same vigor8 ,if that be the case1 then every effort should be made by the farmer to control and to diminish the rate of transpiration4 ,one of the very earliest experiments on transpiration1 conducted by ,woodward in #afii1 showed that it required less water to produce a pound of dry matter if the soil solution were of the proper concentration and contained the elements necessary for plant growth4 ,little more was done to answer the above questions for over one hundred and fifty years4 ,perhaps the question was not even asked during this period1 for scientific agriculture was just coming into being in countries where the rainfall was abundant4 ,however1 ,tschaplowitz1 in #ahgh1 investigated the subject and found that the increase in dry matter is greatest when the transpiration is the smallest4 ,sorauer1 in researches conducted from #ahhj to #ahhb1 determined with almost absolute certainty that less water is required to produce a pound of dry matter when the soil is fertilized than when it is not fertilized4 ,moreover1 he observed that the enriching of the soil solution by the addition of artificial fertilizers enabled the plant to produce dry matter with less water4 ,he further found that if a soil is properly tilled so as to set free plant-food and in that way to enrich the soil solution the water-cost of dry plant substance is decreased4 ,hellriegel1 in #ahhc1 confirmed this law and laid down the law that poor plant nutrition increases the water-cost of every pound of dry matter produced4 ,it was about this time that the ,rothamsted ,experiment ,station reported that its experiments had shown that during periods of drouth the well-tilled and well-fertilized fields yielded good crops1 while the unfertilized fields yielded poor crops or crop failures--indicating thereby1 since rainfall was the critical factor1 that the fertility of the soil is important in determining whether or not with a small amount of water a good crop can be produced4 ,pagnoul1 working in #ahie with fescue grass1 arrived at the same conclusion4 ,on a poor clay soil it required #aaji pounds of water to produce one pound of dry matter1 while on a rich calcareous soil only #egd pounds were required4 ,gardner of the ,united ,states ,department of ,agriculture1 ,bureau of ,soils1 working in #aijh1 on the manuring of soils1 came to the conclusion that the more fertile the soil the less water is required to produce a pound of dry matter4 ,he incidentally called attention to the fact that in countries of limited rainfall this might be a very important principle to apply in crop production4 ,hopkins in his study of the soils of ,illinois has repeatedly observed1 in connection with certain soils1 that where the land is kept fertile1 injury from drouth is not common1 implying thereby that fertile soils will produce dry matter at a lower water-cost4 ,the most recent experiments on this subject1 conducted by the ,utah ,station1 confirm these conclusions4 ,the experiments1 which covered several years1 were conducted in pots filled with different soils4 ,on a soil1 naturally fertile1 #ijh pounds of water were transpired for each pound of dry matter 7corn7 produced2 by adding to this soil an ordinary dressing of manure' this was reduced to #fac pounds1 and by adding a small amount of sodium nitrate it was reduced to #ehe pounds4 ,if so large a reduction could be secured in practice1 it would seem to justify the use of commercial fertilizers in years when the dry-farm year opens with little water stored in the soil4 ,similar results1 as will be shown below1 were obtained by the use of various cultural methods4 ,it may therefore1 be stated as a law1 that any cultural treatment which enables the soil-water to acquire larger quantities of plant-food also enables the plant to produce dry matter with the use of a smaller amount of water4 ,in dry-farming1 where the limiting factor is water1 this principle must he emphasized in every cultural operation4 ,methods of controlling transpiration ,it would appear that at present the only means possessed by the farmer for controlling transpiration and making possible maximum crops with the minimum amount of water in a properly tilled soil is to keep the soil as fertile as is possible4 ,in the light of this principle the practices already recommended for the storing of water and for the prevention of the direct evaporation of water from the soil are again emphasized4 ,deep and frequent plowing1 preferably in the fall so that the weathering of the winter may be felt deeply and strongly1 is of first importance in liberating plant-food4 ,cultivation which has been recommended for the prevention of the direct evaporation of water is of itself an effective factor in setting free plant-food and thus in reducing the amount of water required by plants4 ,the experiments at the ,utah ,station1 already referred to1 bring out very strikingly the value of cultivation in reducing the transpiration4 ,for instance1 in a series of experiments the following results were obtained4 ,on a sandy loam1 not cultivated1 #fjc pounds of water were transpired to produce one pound of dry matter of corn2 on the same soil1 cultivated1 only #beb pounds were required4 ,on a clay loam1 not cultivated1 #ece pounds of water were transpired for each pound of dry matter1 whereas on the cultivated soil only #dbh pounds were necessary4 ,on a clay soil1 not cultivated1 #gec pounds of water were transpired for each pound of dry matter2 on the cultivated soil1 only #ehb pounds4 ,the farmer who faithfully cultivates the soil throughout the summer and after every rain has therefore the satisfaction of knowing that he is accomplishing two very important things3 he is keeping the moisture in the soil1 and he is making it possible for good crops to be grown with much less water than would otherwise be required4 ,even in the case of a peculiar soil on which ordinary cultivation did not reduce the direct evaporation1 the effect upon the transpiration was very marked4 ,on the soil which was not cultivated1 #dea pounds of water were required to produce one pound of dry matter 7corn71 while on the cultivated soils1 though the direct evaporation was no smaller1 the number of pounds of water for each pound of dry substance was as low as #bfe4 ,one of the chief values of fallowing lies in the liberation of the plant-food during the fallow year1 which reduces the quantity of water required the next year for the full growth of crops4 ,the ,utah experiments to which reference has already been made show the effect of the previous soil treatment upon the water requirements of crops4 ,one half of the three types of soil had been cropped for three successive years1 while the other half had been left bare4 ,during the fourth year both halves were planted to corn4 ,for the sandy loam it was found that1 on the part that had been cropped previously1 #fei pounds of water were required for each pound of dry matter produced1 while on the part that had been bare only #egc pounds were required4 ,for the clay loam #hhi pounds on the cropped part and #eej on the previously bare part were required for each pound of dry matter4 ,for the clay #gdff pounds on the cropped part and #agci pounds on the previously bare part were required for each pound of dry matter4 ,these results teach clearly and emphatically that the fertile condition of the soil induced by fallowing makes it possible to produce dry matter with a smaller amount of water than can be done on soils that are cropped continuously4 ,the beneficial effects of fallowing are therefore clearly twofold3 to store the moisture of two seasons for the use of one crop2 and to set free fertility to enable the plant to grow with the least amount of water4 ,it is not yet fully understood what changes occur in fallowing to give the soil the fertility which reduces the water needs of the plant4 ,the researches of ,atkinson in ,montana1 ,stewart and ,graves in ,utah1 and ,jensen in ,south ,dakota make it seem probable that the formation of nitrates plays an important part in the whole process4 ,if a soil is of such a nature that neither careful1 deep plowing at the right time nor constant crust cultivation are sufficient to set free an abundance of plant-food1 it may be necessary to apply manures or commercial fertilizers to the soil4 ,while the question of restoring soil fertility has not yet come to be a leading one in dry-farming1 yet in view of what has been said in this chapter it is not impossible that the time will come when the farmers must give primary attention to soil fertility in addition to the storing and conservation of soil-moisture4 ,the fertilizing of lands with proper plant-foods1 as shown in the last sections1 tends to check transpiration and makes possible the production of dry matter at the lowest water-cost4 ,the recent practice in practically all dry-farm districts1 at least in the intermountain and far ,west1 to use the header for harvesting bears directly upon the subject considered in this chapter4 ,the high stubble which remains contains much valuable plant-food1 often gathered many feet below the surface by the plant roots4 ,when this stubble is plowed under there is a valuable addition of the plant-food to the upper soil4 ,further1 as the stubble decays1 acid substances are produced that act upon the soil grains to set free the plant-food locked up in them4 ,the plowing under of stubble is therefore of great value to the dry-farmer4 ,the plowing under of any other organic substance has the same effect4 ,in both cases fertility is concentrated near the surface1 which dissolves in the soil-water and enables the crop to mature with the ,ieast quantity of water4 ,the lesson then to be learned from this chapter is1 that it is not aufficient for the dry-farmer to store an abundance of water in the soil and to prevent that water from evaporating directly from the soil2 but the soil must be kept in such a state of high fertility that plants are enabled to utilize the stored moisture in the most economical manner4 ,water storage1 the prevention of evaporation1 and the maintenance of soil fertility go hand in hand in the development of a successful system of farming without irrigation4 ,,chapter ,x ,,plowing ,,and ,,fallowing ,the soil treatment prescribed in the preceding chapters rests upon 7#a7 deep and thorough plowing1 done preferably in the fall2 7#b7 thorough cultivation to form a mulch over the surface of the land1 and 7#c7 clean summer fallowing every other year under low rainfall or every third or fourth year under abundant rainfall4 ,students of dry-farming all agree that thorough cultivation of the topsoil prevents the evaporation of soil-moisture1 but some have questioned the value of deep and fall plowing and the occasional clean summer fallow4 ,it is the purpose of this chapter to state the findings of practical men with reference to the value of plowing and fallowing in producing large crop yields under dry-farm conditions4 ,it will be shown in ,chapter ,,xviii that the first attempts to produce crops without irrigation under a limited rainfall were made independently in many diverse places4 ,california1 ,utah1 and the ,columbia ,basin1 as far as can now be learned1 as well as the ,great ,plains area1 were all independent pioneers in the art of dry-farming4 ,it is a most significant fact that these diverse localities1 operating under different conditions as to soil and climate1 have developed practically the same system of dry-farming4 ,in all these places the best dry-farmers practice deep plowing wherever the subsoil will permit it2 fall plowing wherever the climate will permit it2 the sowing of fall grain wherever the winters will permit it1 and the clean summer fallow every other year1 or every third or fourth year4 ,h4 ,w4 ,campbell1 who has been the leading exponent of dry-farming in the ,great ,plains area1 began his work without the clean summer fallow as a part of his system1 but has long since adopted it for that section of the country4 ,it is scarcely to be believed that these practices1 developed laboriously through a long succession of years in widely separated localities1 do not rest upon correct scientific principles4 ,in any case1 the accumulated experience of the dry-farmers in this country confirms the doctrines of soil tillage for dry-farms laid down in the preceding chapters4 ,at the ,dry-,farming ,congresses large numbers of practical farmers assemble for the purpose of exchanging experiences and views4 ,the reports of the ,congress show a great difference of opinion on minor matters and a wonderful unanimity of opinion on the more fundamental questions4 ,for instance1 deep plowing was recommended by all who touched upon the subject in their remarks2 though one farmer1 who lived in a locality the subsoil of which was very inert1 recommended that the depth of plowing should be increased gradually until the full depth is reached1 to avoid a succession of poor crop years while the lifeless soil was being vivified4 ,the states of ,utah1 ,montana1 ,wyoming1 ,south ,dakota1 ,colorado1 ,kansas1 ,nebraska1 and the provinces of ,alberta and ,saskatchewan of ,canada all specifically declared through one to eight representatives from each state in favor of deep plowing as a fundamental practice in dry-farming4 ,fall plowing1 wherever the climatic conditions make it possible1 was similarly advocated by all the speakers4 ,farmers in certain localities had found the soil so dry in the fall that plowing was difficult1 but ,campbell insisted that even in such places it would be profitable to use power enough to break up the land before the winter season set in4 ,numerous speakers from the states of ,utah1 ,wyoming1 ,montana1 ,nebraska1 and a number of the ,great ,plains states1 as well as from the ,chinese ,empire1 declared themselves as favoring fall plowing4 ,scareely a dissenting voice was raised4 ,in the discussion of the clean summer fallow as a vital principle of dry-farming a slight difference of opinion was discovered4 ,farmers from some of the localities insisted that the clean summer fallow every other year was indispensable2 others that one in three years was sufficient2 and others one in four years1 and a few doubtful the wisdom of it altogether4 ,however1 all the speakers agreed that clean and thorough cultivation should be practiced faithfully during the spring1 and fall of the fallow year4 ,the appreciation of the fact that weeds consume precious moisture and fertility seemed to be general among the dry-farmers from all sections of the country4 ,the following states1 provinces1 and countries declared themselves as being definitely and emphatically in favor of clean summer fallowing3 ,california1 ,utah1 ,nevada1 ,washington1 ,montana1 ,idaho1 ,colorado1 ,new ,mexico1 ,north ,dakota1 ,nebraska1 ,alberta1 ,saskatchewan1 ,russia1 ,turkey1 the ,transvaal1 ,brazil1 and ,australia4 ,each of these many districts was represented by one to ten or more representatives4 ,the only state to declare somewhat vigorously against it was from the ,great ,plains area1 and a warning voice was heard from the ,united ,states ,department of ,agriculture4 ,the recorded practical experience of the farmers over the whole of the dry-farm territory of the ,united ,states leads to the conviction that fallowing must he accepted as a practice which resulted in successful dry-farming4 ,further1 the experimental leaders in the dry-farm movement1 whether working under private1 state1 or governmental direction1 are1 with very few exceptions1 strongly in favor of deep fall plowing and clean summer fallowing as parts of the dry-farm system4 ,the chief reluctance to accept clean summer fallowing as a principle of dry-farming appears chicfly among students of the ,great ,plains area4 ,even there it is admitted by all that a wheat crop following a fallow year is larger and better than one following wheat4 ,there seem1 however1 to be two serious reasons for objecting to it4 ,first1 a fear that a clean summer fallow1 practiced every second1 third1 or fourth year1 will cause a large diminution of the organic matter in the soil1 resulting finally in complete crop failure2 and second1 a belief that a hoed crop1 like corn or potatoes1 exerts the same beneficial effect4 ,it is undoubtedly true that the thorough tillage involved in dry-farming exposes to the action of the elements the organic matter of the soil and thereby favors rapid oxidation4 ,for that reason the different ways in which organic matter may be supplied regularly to dry-farms are pointed out in ,chapter ,,xiv4 ,it may also be observed that the header harvesting system employed over a large part of the dry-farm territory leaves the large header stubble to be plowed under1 and it is probable that under such methods more organic matter is added to the soil during the year of cropping than is lost during the year of fallowing4 ,it may1 moreover1 be observed that thorough tillage of a crop like corn or potatoes tends to cause a loss of the organic matter of the soil to a degree nearly as large as is the case when a fallow field is well cultivated4 ,the thorough stirring of the soil under an arid or semiarid climate1 which is an essential feature of dry-farming1 will always result in a decrease in organic matter4 ,it matters little whether the soil is fallow or in crop during the process of cultivation1 so far as the result is concerned4 ,a serious matter connected with fallowing in the ,great ,plains area is the blowing of the loose well-tilled soil of the fallow fields1 which results from the heavy winds that blow so steadily over a large part of the western slope of the ,mississippi ,valley4 ,this is largely avoided when crops are grown on the land1 even when it is well tilled4 ,the theory1 recently proposed1 that in the ,great ,plains area1 where the rains come chicfly in summer1 the growing of hoed crops may take the place of the summer fallow1 is said to be based on experimental data not yet published4 ,careful and conscientious experimenters1 as ,chilcott and his co-laborers1 indicate in their statements that in many cases the yields of wheat1 after a hoed crop1 have been larger than after a fallow year4 ,the doctrine has1 therefore1 been rather widely disseminated that fallowing has no place in the dry-farming of the ,great ,plains area and should be replaced by the growing of hoed crops4 ,chilcott1 who is the chief exponent of this doctrine1 declares1 however1 that it is only with spring-grown crops and for a succession of normal years that fallowing may be omitted1 and that fallowing must be resorted to as a safeguard or temporary expedient to guard against total loss of crop where extreme drouth is anticipated2 that is1 where the rainfall falls below the average4 ,he further explains that continuous grain cropping1 even with careful plowing and spring and fall tillage1 is unsuccessful2 but holds that certain rotations of crops1 including grain and a hoed crop every other year1 are often more profitable than grain alternating with clean summer fallow4 ,he further believes that the fallow year every third or fourth year is sufficient for ,great ,plains conditions4 ,jardine explains that whenever fall grain is grown in the ,great ,plains area1 the fallow is remarkably helpful1 and in fact because of the dry winters is practically indispensable4 ,this latter view is confirmed by the experimental results obtained by ,atkinson and others at the ,montana ,experiment ,stations1 which are conducted under approximately ,great ,plains conditions4 ,it should be mentioned also that in ,saskatchewan1 in the north end of the ,great ,plains area1 and which is characteristic1 except for a lower annual temperature1 of the whole area1 and where dry-farming has been practiced for a quarter of a century1 the clean summer fallow has come to be an established practice4 ,this recent discussion of the place of fallowing in the agriculture of the ,great ,plains area illustrates what has been said so often in this volume about the adapting of principles to local conditions4 ,wherever the summer rainfall is sufficient to mature a crop1 fallowing for the purpose of storing moisture in the soil is unnecessary2 the only value of the fallow year under such conditions would be to set free fertility4 ,in the ,great ,plains area the rainfall is somewhat higher than elsewhere in the dry-farm territory and most of it comes in summer2 and the summer precipitation is probably enough in average years to mature crops1 providing soil conditions are favorable4 ,the main considerations1 then1 are to keep the soils open for the reception of water and to maintain the soils in a sufficiently fertile condition to produce1 as explained in ,chapter ,,ix1 plants with a minimum amount of water4 ,this is accomplished very largely by the year of hoed crop1 when the soil is as well stirred as under a clean fallow4 ,the dry-farmer must never forget that the critical element in dry-farming is water and that the annual rainfall will in the very nature of things vary from year to year1 with the result that the dry year1 or the year with a precipitation below the average1 is sure to come4 ,in somewhat wet years the moisture stored in the soil is of comparatively little consequence1 but in a year of drouth it will be the main dependence of the farmer4 ,now1 whether a crop be hoed or not1 it requires water for its growth1 and land which is continuously cropped even with a variety of crops is likely to be so largely depleted of its moisture that1 when the year of drouth comes1 failure will probably result4 ,the precariousness of dry-farming must be done away with4 ,the year of drouth must be expected every year4 ,only as certainty of crop yield is assured will dry-farming rise to a respected place by the side of other branches of agriculture4 ,to attain such certainty and respect clean summer fallowing every second1 third1 or fourth year1 according to the average rainfall1 is probably indispensable2 and future investigations1 long enough continued1 will doubtless confirm this prediction4 ,undoubtedly1 a rotation of crops1 including hoed crops1 will find an important place in dry-farming1 but probably not to the complete exclusion of the clean summer fallow4 ,jethro ,tull1 two hundred years ago1 discovered that thorough tillage of the soil gave crops that in some cases could not be produced by the addition of manure1 and he came to the erroneous conclusion that tillage is manure4 ,in recent days we have learned the value of tillage in conserving moisture and in enabling plants to reach maturity with the least amount of water1 and we may be tempted to believe that tillage is moisture4 ,this1 like ,tull's statement1 is a fallacy and must be avoided4 ,tillage can take the place of moisture only to a limited degree4 ,water is the essential consideration in dry-farming1 else there would be no dry-farming4 ,,chapter ,,xi ,,sowing ,,and ,,harvesting ,the careful application of the principles of soil treatment discussed in the preceding chapters will leave the soil in good condition for sowing1 either in the fall or spring4 ,nevertheless1 though proper dry-farming insures a first-class seed-bed1 the problem of sowing is one of the most difficult in the successful production of crops without irrigation4 ,this is chiefly due to the difficulty of choosing1 under somewhat rainless conditions1 a time for sowing that will insure rapid and complete germination and the establishmcnt of a root system capable of producing good plants4 ,in some respects fewer definite1 reliable principles can be laid down concerning sowing than any other principle of important application in the practice of dry-farming4 ,the experience of the last fifteen years has taught that the occasional failures to which even good dry-farmers have been subjected have been caused almost wholly by uncontrollable unfavorable conditions prevailing at the time of sowing4 ,conditions of germination ,three conditions determine germination3 7#a7 heat1 7#b7 oxygen1 and 7#c7 water4 ,unless these three conditions are all favorable1 seeds cannot germinate properly4 ,the first requisite for successful seed germination is a proper degree of heat4 ,for every kind of seed there is a temperature below which germination does not occur2 another1 above which it does not occur1 and another1 the best1 at which1 providing the other factors are favorable1 germination will go on most rapidly4 ,the following table1 constructed by ,goodale1 shows the latest1 highest1 and best germination temperatures for wheat1 barley1 and corn4 ,other seeds germinate approximately within the same ranges of temperature3-- ,germination ,temperatures 7,degrees ,farenheit7 ,lowest ,highest ,best ,wheat #da #ajh #hd ,barley #da #ajj #hd ,corn #di #aae #ia ,germination occurs within the considerable range between the highest and lowest temperatures of this table1 though the rapidity of germination decreases as the temperature recedes from the best4 ,this explains the early spring and late fall germination when the temperature is comparatively low4 ,if the temperature falls below the lowest required for germination1 dry seeds are not injured1 and even a temperature far below the freezing point of water will not affect seeds unfavorably if they are not too moist4 ,the warmth of the soil1 essential to germination1 cannot well be controlled by the farmer2 and planting must1 therefore1 be done in seasons when1 from past experience1 it is probable that the temperature is and will remain in the neighborhood of the best degree for germination4 ,more heat is required to raise the temperature of wet soils2 therefore1 seeds will generally germinate more slowly in wet than in dry soils1 as is illustrated in the rapid germination often observed in well-tilled dry-farm soils4 ,consequently1 it is safer at a low temperature to sow in dry soils than in wet ones4 ,dark soils absorb heat more rapidly than lighter colored ones1 and under the same conditions of temperature germination is therefore more likely to go on rapidly in dark colored soils4 ,over the dry-farm territory the soils are generally light colored1 which would tend to delay germination4 ,the incorporation of organic matter with the soil1 which tends to darken the soil1 has a slight though important bearing on germination as well as on the general fertility of the soil1 and should be made an important dry-farm practice4 ,meanwhile1 the temperature of the soil depends almost wholly upon the prevailing temperature conditions in the district and is not to any material degree under the control of the farmer4 ,a sufficient supply of oxygen in the soil is indispensable to germination4 ,oxygen1 as is well known1 forms about one fifth of the atmosphere and is the active principle in combustion and in tile changes in the animal body occasioned by respiration4 ,oxygen should be present in the soil air in approximately the proportion in which it is found in the atmosphere4 ,germination is hindered by a larger or smaller proportion than is found in the atmosphere4 ,the soil must be in such a condition that the air can easily enter or leave the upper soil layer2 that is1 the soil must be somewhat loose4 ,in order that the seeds may have access to the necessary oxygen1 then1 sowing should not be done in wet or packed soils1 nor should the sowing implements be such as to press the soil too closely around the seeds4 ,well-fallowed soil is in an ideal condition for admitting oxygen4 ,if the temperature is right1 germination begins by the forcible absorption of water by the seed from the surrounding soil4 ,the force of this absorption is very great1 ranging from four hundred to five hundred pounds per square inch1 and continues until the seed is completely saturated4 ,the great vigor with which water is thus absorbed from the soil explains how seeds are able to secure the necessary water from the thin water film surrounding the soil grains4 ,the following table1 based upon numerous investigations conducted in ,germany and in ,utah1 shows the maximum percentages of water contained by seeds when the absorption is complete4 ,these quantities are reached only when water is easily accessible3-- ,percentage of ,water contained by ,seeds at ,saturation ,german ,utah ,rye #eh -- ,wheat #eg #eb ,oats #eh #dc ,barley #ef #dd ,corn #dd #eg ,beans #ie #hh ,lucern #gh #fg ,germination itself does not go on freely until this maximum saturation has been reached4 ,therefore1 if the moisture in the soil is low1 the absorption of water is made difficult and germination is retarded4 ,this shows itself in a decreased percentage of germination4 ,the effect upon germination of the percentage of water in the soil is well shown by some of the ,utah experiments1 as follows3-- ,effect of ,varying ,amounts of ,water on ,percentage of ,germination ,percent water in soil #g4e #aj #ab4e #ae #ag4e #bj #bb4e #be ,wheat in sandy loam #j4j #ih #id #hf #hb #hb #hb #f ,wheat in clay #cj #dh #hd #id #hd #hb #hf #eh ,beans in sandy loam #j #j #bj #df #ff #ah #h #i ,beans in clay #j #j #f #bj #bb #cb #cj #cf ,lucern in ,sandy loam #j #ah #fh #ed #ed #h #h #i ,lucern in clay #h #h #ed #dh #ej #cb #ae #ad ,in a sandy soil a small percentage of water will cause better germination than in a clay soil4 ,while different seeds vary in their power to abstract water from soils1 yet it seems that for the majority of plants1 the best percentage of soil-water for germination purposes is that which is in the neighborhood of the maximum field capacity of soils for water1 as explained in ,chapter ,,vii4 ,bogdanoff has estimated that the best amount of water in the soil for germination purposes is about twice the maximum percentage of hygroscopic water4 ,this would not be far from the field-water capacity as described in the preceding chapter4 ,during the absorption of water1 seeds swell considerably1 in many cases from two to three times their normal size4 ,this has the very desirable effect of crowding the seed walls against the soil particles and thus1 by establishing more points of contact1 enabling the seed to absorb moisture with greater facility4 ,as seeds begin to absorb water1 heat is also produced4 ,in many cases the temperature surrounding the seeds is increased one degree on the ,centigrade scale by the mere process of water absorption4 ,this favors rapid germination4 ,moreover1 the fertility of the soil has a direct influence upon germination4 ,in fertile soils the germination is more rapid and more complete than in infertile soils4 ,especially active in favoring direct germination are the nitrates4 ,when it is recalled that the constant cultivation and well-kept summer fallow of dry-farming develop large quantities of nitrates in the soil1 it will be understood that the methods of dry-farming as already outlined accelerate germination very greatly4 ,it scareely need be said that the soil of the seed-bed should be fine1 mellow1 and uniform in physical texture so that the seeds can be planted evenly and in close contact with the soil particles4 ,all the requisite conditions for germination are best met by the conditions prevailing in a well-kept summer fallowed soil4 ,time to sow ,in the consideration of the time to sow1 the first question to be disposed of by the dry-farmer is that of fall as against spring sowing4 ,the small grains occur as fall and spring varieties1 and it is vitally important to determine which season1 under dry-farm conditions1 is the best for sowing4 ,the advantages of fall sowing are many4 ,as stated1 successful germination is favored by the presence of an abundance of fertility1 especially of nitrates1 in the soil4 ,in summer-fallowed land nitrates are always found in abundance in the fall1 ready to stimulate the seed into rapid germination and the young plants into vigorous growth4 ,during the late fall and winter months the nitrates disappear1 at least in part1 anti from the point of view of fertility the spring is not so desirable as the fall for germination4 ,more important1 grain sown in the fall under favorable conditions will establish a good root system which is ready for use and in action in the early spring as soon as the temperature is right and long before the farmer can go out on the ground with his implements4 ,as a result1 the crop has the use of the early spring moisture1 which under the conditions of spring sowing is evaporated into the air4 ,where the natural precipitation is light and the amount of water stored in the soil is not large1 the gain resulting from the use of the early spring moisture4 often decides the question in favor of fall sowing4 ,the disadvantages of fall sowing are also many4 ,the uncertainty of the fall rains must first be considered4 ,in ordinary practice1 seed sown in the fall does not germinate until a rain comes1 unless indeed sowing is done immediately after a rain4 ,the fall rains are uncertain as to quantity4 ,in many cases they are so light that they suffice only to start germination and not to complete it and give the plants the proper start4 ,such incomplete germination frequently causes the total loss of the crop4 ,even if the stand of the fall crop is satisfactory1 there is always the danger of winter-killing to be reckoned with4 ,the real cause of winter-killing is not yet clearly understood1 though it seems that repeated thawing and freezing1 drying winter winds1 accompanied by dry cold or protracted periods of intense cold1 destroy the vitality of the seed and young root system4 ,continuous but moderate cold is not ordinarily very injurious4 ,the liability to winter-killing is1 therefore1 very much greater wherever the winters are open than in places where the snow covers the ground the larger part of the winter4 ,it is also to be kept in mind that some varieties are very resistant to winter-killing1 while others require well-covered winters4 ,fall sowing is preferable wherever the bulk of the precipitation comes in winter and spring and where the winters are covered for some time with snow and the summers are dry4 ,under such conditions it is very important that the crop make use of the moisture stored in the soil in the early spring4 ,wherever the precipitation comes largely in late spring and summer1 the arguments in favor of fall sowing are not so strong1 and in such localities spring sowing is often more desirable than fall sowing4 ,in the ,great ,plains district1 therefore1 spring sowing is usually recommended1 though fall-sown crops nearly always1 even there1 yield the larger crops4 ,in the intermountain states1 with wet winters and dry summers1 fall sowing has almost wholly replaced spring sowing4 ,in fact1 ,farrell reports that upon the ,nephi 7,utah7 substation the average of six years shows about twenty bushels of wheat from fall-sown seed as against about thirteen bushels from spring-sown seed4 ,under the ,california climate1 with wet winters and a winter temperature high enough for plant growth1 fall sowing is also a general practice4 ,wherever the conditions are favorable1 fall sowing should be practiced1 for it is in harmony with the best principles of water conservation4 ,even in districts where the precipitation comes chiefly in the summer1 it may be found that fall sowing1 after all1 is preferable4 ,the right time to sow in the fall can be fixed only with great difficulty1 for so much depends upon the climatic conditions4 ,in fact the practice varies in accordance with differences in fall precipitation and early fall frosts4 ,where numerous fall rains maintain the soil in a fairly moist condition and the temperature is not too low1 the problem is comparatively simple4 ,in such districts1 for latitudes represented by the dry-farm sections of the ,united ,states1 a good time for fall planting is ordinarily from the first of ,september to the middle of ,october4 ,if sown much earlier in such districts1 the growth is likely to be too rank and subject to dangerous injury by frosts1 and as suggested by ,farrell the very large development of the root system in the fall may cause1 the following summer1 a dangerously large growth of foliage2 that is1 the crop may run to straw at the expense of the grain4 ,if sown much later1 the chances are that the crop will not possess sufficient vitality to withstand the cold of late fall and winter4 ,in localities where the late summer and the early fall are rainless1 it is much more difficult to lay down a definite rule covering the time of fall sowing4 ,the dry-farmers in such places usually sow at any convenient time in the hope that an early rain will start the process of germination and growth4 ,in other cases planting is delayed until the arrival of the first fall rain4 ,this is an certain and usually unsatisfactory practice1 since it often happens that the sowing is delayed until too late in the fall for the best results4 ,in districts of dry late summer and fall1 the greatest danger in depending upon the fall rains for germination lies in the fact that the precipitation is often so small that it initiates germination without being sufficient to complete it4 ,this means that when the seed is well started in germination1 the moisture gives out4 ,when another slight rain comes a little later1 germination is again started and possibly again stopped4 ,in some seasons this may occur several times1 to the permanent injury of the crop4 ,dry-farmers try to provide against this danger by using an unusually large amount of seed1 assuming that a certain amount will fail to come up because of the repeated partial germinations4 ,a number of investigators have demonstrated that a seed may start to germinate1 then be dried1 and again be started to germinate several times in succession without wholly destroying the vitality of the seed4 ,in these experiments wheat and other seeds were allowed to germinate and dry seven times in succession4 ,with each partial germination the percentage of total germination decreased until at the seventh germination only a few seeds of wheat1 barley1 and oats retained their power4 ,this1 however1 is practically the condition in dry-farm districts with rainless summers and falls1 where fall seeding is practiced4 ,in such localities little dependence should be placed on the fall rains and greater reliance placed on a method of soil treatment that will insure good germination4 ,for this purpose the summer fallow has been demonstrated to be the most desirable practice4 ,if the soil has been treated according to the principles laid down in earlier chapters1 the fallowed land will1 in the fall1 contain a sufficient amount of moisture to produce complete germination though no rains may fall4 ,under such conditions the main consideration is to plant the seed so deep that it may draw freely upon the stored soil-moisture4 ,this method makes fall germination sure in districts where the natural precipitation is not to be depended upon4 ,when sowing is done in the spring1 there are few factors to consider4 ,whenever the temperature is right and the soil has dried out sufficiently so that agricultural implements may be used properly1 it is usually safe to begin sowing4 ,the customs which prevail generally with regard to the time of spring sowing may be adopted in dry-farm practices also4 ,depth of seeding ,the depth to which seed should be planted in the soil is of importance in a system of dry-farming4 ,the reserve materials in seeds are used to produce the first roots and the young plants4 ,no new nutriment beyond that stored in the soil can be obtained by the plant until the leaves are above the ground able to gather ,carleton from the atmosphere4 ,the danger of deep planting lies1 therefore1 in exhausting the reserve materials of the seeds before the plant has been able to push its leaves above the ground4 ,should this occur1 the plant will probably die in the soil4 ,on the other hand1 if the seed is not planted deeply enough1 it may happen that the roots cannot be sent down far enough to connect with the soil-water reservoir below4 ,then1 the root system will not be strong and deep1 but will have to depend for its development upon the surface water1 which is always a dangerous practice in dry-farming4 ,the rule as to the depth of seeding is simply3 ,plant as deeply as is safe4 ,the depth to which seeds may be safely placed depends upon the nature of the soil1 its fertility1 its physical condition1 and the water that it contains4 ,in sandy soils1 planting may be deeper than in clay soils1 for it requires less energy for a plant to push roots1 stems1 and leaves through the loose sandy soil than through the more compact clay soil2 in a dry soil planting may be deeper than in wet soils2 likewise1 deep planting is safer in a loose soil than in one firmly compacted2 finally1 where the moist soil is considerable distance below the surface1 deeper planting may be practiced than when the moist soil is near the surface4 ,countless experiments have been conducted on the subject of depth of seeding4 ,in a few cases1 ordinary agricultural seeds planted eight inches deep have come up and produced satisfactory plants4 ,however1 the consensus of opinion is that from one to three inches are best in humid districts1 but that1 everything considered1 four inches is the best depth under dry-farm conditions4 ,under a low natural precipitation1 where the methods of dry-farming are practiced1 it is always safe to plant deeply1 for such a practice will develop and strengthen the root system1 which is one big step toward successful dry-farming4 ,quantity to sow ,numerous dry-farm failures may be charged wholly to ignorance concerning the quantity of seed to sow4 ,in no other practice has the custom of humid countries been followed more religiously by dry-farmers1 and failure has nearly always resulted4 ,the discussions in this volume have brought out the fact that every plant of whatever character requires a large amount of water for its growth4 ,from the first day of its growth to the day of its maturity1 large amounts of water are taken from the soil through the plant and evaporated into the air through the leaves4 ,when the large quantities of seed employed in humid countries have been sown on dry lands1 the result has usually been an excellent stand early in the season1 with a crop splendid in appearance up to early summer4 4,a luxuriant spring crop reduces1 however1 the water content of the soil so greatly that when the heat of the summer arrives1 there is not sufficient water left in the soil to support the final development and ripening4 ,a thick stand in early spring is no assurance to the dry-farmer of a good harvest4 ,on the contrary1 it is usually the field with a thin stand in spring that stands up best through the summer and yields most at the time of harvest4 ,the quantity of seed sown should vary with the soil conditions3 the more fertile the soil is1 the more seed may be used2 the more water in the soil1 the more seed may be sown2 as the fertility or the water content diminishes1 the amount of seed should likewise be diminished4 ,under dry-farm conditions the fertility is good1 but the moisture is low4 ,as a general principle1 therefore1 light seeding should be practiced on dry-farms1 though it should be sufficient to yield a crop that will shade the ground well4 ,if the sowing is done early1 in fall or spring1 less seed may be used than if the sowing is late1 because the early sowing gives a better chance for root development1 which results1 ordinarily1 in more vigorous plants that consume more moisture than the smaller and weaker plants of later sowing4 ,if the winters are mild and well covered with snow1 less seed may be used than in districts where severe or open winters cause a certain amount of winter-killing4 ,on a good seed-bed of fallowed soil less seed may be used than where the soil has not been carefully tilled and is somewhat rough and lumpy and unfavorable for complete germination4 ,the yield of any crop is not directly proportional to the amount sown1 unless all factors contributing to germination are alike4 ,in the case of wheat and other grains1 thin seeding also gives a plant a better chance for stooling1 which is ,nature's method of adapting the plant to the prevailing moisture and fertility conditions4 ,when plants are crowded1 stooling cannot occur to any marked degree1 and the crop is rendered helpless in attempts to adapt itself to surrounding conditions4 ,in general the rule may be laid down that a little more than one half as much seed should be used in dry-farm districts with an annual rainfall of about fifteen inches than is used in humid districts4 ,that is1 as against the customary five pecks of wheat used per acre in humid countries about three pecks or even two pecks should be used on dry-farms4 ,merrill recommends the seeding of oats at the rate of about three pecks per acre2 of barley1 about three pecks2 of rye1 two pecks2 of alfalfa1 six pounds2 of corn1 two kernels to the hill1 and other crops in the same proportion4 ,no invariable rule can be laid down for perfect germination4 ,a small quantity of seed is usually sufficient2 but where germination frequently fails in part1 more seed must be used4 ,if the stand is too thick at the beginning of the growing season1 it must be harrowed out4 ,naturally1 the quantity of seed to be used should be based on the number of kernels as well as on the weight4 ,for instance1 since the larger the individual wheat kernels the fewer in a bushel1 fewer plants would be produced from a bushel of large than from a bushel of small seed wheat4 ,the size of the seed in determining the amount for sowing is often important and should be determined by some simple method1 such as counting the seeds required to fill a small bottle4 ,method of sowing ,there should really be no need of discussing the method of sowing were it not that even at this day there are farmers in the dry-farm district who sow by broadcasting and insist upon the superiority of this method4 ,the broadcasting of seed has no place in any system of scientific agriculture1 least of all in dry-farming1 where success depends upon the degree with which all conditions are controlled4 ,in all good dry-farm practice seed should be placed in rows1 preferably by means of one of the numerous forms of drill seeders found upon the market4 ,the advantages of the drill are almost self-evident4 ,it permits uniform distribution of the seed1 which is indispensable for success on soils that receive limited rainfall4 ,the seed may be placed at an even depth1 which is very necessary1 especially in fall sowing1 where the seed depends for proper germination upon the moisture already stored in the soil4 ,the deep seeding often necessary under dry-farm conditions makes the drill indispensable4 ,moreover1 ,hunt has explained that the drill furrows themselves have definite advantages4 ,during the winter the furrows catch the snow1 and because of the protection thus rendered1 the seed is less likely to be heaved out by repeated freezing and thawing4 ,the drill furrow also protects to a certain extent against the drying action of winds and in that way1 though the furrows are small1 they aid materially in enabling the young plant to pass through the winter successfully4 ,the rains of fall and spring are accumulated in the furrows and made easily accessible to plants4 ,moreover1 many of the drills have attachments whereby the soil is pressed around the seed and the topsoil afterwards stirred to prevent evaporation4 ,this permits of a much more rapid and complete germination4 ,the drill1 the advantages of which were taught two hundred years ago by ,jethro ,tull1 is one of the most valuable implements of modern agriculture4 ,on dry-farms it is indispensable4 ,the dry-farmer should make a careful study of the drills on the market and choose such as comply with the principles of the successful prosecution of dry-farming4 ,drill culture is the only method of sowing that can be permitted if uniform success is desired4 ,the care of the crop ,excepting the special treatment for soil-moisture conservation1 dry-farm crops should receive the treatment usually given crops growing under humid conditions4 ,the light rains that frequently fall in autumn sometimes form a crust on the top of the soil1 which hinders the proper germination and growth of the fall-sown crop4 ,it may be necessary1 therefore1 for the farmer to go over the land in the fall with a disk or more preferably with a corrugated roller4 ,ordinarily1 however1 after fall sowing there is no further need of treatment until the following spring4 ,the spring treatment is of considerably more importance1 for when the warmth of spring and early summer begins to make itself felt1 a crust forms over many kinds of dry-farm soils4 ,this is especially true where the soil is of the distinctively arid kind and poor in organic matter4 ,such a crust should be broken early in order to give the young plants a chance to develop freely4 ,this may be accomplished1 as above stated1 by the use of a disk1 corrugated roller1 or ordinary smoothing harrow4 ,when the young grain is well under way1 it may be found to be too thick4 ,if so1 the crop may be thinned by going over the field with a good irontooth harrow with the teeth so set as to tear out a portion of the plants4 ,this treatment may enable the remaining plants to mature with the limited amount of moisture in the soil4 ,paradoxically1 if the crop seems to be too thin in the spring1 harrowing may also be of service4 ,in such a case the teeth should be slanted backwards and the harrowing done simply for the purpose of stirring the soil without injury to the plant1 to conserve the moisture stored in the soil and to accelerate the formation of nitrates4--,the conserved moisture and added fertility will strengthen the growth and diminish the water requirements of the plants1 and thus yield a larger crop4 ,the iron-tooth harrow is a very useful implement on the dry-farm when the crops are young4 ,after the plants are up so high that the harrow cannot be used on them no special care need be given them1 unless indeed they are cultivated crops like corn or potatoes which1 of course1 as explained in previous chapters1 should receive continual cultivation4 ,harvesting ,the methods of harvesting crops on dry-farms are practically those for farms in humid districts4 ,the one great exception may be the use of the header on the grain farms of the dry-farm sections4 ,the header has now become well-nigh general in its use4 ,instead of cutting and binding the grain1 as in the old method1 the heads are simply cut off and piled in large stacks which later are threshed4 ,the high straw which remains is plowed under in the fall and helps to supply the soil with organic matter4 ,the maintenance of dry-farms for over a generation without the addition of manures has been made possible by the organic matter added to the soil in the decay of the high vigorous straw remaining after the header4 ,in fact1 the changes occurring in the soil in connection with the decaying of the header stubble appear to have actually increased the available fertility4 ,hundreds of ,utah dry wheat farms during the last ten or twelve years have increased in fertility1 or at least in productive power1 due undoubtedly to the introduction of the header system of harvesting4 ,this system of harvesting also makes the practice of fallowing much more effective1 for it helps maintain the organic matter which is drawn upon by the fallow seasons4 ,the header should be used wherever practicable4 ,the fear has been expressed that the high header straw plowed under will make the soil so loose as to render proper sowing difficult and also1 because of the easy circulation of air in the upper soil layers1 cause a large loss of soil-moisture4 ,this fear has been found to be groundless1 for wherever the header straw has been plowed under2 especially in connection with fallowing1 the soil has been benefited4 ,rapidity and economy in harvesting are vital factors in dry-farming1 and new devices are constantly being offered to expedite the work4 ,of recent years the combined harvester and thresher has come into general use4 ,it is a large header combined with an ordinary threshing machine4 ,the grain is headed and threshed in one operation and the sacks dropped along the path of the machine4 ,the straw is scattered over the field where it belongs4 ,all in all1 the question of sowing1 care of crop1 and harvesting may be answered by the methods that have been so well developed in countries of abundant rainfall1 except as new methods may be required to offset the deficiency in the rainfall which is the determining condition of dry-farming4 ,,chapter ,,xii ,,crops ,,for ,,dry-,,farming ,the work of the dry-farmer is only half done when the soil has been properly prepared1 by deep plowing1 cultivation1 fallowing1 for the planting of the crop4 ,the choice of the crop1 its proper seeding1 and its correct care and harvesting are as important as rational soil treatment in the successful pursuit of dry-farming4 ,it is true that in general the kinds of crops ordinarily cultivated in humid regions are grown also on arid lands1 but varieties especially adapted to the prevailing dry-farm conditions must be used if any certainty of harvest is desired4 ,plants possess a marvelous power of adaptation to environment1 and this power becomes stronger as successive generations of plants are grown under the given conditions4 ,thus1 plants which have been grown for long periods of time in countries of abundant rainfall and characteristic humid climate and soil yield well under such conditions1 but usually suffer and die or at best yield scantily if planted in hot rainless countries with deep soils4 ,yet1 such plants1 if grown year after year under arid conditions1 become accustomed to warmth and dryness and in time will yield perhaps nearly as well or it may be better in their new surroundings4 ,the dry-farmer who looks for large harvests must use every care to secure varieties of crops that through generations of breeding have become adapted to the conditions prevailing on his farm4 ,home-grown seeds1 if grown properly1 are therefore of the highest value4 ,in fact1 in the districts where dry-farming has been practiced longest the best yielding varieties are1 with very few exceptions1 those that have been grown for many successive years on the same lands4 ,the comparative newness of the attempts to produce profitable crops in the present dry-farming territory and the consequent absence of home-grown seed has rendered it wise to explore other regions of the world1 with similar climatic conditions1 but long inhabited1 for suitable crop varieties4 ,the ,united ,states ,department of ,agriculture has accomplished much good work in this direction4 ,the breeding of new varieties by scientific methods is also important1 though really valuable results cannot be expected for many years to come4 ,when results do come from breeding experiments1 they will probably be of the greatest value to the dry-farmer4 ,meanwhile1 it must be acknowledged that at the present1 our knowledge of dry-farm crops is extremely limited4 ,every year will probably bring new additions to the list and great improvements of the crops and varieties now recommended4 ,the progressive dry-farmer should therefore keep in close touch with state and government workers concerning the best varieties to use4 ,moreover1 while the various sections of the dry-farming territory are alike in receiving a small amount of rainfall1 they are widely different in other conditions affecting plant growth1 such as soils1 winds1 average temperature1 and character and severity of the winters4 ,until trials have been made in all these varying localities1 it is not safe to make unqualified recommendations of any crop or crop variety4 ,at the present we can only say that for dry-farm purposes we must have plants that will produce the maximum quantity of dry matter with the minimum quantity of water2 and that their periods of growth must be the shortest possible4 ,however1 enough work has been done to establish some general rules for the guidance of the dry-farmer in the selection of crops4 ,undoubtedly1 we have as yet had only a glimpse of the vast crop possibilities of the dry-farming territory in the ,united ,states1 as well as in other countries4 ,wheat ,wheat is the leading dry-farm crop4 ,every prospect indicates that it will retain its preminence4 ,not only is it the most generally used cereal1 but the world is rapidly learning to depend more and more upon the dry-farming areas of the world for wheat production4 ,in the arid and semiarid regions it is now a commonly accepted doctrine that upon the expensive irrigated lands should be grown fruits1 vegetables1 sugar beets1 and other intensive crops1 while wheat1 corn1 and other grains and even much of the forage should be grown as extensive crops upon the non-irrigated or dry-farm lands4 ,it is to be hoped that the time is near at hand when it will be a rarity to see grain grown upon irrigated soil1 providing the climatic conditions permit the raising of more extensive crops4 ,in view of the present and future greatness of the wheat crop on semiarid lands1 it is very important to secure the varieties that will best meet the varying dry-farm conditions4 ,much has been done to this end1 but more needs to be done4 ,our knowledge of the best wheats is still fragmentary4 ,this is even more true of other dry-farm crops4 ,according to ,jardine1 the dry-farm wheats grown at present in the ,united ,states may be classificd as follows3-- ,i4 ,hard spring wheats3 7a7 ,common 7b7 ,durum ,,ii4 ,winter wheats3 7a7 ,hard wheats 7,crimean7 7b7 ,semihard wheats 7,intermountain7 7c7 ,soft wheats 7,pactfic7 ,the common varieties of hard spring wheats are grown principally in districts where winter wheats have not as yet been successful2 that is1 in the ,dakotas1 northwestern ,nebraska1 and other localities with long winters and periods of alternate thawing and severe freezing4 ,the superior value of winter wheat has been so clearly demonstrated that attempts are being made to develop in every locality winter wheats that can endure the prevailing climatic conditions4 ,spring wheats are also grown in a scattering way and in small quantities over the whole dry-farm territory4 ,the two most valuable varieties of the common hard spring wheat are ,blue ,stem and ,red ,fife1 both well-established varieties of excellent milling qualities1 grown in immense quantities in the ,northeastern corner of the dry-farm territory of the ,united ,states and commanding the best prices on the markets of the world4 ,it is notable that ,red ,fife originated in ,russia1 the country which has given us so many good dry-farm crops4 ,the durum wheats or macaroni wheats1 as they are often called1 are also spring wheats which promise to displace all other spring varieties because of their excellent yields under extreme dry-farm conditions4 ,these wheats1 though known for more than a generation through occasional shipments from ,russia1 ,algeria1 and ,chile1 were introduced to the farmers of the ,united ,states only in #aijj1 through the explorations and enthusiastic advocacy of ,carleton of the ,united ,states ,department of ,agriculture4 ,since that time they have been grown in nearly all the dryfarm states and especially in the ,great ,plains area4 ,wherever tried they have yielded well1 in some cases as much as the old established winter varieties4 ,the extreme hardness of these wheats made it difficult to induce the millers operating mills fitted for grinding softer wheats to accept them for flourmaking purposes4 ,this prejudice has1 however1 gradually vanished1 and to-day the durum wheats are in great demand1 especially for blending with the softer wheats and for the making of macaroni4 ,recently the popularity of the durum wheats among the farmers has been enhanced1 owing to the discovery that they are strongly rust resistant4 ,the winter wheats1 as has been repeatedly suggested in preceding chapters1 are most desirable for dry-farm purposes1 wherever they can be grown1 and especially in localities where a fair precipitation occurs in the winter and spring4 ,the hard winter wheats are represented mainly by the ,crimean group1 the chief members of which are ,turkey1 ,kharkow1 and ,crimean4 ,these wheats also originated in ,russia and are said to have been brought to the ,united ,states a generation ago by ,mennonite colonists4 ,at present these wheats are grown chiefly in the central and southern parts of the ,great ,plains area and in ,canada1 though they are rapidly spreading over the intermountain country4 ,these are good milling wheats of high gluten content and yielding abundantly under dry-farm conditions4 ,it is quite clear that these wheats will soon displace the older winter wheats formerly grown on dry-farms4 ,turkey wheat promises to become the leading dry-farm wheat4 ,the semisoft winter wheats are grown chiefly in the intermountain country4 ,they are represented by a very large number of varieties1 all tending toward softness and starchiness4 ,this may in part be due to climatic1 soil1 and irrigation conditions1 but is more likely a result of inherent qualities in the varieties used4 ,they are rapidly being displaced by hard varieties4 ,the group of soft winter wheats includes numerous varieties grown extensively in the famous wheat districts of ,california1 ,oregon1 ,washington1 and northern ,idaho4 ,the main varieties are ,red ,russian and ,palouse ,blue ,stem1 in ,washington and ,idaho1 ,red ,chaff and ,foise in ,oregon1 and ,defiance1 ,little ,club1 ,sonora1 and ,white ,australian in ,california4 ,these are all soft1 white1 and rather poor in gluten4 ,it is believed that under given climatic1 soil1 and cultural conditions1 all wheat varieties will approach one type1 distinctive of the conditions in question1 and that the ,california wheat type is a result of prevailing unchangeable conditions4 ,more researeh is needed1 however1 before definite principles can be laid down concerning the formation of distinctive wheat types in the various dry-farm sections4 ,under any condition1 a change of seed1 keeping improvement always in view1 should be baneficial4 ,jardine has reminded the dry-farmers of the ,united ,states that before the production of wheat on the dry-farms can reach its full possibilities under any acreage1 sufficient quantities must be grown of a few varieties to affect the large markets4 ,this is especially important in the intermountain country where no uniformity exists1 but the warning should be heeded also by the ,pacific coast and ,great ,plains wheat areas4 ,as soon as the best varieties are found they should displace the miscellaneous collection of wheat varieties now grown4 ,the individual farmer can be a law unto himself no more in wheat growing than in fruit growing1 if he desires to reap the largest reward of his efforts4 ,only by uniformity of kind and quality and large production will any one locality impress itself upon the markets and create a demand4 ,the changes now in progress by the dry-farmers of the ,united ,states indicate that this lesson has been taken to heart4 ,the principle is equally important for all countries where dry-farming is practiced4 ,other small grains ,oats is undoubtedly a coming dry-farm crop4 ,several varieties have been found which yield well on lands that receive an average annual rainfall of less than fifteen inches4 ,others will no doubt be discovered or developed as special attention is given to dry-farm oats4 ,oats occurs as spring and winter varieties1 but only one winter variety has as yet found place in the list of dry-farm crops4 ,the leading2 spring varieties of oats are the ,sixty-,day1 ,kherson1 ,burt1 and ,swedish ,select4 ,the one winter variety1 which is grown chiefly in ,utah1 is the ,boswell1 a black variety originally brought from ,england about #aija4 ,barley1 like the other common grains1 occurs in varieties that grow well on dry-farms4 ,in comparison with wheat very little seareh has been made for dry-farm barleys1 and1 naturally1 the list of tested varieties is very small4 ,like wheat and oats1 barley occurs in spring and winter varieties1 but as in the case of oats only one winter variety has as yet found its way into the approved list of dry-farm crops4 ,the best dry-farm spring barleys are those belonging to the beardless and hull-less types1 though the more common varieties also yield well1 especially the six-rowed beardless barley4 ,the winter variety is the ,tennessee ,winter1 which is already well distributed over the ,great ,plains district4 ,rye is one of the surest dry-farm crops4 ,it yields good crops of straw and grain1 both of which are valuable stock foods4 ,in fact1 the great power of rye to survive and grow luxuriantly under the most trying dry-farm conditions is the chief objection to it4 ,once started1 it is hard to eradicate4 ,properly cultivated and used either as a stock feed or as green manure1 it is very valuable4 ,rye occurs as both spring and winter varieties4 ,the winter varieties are usually most satisfactory4 ,carleton has recommended emmer as a crop peculiarly adapted to semiarid conditions4 ,emmer is a species of wheat to the berries of which the chaff adheres very closely4 ,it is highly prized as a stock feed4 ,in ,russia and ,germany it is grown in very large quantities4 ,it is especially adapted to arid and semiarid conditions1 but will probably thrive best where the winters are dry and summers wet4 ,it exists as spring and winter varieties4 is with the other small grains1 the success of emmer will depend largely upon the satisfactory development of winter varieties4 ,corn ,of all crops yet tried on dry-farms1 corn is perhaps the most uniformly successful under extreme dry conditions4 ,if the soil treatment and planting have been right1 the failures that have been reported may invariably be traced to the use of seed which had not been acclimated4 ,the ,american ,indians grow corn which is excellent for dry-farm purposes2 many of the western farmers have likewise produced strains that use the minimum of moisture1 and1 moreover1 corn brought from humid sections adapts itself to arid conditions in a very few years4 ,escobar reports a native corn grown in ,mexico with low stalks and small ears that well endures desert conditions4 ,in extremely dry years corn does not always produce a profitable crop of seed1 but the crop as a whole1 for forage purposes1 seldom fails to pay expenses and leave a margin for profit4 ,in wetter years there is a corresponding increase of the corn crop4 ,the dryfarming territory does not yet realize the value of corn as a dry-farm crop4 ,the known facts concerning corn make it safe to predict1 however1 that its dry farm acreage will increase rapidly1 and that in time it will crowd the wheat crop for preminence4 ,sorghums ,among dry-farm crops not popularly known are the sorghums1 which promise to become excellent yielders under arid conditions4 ,the sorghums are supposed to have come grown the tropical sections of the globe1 but they are now scattered over the earth in all climes4 ,the sorghums have been known in the ,united ,states for over half a century1 but it was only when dry-farming began to develop so tremendously that the drouth-resisting power of the sorghums was recalled4 ,according to ,ball1 the sorghums fall into the following classes3-- ,,the ,,sorghums #a4 ,broom corns #b4 ,sorgas or sweet sorghums #c4 ,kafirs #d4 ,durras ,the broom corns are grown only for their brush1 and are not considered in dry-farming2 the sorgas for forage and sirups1 and are especially adapted for irrigation or humid conditions1 though they are said to endure dry-farm conditions better than corn4 ,the ,kafirs are dry-farm crops and are grown for grain and forage4 ,this group includes ,red ,kafir1 ,white ,kafir1 ,black-hulled ,white ,kafir1 and ,white ,milo1 all of which are valuable for dry-farming4 ,the ,durras are grown almost exclusively for seed and include ,jerusalem corn1 ,brown ,durra1 and ,milo4 ,the work of ,ball has made ,milo one of the most important dry-farm crops4 ,as improved1 the crop is from four to four and a half feet high1 with mostly erect heads1 carrying a large quantity of seeds4 ,milo is already a staple crop in parts of ,texas1 ,oklahoma1 ,kansas1 and ,new ,mexico4 ,it has further been shown to be adapted to conditions in the ,dakotas1 ,nebraska1 ,colorado1 ,arizona1 ,utah1 and ,idaho4 ,it will probably be found1 in some varietal form1 valuable over the whole dry-farm territory where the altitude is not too high and the average temperature not too low4 ,it has yielded an average of forty bushels of seed to the acre4 ,lucern or alfalfa ,next to human intelligence and industry1 alfalfa has probably been the chief factor in the development of the irrigated ,west4 ,it has made possible a rational system of agriculture1 with the live-stock industry and the maintenance of soil fertility as the central considerations4 ,alfalfa is now being recognized as a desirable crop in humid as well as in irrigated sections1 and it is probable that alfalfa will soon become the chief hay crop of the ,united ,states4 ,originally1 lucern came from the hot dry countries of ,asia1 where it supplied feed to the animals of the first historical peoples4 ,moreover1 its long2 tap roots1 penetrating sometimes forty or fifty feet into the ground1 suggest that lucern may make ready use of deeply stored soil-moisture4 ,on these considerations1 alone1 lucern should prove itself a crop well suited for dry-farming4 ,in fact1 it has been demonstrated that where conditions are favorable1 lucern may be made to yield profitable crops under a rainfall between twelve and fifteen inches4 ,alfalfa prefers calcareous loamy soils2 sandy and heavy clay soils are not so well adapted for successful alfalfa production4 ,under dry-farm conditions the utmost care must be used to prevent too thick seeding4 ,the vast majority of alfalfa failures on dry-farms have resulted from an insufficient supply of moisture for the thickly planted crop4 ,the alfalfa field does not attain its maturity until after the second year1 and a crop which looks just right the second year will probably be much too thick the third and fourth years4 ,from four to six pounds of seed per acre are usually ample4 ,another main cause of failure is the common idea that the lucern field needs little or no cultivation1 when1 in fact1 the alfalfa field should receive as careful soil treatment as the wheat field4 ,heavy1 thorough disking in spring or fall1 or both1 is advisable1 for it leaves the topsoil in a condition to prevent evaporation and admit air4 ,in ,asiatic and ,north ,african countries1 lucern is frequently cultivated between rows throughout the hot season4 ,this has been tried by ,brand in this country and with very good results4 ,since the crop should always be sown with a drill1 it is comparatively easy to regulate the distance between the rows so that cultivating implements may be used4 ,if thin seeding and thorough soil stirring are practiced1 lucern usually grows well1 and with such treatment should become one of the great dry-farm crops4 ,the yield of hay is not large1 but sufficient to leave a comfortable margin of profit4 ,many farmers find it more profitable to grow dry-farm lucern for seed4 ,in good years from fifty to one hundred and fifty dollars may be taken from an acre of lucern seed4 ,however1 at the present1 the principles of lucern seed production are not well established1 and the seed crop is uncertain4 ,alfalfa is a leguminous crop and gathers nitrogen from the air4 ,it is therefore a good fertilizer4 ,the question of soil fertility will become more important with the passing of the years1 and the value of lucern as a land improver will then be more evident than it is to-day4 ,other leguminous crops ,the group of leguminous or pod-bearing crops is of great importance2 first1 because it is rich in nitrogenous substances which are valuable animal foods1 and1 secondly1 because it has the power of gathering nitrogen from the air1 which can be used for maintaining the fertility of the soil4 ,dry-farming will not be a wholly safe practice of agriculture until suitable leguminous crops are found and made part of the crop system4 ,it is notable that over the whole of the dry-farm territory of this and other countries wild leguminous plants flourish4 ,that is1 nitrogen-gathering plants are at work on the deserts4 ,the farmer upsets this natural order of things by cropping the land with wheat and wheat only1 so long as the land will produce profitably4 ,the leguminous plants native to dry-farm areas have not as yet been subjected to extensive economic study1 and in truth very little is known concerning leguminous plants adapted to dry-farming4 ,in ,california1 ,colorado1 and other dry-farm states the field pea has been grown with great profit4 ,indeed it has been found much more profitable than wheat production4 ,the field bean1 likewise1 has been grown successfully under dry-farm conditions1 under a great variety of climates4 ,in ,mexico and other southern climates1 the native population produce large quantities of beans upon their dry lands4 ,shaw suggests that sanfoin1 long famous for its service to ,european agriculture1 may be found to be a profitable dry-farm crop1 and that sand vetch promises to become an excellent dry-farm crop4 ,it is very likely1 however1 that many of the leguminous crops which have been developed under conditions of abundant rainfall will be valueless on dry-farm lands4 ,every year will furnish new and more complete information on this subject4 ,leguminous plants will surely become important members of the association of dry-farm crops4 ,trees and shrubs ,so far1 trees cannot be said to be dry-farm crops1 though facts are on record that indicate that by the application of correct dry-farm principles trees may be made to grow and yield profitably on dry-farm lands4 ,of course1 it is a well-known fact that native trees of various kinds are occasionally found growing on the deserts1 where the rainfall is very light and the soil has been given no care4 ,examples of such vegetation are the native cedars found throughout the ,great ,basin region and the mesquite tree in ,arizona and the ,southwest4 ,few farmers in the arid region have as yet undertaken tree culture without the aid of irrigation4 ,at least one peach orchard is known in ,utah which grows under a rainfall of about fifteen inches without irrigation and produces regularly a small crop of most delicious fruit4 ,parsons describes his ,colorado dry-farm orchard in which1 under a rainfall of almost fourteen inches1 he grows1 with great profit1 cherries1 plums1 and apples4 ,a number of prospering young orchards are growing without irrigation in the ,great ,plains area4 ,mason discovered a few years ago two olive orchards in ,arizona and the ,colorado desert which1 planted about fourteen years previously1 were thriving under an annual rainfall of eight and a half and four and a half inches1 respectively4 ,these olive orchards had been set out under canals which later failed4 ,such attested facts lead to the thought that trees may yet take their place as dry-farm crops4 ,this hope is strengthened when it is recalled that the great nations of antiquity1 living in countries of low rainfall1 grew profitably and without irrigation many valuable trees1 some of which are still cultivated in those countries4 ,the olive industry1 for example1 is even now being successfully developed by modern methods in ,asiatic and ,african sections1 where the average annual rainfall is under ten inches4 ,since #ahha1 under ,french management1 the dry-farm olive trees around ,tunis have increased from #de1jjj to #djj1jjj individuals4 ,mason and also ,aaronsohn suggest as trees that do well in the arid parts of the old world the so-called ,chinese date or ,ju,jube tree1 the sycamore fig1 and the ,carob tree1 which yields the ,st4 ,john's ,bread so dear to childhood4 ,of this last tree1 ,aaronsolm says that twenty trees to the acre1 under a rainfall of twelve inches1 will produce #hjjj pounds of fruit containing #dj per cent of sugar and #g to #h per cent of protein4 ,this surpasses the best harvest of alfalfa4 ,kearnley1 who has made a special study of dry-land olive culture in northern ,africa1 states that in his belief a large variety of fruit trees may be found which will do well under arid and semiarid conditions1 and may even yield more profit than the grains4 ,it is also said that many shade and ornamental and other useful plants can be grown on dry-farms2 as1 for instance1 locust1 elm1 black walnut1 silverpoplar1 catalpa1 live oak1 black oak1 yellow pine1 red spruce1 ,douglas fir1 and cedar4 ,the secret of success in tree growing on dry-farms seems to lie1 first1 in planting a few trees per acre1--the distance apart should be twice the ordinary distance1--and1 secondly1 in applying vigorously and unceasingly the established principles of soil cultivation4 ,in a soil stored deeply with moisture and properly cultivated1 most plants will grow4 ,if the soil has not been carefully fallowed before planting1 it may be necessary to water the young trees slightly during the first two seasons4 ,small fruits have been tried on many farms with great success4 ,plums1 currants1 and gooseberries have all been successful4 ,grapes grow and yield well in many dry-farm districts1 especially along the warm foothills of the ,great ,basin4 ,tree growing on dry-farm lands is not yet well established and1 therefore1 should be undertaken with great care4 ,varieties accustomed to the climatic environment should be chosen1 and the principles outlined in the preceding pages should be carefully used4 ,potatoes ,in recent years1 potatoes have become one of the best dry-farm crops4 ,almost wherever tried on lands under a rainfall of twelve inches or more potatoes have given comparatively large yields4 ,to-day1 the growing of dry-farm potatoes is becoming an important industry4 ,the principles of light seeding and thorough cultivation are indispensable for success4 ,potatoes are well adapted for use in rotations1 where summer fallowing is not thought desirable4 ,macdonald enumerates the following as the best varieties at present used on dry-farms3 ,ohio1 ,mammoth1 ,pearl1 ,rural ,new ,yorker1 and ,burbank4 ,miscellaneous ,a further list of dry-farm crops would include representatives of nearly all economic plants1 most of them tried in small quantity in various localities4 ,sugar beets1 vegetables1 bulbous plants1 etc41 have all been grown without irrigation under dry-farm conditions4 ,some of these will no doubt be found to be profitable and will then be brought into the commercial scheme of dry-farming4 ,meanwhile1 the crop problems of dry-farming demand that much careful work be done in the immediate future by the agencies having such work in charge4 ,the best varieties of crops already in profitable use need to be determined4 ,more new plants from all parts of the world need to be brought to this new dry-farm territory and tried out4 ,many of the native plants need examination with a view to their economic use4 ,for instance1 the sego lily bulbs1 upon which the ,utah pioneers subsisted for several seasons of famine1 may possibly be made a cultivated crop4 ,finally1 it remains to be said that it is doubtful wisdom to attempt to grow the more intensive crops on dry-farms4 ,irrigation and dry-farming will always go together4 ,they are supplementary systems of agriculture in arid and semiarid regions4 ,on the irrigated lands should be grown the crops that require much labor per acre and that in return yield largely per acre4 ,new crops and varieties should besought for the irrigated farms4 ,on the dry-farms should be grown the crops that can be handled in a large way and at a small cost per acre1 and that yield only moderate acre returns4 ,by such cooperation between irrigation and dry-farming will the regions of the world with a scanty rainfall become the healthiest1 wealthiest1 happiest1 and most populous on earth4 ,,chapter ,,xiii ,,the ,,composition ,,of ,,dry-,,farm ,,crops ,the acre-yields of crops on dry-farms1 even under the most favorable methods of culture1 are likely to be much smaller than in humid sections with fertile soils4 ,the necessity for frequent fallowing or resting periods over a large portion of the dry-farm territory further decreases the average annual yield4 ,it does not follow from this condition that dry-farming is less profitable than humid-or irrigation-farming1 for it has been fully demonstrated that the profit on the investment is as high under proper dry-farming as under any other similar generally adopted system of farming in any part of the world4 ,yet the practice of dry-farming would appear to be1 and indeed would be1 much more desirable could the crop yield be increased4 ,the discovery of any condition which will offset the small annual yields is1 therefore1 of the highest importance to the advancement of dry-farming4 ,the recognition of the superior quality of practically all crops grown without irrigation under a limited rainfall has done much to stimulate faith in the great profitableness of dry-farming4 ,as the varying nature of the materials used by man for food1 clothing1 and shelter has become more clearly understood1 more attention has been given to the valuation of commercial products on the basis of quality as well as of quantity4 ,sugar beets1 for instance1 are bought by the sugar factories under a guarantee of a minimum sugar content2 and many factories of ,europe vary the price paid according to the sugar contained by the beets4 ,the millers1 especially in certain parts of the country where wheat has deteriorated1 distinguish carefully between the flour-producing qualities of wheats from various sections and fix the price accordingly4 ,even in the household1 information concerning the real nutritive value of various foods is being sought eagerly1 and foods let down to possess the highest value in the maintenance of life are displacing1 even at a higher cost1 the inferior products4 ,the quality valuation is1 in fact1 being extended as rapidly as the growth of knowledge will permit to the chief food materials of commerce4 ,as this practice becomes fixed the dry-farmer will be able to command the best market prices for his products1 for it is undoubtedly true that from the point of view of quality1 dry-farm food products may be placed safely in competition with any farm products on the markets of the world4 ,proportion of plant parts ,it need hardly be said1 after the discussions in the preceding chapters1 that the nature of plant growth is deeply modified by the arid conditions prevailing in dry-farming4 ,this shows itself first in the proportion of the various plant parts1 such as roots1 stems1 leaves1 and seeds4 ,the root systems of dry-farm crops are generally greatly developed1 and it is a common observation that in adverse seasons the plants that possess the largest and most vigorous roots endure best the drouth and burning heat4 ,the first function of the leaves is to gather materials for the building and strengthening of the roots1 and only after this has been done do the stems lengthen and the leaves thicken4 ,usually1 the short season is largely gone before the stem and leaf growth begins1 and1 consequently1 a somewhat dwarfed appearance is characteristic of dry-farm crops4 ,the size of sugar beets1 potato tubers1 and such underground parts depends upon the available water and food supply when the plant has established a satisfactory root and leaf system4 ,if the water and food are scarce1 a thin beet results2 if abundant1 a well-filled beet may result4 ,dry-farming is characterized by a somewhat short season4 ,even if good growing weather prevails1 the decrease of water in the soil has the effect of hastening maturity4 ,the formation of flowers and seed begins1 therefore1 earlier and is completed more quickly under arid than under humid conditions4 ,moreover1 and resulting probably from the greater abundance of materials stored in the root system1 the proportion of heads to leaves and stems is highest in dry-farm crops4 ,in fact1 it is a general law that the proportion of heads to straw in grain crops increases as the water supply decreases4 ,this is shown very well even under humid or irrigation conditions when different seasons or different applications of irrigation water are compared4 ,for instance1 ,hall quotes from the ,rothamsted experiments to the effect that in #ahgi1 which was a wet year 7#da inches71 the wheat crop yielded #ch pounds of grain for every #ajj pounds of straw2 whereas1 in #ahic1 which was a dry year 7#bc inches71 the wheat crop yielded #ie pounds of grain to every #ajj pounds of straw4 ,the ,utah station likewise has established the same law under arid conditions4 ,in one series of experiments it was shown as an average of three years' trial that a field which had received #bb4e inches of irrigation water produced a wheat crop that gave #fg pounds of grain to every #ajj pounds of straw2 while another field which received only #g4e inches of irrigation water produced a crop that gave #ajj pounds of grain for every #ajj pounds of straw4 ,since wheat is grown essentially for the grain1 such a variation is of tremendous importance4 ,the amount of available water affects every part of the plant4 ,thus1 as an illustration1 ,carleton states that the per cent of meat in oats grown in ,wisconsin under humid conditions was #fg4bd1 while in ,north ,dakota1 ,kansas1 and ,montana1 under arid and semiarid conditions1 it was #ga4ea4 ,similar variations of plant parts may be observed as a direct result of varying the amount of available water4 ,in general then1 it may be said that the roots of dry-farm crops are well developed2 the parts above ground somewhat dwarfed2 the proportion of seed to straw high1 and the proportion of meat or nutritive materials in the plant parts likewise high4 ,the water in dry-farm crops ,one of the constant constituents of all plants and plant parts is water4 ,hay1 flour1 and starch contain comparatively large quantities of water1 which can be removed only by heat4 ,the water in green plants is often very large4 ,in young lucern1 for instance1 it reaches #he per cent1 and in young peas nearly #ij per cent1 or more than is found in good cow's milk4 ,the water so held by plants has no nutritive value above ordinary water4 ,it is1 therefore1 profitable for the consumer to buy dry foods4 ,in this particular1 again1 dry-farm crops have a distinct advantage3 ,during growth there is not perhaps a great difference in the water content of plants1 due to climatic differences1 but after harvest the drying-out process goes on much more completely in dry-farm than in humid districts4 ,hay1 cured in humid regions1 often contains from #ab to #bj per cent of water2 in arid climates it contains as little as #e per cent and seldom more than #ab per cent4 ,the drier hay is naturally more valuable pound for pound than the moister hay1 and a difference in price1 based upon the difference in water content1 is already being felt in certain sections of the ,west4 ,the moisture content of dry-farm wheat1 the chief dry-farm crop1 is even more important4 ,according to ,wiley the average water content of wheat for the ,united ,states is #aj4fb per cent1 ranging from #ae to #g per cent4 ,stewart and ,greaves examined a large number of wheats grown on the dry-farms of ,utah and found that the average per cent of water in the common bread varieties was #h4df and in the durum varieties #h4hi4 ,this means that the ,utah dry-farm wheats transported to ordinary humid conditions would take up enough water from the air to increase their weight one fortieth1 or #b4b per cent1 before they reached the average water content of ,american wheats4 ,in other words1 #a1jjj1jjj bushels of ,utah dry-farm wheat contain as much nutritive matter as #a1jbe1jjj bushels of wheat grown and kept under humid conditions4 ,this difference should be and now is recognized in the prices paid4 ,in fact1 shrewd dealers1 acquainted with the dryness of dry-farm wheat1 have for some years bought wheat from the dry-farms at a slightly increased price1 and trusted to the increase in weight due to water absorption in more humid climates for their profits4 ,the time should be near at hand when grains and similar products should be purchased upon the basis of a moisture test4 ,while it is undoubtedly true that dry-farm crops are naturally drier than those of humid countries1 yet it must also be kept in mind that the driest dry-farm crops are always obtained where the summers are hot and rainless4 ,in sections where the precipitation comes chiefly in the spring and summer the difference would not be so great4 ,therefore1 the crops raised on the ,great ,plains would not be so dry as those raised in ,california or in the ,great ,basin4 ,yet1 wherever the annual rainfall is so small as to establish dry-farm conditions1 whether it comes in the winter or summer1 the cured crops are drier than those produced under conditions of a much higher rainfall1 and dry farmers should insist that1 so far as possible in the future1 sales be based on dry matter4 ,the nutritive substances in crops ,the dry matter of all plants and plant parts consists of three very distinct classes of substances3 ,first1 ash or the mineral constituents4 ,ash is used by the body in building bones and in supplying the blood with compounds essential to the various life processes4 ,second1 protein or the substances containing the element nitrogen4 ,protein is used by the body in making blood1 muscle1 tendons1 hair1 and nails1 and under certain conditions it is burned within the body for the production of heat4 ,protein is perhaps the most important food constituent4 ,third1 non-nitrogenous substances1 including fats1 woody fiber1 and nitrogen-free extract1 a name given to the group of sugars1 starehes1 and related substances4 ,these substances are used by the body in the production of fat1 and are also burned for the production of heat4 ,of these valuable food constituents protein is probably the most important1 first1 because it forms the most important tissues of the body and1 secondly1 because it is less abundant than the fats1 starches1 and sugars4 ,indeed1 plants rich in protein nearly always command the highest prices4 ,the composition of any class of plants varies considerably in different localities and in different seasons4 ,this may be due to the nature of the soil1 or to the fertilizer applied1 though variations in plant composition resulting from soil conditions are comparatively small4 ,the greater variations are almost wholly the result of varying climate and water supply4 ,as far as it is now known the strongest single factor in changing the composition of plants is the amount of water available to the growing plant4 ,variations due to varying water supply ,the ,utah station has conducted numerous experiments upon the effect of water upon plant composition4 ,the method in every case has been to apply different amounts of water throughout the growing season on contiguous plats of uniform land4 ,lengthy table deleated from this edition4 ,even a casual study of 4 4 4 the results show that the quantity of water used influenced the composition of the plant parts4 ,the ash and the fiber do not appear to be greatly influenced1 but the other constituents vary with considerable regularity with the variations in the amount of irrigation water4 ,the protein shows the greatest variation4 ,as the irrigation water is increased1 the percentage of protein decreases4 ,in the case of wheat the variation was over #i per cent4 ,the percentage of fat and nitrogen-free extract1 on the other hand1 becomes larger as the water increases4 ,that is1 crops grown with little water1 as in dry-farming1 are rich in the important flesh-and blood-forming substance protein1 and comparatively poor in fat1 sugar1 stareh1 and other of the more abundant heat and fat-producing substances4 ,this difference is of tremendous importance in placing dry-farming products on the food markets of the world4 ,not only seeds1 tubers1 and roots show this variation1 but the stems and leaves of plants grown with little water are found to contain a higher percentage of protein than those grown in more humid climates4 ,the direct effect of water upon the composition of plants has been observed by many students4 ,for instance1 ,mayer1 working in ,holland1 found that1 in a soil containing throughout the season #aj per cent of water1 oats was produced containing #aj4f per cent of protein2 in soil containing #cj per cent of water1 the protein percentage was only #e4f per cent1 and in soil containing #gj per cent of water1 it was only #e4b per cent4 ,carleton1 in a study of analyses of the same varieties of wheat grown in humid and semi-arid districts of the ,united ,states1 found that the percentage of protein in wheat from the semiarid area was #ad4d per cent as against #aa4id per cent in the wheat from the humid area4 ,the average protein content of the wheat of the ,united ,states is a little more than #ab per cent2 ,stewart and ,greaves found an average of #af4gf per cent of protein in ,utah dry-farm wheats of the common bread varieties and #ag4ad per cent in the durum varieties4 ,the experiments conducted at ,rothamsted1 ,england1 as given by ,hall1 confirm these results4 ,for example1 during #ahic1 a very dry year1 barley kernels contained #ab4ii per cent of protein1 while in #ahid1 a wet1 though free-growing year1 the barley contained only #i4ha per cent of protein4 ,quotations might be multiplied confirming the principle that crops grown with little water contain much protein and little heat-and fat-producing substances4 ,climate and composition ,the general climate1 especially as regards the length of the growing season and naturally including the water supply1 has a strong effect upon the composition of plants4 ,carleton observed that the same varieties of wheat grown at ,nephi1 ,utah1 contained #af4fa per cent protein2 at ,amarillo1 ,texas1 #ae4be per cent2 and at ,mc,pherson1 ,kansas1 a humid station1 #ac4jd per cent4 ,this variation is undoubtedly due in part to the varying annual precipitation but1 also1 and in large part1 to the varying general climatic conditions at the three stations4 ,an extremely interesting and important experiment1 showing the effect of locality upon the composition of wheat kernels1 is reported by ,le,clerc and ,leavitt4 ,wheat grown in #aije in ,kansas was planted in #aijf in ,kansas1 ,california1 and ,texas ,in #aijg samples of the seeds grown at these three points were planted side by side at each of the three states ,all the crops from the three localities were analyzed separately each year4 ,the results are striking and convincing4 ,the original seed grown in ,kansas in #aije contained #af4bb per cent of protein4 ,the #aijf crop grown from this seed in ,kansas contained #ai4ac per cent protein2 in ,california1 #aj4ch percent2 and in ,texas1 #ab4ah percent4 ,in #aijg the crop harvested in ,kansas from the #aijf seed from these widely separated places and of very different composition contained uniformly somewhat more than #bb per cent of protein2 harvested in ,california1 somewhat more than #aa per cent2 and harvested in ,texas1 about #ah per cent4 ,in short1 the composition of wheat kernels is independent of the composition of the seed or the nature of the soil1 but depends primarily upon the prevailing climatic conditions1 including the water supply4 ,the weight of the wheat per bushel1 that is1 the average size and weight of the wheat kernel1 and also the hardness or flinty character of the kernels1 were strongly affected by the varying climatic conditions4 ,it is generally true that dry-farm grain weighs more per bushel than grain grown under humid conditions2 hardness usually accompanies a high protein content and is therefore characteristic of dry-farm wheat4 ,these notable lessons teach the futility of bringing in new seed from far distant places in the hope that better and larger crops may be secured4 ,the conditions under which growth occurs determine chiefly the nature of the crop4 ,it is a common experience in the ,west that farmers who do not understand this principle send to the ,middle ,west for seed corn1 with the result that great crops of stalks and leaves with no ears are obtained4 ,the only safe rule for the dry-farmer to follow is to use seed which has been grown for many years under dry-farm conditions4 ,a reason for variation in composition ,it is possible to suggest a reason for the high protein content of dry-farm crops4 ,it is well known that all plants secure most of their nitrogen early in the growing period4 ,from the nitrogen1 protein is formed1 and all young plants are1 therefore1 very rich in protein4 ,as the plant becomes older1 little more protein is added1 but more and more carbon is taken from the air to form the fats1 starches1 sugars1 and other non-nitrogenous substances4 ,consequently1 the proportion or percentage of protein becomes smaller as the plant becomes older4 ,the impelling purpose of the plant is to produce seed4 ,whenever the water supply begins to give out1 or the season shortens in any other way1 the plant immediately begins to ripen4 ,now1 the essential effect of dry-farm conditions is to shorten the season2 the comparatively young plants1 yet rich in protein1 begin to produce seed2 and at harvest1 seed1 and leaves1 and stalks are rich in the flesh-and blood-forming element of plants4 ,in more humid countries plants delay the time of seed production and thus enable the plants to store up more carbon and thus reduce the percent of protein4 ,the short growing season1 induced by the shortness of water1 is undoubtedly the main reason for the higher protein content and consequently higher nutritive value of all dry-farm crops4 ,nutritive value of dry-farm hay1 straw1 and flour ,all the parts of dry-farm crops are highly nutritious4 ,this needs to be more clearly understood by the dry-farmers4 ,dry-farm hay1 for instance1 because of its high protein content1 may be fed with crops not so rich in this element1 thereby making a larger profit for the farmer4 ,dry-farm straw often has the feeding value of good hay1 as has been demonstrated by analyses and by feeding tests conducted in times of hay scarcity4 ,especially is the header straw of high feeding value1 for it represents the upper and more nutritious ends of the stalks4 ,dry-farm straw1 therefore1 should be carefully kept and fed to animals instead of being scattered over the ground or even burned as is too often the case4 ,only few feeding experiments having in view the relative feeding value of dry-farm crops have as yet been made1 but the few on record agree in showing the superior value of dry-farm crops1 whether fed singly or in combination4 ,the differences in the chemical composition of plants and plant products induced by differences in the water-supply and climatic environment appear in the manufactured products1 such as flour1 bran1 and shorts4 ,flour made from ,fife wheat grown on the dry-farms of ,utah contained practically #af per cent of protein1 while flour made from ,fife wheat grown in ,lorraine and the ,middle ,west is reported by the ,maine ,station as containing from #ac4jc to #ac4ge per cent of protein4 ,flour made from ,blue ,stem wheat grown on the ,utah dry-farms contained #ae4eb per cent of protein2 from the same variety grown in ,maine and in the ,middle ,west #aa4fi and #aa4ea per cent of protein respectively4 ,the moist and dry gluten1 the gliadin and the glutenin1 all of which make possible the best and most nourishing kinds of bread1 are present in largest quantity and best proportion in flours made from wheats grown under typical dry-farm conditions4 ,the by-products of the milling process1 likewise1 are rich in nutritive elements4 ,future ,needs ,it has already been pointed out that there is a growing tendency to purchase food materials on the basis of composition4 ,new discoveries in the domains of plant composition and animal nutrition and the improved methods of rapid and accurate valuation will accelerate this tendency4 ,even now1 manufacturers of food products print on cartons and in advertising matter quality reasons for the superior food values of certain articles4 ,at least one firm produces two parallel sets of its manufactured foods1 one for the man who does hard physical labor1 and the other for the brain worker4 ,quality1 as related to the needs of the body1 whether of beast or man1 is rapidly becoming the first question in judging any food material4 ,the present era of high prices makes this matter even more important4 ,in view of this condition and tendency1 the fact that dry-farm products are unusually rich in the most valuable nutritive materials is of tremendous importance to the development of dry-farming4 ,the small average yields of dry-farm crops do not look so small when it is known that they command higher prices per pound in competition with the larger crops of more humid climates4 ,more elaborate investigations should be undertaken to determine the quality of crops grown in different dry-farm districts4 ,as far as possible each section1 great or small1 should confine itself to the growing of a variety of each crop yielding well and possessing the highest nutritive value4 ,in that manner each section of the great dry-farm territory would soon come to stand for some dependable special quality that would compel a first-class market4 ,further1 the superior feeding value of dry-farm products should be thoroughly advertised among the consumers in order to create a demand on the markets for a quality valuation4 ,a few years of such systematic honest work would do much to improve the financial basis of dry-farming4 ,,chaper ,,xiv ,,maintaining ,,the ,,soil ,,fertility ,all plants when carefully burned leave a portion of ash1 ranging widely in quantity1 averaging about #e per cent1 and often exceeding #aj per cent of the dry weight of the plant4 ,this plant ash represents inorganic substances taken from the soil by the roots4 ,in addition1 the nitrogen of plants1 averaging about #b per cent and often amounting to #d per cent1 which1 in burning1 passes off in gaseous form1 is also usually taken from the soil by the plant roots4 ,a comparatively large quantity of the plant is1 therefore1 drawn directly from the soil4 ,among the ash ingredients are many which are taken up by the plant simply because they are present in the soil2 others1 on the other hand1 as has been shown by numerous classical investigations1 are indispensable to plant growth4 ,if any one of these indispensable ash ingredients be absent1 it is impossible for a plant to mature on such a soil4 ,in fact1 it is pretty well established that1 providing the physical conditions and the water supply are satisfactory1 the fertility of a soil depends largely upon the amount of available ash ingredients1 or plant-food4 ,a clear distinction must be made between the total and available plant-food4 ,the essential plant-foods often occur in insoluble combinations1 valueless to plants2 only the plant-foods that are soluble in the soil-water or in the juices of plant roots are of value to plants4 ,it is true that practically all soils contain all the indispensable plant-foods2 it is also true1 however1 that in most soils they are present1 as available plant-foods1 in comparatively small quantities4 ,when crops are removed from the land year after year1 without any return being made1 it naturally follows that under ordinary conditions the amount of available plant-food is diminished1 with a strong probability of a corresponding diminution in crop-producing power4 ,in fact1 the soils of many of the older countries have been permanently injured by continuous cropping1 with nothing returned1 practiced through centuries4 ,even in many of the younger states1 continuous cropping to wheat or other crops for a generation or less has resulted in a large decrease in the crop yield4 ,practice and experiment have shown that such diminishing fertility may be retarded or wholly avoided1 first1 by so working or cultivating the soil as to set free much of the insoluble plant-food and1 secondly1 by returning to the soil all or part of the plant-food taken away4 ,the recent development of the commercial fertilizer industry is a response to this truth4 ,it may be said that1 so far as the agricultural soils of the world are now known1 only three of the essential plant-foods are likely to be absent1 namely1 potash1 phosphoric acid1 and nitrogen2 of these1 by far the most important is nitrogen4 ,the whole question of maintaining the supply of plant-foods in the soil concerns itself in the main with the supply of these three substances4 ,the persistent fertility of dry-farms ,in recent years1 numerous farmers and some investigators have stated that under dry-farm conditions the fertility of soils is not impaired by cropping without manuring4 ,this view has been taken because of the well-known fact that in localities where dry-farming has been practiced on the same soils from twenty-five to forty-five years1 without the addition of manures1 the average crop yield has not only failed to diminish1 but in most cases has increased4 ,in fact1 it is the almost unanimous testimony of the oldest dry-farmers of the ,united ,states1 operating under a rainfall from twelve to twenty inches1 that the crop yields have increased as the cultural methods have been perfected4 ,if any adverse effect of the steady removal of plant-foods has occurred1 it has been wholly overshadowed by other factors4 ,the older dry-farms in ,utah1 for instance1 which are among the oldest of the country1 have never been manured1 yet are yielding better to-day than they did a generation ago4 ,strangely enough1 this is not true of the irrigated farms1 operating under like soil and climatic conditions4 ,this behavior of crop production under dry-farm conditions has led to the belief that the question of soil fertility is not an important one to dry-farmers4 ,nevertheless1 if our present theories of plant nutrition are correct1 it is also true that1 if continuous cropping is practiced on our dry-farm soils without some form of manuring1 the time must come when the productive power of the soils will be injured and the only recourse of the farmer will be to return to the soils some of the plant-food taken from it4 ,the view that soil fertility is not diminished by dry-farming appears at first sight to be strengthened by the results obtained by investigators who have made determinations of the actual plant-food in soils that have long been dry-farmed4 ,the sparsely settled condition of the dry-farm territory furnishes as yet an excellent opportunity to compare virgin and dry-farmed lands and which frequently may be found side by side in even the older dry-farm sections4 ,stewart found that ,utah dry-farm soils1 cultivated for fifteen to forty years and never manured1 were in many cases richer in nitrogen than neighboring virgin lands4 ,bradley found that the soils of the great dry-farm wheat belt of ,eastern ,oregon contained1 after having been farmed for a quarter of a century1 practically as much nitrogen as the adjoining virgin lands4 ,these determinations were made to a depth of eighteen inches4 ,alway and ,trumbull1 on the other hand1 found in a soil from ,indian ,head1 ,saskatchewan1 that in twenty-five years of cultivation the total amount of nitrogen had been reduced about one third1 though the alternation of fallow and crop1 commonly practiced in dry-farming1 did not show a greater loss of soil nitrogen than other methods of cultivation4 ,it must be kept in mind that the soil of ,indian ,head contains from two to three times as much nitrogen as is ordinarily found in the soils of the ,great ,plains and from three to four times as much as is found in the soils of the ,great ,basin and the ,high ,plateaus4 ,it may be assumed1 therefore1 that the ,indian ,head soil was peculiarly liable to nitrogen losses4 ,headden1 in an investigation of the nitrogen content of ,colorado soils1 has come to the conclusion that arid conditions1 like those of ,colorado1 favor the direct accumulation of nitrogen in soils4 ,all in all1 the undiminished crop yield and the composition of the cultivated fields lead to the belief that soil-fertility problems under dry-farm conditions are widely different from the old well-known problems under humid conditions4 ,reasons for dry-farming fertility ,it is not really difficult to understand why the yields and1 apparently1 the fertility of dry-farms have continued to increase during the period of recorded dry-farm history--nearly half a century4 ,first1 the intrinsic fertility of arid as compared with humid soils is very high4 7,see ,chapter ,v47 ,the production and removal of many successive bountiful crops would not have as marked an effect on arid as on humid soils1 for both yield and composition change more slowly on fertile soils4 ,the natural extraordinarily high fertility of dry-farm soils explains1 therefore1 primarily and chiefly1 the increasing yields on dry-farm soils that receive proper cultivation4 ,the intrinsic fertility of arid soils is not alone sufficient to explain the increase in plant-food which undoubtedly occurs in the upper foot or two of cultivated dry-farm lands4 ,in seeking a suitable explanation of this phenomenon it must be recalled that the proportion of available plant-food in arid soils is very uniform to great depths1 and that plants grown under proper dry-farm conditions are deep rooted and gather much nourishment from the lower soil layers4 ,as a consequence1 the drain of a heavy crop does not fall upon the upper few feet as is usually the case in humid soils4 ,the dry-farmer has several farms1 one upon the other1 which permit even improper methods of farming to go on longer than would be the case on shallower soils4 ,the great depth of arid soils further permits the storage of rain and snow water1 as has been explained in previous chapters1 to depths of from ten to fifteen feet4 ,as the growing season proceeds1 this water is gradually drawn towards the surface1 and with it much of the plant-food dissolved by the water in the lower soil layers4 ,this process repeated year after year results in a concentration in the upper soil layers of fertility normally distributed in the soil to the full depth reach by the soil-moisture4 ,at certain seasons1 especially in the fall1 this concentration may be detected with greatest certainty4 ,in general1 the same action occurs in virgin lands1 but the methods of dry-farm cultivation and cropping which permit a deeper penetration of the natural precipitation and a freer movement of the soil-water result in a larger quantity of plant-food reaching the upper two or three feet from the lower soil depths4 ,such concentration near the surface1 when it is not excessive1 favors the production of increased yields of crops4 ,the characteristic high fertility and great depth of arid soils are probably the two main factors explaining the apparent increase of the fertility of dry-farms under a system of agriculture which does not include the practice of manuring4 ,yet1 there are other conditions that contribute largely to the result4 ,for instance1 every cultural method accepted in dry-farming1 such as deep plowing1 fallowing1 and frequent cultivation1 enables the weathering forces to act upon the soil particles4 ,especially is it made easy for the air to enter the soil4 ,under such conditions1 the plant-food unavailable to plants because of its insoluble condition is liberated and made available4 ,the practice of dry-farming is of itself more conducive to such accumulation of available plant food than are the methods of humid agriculture4 ,further1 the annual yield of any crop under conditions of dry-farming is smaller than under conditions of high rainfall4 ,less fertility is1 therefore1 removed by each crop and a given amount of available fertility is sufficient to produce a large number of crops without showing signs of deficiency4 ,the comparatively small annual yield of dry-farm crops is emphasized in view of the common practice of summer fallowing1 which means that the land is cropped only every other year or possibly two years out of three4 ,under such conditions the yield in any one year is cut in two to give an annual yield4 ,the use of the header wherever possible in harvesting dry-farm grain also aids materially in maintaining soil fertility4 ,by means of the header only the heads of the grain are clipped off3 the stalks are left standing4 ,in the fall1 usually1 this stubble is plowed under and gradually decays4 ,in the earlier dry-farm days farmers feared that under conditions of low rainfall1 the stubble or straw plowed under would not decay1 but would leave the soil in a loose dry condition unfavorable for the growth of plants4 ,during the last fifteen years it has been abundantly demonstrated that if the correct methods of dry farming are followed1 so that a fair balance of water is always found in the soil1 even in the fall1 the heavy1 thick header stubble may be plowed into the soil with the certainty that it will decay and thus enrich the soil4 ,the header stubble contains a very large proportion of the nitrogen that the crop has taken from the soil and more than half of the potash and phosphoric acid4 ,plowing under the header stubble returns all this material to the soil4 ,moreover1 the bulk of the stubble is carbon taken from the air4 ,this decays1 forming various acid substances which act on the soil grains to set free the fertility which they contain4 ,at the end of the process of decay humus is formed1 which is not only a storehouse of plant-food1 but effective in maintaining a good physical condition of the soil4 ,the introduction of the header in dry-farming was one of the big steps in making the practice certain and profitable4 ,finally1 it must be admitted that there are a great many more or less poorly understood or unknown forces at work in all soils which aid in the maintenance of soil-fertility4 ,chief among these are the low forms of life known as bacteria4 ,many of these1 under favorable conditions1 appear to have the power of liberating food from the insoluble soil grains4 ,others have the power when settled on the roots of leguminous or pod-bearing plants to fix nitrogen from the air and convert it into a form suitable for the need of plants4 ,in recent years it has been found that other forms of bacteria1 the best known of which is azotobacter1 have the power of gathering nitrogen from the air and combining it for the plant needs without the presence of leguminous plants4 ,these nitrogen-gathering bacteria utilize for their life processes the organic matter in the soil1 such as the decaying header stubble1 and at the same time enrich the soil by the addition of combined nitrogen4 ,now1 it so happens that these important bacteria require a soil somewhat rich in lime1 well aerated and fairly dry and warm4 ,these conditions are all met on the vast majority of our dry-farm soils1 under the system of culture outlined in this volume4 ,hall maintains that to the activity of these bacteria must be ascribed the large quantities of nitrogen found in many virgin soils and probably the final explanation of the steady nitrogen supply for dry farms is to be found in the work of the azatobacter and related forms of low life4 ,the potash and phosphoric acid supply can probably be maintained for ages by proper methods of cultivation1 though the phosphoric acid will become exhausted long before the potash4 ,the nitrogen supply1 however1 must come from without4 ,the nitrogen question will undoubtedly soon be the one before the students of dry-farm fertility4 ,a liberal supply of organic matter ,in the soil with cultural methods favoring the growth of the nitrogen-gathering bacteria appears at present to be the first solution of the nitrogen question4 ,meanwhile1 the activity of the nitrogen-gathering bacteria1 like azotobacter1 is one of our best explanations of the large presence of nitrogen in cultivated dry-farm soils4 ,to summarize1 the apparent increase in productivity and plant-food content of dry-farm soils can best be explained by a consideration of these factors3 7#a7 the intrinsically high fertility of the arid soils2 7#b7 the deep feeding ground for the deep root systems of dry-farm crops2 7#c7 the concentration of the plant food distributed throughout the soil by the upward movement of the natural precipitation stored in the soil2 7#d7 the cultural methods of dry-farming which enable the weathering agencies to liberate freely and vigorously the plant-food of the soil grains2 7#e7 the small annual crops2 7#f7 the plowing under of the header straw1 and 7#g7 the activity of bacteria that gather nitrogen directly from the air4 ,methods of conserving soil-fertility ,in view of the comparatively small annual crops that characterize dry-farming it is not wholly impossible that the factors above discussed1 if properly applied1 could liberate the latent plant-food of the soil and gather all necessary nitrogen for the plants4 ,such an equilibrium1 could it once be established1 would possibly continue for long periods of time1 but in the end would no doubt lead to disaster2 for1 unless the very cornerstone of modern agricultural science is unsound1 there will be ultimately a diminution of crop producing power if continuous cropping is practiced without returning to the soil a goodly portion of the elements of soil fertility taken from it4 ,the real purpose of modern agricultural researeh is to maintain or increase the productivity of our lands2 if this cannot be done1 modern agriculture is essentially a failure4 ,dry-farming1 as the newest and probably in the future one of the greatest divisions of modern agriculture1 must from the beginning seek and apply processes that will insure steadiness in the productive power of its lands4 ,therefore1 from the very beginning dry-farmers must look towards the conservation of the fertility of their soils4 ,the first and most rational method of maintaining the fertility of the soil indefinitely is to return to the soil everything that is taken from it4 ,in practice this can be done only by feeding the products of the farm to live stock and returning to the soil the manure1 both solid and liquid1 produced by the animals4 ,this brings up at once the much discussed question of the relation between the live stock industry and dry-farming4 ,while it is undoubtedly true that no system of agriculture will be wholly satisfactory to the farmer and truly beneficial to the state1 unless it is connected definitely with the production of live stock1 yet it must be admitted that the present prevailing dry-farm conditions do not always favor comfortable animal life4 ,for instance1 over a large portion of the central area of the dry-farm territory the dry-farms are at considerable distances from running or well water4 ,in many cases1 water is hauled eight or ten miles for the supply of the men and horses engaged in farming4 ,moreover1 in these drier districts1 only certain crops1 carefully cultivated1 will yield profitably1 and the pasture and the kitchen garden are practical impossibilities from an economic point of view4 ,such conditions1 though profitable dry-farming is feasible1 preclude the existence of the home and the barn on or even near the farm4 ,when feed must be hauled many miles1 the profits of the live stock industry are materially reduced and the dry-farmer usually prefers to grow a crop of wheat1 the straw of which may be plowed under the soil to the great advantage of the following crop4 ,in dry-farm districts where the rainfall is higher or better distributed1 or where the ground water is near the surface1 there should be no reason why dry-farming and live stock should not go hand in hand4 ,wherever water is within reach1 the homestead is also possible4 ,the recent development of the gasoline motor for pumping purposes makes possible a small home garden wherever a little water is available4 ,the lack of water for culinary purposes is really the problem that has stood between the joint development of dry-farming and the live stock industry4 ,the whole matter1 however1 looks much more favorable to-day1 for the efforts of the ,federal and state governments have succeeded in discovering numerous subterranean sources of water in dry-farm districts4 ,in addition1 the development of small irrigation systems in the neighborhood of dry-farm districts is helping the cause of the live stock industry4 ,at the present time1 dry-farming and the live stock industry are rather far apart1 though undoubtedly as the desert is conquered they will become more closely associated4 ,the question concerning the best maintenance of soil-fertility remains the same2 and the ideal way of maintaining fertility is to return to the soil as much as is possible of the plant-food taken from it by the crops1 which can best be accomplished by the development of the business of keeping live stock in connection with dry-farming4 ,if live stock cannot be kept on a dry-farm1 the most direct method of maintaining soil-fertility is by the application of commercial fertilizers4 ,this practice is followed extensively in the ,eastern states and in ,europe4 ,the large areas of dry-farms and the high prices of commercial fertilizers will make this method of manuring impracticable on dry-farms1 and it may be dismissed from thought until such a day as conditions1 especially with respect to price of nitrates and potash1 are materially changed4 ,nitrogen1 which is the most important plant-food that may be absent from dry-farm soils1 may be secured by the proper use of leguminous crops4 ,all the pod-bearing plants commonly cultivated1 such as peas1 beans1 vetch1 clover1 and lucern1 are able to secure large quantities of nitrogen from the air through the activity of bacteria that live and grow on the roots of such plants4 ,the leguminous crop should be sown in the usual way1 and when it is well past the flowering stage should be plowed into the ground4 ,naturally1 annual legumes1 such as peas and beans1 should be used for this purpose4 ,the crop thus plowed under contains much nitrogen1 which is gradually changed into a form suitable for plant assimilation4 ,in addition1 the acid substances produced in the decay of the plants tend to liberate the insoluble plant-foods and the organic matter is finally changed into humus4 ,in order to maintain a proper supply of nitrogen in the soil the dry-farmer will probably soon find himself obliged to grow1 every five years or oftener1 a crop of legumes to be plowed under4 ,non-leguminous crops may also be plowed under for the purpose of adding organic matter and humus to the soil1 though this has little advantage over the present method of heading the grain and plowing under the high stubble4 ,the header system should be generally adopted on wheat dry-farms4 ,on farms where corn is the chief crop1 perhaps more importance needs to be given to the supply of organic matter and humus than on wheat farms4 ,the occasional plowing under of leguminous crops would he the most satisfactory method4 ,the persistent application of the proper cultural methods of dry-farming will set free the most important plant-foods1 and on well-cultivated farms nitrogen is the only element likely to be absent in serious amounts4 ,the rotation of crops on dry-farms is usually advocated in districts like the ,great ,plains area1 where the annual rainfall is over fifteen inches and the major part of the precipitation comes in spring and summer4 ,the various rotations ordinarily include one or more crops of small grains1 a hoed crop like corn or potatoes1 a leguminous crop1 and sometimes a fallow year4 ,the leguminous crop is grown to secure a fresh supply of nitrogen2 the hoed crop1 to enable the air and sunshine to act thoroughly on the soil grains and to liberate plant-food1 such as potash and phosphoric acid2 and the grain crops to take up plant-food not reached by the root systems of the other plants4 ,the subject of proper rotation of crops has always been a difficult one1 and very little information exists on it as practiced on dry-farms4 ,chilcott has done considerable work on rotations in the ,great ,plains district1 hut he frankly admits that many years of trial will he necessary for the elucidation of trustworthy principles4 ,some of the best rotations found by ,chilcott up to the present are3-- ,corn--,wheat--,oats ,barley--,oats--,corn ,fallow--,wheat--,oats ,rosen states that rotation is very commonly practiced in the dry sections of southern ,russia1 usually including an occasional ,summer fallow4 ,as a type of an eight-year rotation practiced at the ,poltava ,station1 the following is given3 7#a7 ,summer tilled and manured2 7#b7 winter wheat2 7#c7 hoed crop2 7#d7 spring wheat2 7#e7 summer fallow2 7#f7 winter rye2 7#g7 buckwheat or an annual legume2 7#h7 oats4 ,this rotation1 it may be observed1 includes the grain crop1 hoed crop1 legume1 and fallow every four years4 ,as has been stated elsewhere1 any rotation in dry-farming which does not include the summer fallow at least every third or fourth year is likely to be dangerous ,in years of deficient rainfall4 ,this review of the question of dry-farm fertility is intended merely as a forecast of coming developments4 ,at the present time soil-fertility is not giving the dry-farmers great concern1 but as in the countries of abundant rainfall the time will come when it will be equal to that of water conservation1 unless indeed the dry-farmers heed the lessons of the past and adopt from the start proper practices for the maintenance of the plant-food stored in the soil4 ,the principle explained in ,chapter ,,ix1 that the amount of water required for the production of one pound of water diminishes as the fertility increases1 shows the intimate relationship that exists between the soil-fertility and the soil-water and the importance of maintaining dry-farm soils at a high state of fertility4 ,,chapter ,,xv ,,implements ,,for ,,dry-,,farming ,cheap land and relatively small acre yields characterize dry-farming4 ,consequently ,iarger areas must be farmed for a given return than in humid farming1 and the successful pursuit of dry-farming compels the adoption of methods that enable a man to do the largest amount of effective work with the smallest expenditure of energy4 ,the careful observations made by ,grace1 in ,utah1 lead to the belief that1 under the conditions prevailing in the intermountain country1 one man with four horses and a sufficient supply of machinery can farm #afj acres1 half of which is summer-fallowed every year2 and one man may1 in favorable seasons under a carefully planned system1 farm as much as #bjj acres4 ,if one man attempts to handle a larger farm1 the work is likely to be done in so slipshod a manner that the crop yield decreases and the total returns are no larger than if #bjj acres had been well tilled4 ,one man with four horses would be unable to handle even #afj acres were it not for the possession of modern machinery2 and dry-farming1 more than any other system of agriculture1 is dependent for its success upon the use of proper implements of tillage4 ,in fact1 it is very doubtful if the reclamation of the great arid and semiarid regions of the world would have been possible a few decades ago1 before the invention and introduction of labor-saving farm machinery4 ,it is undoubtedly further a fact that the future of dry-farming is closely bound up with the improvements that may be made in farm machinery4 ,few of the agricultural implements on the market to-day have been made primarily for dry-farm conditions4 ,the best that the dry-farmer can do is to adapt the implements on the market to his special needs4 ,possibly the best field of investigation for the experiment stations and inventive minds in the arid region is farm mechanics as applied to the special needs of dry-farming4 ,clearing and breaking ,a large portion of the dry-farm territory of the ,united ,states is covered with sagebrush and related plants4 ,it is always a difficult and usually an expensive problem to clear sagebrush land1 for the shrubs are frequently from two to six feet high1 correspondingly deep-rooted1 with very tough wood4 ,when the soil is dry1 it is extremely difficult to pull out sagebrush1 and of necessity much of the clearing must be done during the dry season4 ,numerous devices have been suggested and tried for the purpose of clearing sagebrush land4 ,one of the oldest and also one of the most effective devices is two parallel railroad rails connected with heavy iron chains and used as a drag over the sagebrush land4 ,the sage is caught by the two rails and torn out of the ground4 ,the clearing is fairly complete1 though it is generally necessary to go over the ground two or three times before the work is completed4 ,even after such treatment a large number of sagebrush clumps1 found standing over the field1 must be grubbed up with the hoe4 ,another and effective device is the so-called mankiller4 ,this implement pulls up the sage very successfully and drops it at certain definite intervals4 ,it is1 however1 a very dangerous implement and frequently results in injury to the men who work it4 ,of recent years another device has been tried with a great deal of success4 ,it is made like a snow plow of heavy railroad irons to which a number of large steel knives have been bolted4 ,neither of these implements is wholly satisfactory1 and an acceptable machine for grubbing sagebrush is yet to be devised4 ,in view of the large expense attached to the clearing of sagebrush land such a machine would be of great help in the advancement of dry-farming4 ,away from the sagebrush country the virgin dry-farm land is usually covered with a more or less dense growth of grass1 though true sod is seldom found under dry-farm conditions4 ,the ordinary breaking plow1 characterized by a long sloping moldboard1 is the best known implement for breaking all kinds of sod4 7,see ,fig4 #g;a a47 ,where the sod is very light1 as on the far western prairies1 the more ordinary forms of plows may be used4 ,in still other sections1 the dry-farm land is covered with a scattered growth of trees1 frequently pinion pine and cedars1 and in ,arizona and ,new ,mexico the mesquite tree and cacti are to be removed4 ,such clearing has to be done in accordance with the special needs of the locality4 ,plowing ,plowing1 or the turning over of the soil to a depth of from seven to ten inches for every crop1 is a fundamental operation of dry-farming4 ,the plow1 therefore1 becomes one of the most important implements on the dry-farm4 ,though the plow as an agricultural implement is of great antiquity1 it is only within the last one hundred years that it has attained its present perfection4 ,it is a question even to-day1 in the minds of a great many students1 whether the modern plow should not be replaced by some machine even more suitable for the proper turning and stirring of the soil4 ,the moldboard plow is1 everything considered1 the most satisfactory plow for dry-farm purposes4 ,a plow with a moldboard possessing a short abrupt curvature is generally held to be the most valuable for dry-farm purposes1 since it pulverizes the soil most thoroughly1 and in dry-farming it is not so important to turn the soil over as to crumble and loosen it thoroughly4 ,naturally1 since the areas of dry-farms are very large1 the sulky or riding plow is the only kind to be used4 ,the same may be said of all other dry-farm implements4 ,as far as possible1 they should be of the riding kind since in the end it means economy from the resulting saving of energy4 ,the disk plow has recently come into prominent use throughout the land4 ,it consists1 as is well known1 of one or more large disks which are believed to cause a smaller draft1 as they cut into the ground1 than the draft due to the sliding friction upon the moldboard4 ,davidson and ,chase say1 however1 that the draft of a disk plow is often heavier in proportion to the work done and the plow itself is more clumsy than the moldboard plow4 ,for ordinary dry-farm purposes the disk plow has no advantage over the modern moldboard plow4 ,many of the dry-farm soils are of a heavy clay and become very sticky during certain seasons of the year4 ,in such soils the disk plow is very useful4 ,it is also true that dry-farm soils1 subjected to the intense heat of the western sun become very hard4 ,in the handling of such soils the disk plow has been found to be most useful4 ,the common experience of dry-farmers is that when sagebrush lands have been the first plowing can be most successfully done with the disk plow1 but that after4 the first crop has been harvested1 the stubble land can be best handled with the moldboard plow4 ,all this1 however1 is yet to be subjected to further tests4 ,while subsoiling results in a better storage reservoir for water and consequently makes dry-farming more secure1 yet the high cost of the practice will probably never make it popular4 ,subsoiling is accomplished in two ways3 either by an ordinary moldboard plow which follows the plow in the plow furrow and thus turns the soil to a greater depth1 or by some form of the ordinary subsoil plow4 ,in general1 the subsoil plow is simply a vertical piece of cutting iron1 down to a depth of ten to eighteen inches1 at the bottom of which is fastened a triangular piece of iron like a shovel1 which1 when pulled through the ground1 tends to loosen the soil to the full depth of the plow4 ,the subsoil plow does not turn the soil2 it simply loosens the soil so that the air and plant roots can penetrate to greater depths4 ,in the choice of plows and their proper use the dryfarmer must be guided wholly by the conditions under which he is working4 ,it is impossible at the present time to lay down definite laws stating what plows are best for certain soils4 ,the soils of the arid region are not well enough known1 nor has the relationship between the plow and the soil been sufficiently well established4 ,as above remarked1 here is one of the great fields for investigation for both scientific and practical men for years to come4 ,making and maintaining a soil-mulch ,after the land has been so well plowed that the rains can enter easily1 the next operation of importance in dry-farming is the making and maintaining of a soil-mulch over the ground to prevent the evaporation of water from the soil4 ,for this purpose some form of harrow is most commonly used4 ,the oldest and best-known harrow is the ordinary smoothing harrow1 which is composed of iron or steel teeth of various shapes set in a suitable frame4 7,see ,fig4 #gi47 ,for dry-farm purposes the implement must be so made as to enable the farmer to set the harrow teeth to slant backward or forward4 ,it frequently happens that in the spring the grain is too thick for the moisture in the soil1 and it then becomes necessary to tear out some of the young plants4 ,for this purpose the harrow teeth are set straight or forward and the crop can then be thinned effectively4 ,at other times it may be observed in the spring that the rains and winds have led to the formation of a crust over the soil1 which must be broken to let the plants have full freedom of growth and development4 ,this is accomplished by slanting the harrow teeth backward1 and the crust may then be broken without serious injury to the plants4 ,the smoothing harrow is a very useful implement on the dry-farm4 ,for following the plow1 however1 a more useful implement is the disk harrow1 which is a comparatively recent invention4 ,it consists of a series of disks which may be set at various angles with the line of traction and thus be made to turn over the soil while at the same time pulverizing it4 ,the best dry-farm practice is to plow in the fall and let the soil lie in the rough during the winter months4 ,in the spring the land is thoroughly disked and reduced to a fine condition4 ,following this the smoothing harrow is occasionally used to form a more perfect mulch4 ,when seeding is to be done immediately after plowing1 the plow is followed by the disk harrow1 and that in turn is followed by the smoothing harrow4 ,the ground is then ready for seeding4 ,the disk harrow is also used extensively throughout the summer in maintaining a proper mulch4 ,it does its work more effectively than the ordinary smoothing harrow and is1 therefore1 rapidly displacing all other forms of harrows for the purpose of maintaining a layer of loose soil over the dry-farm4 ,there are several kinds of disk harrows used by dry-farmers4 ,the full disk is1 everything considered1 the most useful4 ,the cutaway harrow is often used in cultivating old alfalfa land2 the spade disk harrow has a very limited application in dry-farming2 and the orchard disk harrow is simply a modlfication of the full disk harrow whereby the farmer is able to travel between the rows of trees and so to cultivate the soil under the branches of the trees without injuring the leaves or fruit4 ,one of the great difficulties in dry-farming concerns itself with the prevention of the growth of weeds or volunteer crops4 ,as has been explained in previous chapters1 weeds require as much water for their growth as wheat or other useful crops4 ,during the fallow season1 the farmer is likely to be overtaken by the weeds and lose much of the value of the fallow by losing soil-moisture through the growth of weeds4 ,under the most favorable conditions weeds are difficult to handle4 ,the disk harrow itself is not effective4 ,the smoothing harrow is of less value4 ,there is at the present time great need for some implement that will effectively destroy young weeds and prevent their further growth4 ,attempts are being made to invent such implements1 but up to the present without great success4 ,hogenson reports the finding of an implement on a western dry-farm constructed by the farmer himself which for a number of years has shown itself of high efficiency in keeping the dry-farm free from weeds4 ,several improved modifications of this implement have been made and tried out on the famous dry-farm district at ,nephi1 ,utah1 and with the greatest success4 ,hunter reports a similar implement in common use on the dry-farms of the ,columbia ,basin4 ,spring tooth harrows are also used in a small way on the dry-farms4 ,they have no special advantage over the smoothing harrow or the disk harrow1 except in places where the attempt is made to cultivate the soil between the rows of wheat4 ,the curved knife tooth harrow is scareely ever used on dry-farms4 ,it has some value as a pulverizer1 but does not seem to have any real advantage over the ordinary disk harrow4 ,cultivators for stirring the land on which crops are growing are not used extensively on dry-farms4 ,usually the spring tooth harrow is employed for this work4 ,in dry-farm sections1 where corn is grown1 the cultivator is frequently used throughout the season4 ,potatoes grown on dry-farms should be cultivated throughout the season1 and as the potato industry grows in the dry-farm territory there will be a greater demand for suitable cultivators4 ,the cultivators to be used on dry-farms are all of the riding kind4 ,they should be so arranged that the horse walking between two rows carries a cultivator that straddles several rows of plants and cultivates the soil between4 ,disks1 shovels1 or spring teeth may be used on cultivators4 ,there is a great variety on the market1 and each farmer will have to choose such as meet most definitely his needs4 ,the various forms of harrows and cultivators are of the greatest importance in the development of dry-farming4 ,unless a proper mulch can be kept over the soil during the fallow season1 and as far as possible during the growing season1 first-class crops cannot be fully respected4 ,the roller is occasionally used in dry-farming1 especially in the uplands of the ,columbia ,basin4 ,it is a somewhat dangerous implement to use where water conservation is important1 since the packing resulting from the roller tends to draw water upward from the lower soil layers to be evaporated into the air4 ,wherever the roller is used1 therefore1 it should be followed immediately by a harrow4 ,it is valuable chiefly in the localities where the soil is very loose and light and needs packing around the seeds to permit perfect germination4 ,subsurface packing ,the subsurface packer invented by ,campbell is shown in ,figure #hc--not shown--ed44 ,the wheels of this machine eighteen inches in diameter1 with rims one inch thick at the inner part1 beveled two and a half inches to a sharp outer edge1 are placed on a shaft1 five inches apart4 ,in practice about five hundred pounds of weight are added4 ,this machine1 according to ,campbell1 crowds a one-inch wedge into every five inches of soil with a lateral and a downward pressure and thus packs firmly the soil near the bottom of the plow-furrow4 ,subsurface packing aims to establish full capillary connection between the plowed upper soil and the undisturbed lower soil-layer2 to bring the moist soil in close contact with the straw or organic litter plowed under and thus to hasten decomposition1 and to provide a firm seed bed4 ,the subsurface packer probably has some value where the plowed soil containing the stubble is somewhat loose2 or on soils which do not permit of a rapid decay of stubble and other organic matter that may be plowed under from season to season4 ,on such soils the packing tendency of the subsurface packer may help prevent loss of soil water1 and may also assist in furnishing a more uniform medium through which plant roots may force their way4 ,for all these purposes1 the disk is usually equally efficient4 ,sowing ,it has already been indicated in previous chapters that proper sowing is one of the most important operations of the dry-farm1 quite comparable in importance with plowing or the maintaining of a mulch for retaining soil-moisture4 ,the old-fashioned method of broadcasting has absolutely no place on a dry-farm4 ,the success of dry-farming depends entirely upon the control that the farmer has of all the operations of the farm4 ,by broadcasting1 neither the quantity of seed used nor the manner of placing the seed in the ground can be regulated4 ,drill culture1 therefore1 introduced by ,jethro ,tull two hundred years ago1 which gives the farmer full control over the process of seeding1 is the only system to be used4 ,the numerous seed drills on the market all employ the same principles4 ,their variations are few and simple4 ,in all seed drills the seed is forced into tubes so placed as to enable the seed to fall into the furrows in the ground4 ,the drills themselves are distinguished almost wholly by the type of the furrow opener and the covering devices which are used4 ,the seed furrow is opened either by a small hoe or a so-called shoe or disk4 ,at the present time it appears that the single disk is the coming method of opening the seed furrow and that the other methods will gradually disappear4 ,as the seed is dropped into the furrow thus made it is covered by some device at the rear of the machine4 ,one of the oldest methods as well as one of the most satisfactory is a series of chains dragging behind the drill and covering the furrow quite completely4 ,it is1 however1 very desirable that the soil should be pressed carefully around the seed so that germination may begin with the least difficulty whenever the temperature conditions are right4 ,most of the drills of the day are1 therefore1 provided with large light wheels1 one for each furrow1 which press lightly upon the soil and force the soil into intimate contact with the seed ,the weakness of such an arrangement is that the soil along the drill furrows is left somewhat packed1 which leads to a ready escape of the soil-moisture4 ,many of the drills are so arranged that press wheels may be used at the pleasure of the farmer4 ,the seed drill is already a very useful implement and is rapidly being made to meet the special requirements of the dry-farmer4 ,corn planters are used almost exclusively on dry-farms where corn is the leading crop4 ,in principle they are very much the same as the press drills4 ,potatoes are also generally planted by machinery4 ,wherever seeding machinery has been constructed based upon the principles of dry-farming1 it is a very advantageous adjunct to the dry-farm4 ,harvesting ,the immense areas of dry-farms are harvested almost wholly by the most modern machinery4 ,for grain1 the harvester is used almost exclusively in the districts where the header cannot be used1 but wherever conditions permit1 the header is and should be used4 ,it has been explained in previous chapters how valuable the tall header stubble is when plowed under as a means of maintaining the fertility of the soil4 ,besides1 there is an ease in handling the header which is not known with the harvester4 ,there are times when the header leads to some waste as1 for instance1 when the wheat is very low and heads are missed as the machine passes over the ground4 ,in many sections of the dry-farm territory the climatic conditions are such that the wheat cures perfectly while still standing4 ,in such places the combined harvester and thresher is used4 ,the header cuts off the heads of the grain1 which are passed up into the thresher1 and bags filled with threshed grain are dropped along the path of the machine1 while the straw is scattered over the ground4 ,wherever such a machine can be used1 it has been found to be economical and satisfactory4 ,of recent years corn stalks have been used to better advantage than in the past1 for not far from one half of the feeding value of the corn crop is in the stalks1 which up to a few years ago were very largely wasted4 ,corn harvesters are likewise on the market and are quite generally used4 ,it was manifestly impossible on large places to harvest corn by hand and large corn harvesters have1 therefore1 been made for this purpose4 ,steam and other motive power ,recently numerous persons have suggested that the expense of running a dry-farm could be materially reduced by using some motive power other than horses4 ,steam1 gasoline1 and electricity have all been suggested4 ,the steam traction engine is already a fairly well-developed machine and it has been used for plowing purposes on many dry-farms in nearly all the sections of the dry-farm territory4 ,unfortunately1 up to the present it has not shown itself to be very satisfactory4 ,first of all it is to be remembered that the principles of dry-farming require that the topsoil be kept very loose and spongy4 ,the great traction engines have very wide wheels of such tremendous weight that they press down the soil very compactly along their path and in that way defeat one of the important purposes of tillage4 ,another objection to them is that at present their construction is such as to result in continual breakages4 ,while these breakages in themselves are small and inexpensive1 they mean the cessation of all farming operations during the hour or day required for repairs4 ,a large crew of men is thus left more or less idle1 to the serious injury of the work and to the great expense of the owner4 ,undoubtedly1 the traction engine has a place in dry-farming1 but it has not yet been perfected to such a degree as to make it satisfactory4 ,on heavy soils it is much more useful than on light soils4 ,when the traction engine works satisfactorily1 plowing may be done at a cost considerably lower than when horses are employed4 ,in ,england1 ,germany1 and other ,european countries some of the difficulties connected with plowing have been overcome by using two engines on the two opposite sides of a field4 ,these engines move synchronously together and1 by means of large cables1 plows1 harrows1 or seeders1 are pulled back and forth over the field4 ,this method seems to give good satisfaction on many large estates of the old world4 ,macdonald reports that such a system is in successful operation in the ,transvaal in ,south ,africa and is doing work there at a very knew cost4 ,the large initial cost of such a system will1 of course1 prohibit its use except on the very large farms that are being established in the dry-farm territory4 ,gasoline engines are also being tried out1 but up to date they have not shown themselves as possessing superior advantages over the steam engines4 ,the two objections to them are the same as to the steam engine3 first1 their great weight1 which compresses in a dangerous degree the topsoil and1 secondly1 the frequent breakages1 which make the operation slow and expensive4 ,over a great part of the ,west1 water power is very abundant and the suggestion has been made that the electric energy which can be developed by means of water power could be used in the cultural operations of the dry-farm4 ,with the development of the trolley car which does not run on rails it would not seem impossible that in favorable localities electricity could be made to serve the farmer in the mechanical tillage of the dry-farm4 ,the substitution of steam and other energy for horse power is yet in the future4 ,undoubtedly1 it will come1 but only as improvements are made in the machines4 ,there is here also a great field for being of high service to the farmers who are attempting to reclaim the great deserts of the world4 ,as stated at the beginning of this chapter1 dry-farming would probably have been an impossibilityfifty or a hundred years ago because of the absence of suitable machinery4 ,the future of dry-farming rests almost wholly1 so far as its profits are concerned1 upon the development of new and more suitable machinery for the tillage of the soil in accordance with the established principles of dry-farming4 ,finally1 the recommendations made by ,merrill may here be inserted4 ,a dry-farmer for best work should be supplied with the following implements in addition to the necessary wagons and hand tools3-- ,one ,plow4 ,one ,disk4 ,one ,smoothing ,harrow4 ,one ,drill ,seeder4 ,one ,harvester or ,header4 ,one ,mowing ,machine4 ,,chapter ,,xvi ,,irrigation ,,and ,,dry-,,farming ,irrigation-farming and dry-farming are both systems of agriculture devised for the reclamation of countries that ordinarily receive an annual rainfall of twenty inches or less4 ,irrigation-farming cannot of itself reclaim the arid regions of the world1 for the available water supply of arid countries when it shall have been conserved in the best possible way cannot be made to irrigate more than one fifth of the thirsty land4 ,this means that under the highest possible development of irrigation1 at least in the ,united ,states1 there will be five or six acres of unirrigated or dry-farm land for every acre of irrigated land4 ,irrigation development cannot possibly1 therefore1 render the dry-farm movement valueless4 ,on the other hand1 dry-farming is furthered by the development of irrigation farming1 for both these systems of agriculture are characterized by advantages that make irrigation and dry-farming supplementary to each other in the successful development of any arid region4 ,under irrigation1 smaller areas need to be cultivated for the same crop returns1 for it has been amply demonstrated that the acre yields under proper irrigation are very much larger than the best yields under the most careful system of dry-farming4 ,secondly1 a greater variety of crops may be grown on the irrigated farm than on the dry-farm4 ,as has already been shown in this volume1 only certain drouth resistant crops can be grown profitably upon dry-farms1 and these must be grown under the methods of extensive farming4 ,the longer growing crops1 including trees1 succulent vegetables1 and a variety of small fruits1 have not as yet been made to yield profitably under arid conditions without the artificial application of water4 ,further1 the irrigation-farmer is not largely dependent upon the weather and1 therefore1 carries on this work with a feeling of greater security4 ,of course1 it is true that the dry years affect the flow of water in the canals and that the frequent breaking of dams and canal walls leaves the farmer helpless in the face of the blistering heat4 ,yet1 all in all1 a greater feeling of security is possessed by the irrigation farmer than by the dry-farmer4 ,most important1 however1 are the temperamental differences in men which make some desirous of giving themselves to the cultivation of a small area of irrigated land under intensive conditions and others to dry-farming under extensive conditions4 ,in fact1 it is being observed in the arid region that men1 because of their temperamental differences1 are gradually separating into the two classes of irrigation-farmers and dry-farmers4 ,the dry-farms of necessity cover much larger areas than the irrigated farms4 ,the land is cheaper and the crops are smaller4 ,the methods to be applied are those of extensive farming4 ,the profits on the investment also appear to be somewhat larger4 ,the very necessity of pitting intellect against the fierceness of the drouth appears to have attracted many-men to the dry-farms4 ,gradually the certainty of producing crops on dry-farms from season to season is becoming established1 and the essential difference between the two kinds of farming in the arid districts will then he the difference between intensive and extensive methods of culture4 ,men will be attracted to one or other of these systems of agriculture according to their personal inclinations4 ,the scarcity of water ,for the development of a well-rounded commonwealth in an arid region it is1 of course1 indispensable that irrigation be practiced1 for dry-farming of itself will find it difficult to build up populous cities and to supply the great variety of crops demanded by the modern family4 ,in fact1 one of the great problems before those engaged in the development of dry-farming at present is the development of homesteads in the dry-farms4 ,a homestead is possible only where there is a sufficient amount of free water available for household and stock purposes4 ,in the portion of the dry-farm territory where the rainfall approximates twenty inches1 this problem is not so very difficult1 since ground water may be reached easily4 ,in the drier portions1 however1 where the rainfall is between ten and fifteen inches1 the problem is much more important4 ,the conditions that bring the district under the dry-farm designation imply a scarcity of water4 ,on few dry-farms is water available for the needs of the household and the barns4 ,in the ,rocky ,mountain states numerous dry-farms have been developed from seven to fifteen miles from the nearest source of water1 and the main expense of developing these farms has been the hauling of water to the farms to supply the needs of the men and beasts at work on them4 ,naturally1 it is impossible to establish homesteads on the dry-farms unless at least a small supply of water is available2 and dry-farming will never he what it might be unless happy homes can be established upon the farms in the arid regions that grow crops without irrigation4 ,to make a dry-farm homestead possible enough water must be available1 first of all1 to supply the culinary needs of the household4 ,this of itself is not large and1 as will be shown hereafter1 may in most cases be obtained4 ,however1 in order that the family may possess proper comforts1 there should be around the homestead trees1 and shrubs1 and grasses1 and the family garden4 ,to secure these things a certain amount of irrigation water is required4 ,it may be added that dry-farms on which such homesteads are found as a result of the existence of a small supply of irrigation water are much more valuable1 in case of sale1 than equally good farms without the possibility of maintaining homesteads4 ,moreover1 the distinct value of irrigation in producing a large acre yield makes it desirable for the farmer to use all the water at his disposal for irrigation purposes4 ,no available water should be allowed to flow away unused4 ,available surface water ,the sources of water for dry-farms fall readily into classes3 surface waters and subterranean waters4 ,the surface waters1 wherever they may be obtained1 are generally the most profitable4 ,the simplest method of obtaining water in an irrigated region is from some irrigation canal4 ,in certain districts of the intermountain region where the dry farms lie above the irrigation canals and the irrigated lands below1 it is comparatively easy for the farmers to secure a small but sufficient amount of water from the canal by the use of some pumping device that will force the water through the pipes to the homestead4 ,the dry-farm area that may be so supplied by irrigation canals is1 however1 very limited and is not to be considered seriously in connection with the problem4 ,a much more important method1 especially in the mountainous districts1 is the utilization of the springs that occur in great numbers over the whole dry-farm territory4 ,sometimes these springs are very small indeed1 and often1 after development by tunneling into the side of the hill1 yield only a trifling flow4 ,yet1 when this water is piped to the homestead and allowed to accumulate in small reservoirs or cisterns1 it may be amply sufficient for the needs of the family and the live stock1 besides having a surplus for the maintenance of the lawn1 the shade trees1 and the family garden4 ,many dry-farmers in the intermountain country have piped water seven or eight miles from small springs that were considered practically worthless and thereby have formed the foundations for small village communities4 ,of perhaps equal importance with the utilization of the naturally occurring springs is the proper conservation of the flood waters4 ,as has been stated before1 arid conditions allow a very large loss of the natural precipitation as run-off4 ,the numerous gullies that characterize so many parts of the dry-farm territory are evidences of the number and vigor of the flood waters4 ,the construction of small reservoirs in proper places for the purpose of catching the flood waters will usually enable the farmer to supply himself with all the water needed for the homestead4 ,such reservoirs may already be found in great numbers scattered over the whole western ,america4 ,as dry-farming increases their numbers will also increase4 ,when neither canals1 nor springs1 nor flood waters are available for the supply of water1 it is yet possible to obtain a limited supply by so arranging the roof gutters on the farm buildings that all the water that falls on the roofs is conducted through the spouts into carefully protected cisterns or reservoirs4 ,a house thirty by thirty feet1 the roof of which is so constructed that all that water that falls upon it is carried into a cistern will yield annually under a a rainfall of fifteen inches a maximum amount of water equivalent to about #hhjj gallons4 ,allowing for the unavoidable waste due to evaporation1 this will yield enough to supply a household and some live stock with the necessary water4 ,in extreme cases this has been found to be a very satisfactory practice1 though it is the one to be resorted to only in case no other method is available4 ,it is indispensable that some reservoir be provided to hold the surface water that may be obtained until the time it may be needed4 ,the water coming constantly from a spring in summer should be applied to crops only at certain definite seasons of the year4 ,the flood waters usually come at a time when plant growth is not active and irrigation is not needed4 ,the rainfall also in many districts comes most largely at seasons of no or little plant growth4 ,reservoirs must1 therefore1 be provided for the storing of the water until the periods when it is demanded by crops4 ,cement-lined cisterns are quite common1 and in many places cement reservoirs have been found profitable4 ,in other places the occurrence of impervious clay has made possible the establishment and construction of cheap reservoirs4 ,the skillful and permanent construction of reservoirs is a very important subject4 ,reservoir building should be undertaken only after a careful study of the prevailing conditions and under the advice of the state or government officials having such work in charge4 ,in general1 the first cost of small reservoirs is usually somewhat high1 but in view of their permanent service and the value of the water to the dry-farm they pay a very handsome interest on the investment4 ,it is always a mistake for the dry-farmer to postpone the construction of a reservoir for the storing of the small quantities of water that he may possess1 in order to save a little money4 ,perhaps the greatest objection to the use of the reservoirs is not their relatively high cost1 but the fact that since they are usually small and the water shallow1 too large a proportion of the water1 even under favorable conditions1 is lost by evaporation4 ,it is ordinarily assumed that one half of the water stored in small reservoirs throughout the year is lost by direct evaporation4 ,available subterranean water ,where surface waters are not readily available1 the subterranean water is of first importance4 ,it is generally known that1 underlying the earth's surface at various depths1 there is a large quantity of free water4 ,those living in humid climates often overestimate the amount of water so held in the earth's crust1 and it is probably true that those living in arid regions underestimate the quantity of water so found4 ,the fact of the matter seems to be that free water is found everywhere under the earth's surface4 ,those familiar with the arid ,west have frequently been surprised by the frequency with which water has been found at comparatively shallow depths in the most desert locations4 ,various estimates have been made as to the quantity of underlying water4 ,the latest calculation and perhaps the most reliable is that made by ,fuller1 who1 after a careful analysis of the factors involved1 concludes that the total free water held in the earth's crust is equivalent to a uniform sheet of water over the entire surface of the earth ninety-six feet in depth4 ,a quantity of water thus held would be equivalent to about one hundredth part of the whole volume of the ocean4 ,even though the thickness of the water sheet under arid soils is only half this figure there is an amount1 if it could be reached1 that would make possible the establishment of homesteads over the whole dry-farm territory4 ,one of the main efforts of the day is the determination of the occurrence of the subterranean waters in the dry-farm territory4 ,ordinary dug wells frequently reach water at comparatively shallow depths4 ,over the cultivated ,utah deserts water is often found at a depth of twenty-five or thirty feet1 though many wells dug to a depth of one hundred and seventy-five and two hundred feet have failed to reach water4 ,it may be remarked in this connection that even where the distance to the water is small1 the piped well has been found to be superior to the dug well4 ,usually1 water is obtained in the dry-farm territory by driving pipes to comparatively great depths1 ranging from one hundred feet to over one thousand feet4 ,at such depths water is nearly always found4 ,often the geological conditions are such as to force the water up above the surface as artesian wells1 though more often the pressure is simply sufficient to bring the water within easy pumping distance of the surface4 ,in connection with this subject it must be said that many of the subterranean waters of the dry-farm territory are of a saline character4 ,the amount of substances held in solution varies largely1 but frequently is far above the limits of safety for the use of man or beast or plants4 ,the dry-farmer who secures a well of this type should1 therefore1 be careful to have a proper examination made of the constituents of the water before ordinary use is made of it4 ,now1 as has been said1 the utilization of the subterranean waters of the land is one of the living problems of dry-farming4 ,the tracing out of this layer of water is very difficult to accomplish and cannot be done by individuals4 ,it is a work that properly belongs to the state and national government4 ,the state of ,utah1 which was the pioneer in appropriating money for dry-farm experiments1 also led the way in appropriating money for the securing of water for the dry-farms from subterranean sources4 ,the world has been progressing in ,utah since #aije1 and water has been secured in the most unpromising localities4 ,the most remarkable instance is perhaps the finding of water at a depth of about five hundred and fifty feet in the unusually dry ,dog ,valley located some fifteen miles west of ,nephi4 ,pumping water ,the use of small quantities of water on the dry-farms carries with it1 in most cases1 the use of small pumping plants to store and to distribute the water properly4 ,especially1 whenever subterranean sources of water are used and the water pressure is not sufficient to throw the water above the ground1 pumping must be resorted to4 ,the pumping of water for agricultural purposes is not at all new4 ,according to ,fortier1 two hundred thousand acres of land are irrigated with water pumped from driven wells in the state of ,california alone4 ,seven hundred and fifty thousand acres are irrigated by pumping in the ,united ,states1 and ,mead states that there are thirteen million acres of land in ,india which are irrigated by water pumped from subterranean sources4 ,the dry-farmer has a choice among several sources of power for the operation of his pumping plant4 ,in localities where winds are frequent and of sufficient strength windmills furnish cheap and effective power1 especially where the lift is not very great4 ,the gasoline engine is in a state of considerable perfection and may be used economically where the price of gasoline is reasonable4 ,engines using crude oil may be most desirable in the localities where oil wells have been found4 ,as the manufacture of alcohol from the waste products of the farms becomes established1 the alcohol-burning engine could become a very important one4 ,over nearly the whole of the dry-farm territory coal is found in large quantities1 and the steam engine fed by coal is an important factor in the pumping of water for irrigation purposes4 ,further1 in the mountainous part of the dry-farm territory water ,power is very abundant4 ,only the smallest fraction of it has as yet been harnessed for the generation of the electric current4 ,as electric generation increases1 it should be comparatively easy for the farmer to secure sufficient electric power to run the pump4 ,this has already become an established practice in districts where electric power is available4 ,during the last few years considerable work has been done to determine the feasibility of raising water for irrigation by pumping4 ,fortier reports that successful results have been obtained in ,colorado1 ,wyoming1 and ,montana4 ,he declares that a good type of windmill located in a district where the average wind movement is ten miles per hour can lift enough water twenty feet to irrigate five acres of land4 ,wherever the water is near the surface this should be easy of accomplishment4 ,vernon1 ,lovett1 and ,scott1 who worked under ,new ,mexico conditions1 have reported that crops can be produced profitably by the use of water raised to the surface for irrigation4 ,fleming and ,stoneking1 who conducted very careful experiments on the subject in ,new ,mexico1 found that the cost of raising through one foot a quantity of water corresponding to a depth of one foot over one acre of land varied from a cent and an eighth to nearly twenty-nine cents1 with an average of a little more than ten cents4 ,this means that the cost of raising enough water to cover one acre to a depth of one foot through a distance of forty feet would average #d4cf4 ,this includes not only the cost of the fuel and supervision of the pump but the actual deterioration of the plant4 ,smith investigated the same problem under ,arizona conditions and found that it cost approximately seventeen cents to raise one acre foot of water to a height of one foot4 ,a very elaborate investigation of this nature was conducted in ,california by ,le ,conte and ,tait4 ,they studied a large number of pumping plants in actual operation under ,california conditions1 and determined that the total cost of raising one acre foot of water one foot was1 for gasoline power1 four cents and upward2 for electric power1 seven to sixteen cents1 and for steam1 four cents and upward4 ,mead has reported observations on seventy-two windmills near ,garden ,city1 ,kansas1 which irrigated from one fourth to seven acres each at a cost of seventy-five cents to #f per acre4 ,all in all1 these results justify the belief that water may be raised profitably by pumping for the purpose of irrigating crops4 ,when the very great value of a little water on a dry-farm is considered1 the figures here given do not seem at all excessive4 ,it must be remarked again that a reservoir of some sort is practically indispensable in connection with a pumping plant if the irrigation water is to be used in the best way4 ,the use of small quantities of water in irrigation ,now1 it is undoubtedly true that the acre cost of water on dry-farms1 where pumping plants or similar devices must be used with expensive reservoirs1 is much higher than when water is obtained from gravity canals4 ,it is1 therefore1 important that the costly water so obtained be used in the most economical manner4 ,this is doubly important in view of the fact that the water supply obtained on dry-farms is always small and insufficient for all that the farmer would like to do4 ,indeed1 the profit in storing and pumping water rests largely upon the economical application of water to crops4 ,this necessitates the statement of one of the first principles of scientific irrigation practices1 namely1 that the yield of a crop under irrigation is not proportional to the amount of water applied in the form of irrigation water4 ,in other words1 the water stored in the soil by the natural precipitation and the water that falls during the spring and summer can either mature a small crop or bring a crop near maturity4 ,a small amount of water added in the form of irrigation water at the right time will usually complete the work and produce a well-matured crop of large yield4 ,irrigation should only be supplemented to the natural precipitation4 ,as more irrigation water is added1 the increase in yield becomes smaller in proportion to the amount of water employed4 ,this is clearly shown by the following table1 which is taken from some of the irrigation experiments carried on at the ,utah ,station3-- ,effect of ,varying ,irrigations on ,crop ,yields ,per ,acre ,depth of ,water ,wheat ,corn ,alfalfa ,potatoes ,sugar ,beets ,applied 7,inches7 7,bushels7 7,bushels7 7,pounds7 7,bushels7 7,tons7 #e4j #dj #aid #be #g4e #da #fe #aj4j #da #hj #bac #bf #ae4j #df #gh #bec #bg #be4j #di #gg #aj1jef #beh #ce4j #ee #i1adb #bia #bf #ej #fj #hd #ac1jfa ,the soil was a typical arid soil of great depth and had been so cultivated as to contain a large quantity of the natural precipitation4 ,the first five inches of water added to the precipitation already stored in the soil produced forty bushels of wheat4 ,doubling this amount of irrigation water produced only forty-one bushels of wheat4 ,even with an irrigation of fifty inches1 or ten times that which produced forty bushels1 only sixty bushels of wheat1 or an increase of one half1 were produced4 ,a similar variation may be observed in the case of the other crops4 ,the first lesson to be drawn from this important principle of irrigation is that if the soil be so treated as to contain at planting time the largest proportion of the natural precipitation1--that is1 if the ordinary methods of dry-farming be employed1--crops will be produced with a very small amount of irrigation water4 ,secondly1 it follows that it would be a great deal better for the farmer who raises wheat1 for instance1 to cover ten acres of land with water to a depth of five inches than to cover one acre to a depth of fifty inches1 for in the former case four hundred bushels and in the second sixty bushels of wheat would be produced4 ,the farmer who desires to utilize in the most economical manner the small amount of water at his disposal must prepare the land according to dry-farm methods and then must spread the water at his disposal over a larger area of land4 ,the land must be plowed in the fall if the conditions permit1 and fallowing should be practiced wherever possible4 ,if the farmer does not wish to fallow his family garden he can achieve equally good results by planting the rows twice as far apart as is ordinarily the case and by bringing the irrigation furrows near the rows of plants4 ,then1 to make the best use of the water1 he must carefully cover the irrigation furrow with dry dirt immediately after the water has been applied and keep the whole surface well stirred so that evaporation will be reduced to a minimum4 ,the beginning of irrigation wisdom is always the storage of the natural precipitation4 ,when that is done correctly1 it is really remarkable how far a small amount of irrigation water may be made to go4 ,under conditions of water scarcity it is often found profitable to carry water to the garden in cement or iron pipes so that no water may be lost by seepage or evaporation during the conveyance of the water from the reservoir to the garden4 ,it is also often desirable to convey water to plants through pipes laid under the ground1 perforated at various intervals to allow the water to escape and soak into the soil in the neighborhood of the plant roots4 ,all such refined methods of irrigation should be carefully investigated by the who wants the largest results from his limited water supply4 ,though such methods may seem cumbersome and expensive at first1 yet they will be found1 if properly arranged1 to be almost automatic in their operation and also very profitable4 ,forbes has reported a most interesting experiment dealing with the economical use of a small water supply under the long season and intense water dissipating conditions of ,arizona4 ,the source of supply was a well1 #ij feet deep4 ,a #c by #ad-;inch pump cylinder operated by a #ab-;foot geared windmill lifted the water into a #ejjj-;gallon storage reservoir standing on a support #ah feet high4 ,the water was conveyed from this reservoir through black iron pipes buried #a or #b feet from the trees to be watered4 ,small holes in the pipe #ccb inch in diameter allowed the water to escape at desirable intervals4 ,this irrigation plant was under expert observation for considerable time1 and it was found to furnish sufficient water for domestic use for one household1 and irrigated in addition #fa olive trees1 #b cottonwoods1 #h pepper trees1 #a date palm1 #ai pomegranates1 #d grapevines1 #a fig tree1 #i eucalyptus trees1 #a ash1 and #ac miscellancous1 making a total of #hg useful trees1 mainly fruit-bearing1 and #cb vines and bushes4 7,see ,fig4 #ie47 ,if such a result can be obtained with a windmill and with water ninety feet below the surface under the arid conditions of ,arizona1 there should be little difficulty in securing sufficient water over the larger portions of the dry-farm territory to make possible beautiful homesteads4 ,the dry-farmer should carefully avoid the temptation to decry irrigation practices4 ,irrigation and dry-farming of necessity must go hand in hand in the development of the great arid regions of the world4 ,neither can well stand alone in the building of great commonwealths on the deserts of the earth4 ,,chapter ,,xvii ,,the ,,history ,,of ,,dry-,,farming ,the great nations of antiquity lived and prospered in arid and semiarid countries4 ,in the more or less rainless regions of ,china1 ,mesopotamia1 ,palestine1 ,egypt1 ,mexico1 and ,peru1 the greatest cities and the mightiest peoples flourished in ancient days4 ,of the great civilizations of history only that of ,europe has rooted in a humid climate4 ,as ,hilgard has suggested1 history teaches that a high civilization goes hand in hand with a soil that thirsts for water4 ,to-day1 current events point to the arid and semiarid regions as the chief dependence of our modern civilization4 ,in view of these facts it may be inferred that dry-farming is an ancient practice4 ,it is improbable that intelligent men and women could live in ,mesopotamia1 for example1 for thousands of years without discovering methods whereby the fertile soils could be made to produce crops in a small degree at least without irrigation4 ,true1 the low development of implements for soil culture makes it fairly certain that dry-farming in those days was practiced only with infinite labor and patience2 and that the great ancient nations found it much easier to construct great irrigation systems which would make crops certain with a minimum of soil tillage1 than so thoroughly to till the soil with imperfect implements as to produce certain yields without irrigation4 ,thus is explained the fact that the historians of antiquity speak at length of the wonderful irrigation systems1 but refer to other forms of agriculture in a most casual manner4 ,while the absence of agricultural machinery makes it very doubtful whether dry-farming was practiced extensively in olden days1 yet there can be little doubt of the high antiquity of the practice4 ,kearney quotes ,tunis as an example of the possible extent of dry-farming in early historical days4 ,tunis is under an average rainfall of about nine inches1 and there are no evidences of irrigation having been practiced there1 yet at ,el ,djem are the ruins of an amphitheater large enough to accommodate sixty thousand persons1 and in an area of one hundred square miles there were fifteen towns and forty-five villages4 ,the country1 therefore1 must have been densely populated4 ,in the seventh century1 according to the ,roman records1 there were two million five hundred thousand acres of olive trees growing in ,tunis and cultivated without irrigation4 ,that these stupendous groves yielded well is indicated by the statement that1 under the ,caesar's ,tunis was taxed three hundred thousand gallons of olive oil annually4 ,the production of oil was so great that from one town it was piped to the nearest shipping port4 ,this historical fact is borne out by the present revival of olive culture in ,tunis1 mentioned in ,chapter ,,xii4 ,moreover1 many of the primitive peoples of to-day1 the ,chinese1 ,hindus1 ,mexicans1 and the ,american ,indians1 are cultivating large areas of land by dry-farm methods1 often highly perfected1 which have been developed generations ago1 and have been handed down to the present day4 ,martin relates that the ,tarahumari ,indians of northern ,chihuahua1 who are among the most thriving aboriginal tribes of northern ,mexico1 till the soil by dry-farm methods and succeed in raising annually large quantities of corn and other crops4 ,a crop failure among them is very uncommon4 ,the early ,american explorers1 especially the ,catholic fathers1 found occasional tribes in various parts of ,america cultivating the soil successfully without irrigation4 ,all this points to the high antiquity of agriculture without irrigation in arid and semiarid countries4 ,modern dry-farming in the ,united ,states ,the honor of having originated modern dry-farming belongs to the people of ,utah4 ,on ,july #bdth1 #ahdg1 ,brigham ,young with his band of pioneers entered ,great ,salt ,lake ,valley1 and on that day ground was plowed1 potatoes planted1 and a tiny stream of water led from ,city ,creek to cover this first farm4 ,the early endeavors of the ,utah pioneers were devoted almost wholly to the construction of irrigation systems4 ,the parched desert ground appeared so different from the moist soils of ,illinois and ,iowa1 which the pioneers had cultivated1 as to make it seem impossible to produce crops without irrigation4 ,still1 as time wore on1 inquiring minds considered the possibility of growing crops without irrigation2 and occasionally when a farmer was deprived of his supply of irrigation water through the breaking of a canal or reservoir it was noticed by the community that in spite of the intense heat the plants grew and produced small yields4 ,gradually the conviction grew upon the ,utah pioneers that farming without irrigation was not an impossibility2 but the small population were kept so busy with their small irrigated farms that no serious attempts at dry-farming were made during the first seven or eight years4 ,the publications of those days indicate that dry-farming must have been practiced occasionally as early as #ahed or #ahee4 ,about #ahfc the first dry-farm experiment of any consequence occurred in ,utah4 ,a number of emigrants of ,scandinavian descent had settled in what is now known as ,bear ,river ,city1 and had turned upon their farms the alkali water of ,malad ,creek1 and naturally the crops failed4 ,in desperation the starving settlers plowed up the sagebrush land1 planted grain1 and awaited results4 ,to their surprise1 fair yields of grain were obtained1 and since that day dry-farming has been an established practice in that portion of the ,great ,salt ,lake ,valley4 ,a year or two later1 ,christopher ,layton1 a pioneer who helped to build both ,utah and ,arizona1 plowed up land on the famous ,sand ,ridge between ,salt ,lake ,city and ,ogden and demonstrated that dry-farm wheat could be grown successfully on the deep sandy soil which the pioneers had held to be worthless for agricultural purposes4 ,since that day the ,sand ,ridge has been famous as a dry-farm district1 and ,major ,j4 ,w4 ,powell1 who saw the ripened fields of grain in the hot dry sand1 was moved upon to make special mention of them in his volume on the ,arid ,lands of ,utah1 published in #ahgi4 ,about this time1 perhaps a year or two later1 ,joshua ,salisbury and ,george ,l4 ,farrell began dry-farm experiments in the famous ,cache ,valley1 one hundred miles north of ,salt ,lake ,city4 ,after some years of experimentation1 with numerous failures these and other pioneers established the practice of dry-farming in ,cache ,valley1 which at present is one of the most famous dry-farm sections in the ,united ,states4 ,in ,tooele ,county1 ,just south of ,salt ,lake ,city1 dry-farming was practiced in #ahgg--;how much earlier is not known4 ,in the northern ,utah counties dry-farming assumed proportions of consequence only in the later '#gj's and early '#hj's4 ,during the '#hj's it became a thoroughly established and extensive business practice in the northern part of the state4 ,california1 which was settled soon after ,utah1 began dry-farm experiments a little later than ,utah4 ,the available information indicates that the first farming without irrigation in ,california began in the districts of somewhat high precipitation4 ,as the population increased1 the practice was pushed away from the mountains towards the regions of more limited rainfall4 ,according to ,hilgard1 successful dry-farming on an extensive scale has been practiced in ,california since about #ahfh4 ,olin reports that moisture-saving methods were used on the ,californian farms as early as #ahfa4 ,certainly1 ,california was a close second in originating dry-farming4 ,the ,columbia ,basin was settled by ,mareus ,whitman near ,walla ,walla in #ahcf1 but farming did not gain much headway until the railroad pushed through the great ,northwest about #ahhj4 ,those familiar with the history of the state of ,washington declare that dry-farming was in successful operation in isolated districts in the late '#gj's4 ,by #ahij it was a well-established practice1 but received a serious setback by the financial panic of #ahib-ahic4 ,really successful and extensive dry-farming in the ,columbia ,basin began about #ahig4 ,the practice of summer fallow had begun a year or two before4 ,it is interesting to note that both in ,california and ,washington there are districts in which dry-farming has been practiced successfully under a precipitation of about ten inches whereas in ,utah the limit has been more nearly twelve inches4 ,in the ,great ,plains area the history of dry-farming ,is hopelessly lost in the greater history of the development of the eastern and more humid parts of that section of the country4 ,the great influx of settlers on the western slope of the ,great ,plains area occurred in the early '#hj's and overflowed into eastern ,colorado and ,wyoming a few years later4 ,the settlers of this region brought with them the methods of humid agriculture and because of the relatively high precipitation were not forced into the careful methods of moisture conservation that had been forced upon ,utah1 ,california1 and the ,columbia ,basin4 ,consequently1 more failures in dry-farming are reported from those early days in the ,great ,plains area than from the drier sections of the far ,west ,dry-farming was practiced very successfully in the ,great ,plains area during the later '#hj's4 ,according to ,payne1 the crops of #ahhi were very good2 in #ahij1 less so2 in #ahia1 better2 in #ahib such immense crops were raised that the settlers spoke of the section as ,god's country2 in #ahic1 there was a partial failure1 and in #ahid the famous complete failure1 which was followed in #ahie by a partial failure4 ,since that time fair crops have been produced annually4 ,the dry years of #ahic-ahie drove most of the discouraged settlers back to humid sections and delayed1 by many years1 the settlement and development of the western side of the ,great ,plains area4 ,that these failures and discouragements were due almost entirely to improper methods of soil culture is very evident to the present day student of dry-farming4 ,in fact1 from the very heart of the section which was abandoned in #ahic-ahie come reliable records1 dating back to #ahhf1 which show successful crop production every year4 ,the famous ,indian ,head experimental farm of ,saskatchewan1 at the north end of the ,great ,plains area1 has an unbroken record of good crop yields from #ahhh1 and the early '#ij's were quite as dry there as farther south4 ,however1 in spite of the vicissitudes of the section1 dry-farming has taken a firm hold upon the ,great ,plains area and is now a well-established practice4 ,the curious thing about the development of dry-farming in ,utah1 ,california1 ,washington1 and the ,great ,plains is that these four sections appear to have originated dry-farming independently of each other4 ,true1 there was considerable communication from #ahdi onward between ,utah and ,california1 and there is a possibility that some of the many ,utah settlers who located in ,california brought with them accounts of the methods of dry-farming as practiced in ,utah4 ,this1 however1 cannot be authenticated4 ,it is very unlikely that the farmers of ,washington learned dry-farming from their ,california or ,utah neighbors1 for until #ahhj communication between ,washington and the colonies in ,california and ,utah was very difficult1 though1 of course1 there was always the possibility of accounts of agricultural methods being carried from place to place by the moving emigrants4 ,it is fairly certain that the ,great ,plains area did not draw upon the far ,west for dry-farm methods4 ,the climatic conditions are considerably different and the ,great ,plains people always considered themselves as living in a very humid country as compared with the states of the far ,west4 ,it may be concluded1 therefore1 that there were four independent pioneers in dry-farming in ,united ,states4 ,moreover1 hundreds1 probably thousands1 of individual farmers over the semiarid region have practiced dry-farming thirty to fifty years with methods by themselves4 ,although these different dry-farm sections were developed independently1 yet the methods which they have finally adopted are practically identical and include deep plowing1 unless the subsoil is very lifeless2 fall plowing2 the planting of fall grain wherever fall plowing is possible2 and clean summer fallowing4 ,about #ahie the word began to pass from mouth to mouth that probably nearly all the lands in the great arid and semiarid sections of the ,united ,states could be made to produce profitable crops without irrigation4 ,at first it was merely a whisper2 then it was talked aloud1 and before long became the great topic of conversation among the thousands who love the ,west and wish for its development4 ,soon it became a ,national subject of discussion4 ,immediately after the close of the nineteenth century the new awakening had been accomplished and dry-farming was moving onward to conquer the waste places of the earth4 ,h4 ,w4 ,campbell ,the history of the new awakening in dry-farming cannot well be written without a brief account of the work of ,h4 ,w4 ,campbell who1 in the public mind1 has become intimately identified with the dry-farm movement4 ,h4 ,w4 ,campbell came from ,vermont to northern ,south ,dakota in #ahgi1 where in #ahhb he harvested a banner crop1--twelve thousand bushels of wheat from three hundred acres4 ,in #ahhc1 on the same farm he failed completely4 ,this experience led him to a study of the conditions under which wheat and other crops may be produced in the ,great ,plains area4 ,a natural love for investigation and a dogged persistence have led him to give his life to a study of the agricultural problems of the ,great ,plains area4 ,he admits that his direct inspiration came from the work of ,jethro ,tull1 who labored two hundred years ago1 and his disciples4 ,he conceived early the idea that if the soil were packed near the bottom of the plow furrow1 the moisture would be retained better and greater crop certainty would result4 ,for this purpose the first subsurface packer was invented in #ahhe4 ,later1 about #ahie1 when his ideas had crystallized into theories1 he appeared as the publisher of ,campbell's ,soil ,culture and ,farm ,journal4 ,one page of each issue was devoted to a succinct statement of the ,campbell ,method4 ,it was in #ahih that the doctrine of summer tillage was begun to be investigated by him4 ,in view of the crop failures of the early '#ij's and the gradual dry-farm awakening of the later '#ij's1 ,campbell's work was received with much interest4 ,he soon became identified with the efforts of the railroads to maintain demonstration farms for the benefit of intending settlers4 ,while ,campbell has long been in the service of the railroads of the semiarid region1 yet it should be said in all fairness that the railroads and ,mr4 ,campbell have had for their primary object the determination of methods whereby the farmers could be made sure of successful crops4 ,mr4 ,campbell's doctrines of soil culture1 based on his accumulated experience1 are presented in ,campbell's ,soil ,culture ,manual1 the first edition of which appeared about #aijd and the latest edition1 considerably extended1 was published in #aijg4 ,the #aijg manual is the latest official word by ,mr4 ,campbell on the principles and methods of the ,campbell system4 ,the essential features of the system may be summarized as follows3 ,the storage of water in the soil is imperative for the production of crops in dry years4 ,this may be accomplished by proper tillage4 ,disk the land immediately after harvest2 follow as soon as possible with the plow2 follow the plow with the subsurface packer2 and follow the packer with the smoothing harrow4 ,disk the land again as early as possible in the spring and stir the soil deeply and carefully after every rain4 ,sow thinly in the fall with a drill4 ,if the grain is too thick in the spring1 harrow it out4 ,to make sure of a crop1 the land should be summer tilled1 which means that clean summer fallow should be practiced every other year1 or as often as may be necessary4 ,these methods1 with the exception of the subsurface packing1 are sound and in harmony with the experience of the great dry-farm sections and with the principles that are being developed by scientific investigation4 ,the ,campbell system as it stands to-day is not the system first advocated by him4 ,for instance1 in the beginning of his work he advocated sowing grain in ,april and in rows so far apart that spring tooth harrows could be used for cultivating between the rows4 ,this method1 though successful in conserving moisture1 is too expensive and is therefore superseded by the present methods4 ,moreover1 his farm paper of #ahif1 containing a full statement of the ,campbell method1 makes absolutely no mention of summer tillage1 which is now the very keystone of the system4 ,these and other facts make it evident that ,mr4 ,campbell has very properly modified his methods to harmonize with the best experience1 but also invalidate the claim that he is the author of the dry-farm system4 ,a weakness of the ,campbell system is the continual insistence upon the use of the subsurface packer4 ,as has already been shown1 subsurface packing is of questionable value for successful crop production1 and if valuable1 the results may be much more easily and successfully obtained by the use of the disk and harrow and other similar implements now on the market4 ,perhaps the one great weakness in the work of ,campbell is that he has not explained the principles underlying his practices4 ,his publications only hint at the reasons4 ,h4 ,w4 ,campbell1 however1 has done much to popularize the subject of dry-farming and to prepare the way for others4 ,his persistence in his work of gathering facts1 writing1 and speaking has done much to awaken interest in dry-farming4 ,he has been as a voice in the wilderness who has done much to make possible the later and more systematic study of dry-farming4 ,high honor should be shown him for his faith in the semiarid region1 for his keen observation1 and his persistence in the face of difficulties4 ,he is justly entitled to be ranked as one of the great workers in behalf of the reclamation1 without irrigation1 of the rainless sections of the world4 ,the experiment stations ,the brave pioneers who fought the relentless dryness of the ,great ,american ,desert from the memorable entrance of the ,mormon pioneers into the valley of the ,great ,salt ,lake in #ahdg were not the only ones engaged in preparing the way for the present day of great agricultural endeavor4 ,other1 though perhaps more indirect1 forces were also at work for the future development of the semiarid section4 ,the ,morrill ,bill of #ahfb1 making it possible for agricultural colleges to be created in the various states and territories1 indicated the beginning of a public feeling that modern methods should be applied to the work of the farm4 ,the passage in #ahhg of the ,hatch ,act1 creating agricultural experiment stations in all of the states and territories1 finally initiated a new agricultural era in the ,united ,states4 ,with the passage of this bill1 stations for the application of modern science to crop production were for the first time authorized in the regions of limited rainfall1 with the exception of the station connected with the ,university of ,california1 where ,hilgard from #ahgb had been laboring in the face of great difficulties upon the agricultural problems of the state of ,california4 ,during the first few years of their existence1 the stations were busy finding men and problems4 ,the problems nearest at hand were those that had been attacked by the older stations founded under an abundant rainfall and which could not be of vital interest to arid countries4 ,the western stations soon began to attack their more immediate problems1 and it was not long before the question of producing crops without irrigation on the great unirrigated stretches of the ,west was discussed among the station staffs and plans were projected for a study of the methods of conquering the desert4 ,the ,colorado ,station was the first to declare its good intentions in the matter of dry-farming1 by inaugurating definite experiments4 ,by the action of the ,state ,legislature of #ahic1 during the time of the great drouth1 a substation was established at ,cheyenne ,wells1 near the west border of the state and within the foothills of the ,great ,plains area4 ,from the summer of #ahid until #aijj experiments were conducted on this farm4 ,the experiments were not based upon any definite theory of reclamation1 and consequently the work consisted largely of the comparison of varieties1 when soil treatment was the all-important problem to be investigated4 ,true in #ahih1 a trial of the ,campbell method was undertaken4 ,by the time this ,station had passed its pioneer period and was ready to enter upon more systematic investigation1 it was closed4 ,bulletin #ei of the ,colorado ,station1 published in #aijj by ,j4 ,e4 ,payne1 gives a summary of observations made on the ,cheyenne ,wells substation during seven years4 ,this bulletin is the first to deal primarily with the experimental work relating to dry-farming in the ,great ,plains area4 ,it does not propose or outline any system of reclamation4 ,several later publications of the ,colorado ,station deal with the problems peculiar to the ,great ,plains4 ,at the ,utah ,station the possible conquest of the sagebrush deserts of the ,great ,basin without irrigation was a topic of common conversation during the years #ahid and #ahie4 ,in #ahif plans were presented for experiments on the principles of dry-farming4 ,four years later these plans were carried into effect4 ,in the summer of #aija1 the author and ,l4 ,a4 ,merrill investigated carefully the practices of the dry-farms of the state4 ,on the basis of these observations and by the use of the established principles of the relation of water to soils and plants1 a theory of dry-farming was worked out which was published in ,bulletin #ge of the ,utah ,station in ,january1 #aijb4 ,this is probably the first systematic presentation of the principles of dry-farming4 ,a year later the ,legislature of the state of ,utah made provision for the establishment and maintenance of six experimental dry-farms to investigate in different parts of the state the possibility of dry-farming and the principles underlying the art4 ,these stations1 which are still maintained1 have done much to stimulate the growth of dry-farming in ,utah4 ,the credit of first undertaking and maintaining systematic experimental work in behalf of dry-farming should be assigned to the state of ,utah4 ,since dry-farm experiments began in ,utah in #aija1 the subject has been a leading one in the ,station and the ,college4 ,a large number of men trained at the ,utah ,station and ,college have gone out as investigators of dry-farming under state and ,federal direction4 ,the other experiment stations in the arid and semi-arid region were not slow to take up the work for their respective states4 ,fortier and ,linfield1 who had spent a number of years in ,utah and had become somewhat familiar with the dry-farm practices of that state1 initiated dry-farm investigations in ,montana1 which have been prosecuted with great vigor since that time4 ,vernon1 under the direction of ,foster1 who had spent four years in ,utah as ,director of the ,utah ,station1 initiated the work in ,new ,mexico4 ,in ,wyoming the experimental study of dry-farm lands began by the private enterprise of ,h4 ,b4 ,henderson and his associates4 ,later ,v4 ,t4 ,cooke was placed in charge of the work under state auspices1 and the demonstration of the feasibility of dry-farming in ,wyoming has been going on since about #aijg4 ,idaho has also recently undertaken dry-farm investigations4 ,nevada1 once looked upon as the only state in the ,union incapable of producing crops without irrigation1 is demonstrating by means of state appropriations that large areas there are suitable for dry-farming4 ,in ,arizona1 small tracts in this sun-baked state are shown to be suitable for dry-farm lands4 ,the ,washington ,station is investigating the problems of dry-farming peculiar to the ,columbia ,basin1 and the staff of the ,oregon ,station is carrying on similar work4 ,in ,nebraska1 some very important experiments dry-farming are being conducted4 ,in ,north ,dakota there were in #aiaj twenty-one dry-farm demonstration farms4 ,in ,south ,dakota1 ,kansas1 and ,texas1 provisions are similarly made for dry-farm investigations4 ,in fact1 up and down the ,great ,plains area there are stations maintained by the state or ,federal government for the purpose of determining the methods under which crops can be produced without irrigation4 ,at the head of the ,great ,plains area at ,saskatchewan one of the oldest dry-farm stations in ,america is located 7since #ahhh74 ,in ,russia several stations are devoted very largely to the problems of dry land agriculture4 ,to be especially mentioned for the excellence of the work done are the stations at ,odessa1 ,cherson1 and ,poltava4 ,this last-named ,station has been established since #ahhf4 ,in connection with the work done by the experiment stations should be mentioned the assistance given by the railroads4 ,many of the railroads owning land along their respective lines are greatly benefited in the selling of these lands by a knowledge of the methods whereby the lands may be made productive4 ,however1 the railroads depend chiefly for their success upon the increased prosperity of the population along their lines and for the purpose of assisting the settlers in the arid ,west considerable sums have been expended by the railroads in cooperation with the stations for the gathering of information of value in the reclamation of arid lands without irrigation4 ,it is through the efforts of the experiment stations that the knowledge of the day has been reduced to a science of dry-farming4 ,every student of the subject admits that much is yet to be learned before the last word has been said concerning the methods of dry-farming in reclaiming the waste places of the earth4 ,the future of dry-farming rests almost wholly upon the energy and intelligence with which the experiment stations in this and other countries of the world shall attack the special problems connected with this branch of agriculture4 ,the ,united ,states ,department of ,agriculture ,the ,commissioner of ,agriculture of the ,united ,states was given a secretaryship in the ,president's ,cabinet in #ahhi4 ,with this added dignity1 new life was given to the department4 ,under the direction of ,j4 ,sterling ,morton preliminary work of great importance was done4 ,upon the appointment of ,james ,wilson as ,secretary of ,agriculture1 the department fairly leaped into a fullness of organization for the investigation of the agricultural problems of the country4 ,from the beginning of its new growth the ,united ,states ,department of ,agriculture has given some thought to the special problems of the semiarid region1 especially that part within the ,great ,plains4 ,little consideration was at first given to the far ,west4 ,the first method adopted to assist the farmers of the plains was to find plants with drouth resistant properties4 ,for that purpose explorers were sent over the earth1 who returned with great numbers of new plants or varieties of old plants1 some of which1 such as the durum wheats1 have shown themselves of great value in ,american agriculture4 ,the ,bureaus of ,plant ,industry1 ,soils1 ,weather1 and ,chemistry have all from the first given considerable attention to the problems of the arid region4 ,the ,weather ,bureau1 long established and with perfected methods1 has been invaluable in guiding investigators into regions where experiments could be undertaken with some hope of success4 ,the ,department of ,agriculture was somewhat slow1 however1 in recognizing dry-farming as a system of agriculture requiring special investigation4 ,the final recognition of the subject came with the appointment1 in #aije1 of ,chilcott as expert in charge of dry-land investigations4 ,at the present time an office of dry-land investigations has been established under the ,bureau of ,plant ,industry1 which cooperates with a number of other divisions of the ,bureau in the investigation of the conditions and methods of dry-farming4 ,a large number of stations are maintained by the ,department over the arid and semiarid area for the purpose of studying special problems1 many of which are maintained in connection with the state experiment stations4 ,nearly all the departmental experts engaged in dry-farm investigation have been drawn from the service of the state stations and in these stations had received their special training for their work4 ,the ,united ,states ,department of ,agriculture has chosen to adopt a strong conservatism in the matter of dry-farming4 ,it may be wise for the ,department1 as the official head of the agricultural interests of the country1 to use extreme care in advocating the settlement of a region in which1 in the past1 farmers had failed to make a living1 yet this conservatism has tended to hinder the advancement of dry-farming and has placed the departmental investigations of dry-farming in point of time behind the pioneer investigations of the subject4 ,the ,dry-farming ,congress ,as the great dry-farm wave swept over the country1 the need was felt on the part of experts and laymen of some means whereby dry-farm ideas from all parts of the country could be exchanged4 ,private individuals by the thousands and numerous state and governmental stations were working separately and seldom had a chance of comparing notes and discussing problems4 ,a need was felt for some central dry-farm organization4 ,an attempt to fill this need was made by the people of ,denver1 ,colorado1 when ,governor ,jesse ,f4 ,mc,donald of ,colorado issued a call for the first ,dry-farming ,congress to be held in ,denver1 ,january #bd1 #be1 and #bf1 #aijg4 ,these dates were those of the annual stock show which had become a permanent institution of ,denver and1 in fact1 some of those who were instrumental in the calling of the ,dry-farming ,congress thought that it was a good scheme to bring more people to the stock show4 ,to the surprise of many the ,dry-farming ,congress became the leading feature of the week4 ,representatives were present from practically all the states interested in dry-farming and from some of the humid states4 ,utah1 the pioneer dry-farm state1 was represented by a delegation second in size only to that of ,colorado1 where the ,congress was held4 ,the call for this ,congress was inspired1 in part at least1 by real estate men1 who saw in the dry-farm movement an opportunity to relieve themselves of large areas of cheap land at fairly good prices4 ,the ,congress proved1 however1 to be a businesslike meeting which took hold of the questions in earnest1 and from the very first made it clear that the real estate agent was not a welcome member unless he came with perfectly honest methods4 ,the second ,dry-farming ,congress was held ,january #bb to #be1 #aijh1 in ,salt ,lake ,city1 ,utah1 under the presidency of ,fisher ,harris4 ,it was even better attended than the first4 ,the proceedings show that it was a ,congress at which the dry-farm experts of the country stated their findings4 ,a large exhibit of dry-farm products was held in connection with this ,congress1 where ocular demonstrations of the possibility of dry-farming were given any doubting ,thomas4 ,the third ,dry-farming ,congress was held ,february #bc to #be1 #aiji1 at ,cheyenne1 ,wyoming1 under the presidency of ,governor ,w4 ,w4 ,brooks of ,wyoming4 ,an unusually severe snowstorm preceded the ,congress1 which prevented many from attending1 yet the number present exceeded that at any of the preceding ,congresses4 ,this ,congress was made notable by the number of foreign delegates who had been sent by their respective countries to investigate the methods pursued in ,america for the reclamation of the arid districts4 ,among these delegates were representatives from ,canada1 ,australia1 ,the ,transvaal1 ,brazil1 and ,russia4 ,the fourth ,congress was held ,october #bf to #bh1 #aiji1 in ,billings1 ,montana1 under the presidency of ,governor ,edwin ,l4 ,morris of ,montana4 ,the uncertain weather of the winter months had led the previous ,congress to adopt a time in the autumn as the date of the annual meeting4 ,this ,congress became a session at which many of the principles discussed during the three preceding ,congresses were crystallized into definite statements and agreed upon by workers from various parts of the country4 ,a number of foreign representatives were present again4 ,the problems of the ,northwest and ,canada were given special attention4 ,the attendance was larger than at any of the preceding ,congresses4 ,the fifth ,congress will be held under the presidency of ,hon4 ,f4 ,w4 ,mondell of ,wyoming at ,spokane1 ,washington1 during ,october1 #aiaj4 ,it promises to exceed any preceding ,congress in attendance and interest4 ,the ,dry-farming ,congress has made itself one of the most important factors in the development of methods for the reclamation of the desert4 ,its published reports are the most valuable publications dealing with dry-land agriculture4 ,only simple justice is done when it is stated that the success of the ,dry-farming ,congress is due in a large measure to the untiring and intelligent efforts of ,john ,t4 ,burns1 who is the permanent secretary of the ,congress1 and who was a member of the first executive committee4 ,nearly all the arid and semiarid states have organized state dry-farming congresses4 ,the first of these was the ,utah ,dry-farming ,congress1 organized about two months after the first ,congress held in ,denver4 ,the president is ,l4 ,a4 ,merrill1 one of the pioneer dry-farm investigators of the ,rockies4 ,jethro ,tull 7see frontispiece7 ,a sketch of the history of dry-farming would be incomplete without a mention of the life and work of ,jethro ,tull4 ,the agricultural doctrines of this man1 interpreted in the light of modern science1 are those which underlie modern dry-farming4 ,jethro ,tull was born in ,berkshire1 ,england1 #afgd1 and died in #agda4 ,he was a lawyer by profession1 but his health was so poor that he could not practice his profession and therefore spent most of his life in the seclusion of a quiet farm4 ,his life work was done in the face of great physical sufferings4 ,in spite of physical infirmities1 he produced a system of agriculture which1 viewed in the light of our modern knowledge1 is little short of marvelous4 ,the chief inspiration of his system came from a visit paid to south of ,france1 where he observed near ,frontignan and ,setts1 ,languedoc that the vineyards were carefully plowed and tilled in order to produce the largest crops of the best grapes4 ,upon the basis of this observation he instituted experiments upon his own farm and finally developed his system1 which may be summarized as follows3 ,the amount of seed to be used should be proportional to the condition of the land1 especially to the moisture that is in it4 ,to make the germination certain1 the seed should be sown by drill methods4 ,tull1 as has already been observed1 was the inventor of the seed drill which is now a feature of all modern agriculture4 ,plowing should be done deeply and frequently2 two plowings for one crop would do no injury and frequently would result in an increased yield4 ,finally1 as the most important principle of the system1 the soil should be cultivated continually1 the argument being that by continuous cultivation the fertility of the soil would be increased1 the water would be conserved1 and as the soil became more fertile less water would be used4 ,to accomplish such cultivation1 all crops should be placed in rows rather far apart1 so far indeed that a horse carrying a cultivator could walk between them4 ,the horse-hoeing idea of the system became fundamental and gave the name to his famous book1 ,the ,horse ,hoeing ,husbandry1 by ,jethro ,tull1 published in parts from #agca to #agda4 ,tull held that the soil between the rows was essentially being fallowed and that the next year the seed could be planted between the rows of the preceding year and in that way the fertility could be maintained almost indefinitely4 ,if this method were not followed1 half of the soil could lie fallow every other year and be subjected to continuous cultivation4 ,weeds consume water and fertility and1 therefore1 fallowing and all the culture must be perfectly clean4 ,to maintain fertility a rotation of crops should be practiced4 ,wheat should be the main grain crop2 turnips the root crop2 and alfalfa a very desirable crop4 ,it may be observed that these teachings are sound and in harmony with the best knowledge of to-day and that they are the very practices which are now being advocated in all dry-farm sections4 ,this is doubly curious because ,tull lived in a humid country4 ,however1 it may be mentioned that his farm consisted of a very poor chalk soil1 so that the conditions under which he labored were more nearly those of an arid country than could ordinarily be found in a country of abundant rainfall4 ,while the practices of ,jethro ,tull were in themselves very good and in general can be adopted to-day1 yet his interpretation of the principles involved was wrong4 ,in view of the limited knowledge of his day1 this was only to be expected4 ,for instance1 he believed so thoroughly in the value of cultivation of the soil1 that he thought it would take the place of all other methods of maintaining soil-fertility4 ,in fact1 he declared distinctly that tillage is manure1 which we are very certain at this time is fallacious4 ,jethro ,tull is one of the great investigators of the world4 ,in recognition of the fact that1 though living two hundred years ago in a humid country1 he was able to develop the fundamental practices of soil culture now used in dry-farming1 the honor has been done his memory of placing his portrait as the frontispiece of this volume4 ,,chapter ,,xx ,,dry-,,farming ,,in ,a ,,nutshell ,locate the dry-farm in a section with an annual precipitation of more than ten inches and1 if possible1 with small wind movement4 ,one man with four horses and plenty of machinery cannot handle more than from #afj to #bjj acres4 ,farm fewer acres and farm them better4 ,select a clay loam soil4 ,other soils may be equally productive1 but are cultivated properly with somewhat more difficulty4 ,make sure1 with the help of the soil auger1 that the soil is of uniform structure to a depth of at least eight feet4 ,if streaks of loose gravel or layers of hardpan are near the surface1 water may be lost to the plant roots4 ,after the land has been cleared and broken let it lie fallow with clean cultivation1 for one year4 ,the increase in the first and later crops will pay for the waiting4 ,always plow the land early in the fall1 unless abundant experience shows that fall plowing is an unwise practice in the locality4 ,always plow deeply unless the subsoil is infertile1 in which case plow a little deeper each year until eight or ten inches are reached ,plow at least once for each crop4 ,spring plowing2 if practiced1 should be done as early as possible in the season4 ,follow the plow1 whether in the fall or spring1 with the disk and that with the smoothing harrow1 if crops are to be sown soon afterward4 ,if the land plowed in the fall is to lie fallow for the winter1 leave it in the rough condition1 except in localities where there is little or no snow and the winter temperature is high4 ,always disk the land in early spring1 to prevent evaporation4 ,follow the disk with the harrow4 ,harrow1 or in some other way stir the surface of the soil after every rain4 ,if crops are on the land1 harrow as long as the plants will stand it4 ,if hoed crops1 like corn or potatoes1 are grown1 use the cultivator throughout the season4 ,a deep mulch or dry soil should cover the land as far as possible throughout the summer4 ,immediately after harvest disk the soil thoroughly4 ,destroy weeds as soon as they show themselves4 ,a weedy dry-farm is doomed to failure4 ,give the land an occasional rest1 that is1 a clean summer fallow4 ,under a rainfall of less than fifteen inches1 the land should be summer fallowed every other year2 under an annual rainfall of fifteen to twenty inches1 the summer fallow should occur every third or fourth year4 ,where the rainfall comes chiefly in the summer1 the summer fallow is less important in ordinary years than where the summers are dry and the winters wet4 ,only an absolutely clean fallow should be permitted4 ,the fertility of dry-farm soils must be maintained4 ,return the manure2 plow under green leguminous crops occasionally and practice rotation4 ,on fertile soils plants mature with the least water4 ,sow only by the drill method4 ,wherever possible use fall varieties of crops4 ,plant deeply--three or four inches for grain4 ,plant early in the fall1 especially if the land has been summer fallowed4 ,use only about one half as much seed as is recommended for humid-farming4 ,all the ordinary crops may be grown by dry-farming4 ,secure seed that has been raised on dry-farms4 ,look out for new varieties1 especially adapted for dry-farming1 that may be brought in4 ,wheat is king in dry-farming2 corn a close second4 ,turkey wheat promises the best4 ,stock the dry-farm with the best modern machinery4 ,dry-farming is possible only because of the modern plow1 the disk1 the drill seeder1 the harvester1 the header1 and the thresher4 ,make a home on the dry-farm4 ,store the flood waters in a reservoir2 or pump the underground waters1 for irrigating the family garden4 ,set out trees1 plant flowers1 and keep some live stock4 ,learn to understand the reasons back of the principles of dry-farming1 apply the knowledge vigorously1 and the crop cannot fail4 ,always farm as if a year of drouth were coming4 ,man1 by his intelligence1 compels the laws of nature to do his bidding1 and thus he achieves joy4 ,and ,god blessed them--and ,god said unto them1 ,be fruitful and multiply and replenish the earth1 and subdue it4 ,,chapter ,,xix ,,the ,,year ,,of ,,drouth ,the ,shadow of the ,year of ,drouth still obscures the hope of many a dry-farmer4 ,from the magazine page and the public platform the prophet of evil1 thinking himself a friend of humanity1 solemnly warns against the arid region and dry-farming1 for the year of drouth1 he says1 is sure to come again and then will be repeated the disasters of #ahic-ahie4 ,beware of the year of drouth4 ,even successful dry-farmers who have obtained good crops every year for a generation or more are half led to expect a dry year or one so dry that crops will fail in spite of all human effort4 ,the question is continually asked1 ,can crop yields reasonably be expected every year1 through a succession of dry years1 under semiarid conditions1 if the best methods of dry-farming be practiced8 ,in answering this question1 it may be said at the very beginning1 that when the year of drouth is mentioned in connection with dry-farming1 sad reference is always made to the experience on the ,great ,plains in the early years of the '#ij's4 ,now the fact of the matter is1 that while the years of #ahic1ahid1 and #ahie were dry years1 the only complete failure came in #ahid4 ,in spite of the improper methods practiced by the settlers1 the willing soil failed to yield a crop only one year4 ,moreover1 it should not be forgotten that hundreds of farmers in the driest section during this dry period1 who instinctively or otherwise farmed more nearly right1 obtained good crops even in #ahid4 ,the simple practice of summer fallowing1 had it been practiced the year before1 would have insured satisfactory crops in the driest year4 ,further1 the settlers who did not take to their heels upon the arrival of the dry year are still living in large numbers on their homesteads and in numerous instances have accumulated comfortable fortunes from the land which has been held up so long as a warning against settlement beyond a humid climate4 ,the failure of #ahid was due as much to a lack of proper agricultural information and practice as to the occurrence of a dry year4 ,next1 the statement is carelessly made that the recent success in dry-farming is due to the fact that we are now living in a cycle of wet years1 but that as soon as the cycle of dry years strikes the country dry-farming will vanish as a dismal failure4 ,then1 again1 the theory is proposed that the climate is permanently changing toward wetness or dryness and the past has no meaning in reading the riddle of the future4 ,it is doubtless true that no man may safely predict the weather for future generations2 yet1 so far as human knowledge goes1 there is no perceptible average change in the climate from period to period within historical time2 neither are there protracted dry periods followed by protracted wet periods4 ,the fact is1 dry and wet years alternate4 ,a succession of somewhat wet years may alternate with a succession of somewhat dry years1 but the average precipitation from decade to decade is very nearly the same4 ,true1 there will always be a dry year1 that is1 the driest year of a series of years1 and this is the supposedly fearful and fateful year of drouth4 ,the business of the dry-farmer is always to farm so as to be prepared for this driest year whenever it comes4 ,if this be done1 the farmer will always have a crop3 in the wet years his crop will be large2 in the driest year it will be sufficient to sustain him4 ,so persistent is the half-expressed fear that this driest year makes it impossible to rely upon dry-farming as a permanent system of agriculture that a search has been made for reliable long records of the production of crops in arid and semiarid regions4 ,public statements have been made by many perfectly reliable men to the effect that crops have been produced in diverse sections over long periods of years1 some as long as thirty-five or forty year's1 without one failure having occurred4 ,most of these statements1 however1 have been general in their nature and not accompanied by the exact yields from year to year4 ,only three satisfactory records have been found in a somewhat careful search4 ,others no doubt exist4 ,the first record was made by ,senator ,j4 ,g4 ,m4 ,barnes of ,kaysville1 ,utah4 ,kaysville is located in the ,great ,salt ,lake ,valley1 about fifteen miles north of ,salt ,lake ,city4 ,the climate is semiarid2 the precipitation comes mainly in the winter and early spring2 the summers are dry1 and the evaporation is large4 ,senator ,barnes purchased ninety acres of land in the spring of #ahhg and had it farmed under his own supervision until #aijf4 ,he is engaged in commercial enterprises and did not1 himself1 do any of the work on the farm1 but employed men to do the necessary labor4 ,however1 he kept a close supervision of the farm and decided upon the practices which should be followed4 ,from seventy-eight to eighty-nine acres were harvested for each crop1 with the exception of #aijb1 when all but about twenty acres was fired by sparks from the passing railroad train4 ,the plowing1 harrowing1 and weeding were done very carefully4 ,the complete record of the ,barnes dry-farm from #ahhg to #aije is shown in the table on the following page4 ,record of the ,barnes ,dry-farm1 ,salt ,lake ,valley1 ,utah 7#ij acres7 ,year ,annual ,yield ,when ,when ,rainfall per ,acre ,plowed ,sown 7,inches7 7,bu47 #ahhg #aa4ff --- ,may ,sept4 #ahhh #ac4fb ,failure ,may ,sept4 #ahhi #ah4df #bb4e --- ,volunteer #ahij #aj4ch #ae4e --- --- #ahia #ae4ib ,fallow ,may ,fall #ahib #ad4jh #ai4c --- --- #ahic #ag4ce ,fallow ,may ,fall #ahid #ae4bg #bf4j --- --- #ahie #aa4ie ,fallow ,may ,aug4 #ahif #ah4db #bb4j --- --- #ahig #af4gd ,fallow ,spring ,fall #ahih #af4ji #bf4j --- --- #ahii #ag4eg ,fallow ,may ,fall #aijj #aa4ec #bc4e --- --- #aija #af4jh ,fallow ,spring ,fall #aijb #aa4da #bh4i ,sept4 ,fall #aijc #ad4fb #ab4e --- --- #aijd #af4ca ,fallow ,spring ,fall #aije #ad4bc #be4h --- --- ,about four acres were sown on stubble4 ,the first plowing was given the farm in ,may of #ahhg1 and1 with the exception of #aijb1 the land was invariably plowed in the spring4 ,with fall plowing the yields would undoubtedly have been better4 ,the first sowing was made in the fall of #ahhg1 and fall grain was grown during the whole period of observation4 ,the seed sown in the fall of #ahhg came up well1 but was winter-killed4 ,this is ascribed by ,senator ,barnes to the very dry winter1 though it is probable that the soil was not sufficiently well stored with moisture to carry the crop through4 ,the farm was plowed again in the spring of #ahhh1 and another crop sown in ,september of the same year4 ,in the summer of #ahhi1 #bb-a_/b bushels of wheat were harvested to the acre4 ,encouraged by this good crop ,mr4 ,barnes allowed a volunteer crop to grow that fall and the next summer harvested as a result #ae-a_/b bushels of wheat to the acre4 ,the table shows that only one crop smaller than this was harvested during the whole period of nineteen years1 namely1 in #aijc1 when the same thing was done1 and one crop was made to follow another without an intervening fallow period4 ,this observation is an evidence in favor of clean summer fallowing4 ,the largest crop obtained1 #bh4i bushels per acre in #aijb1 was gathered in a year when the next to the lowest rainfall of the whole period occurred1 namely1 #aa4da inches4 ,the precipitation varied during the nineteen years from #aj4cc inches to #ah4df inches4 ,the variation in yield per acre was considerably less than this1 not counting the two crops that were grown immediately after another crop4 ,all in all1 the unique record of the ,barnes dry-farm shows that through a period of nineteen years1 including dry and comparatively wet years1 there was absolutely no sign of failure1 except in the first year1 when probably the soil had not been put in proper condition to support crops4 ,in passing it maybe mentioned that1 according to the records furnished by ,senator ,barnes1 the total cost of operating the farm during the nineteen years was #dhhg4fi2 the total income was #aj1add4hc4 ,the difference1 #ebeg4ad1 is a very fair profit on the investment of #ahjj--the original cost of the farm4 ,the ,indian ,head farm ,an equally instructive record is furnished by the experimental farm located at ,indian ,head in ,saskatchewan1 ,canada1 in the northern part of the ,great ,plains area4 ,according to ,alway1 the country is in appearance very much like western ,nebraska and ,kansas2 the climate is distinctly arid1 and the precipitation comes mainly in the spring and summer4 ,it is the only experimental dry-farm in the ,great ,plains area with records that go back before the dry years of the early '#ij's4 ,in #ahhb the soil of this farm was broken1 and it was farmed continuously until #ahhh1 when it was made an experimental farm under government supervision4 ,the following table shows the yields obtained from the year #ahia1 when the precipitation records were first kept1 to #aiji3-- ,,record ,,of ,,indian ,,head ,,experimental ,,farm ,,and ,,motherwell',s ,,farm1 ,,saskatchewan1 ,,canada ,year ,annual ,bushels of ,wheat ,bushels of ,wheat ,bushels of ,wheat ,rainfall per ,acre per ,acre per ,acre 7,inches7 ,experimental ,experimental ,motherwell's ,farm ,farm--,fallow ,farm--,stubble #ahia #ad4jc #ce #cb #cj #ahib #f4ib #bh #ba #bh #ahic #aj4aa #ce #bb #cd #ahid #c4ij #ag #i #bd #ahie #ab4bh #da #bb #bf #ahif #aj4ei #ci #bi #ca #ahig #ad4fb #cc #bf #ce #ahih #ah4jc #cb --- #bg #ahii #i4dd #cc --- #cc #aijj #aa4gd #ag #e #be #aija #bj4bb #di #ch #ea #aijb #aj4gc #ch #bb #bh #aijc #ae4ee #ce #ae #ca #aijd #aa4if #dj #bi #ce #aije #ai4ag #db #ah #cf #aijf #ac4ba #bf #ac #ch #aijg #ae4jc #ah #ah #ae #aijh #ac4ag #bi #ad #af #aiji #ac4if #bh #ae #bc ,snowfall not included4 ,this has varied from #b4c to #a4c inches of water4 ,the annual rainfall shown in the second column does not include the water which fell in the form of snow4 ,according to the records at hand1 the annual snow fall varied from #b4c to #a4c inches of water1 which should be added to the rainfall given in the table4 ,even with this addition the rainfall shows the district to be of a distinctly semiarid character4 ,it will be observed that the precipitation varied from #c4i to #bj4bb inches1 and that during the early '#ij's several rather dry years occurred4 ,in spite of this large variation good crops have been obtained during the whole period of nineteen years4 ,not one failure is recorded4 ,the lowest yield of #ag bushels per acre came during the very dry year of #ahid and during the somewhat dry year of #aijj4 ,some of the largest yields were obtained in seasons when the rainfall was only near the average4 ,as a record showing that the year of drouth need not be feared when dry-farming is done right1 this table is of very high interest4 ,it may be noted1 incidentally1 that throughout the whole period wheat following a fallow always yielded higher than wheat following the stubble4 ,for the nineteen years1 the difference was as #cb4d bushels is to #bj4e bushels4 ,the ,mother well farm ,in the last column of the table are shown the annual yields of wheat obtained on the farm of ,commissioner ,motherwell of the province of ,saskatchewan4 ,this private farm is located some twenty-five miles away from ,indian ,head1 and the rainfall records of the experimental farm are1 therefore1 only approximately accurate for the ,motherwell farm4 ,the results on this farm may well be compared to the ,barnes results of ,utah1 since they were obtained on a private farm4 ,during the period of nineteen years good crops were invariably obtained2 even during the very dry year of #ahid1 a yield of twenty-four bushels of wheat to the acre was obtained4 ,curiously enough1 the lowest yields of fifteen and sixteen bushels to the acre were obtained in #aijg and #aijh when the precipitation was fairly good1 and must be ascribed to some other factor than that of precipitation4 ,the record of this farm shows conclusively that with proper farming there is no need to fear the year of drouth4 ,the ,utah drouth of #aiaj ,during the year of #aiaj only #b4g inches of rain fell in ,salt ,lake ,city from ,march #a to the ,july harvest1 and all of this in ,march1 as against #g4ah inches during the same period the preceding year4 ,in other parts of the state much less rain fell2 in fact1 in the southern part of the state the last rain fell during the last week of ,december1 #aiji4 ,the drouth remained unbroken until long after the wheat harvests4 ,great fear was expressed that the dry-farms could not survive so protracted a period of drouth4 ,agents1 sent out over the various dry-farm districts1 reported late in ,june that wherever clean summer fallowing had been practiced the crops were in excellent condition2 but that wherever careless methods had been practiced1 the crops were poor or killed4 ,the reports of the harvest in ,july of #aiaj showed that fully #he per cent of an average crop was obtained in spite of the protracted drouth wherever the soil came into the spring well stored with moisture1 and in many instances full crops were obtained4 ,over the whole of the dry-farm territory of the ,united ,states similar conditions of drouth occurred4 ,after the harvest1 however1 every state reported that the crops were well up to the average wherever correct methods of culture had been employed4 ,these well-authenticated records from true semi-arid districts1 covering the two chief types of winter and summer precipitation1 prove that the year of drouth1 or the driest year in a twenty-year period1 does not disturb agricultural conditions seriously in localities where the average annual precipitation is not too low1 and where proper cultural methods arc followed4 ,that dry-farming is a system of agricultural practice which requires the application of high skill and intelligence is admitted2 that it is precarious is denied4 ,the year of drouth is ordinarily the year in which the man failed to do properly his share of the work4 ,,chapter ,,xviii ,,the ,,present ,,status ,,of ,,dry-,,farming ,it is difficult to obtain a correct view of the present status of dry-farming1 first1 because dry-farm surveys are only beginning to be made and1 secondly1 because the area under dry-farm cultivation is increasing daily by leaps and bounds4 ,all arid and semiarid parts of the world are reaching out after methods of soil culture whereby profitable crops may be produced without irrigation1 and the practice of dry-farming1 according to modern methods1 is now followed in many diverse countries4 ,the ,united ,states undoubtedly leads at present in the area actually under dry-farming1 but1 in view of the immense dry-farm districts in other parts of the world1 it is doubtful if the ,united ,states will always maintain its supremacy in dry-farm acreage4 ,the leadership in the development of a science of dry-farming will probably remain with the ,united ,states for years1 since the numerous experiment stations established for the study of the problems of farming without irrigation have their work well under way1 while1 with the exception of one or two stations in ,russia and ,canada1 no other countries have experiment stations for the study of dry-farming in full operation4 ,the reports of the ,dry-farming ,congress furnish practically the only general information as to the status of dry-farming in the states and territories of the ,united ,states and in the countries of the world4 ,california ,in the state of ,california dry-farming has been firmly established for more than a generation4 ,the chief crop of the ,california dry-farms is wheat1 though the other grains1 root crops1 and vegetables are also grown without irrigation under a comparatively small rainfall4 ,the chief dry-farm areas are found in the ,sacramento and the ,san ,joaquin valleys4 ,in the ,sacramento ,valley the precipitation is fairly large1 but in the ,san ,joaquin ,valley it is very small4 ,some of the most successful dry-farms of ,california have produced well for a long succession of years under a rainfall of ten inches and less4 ,california offers a splendid example of the great danger that besets all dry-farm sections4 ,for a generation wheat has been produced on the fertile ,californian soils without manuring of any kind4 ,as a consequence1 the fertility of the soils has been so far depleted that at present it is difficult to obtain paying crops without irrigation on soils that formerly yielded bountifully4 ,the living problem of the dry-farms in ,california is the restoration of the fertility which has been removed from the soils by unwise cropping4 ,all other dry-farm districts should take to heart this lesson1 for1 though crops may be produced on fertile soils for one1 two1 or even three generations without manuring1 yet the time will come when plant-food must be added to the soil in return for that which has been removed by the crops4 ,meanwhile1 ,california offers1 also1 an excellent example of the possibility of successful dry-farming through long periods and under varying climatic conditions4 ,in the ,golden ,state dry-farming is a fully established practice2 it has long since passed the experimental stage4 ,columbia ,river ,basin ,the ,columbia ,river ,basin includes the state of ,washington1 most of ,oregon1 the northern and central part of ,idaho1 western ,montana1 and extends into ,british ,columbia4 ,it includes the section often called the ,inland ,empire1 which alone covers some one hundred and fifty thousand square miles4 ,the chief dry-farm crop of this region is wheat2 in fact1 western ,washington or the ,palouse country is famous for its wheat-producing powers4 ,the other grains1 potatoes1 roots1 and vegetables are also grown without irrigation4 ,in the parts of this dry-farm district where the rainfall is the highest1 fruits of many kinds and of a high quality are grown without irrigation4 ,it is estimated that at least two million acres are being dry-farmed in this district4 ,dry-farming is fully established in the ,columbia ,river ,basin4 ,one farmer is reported to have raised in one year on his own farm two hundred and fifty thousand bushels of wheat4 ,in one section of the district where the rainfall for the last few years has been only about ten or eleven inches1 wheat has been produced successfully4 ,this corroborates the experience of ,california1 that wheat may really be grown in localities where the annual rainfall is not above ten inches4 ,the most modern methods of dry-farming are followed by the farmers of the ,columbia ,river ,basin1 but little attention has been given to soil-fertility1 since soils that have been farmed for a generation still appear to retain their high productive powers4 ,undoubtedly1 however1 in this district1 as in ,california1 the question of soil-fertility will be an important one in the near future4 ,this is one of the great dry-farm districts of the world4 ,the ,great ,basin ,the ,great ,basin includes ,nevada1 the western half of ,utah1 a small part of southern ,oregon and ,idaho1 and also a part of ,southern ,california4 ,it is a great interior basin with all its rivers draining into salt lakes or dry sinks4 ,in recent geological times the ,great ,basin was filled with water1 forming the great ,lake ,bonneville which drained into the ,columbia ,river4 ,in fact1 the ,great ,basin is made up of a series of great valleys1 with very level floors1 representing the old lake bottom4 ,on the bench lands are seen1 in many places1 the effects of the wave action of the ancient lake4 ,the chief dry-farm crop of this district is wheat1 but the other grains1 including corn1 are also produced successfully4 ,other crops have been tried with fair success1 but not on a commercial scale4 ,grapevines have been made to grow quite successfully without irrigation on the bench lands4 ,several small orchards bearing luscious fruit are growing on the deep soils of the ,great ,basin without the artificial application of water4 ,though the first dry-farming by modern peoples was probably practiced in the ,great ,basin1 yet the area at present under cultivation is not large1 possibly a little more than four hundred thousand acres4 ,dry-farming1 however1 is well established4 ,there are large areas1 especially in ,nevada1 that receive less than ten inches of rainfall annually1 and one of the leading problems before the dry-farmers of this district is the determination of the possibility of producing crops upon such lands without irrigation4 ,on the older dry-farms1 which have existed in some cases from forty to fifty years1 there are no signs of diminution of soil-fertility4 ,undoubtedly1 however1 even under the conditions of extremely high fertility prevailing in the ,great ,basin1 the time will soon come when the dry-farmer must make provision for restoring to the soil some of the fertility taken away by crops4 ,there are millions of acres in the ,great ,basin yet to be taken up and subjected to the will of the dry-farmer4 ,colorado and ,rio ,grande ,river ,basins ,the ,colorado and ,rio ,grande ,river ,basins include ,arizona and the western part of ,new ,mexico4 ,the chief dry-farm crops of this dry district are wheat1 corn1 and beans4 ,other crops have also been grown in small quantities and with some success4 ,the area suitable for dry-farming in this district has not yet been fully determined and1 therefore1 the ,arizona and ,new ,mexico stations are undertaking dry-farm surveys of their respective states4 ,in spite of the fact that ,arizona is generally looked upon as one of the driest states of the ,union1 dry-farming is making considerable headway there4 ,in ,new ,mexico1 five sixths of all the homestead applications during the last year were for dry-farm lands2 and1 in fact1 there are several prosperous communities in ,new ,mexico which are subsisting almost wholly on dry-farming4 ,it is only fair to say1 however1 that dry-farming is not yet well established in this district1 but that the prospects are that the application of scientific principles will soon make it possible to produce profitable crops without irrigation in large parts of the ,colorado and ,rio ,grande ,river ,basins4 ,the mountain states ,this district includes a part of ,montana1 nearly the whole of ,wyoming and ,colorado1 and part of eastern ,idaho4 ,it is located along the backbone of the ,rocky ,mountains4 ,the farms are located chiefly in valleys and on large rolling table-lands4 ,the chief dry-farm crop is wheat1 though the other crops which are grown elsewhere on dry-farms may be grown here also4 ,in ,montana there is a very large area of land which has been demonstrated to be well adapted for dry-farm purposes4 ,in ,wyoming1 especially on the eastern as well as on the far western side1 dry-farming has been shown to be successful1 but the area covered at the present time is comparatively small4 ,in ,idaho1 dry-farming is fairly well established4 ,in ,colorado1 likewise1 the practice is very well established and the area is tolerably large4 ,all in all1 throughout the mountain states dry-farming may be said to be well established1 though there is a great opportunity for the extension of the practice4 ,the sparse population of the western states naturally makes it impossible for more than a small fraction of the land to be properly cultivated4 ,the ,great ,plains ,area ,this area includes parts of ,montana1 ,north ,dakota1 ,south ,dakota1 ,nebraska1 ,kansas1 ,wyoming1 ,colorado1 ,new ,mexico1 ,oklahoma1 and ,texas4 ,it is the largest area of dry-farm land under approximately uniform conditions4 ,its drainage is into the ,mississippi1 and it covers an area of not less than four hundred thousand square miles4 ,dry-farm crops grow well over the whole area2 in fact1 dry-farming is well established in this district4 ,in spite of the failures so widely advertised during the dry season of #ahid1 the farmers who remained on their farms and since that time have employed modern methods have secured wealth from their labors4 ,the important question before the farmers of this district is that of methods for securing the best results4 ,from the ,dakotas to ,texas the farmers bear the testimony that wherever the soil has been treated right1 according to approved methods1 there have been no crop failures4 ,canada ,dry-farming has been pushed vigorously in the semiarid portions of ,canada1 and with great success4 ,dry-farming is now reclaiming large areas of formerly worthless land1 especially in ,alberta1 ,saskatchewan1 and the adjoining provinces4 ,dry-farming is comparatively recent in ,canada1 yet here and there are semiarid localities where crops have been raised without irrigation for upwards of a quarter of a century4 ,in ,alberta and other places it has been now practiced successfully for eight or ten years1 and it may be said that dry-farming is a well-established practice in the semiarid regions of the ,dominion of ,canada4 ,mexico ,in ,mexico1 likewise1 dry-farming has been tried and found to be successful4 ,the natives of ,mexico have practiced farming without irrigation for centuries--and modern methods are now being applied in the zone midway between the extremely dry and the extremely humid portions4 ,the irregular distribution of the precipitation1 the late spring and early fall frosts1 and the fierce winds combine to make the dry-farm problem somewhat difficult1 yet the prospects are that1 with government assistance1 dry-farming in the near future will become an established practice in ,mexico4 ,in the opinion of the best students of ,mexico it is the only method of agriculture that can be made to reclaim a very large portion of the country4 ,brazil ,brazil1 which is greater in area than the ,united ,states1 also has a large arid and semiarid territory which can be reclaimed only by dry-farm methods4 ,through the activity of leading citizens experiments in behalf of the dry-farm movement have already been ordered4 ,the dry-farm district of ,brazil receives an annual precipitation of about twenty-five inches1 but irregularly distributed and under a tropical sun4 ,in the opinion of those who are familiar with the conditions the methods of dry-farming may be so adapted as to make dry-farming successful in ,brazil4 ,australia ,australia1 larger than the continental ,united ,states1 is vitally interested in dry-farming1 for one third of its vast area is under a rainfall of less than ten inches1 and another third is under a rainfall of between ten and twenty inches4 ,two thirds of the area of ,australia1 if reclaimed at all1 must be reclaimed by dry-farming4 ,the realization of this condition has led several ,australians to visit the ,united ,states for the purpose of learning the methods employed in dry-farming4 ,the reports on dry-farming in ,america by ,surveyor-,general ,strawbridge and ,senator ,j4 ,h4 ,mc,coll have done much to initiate a vigorous propaganda in behalf of dry-farming in ,australia4 ,investigation has shown that occasional farmers are found in ,australia1 as in ,america1 who have discovered for themselves many of the methods of dry-farming and have succeeded in producing crops profitably4 ,undoubtedly1 in time1 ,australia will be one of the great dry-farming countries of the world4 ,africa ,up to the present1 ,south ,africa only has taken an active interest in the dry-farm movement1 due to the enthusiastic labors of ,dr4 ,william ,macdonald of the ,transvaal4 ,the ,transvaal has an average annual precipitation of twenty-three inches1 with a large district that receives between thirteen and twenty inches4 ,the rain comes in the summer1 making the conditions similar to those of the ,great ,plains4 ,the success of dry-farming has already been practically demonstrated4 ,the question before the ,transvaal farmers is the determination of the best application of water conserving methods under the prevailing conditions4 ,under proper leadership the ,transvaal and other portions of ,africa will probably join the ranks of the larger dry-farming countries of the world4 ,russia ,more than one fourth of the whole of ,russia is so dry as to be reclaimable only by dry-farming4 ,the arid area of southern ,european ,russia has a climate very much like that of the ,great ,plains4 ,turkestan and middle ,asiatic ,russia have a climate more like that of the ,great ,basin4 ,in a great number of localities in both ,european and ,asiatic ,russia dry-farming has been practiced for a number of years4 ,the methods employed have not been of the most refined kind1 due1 possibly1 to the condition of the people constituting the farming class4 ,the government is now becoming interested in the matter and there is no doubt that dry-farming will also be practiced on a very large scale in ,russia4 ,turkey ,turkey has also a large area of arid land and1 due to ,american assistance1 experiments in dry-farming are being carried on in various parts of the country4 ,it is interesting to learn that the experiments there1 up to date1 have been eminently successful and that the prospects now are that modern dry-farming will soon be conducted on a large scale in the ,ottoman ,empire4 ,palestine ,the whole of ,palestine is essentially arid and semi-arid and dry-farming there has been practiced for centuries4 ,with the application of modern methods it should be more successful than ever before4 ,dr4 ,aaronsohn states that the original wild wheat from which the present varieties of wheat have descended has been discovered to be a native of ,palestine4 ,china ,china is also interested in dry-farming4 ,the climate of the drier portions of ,china is much like that of the ,dakotas4 ,dry-farming there is of high antiquity1 though1 of course1 the methods are not those that have been developed in recent years4 ,under the influence of the more modern methods dry-farming should spread extensively throughout ,china and become a great source of profit to the empire4 ,the results of dry-farming in ,china are among the best4 ,these countries have been mentioned simply because they have been represented at the recent ,dry-farming ,congresses4 ,nearly all of the great countries of the world having extensive semiarid areas are directly interested in dry-farming4 ,the map on pages #cj and #ca shows that more than #ee per cent of the world's surface receives an annual rainfall of less than twenty inches4 ,dry-farming is a world problem and as such is being received by the nations4