,the ,farm ,that ,won't ,wear ,out ,by ,cyril ,g4 ,hopkins ,preface ,,the ,,farm ,,that ,,won',t ,,wear ,,out ,,was ,,first published serially in ,,the ,,country ,,gentleman1 the privilege having been granted the author of subsequent publication4 ,it is now issued in book form in response to numerous requests coming especially from the ,central1 ,eastern1 and ,southern ,states4 ,,cyril ,g4 ,,hopkins4 ,,champaign1 ,,ill4 ,population must increase rapidly1 more rapidly than in former times1 and ere long the most valuable of all arts will be the art of deriving a comfortable subsistence from the smallest area of soil4--,lincoln4 ,it is not the land itself that constitutes the farmer's wealth1 but it is in the constituents of the soil1 which serve for the nutrition of plants1 that this wealth truly consists4--,liebig4 ,,contents ,,chapter ,i3 ,what ,goes ,to ,make ,up ,permanent ,fertility ,,chapter ,,ii3 ,the ,nitrogen ,problem ,and ,its ,economical ,solution ,,chapter ,,iii3 ,phosphorus3 ,the ,master ,key ,to ,permanent ,agriculture ,,chapter ,,iv3 ,permanent ,soil ,fertility3 ,its ,relation to ,profits and ,future ,values ,,chapter ,i ,,what ,,goes ,,to ,,make ,,up ,,permanent ,,fertility ,,it ,,is an old saying that any fool can farm1 and this was almost the truth when farming consisted chiefly in reducing the fertility of new1 rich land secured at practically no cost from a generous ,government4 ,but to restore depleted soils to high productive power in economic systems is no fool's job1 for it requires mental as well as muscular energy2 and no apologies should be expected from those who necessarily make use of technical terms in the discussion of this technical subject1 notwithstanding the common foolish advice that farmers should be given a sort of parrot instruction in almost baby language instead of established facts and principles in definite and permanent scientific terms4 ,the farmer should be as familiar with the names of the ten essential elements of plant food as he is with the names of his ten nearest neighbors4 ,safe and permanent systems of soil improvement and preservation may come with intelligence--never with ignorance--on the part of the landowners4 ,when the knowledge becomes general that food for plants is just as necessary as food for animals1 then ,american agriculture will mean more than merely working the land for all that's in it4 ,this knowledge is as well established as the fact that the earth is round1 although the people are relatively few who understand or make intelligent application of the existing information4 ,agricultural plants consist of ten elements1 known as the essential elements of plant food2 and not a kernel of corn or a grain of wheat1 not a leaf of clover or a spear of grass can be produced if the plant fails to secure any one of these ten elements4 ,some of these are supplied to plants in abundance by natural processes2 others are not so provided and must be supplied by the farmer1 or his land becomes impoverished and unproductive4 ,foods ,that ,plants ,live ,on ,two elements1 carbon and oxygen1 are contained in normal air in the form of a gas called carbon dioxid1 and this compound is taken into the plant through the breathing pores1 which are microscopic openings located chiefly on the under side of the leaves4 ,some plants have more than a hundred thousand breathing pores to the square inch of leaf surface4 ,when plants or plant products are burned or decomposed the carbon of the combustible material--grass1 wood1 coal1 and so forth--unites with the free oxygen of the atmosphere to re-form the carbon dioxid1 which thus returns as a gas to the air4 ,even the food taken into the animal system1 after being digested and carried into the blood1 is brought1 into contact with the oxygen of the air--which also passes into the blood through the cell walls of the lungs--and a form of combustion takes place1 the heat generated serving to warm the body while the carbon dioxid passes back into the lungs and is exhaled into the open air4 ,by these circulation processes the supply of carbon dioxid in the atmosphere is renewed and maintained without any special effort on the part of man4 ,hydrogen is one of the elements of which water is composed4 ,water is taken into the plant through the roots1 carried through the stems to the leaves1 and there1 under the influence of chlorophyll1 sunlight and the life principle1 the carbon1 oxygen and hydrogen are made to unite into some of the most important plant compounds1 such as the sugars1 which are later transformed into starch and fiber4 ,though these three elements constitute the larger part of the mature agricultural plant they are no more necessary for plant growth than the seven which are supplied by the soil4 ,iron is one of the essential elements of plant food2 but the amount required by plants is so small and the amount contained in the soil is so large that soils have never been known to become deficient in iron4 ,though sulfur is found in plants in very appreciable amounts and is known to be essential to plant growth1 it is evident that plants do not need so much sulfur as they often contain1 some of it being taken up and merely tolerated1 as is the case with all of the sodium and silicon found in plants1 neither of these being required for normal growth1 although commonly found in plants in very considerable amounts4 ,the supply of sulfur in normal soils is not large2 but1 with the combustion and decay of organic materials--coal1 wood1 grass1 leaves1 and so forth--sulfur passes into the air and is brought back to the soil dissolved in rain or absorbed by direct contact of soil and air4 ,thus under normal conditions the supply of sulfur naturally provided is ample to meet the needs of the staple farm crops1 although there are some plants1 such as cabbage1 for example1 which may possibly be benefited by fertilizing with sulfur4 ,but there are five other essential elements of plant food1 and these require special consideration in connection with permanent soil fertility4 ,they are potassium1 magnesium1 calcium1 phosphorus and nitrogen4 ,there are also five important points to be kept in mind in relation to each of these elements3 7#a7 the soil's supply1 7#b7 the crop requirements1 7#c7 the loss by leaching1 7#d7 the methods of liberation1 and 7#e7 the means of renewal4 ,the neglect of one or more of these important points in relation to one or more of these five elements has reduced the fertility of most cultivated soils in the ,united ,states1 has greatly impoverished the older farm lands1 and has brought agricultural abandonment to millions of acres in the original thirteen states4 ,on the other hand1 intelligent attention to these same factors will bring restoration and high productive power to such lands4 ,england's ,best ,lesson in ,farming ,where these five elements were supplied regularly to land on the ,rothamsted ,experiment ,station the average yield of wheat for the thirty years1 #aheb to #ahha1 was #ce4i bushels an acre1 while #ac4f was the average yield of similar unfertilized land2 and during the next thirty years--#ahhb to #aiaa--the corresponding average yields were #ch bushels an acre on the fertilized land1 and #aa4g bushels where no plant food was applied4 ,these statements are not mere opinions1 but determined facts whose accuracy stands unquestioned4 ,on another field at ,rothamsted1 ,england1 the average yield of barley for the same sixty years was #dc bushels an acre where nitrogen1 phosphorus and calcium were regularly applied1 #db4f where all five elements--including potassium and magnesium--were added1 but only #ad4c on unfertilized land4 ,on still another ,rothamsted experiment field1 where a four-year crop rotation of turnips1 barley1 clover 7or beans7 and wheat has been practiced since #ahdh1 the yield of turnips in #aijh was #gag pounds an acre on unfertilized land and #ce1afh pounds where the five important elements of plant food had been regularly applied once every four years--for the turnips only--since #ahdh4 ,in #aiji the barley yielded #cc4d bushels an acre on the fertilized land1 but only #aj bushels where no plant food was applied4 ,the yield of clover in #aiaj was #heij pounds an acre on the land fertilized for turnips1 but only #aidi on the unfertilized land4 ,the wheat following the clover with no other fertilizer produced #bd4e bushels an acre in #aiaa1 but #ch bushels where plant food is always applied for turnips grown three years before4 ,these are the established facts from the longest accurate record1 and thus the most trustworthy data the world affords2 and when one hears promulgated the very pleasing doctrine that the rotation of crops will maintain the fertility of the soil it is time to remember that to err is human4 ,fertility in ,normal ,soils ,of the four important mineral elements1 potassium is by far the most abundant in common soils4 ,thus1 as an average of ten residual soils from ten different geological formations in the eastern part of ,united ,states1 two million pounds of subsurface soil were found to contain3 ,potassium #cg1hfj pounds ,magnesium #ad1jhj pounds ,calcium #g1haj pounds ,phosphorus #a1ajj pounds ,even the depleted1 and to some extent abandoned1 gently undulating upland ,leonardtown loam1 which was farmed for generations and which1 according to the surveys of the ,federal ,bureau of ,soils1 covers #da per cent of ,st4 ,mary's ,county1 ,maryland1 and more than #de1jjj acres of ,prince ,george's ,county--still contains in two million pounds of surface soil--corresponding to the plowed soil of an acre about #f-b_/c inches deep3 ,potassium #ah1ejj pounds ,magnesium #c1dhj pounds ,calcium #a1jjj pounds ,phosphorus #afj pounds ,the brown silt loam prairie soil of the early ,wisconsin glaciation is the most common type of the greatest soil area in the ,illinois ,corn ,belt4 ,two million pounds of this surface soil contain as an average3 ,potassium #cf1bej pounds ,magnesium #h1gij pounds ,calcium #aa1dej pounds ,phosphorus #a1aij pounds ,the older gray silt loam prairie1 the most extensive soil of ,southern ,illinois1 contains in two million pounds of soil3 ,potassium #bd1idj pounds ,magnesium #d1fij pounds ,calcium #c1dbj pounds ,phosphorus #hdj pounds ,these data represent averages involving hundreds of soil analyses1 and they emphasize the fact that normal soils are rich in potassium and poor in phosphorus4 ,this is to be expected1 for most soils are made from the earth's crust1 and normal soils should bear some relation in composition to the average of the earth's crust1 which contains in two million pounds #di1bjj pounds of potassium and #b1bjj pounds of phosphorus1 as shown by the weighted averages of analyses involving about two thousand samples of representative rocks1 reported by the ,united ,states ,geological ,survey4 ,measuring ,fertility ,losses ,the plant food required for one acre of wheat yielding #ej bushels1 one acre each of corn and oats yielding #ajj bushels1 and one acre of clover yielding four tons1 includes for the total crops3 ,potassium #cbj pounds ,magnesium #fh pounds ,calcium #afh pounds ,phosphorus #gg pounds ,if only the grain1 including a yield of #d bushels an acre of clover seed1 is considered1 the straw1 stalks and hay being returned to the soil--either directly or in farm fertilizer--then the loss per acre from four years of cropping as above would be as follows3 ,potassium #ea pounds ,magnesium #af pounds ,calcium #e pounds ,phosphorus #db pounds ,the average annual loss by leaching from good soils in humid sections is known by the results of many analyses to be about as follows per acre3 ,potassium #aj pounds ,calcium #cjj pounds ,phosphorus #b pounds ,the average annual loss of magnesium in drainage water from good soils is probably #cj pounds or more an acre1 but the data thus far secured are inconclusive with respect to that element4 ,a careful consideration of the trustworthy data clearly reveals the fact that potassium is very abundant in normal soils1 while phosphorus is relatively very deficient2 and1 all things considered1 calcium--and probably magnesium--is of much greater significance than potassium1 from the standpoint of the maintenance of usable plant food in the soil4 ,it should be noted1 too1 that certain crops which are exceedingly important for economic systems of permanent agriculture require very large amounts of calcium as plant food4 ,thus a four-ton crop of clover hay takes about #abj pounds of calcium from the soil1 or the same amount as of potassium2 while such a crop of alfalfa requires about #ade pounds of calcium1 but only #if pounds of potassium4 ,when it is known that the abandoned ,leonardtown loam still contains in two million pounds of surface soil #ah1ejj pounds of potassium and only #ajjj pounds of total calcium1 the significance of these chemical and mathematical data must be apparent4 ,the ,liberation of ,fertility ,probably there has never been a greater waste of time and effort in the name of science than in the endeavor to determine the available plant food in soils4 ,the almost universal assumption has been that the plant food in the soil exists in two distinct conditions1 available and unavailable1 and that the determination of the available plant food would reveal both the crop-producing power of the soil and the fundamental fertilizer requirements for the improvement of the soil for crop production4 ,after ascertaining the total stock of plant food in the plowed soil1 the next important question is not how much is available1 but rather how much can be made available during the crop season1 year after year4 ,in other words we must make plant food available by practical methods of liberation1 by converting it from insoluble compounds into soluble and usable forms2 for plant food must be in solution before the plant can take it from the soil4 ,for the present1 space is taken only to emphasize the value of decaying organic manures in the important matter of making plant food available2 and attention is also called to the fact that the decomposition of the organic matter of the soil--including both fresh materials and old humus--is hastened by tillage and by underdrainage1 which permit the oxygen of the air to enter the soil more freely1 oxygen being a most active agent in nitrification and other decomposition processes of organic matter1 as well as in the more common combustion of wood1 coal1 and so forth4 ,the ,renewal of ,fertility ,in rational systems of general farming the supply of any element which is normally very abundant may be renewed from the subsoil by even the very slight erosion which occurs on all ordinary lands in humid sections4 ,this statement applies to iron and potassium1 and often to magnesium4 ,if two million pounds of normal surface soil contain #cj1jjj pounds of potassium1 one inch an acre would contain #dejj pounds of that element2 and if a third of this--#aejj pounds--were removed by cropping and leaching before its removal by surface washing1 then two-thirds of a century could be allowed for the erosion of one inch of soil1 with crop yields of #ej bushels of wheat1 #ajj bushels of corn and oats1 and #d bushels of clover seed to the acre1 provided the stalks1 straw and clover hay were returned to the land1 either directly or in farm manure4 ,this amount of surface washing is likely to occur on land sufficiently undulating for good surface drainage1 provided the land is plowed and cultivated as frequently as would be required for a four-year rotation as suggested above4 ,where hay1 straw1 potatoes1 root crops or common market garden crops are sold1 very much larger amounts of potassium leave the farm than in grain farming or live-stock farming1 and in such cases potassium must ultimately be purchased and returned to the soil1 either in commercial form or in animal manures from the cities4 ,thirty ,bushels for ,potassium ,there are some soils1 however1 which are not normal--soils whose composition bears no sort of relation to the average of the earth's crust2 such1 for example1 as peaty swamp soil or bog lands1 which consist largely of partly decayed moss and swamp grasses4 ,these soils are exceedingly poor in potassium1 and they are markedly and very profitably improved by potassium fertilizers1 such as potassium sulphate and potassium chloride--commonly but erroneously called muriate of potash4 ,thus1 as an average of triplicate tests each year1 the addition of potassium to such land on the ,university of ,illinois experiment field near ,manito1 ,mason county1 increased the yield by #bj4g bushels more corn to the acre in #aijb1 by #bc4e in #aijc1 by #bi in #aijd and by #cf4h in #aije2 and the proceedings of the midsummer session of the ,illinois ,state ,farmers' ,institute for #aiaa report that the use of #bb1ejj in potassium salts on the peaty swamp lands in the neighborhood of ,tampico1 ,whiteside county1 increased the value of the corn crop in #aiaj by #baj1jjj1 the average increase for potassium being about #cj bushels of corn to the acre4 ,some sand soils1 particularly residual sands1 which often consist largely of quartz-silicon dioxid--are very deficient in potassium2 consequently the experiments or demonstrations conducted by the potash syndicate at ,southern ,pines1 ,north ,carolina1 show very marked increases from the use of potassium salts on such soil1 although the result ought not to be used to encourage the use of such fertilizers on normal soils1 which are exceedingly rich in potassium4 ,even in soils abundantly supplied with potassium temporary use may well be made of soluble potassium salts when no adequate supply of decaying organic matter can be provided4 ,for this purpose1 kainit--which contains potassium and also magnesium and sodium in chlorides and sulfates--is preferred to the more concentrated and more expensive potassium salts4 ,about #fjj pounds an acre every four years is a good application4 ,the kainit will not only furnish soluble potassium and magnesium but will also help to dissolve and thus make available other mineral plant food naturally present or supplied1 such as natural phosphates4 ,when the supply of organic matter produced in crops and returned either in farm manure or in crop residues becomes sufficiently abundant1 then the addition of kainit may be discontinued on normal soil4 ,thus1 as an average of #aab separate tests covering four different years1 on the ,southern ,illinois experiment field on worn1 thin land1 at ,fairfield1 the use of #fjj pounds an acre of kainit once in four years increased the yield of corn by #aj4g bushels where no organic manure was used1 and by only #a4g bushels when applied with eight tons of farm manure4 ,liming the ,soil ,in the form of ashes1 marl or chalk1 lime has been used as a fertilizer for thousands of years4 ,it serves two very important purposes3 to correct the acidity of sour soils and to supply calcium and sometimes magnesium as plant food4 ,burned lime has also been much used1 but in more recent years the development of machinery for crushing and pulverizing rock--especially in cement manufacture--has made possible the production of pulverized natural limestone1 and at much less expense than for caustic lime made by burning and slaking4 ,where ground limestone can be easily procured it takes the place of burned lime1 and it produces better results at less expense1 even though #a-c_/d tons of ground limestone are required to equal #a ton of quicklime in calcium content and in power to correct acidity4 ,furthermore1 ground limestone can be applied in any amount with no injurious results1 while caustic lime destroys the organic matter or humus of the soil1 dissipates soil nitrogen1 is disagreeable to handle1 and may injure the crop unless applied in limited amounts or several months before the crop is to be planted4 ,the most valuable and trustworthy investigation on record in regard to the comparative value of burned lime and ground limestone has been conducted by the ,pennsylvania ,experiment ,station4 ,a four-year rotation of crops was practiced1 including corn1 oats1 wheat and hay 7clover and timothy7 on four different fields1 each crop being represented every year4 ,after twenty years the results for the four acres showed that the land treated with ground limestone had produced #ii bushels more corn1 #aaf bushels more oats1 #ac bushels more wheat and #e4f tons more hay than the land treated with about an equivalent amount of burned lime4 ,at the end of sixteen years the analysis of the soil showed that the burned lime had destroyed #d4g tons of humus and had dissipated #cge pounds of nitrogen to the acre1 as compared with the ground limestone1 this loss being equivalent to #cg-a_/b tons of farm manure4 ,other trustworthy experiments by the ,maryland and ,ohio ,experiment ,stations confirm the ,pennsylvania results in showing better crop yields when unburned lime carbonate was used2 and more extensive experiments by the ,tennessee ,experiment ,station also agree with the ,pennsylvania data in regard to the destruction of organic matter and loss of soil nitrogen from the use of burned lime4 ,if dolomitic limestone is used1 magnesium as well as calcium is thus added to the soil4 ,limestone need not be very finely pulverized4 ,if ground so that it will pass through a ten-mesh sieve it is amply fine1 assuming that the entire product is used1 including the finer dust produced in grinding1 and it is very possible that final investigations will show that the entire product from a quarter-inch screen is even more economical and profitable in permanent systems4 ,limestone is quite easily soluble in soil water carrying carbonic acid4 ,it is thus readily available2 in fact1 it is too available to be durable if very finely ground2 and in humid sections the loss by leaching far exceeds that removed by cropping4 ,in practical economic systems of farming about two tons an acre of ground limestone should be applied every four years1 or corresponding amounts for other rotation periods4 ,the essential facts relating to potassium1 magnesium and calcium and to the use and value of different forms of lime have been stated above1 and they may be accepted with confidence for use in economic systems of farming on normal soils4 ,,chapter ,,ii ,,the ,,nitrogen ,,problem ,,and ,,its ,,economical ,,solution ,,in ,,the previous chapter emphasis has been laid upon the fact that plants as well as animals must have food1 and that the neglect or ignorance of this factor in ,american agriculture has led to soil depletion and land ruin on vast areas1 especially in the older states4 ,it has been shown that of the ten essential elements of plant food1 five are provided by natural processes without the intervention of man2 that1 of the remaining five1 potassium is the most abundant in normal soil1 but requires liberation by good systems of farming2 that ground natural limestone is the ideal material with which to supply calcium and to prevent or correct soil acidity2 and that if dolomitic limestone be used magnesium is also supplied in suitable form for plant food1 ,thus only nitrogen and phosphorus remain for consideration4 ,keeping in mind that systems of permanent profitable agriculture in ,america must be founded upon an intelligent understanding of the foundation principles involved1 let us pray for strength to acknowledge the truth and cease trying to deceive ourselves4 ,the truth is that by soil enrichment alone the average crop yields of the ,united ,states could be doubled1 with the same seed and seasons and with but little more work than is now devoted to the fields2 and we should cease trying to deceive ourselves in the hope or belief that the fertility of our soil will be maintained if we continue year after year to take crops from the land and fail to make adequate return4 ,nitrogen is both the most abundant agriculturally and the most expensive commercially of all the elements of plant food2 and yet there is a method by which it can be secured not only without money but with profit in the process4 ,the percentage of nitrogen in normal soils decreases with depth1 so that subsoils are almost devoid of nitrogen4 ,this would be more generally understood if it were known that the supply of soil nitrogen in humid countries is contained only in the organic matter4 ,this organic or vegetable matter consists of the partly decomposed residues of plants1 including the roots and fallen leaves which may accumulate naturally1 and the green manure crops1 crop residues and farm manure which may be supplied in farm practice4 ,thus the nitrogen of a soil is measured approximately by its content of organic matter2 and1 vice versa1 the percentage of nitrogen is an approximate measure of the organic matter1 because nitrogen is a regular constituent of the organic matter normally contained in soils4 ,consequently if the organic matter of a soil is reduced the supply of nitrogen is also reduced4 ,in the most depleted soils nitrogen is usually the most deficient element1 although it may not be the only deficiency4 ,thus in the depleted ,leonardtown loam1 which occupies such extensive areas of land in ,southern ,maryland1 near the ,district of ,columbia1 and which has been to a large extent agriculturally abandoned after one or two centuries of farming1 only #ijj pounds of nitrogen are found in the plowed soil of an acre--that is1 in #b1jjj1jjj pounds of surface soil1 corresponding to about #f-b_/c inches an acre4 ,this total amount if made available would be sufficient for only six such crops of corn as are actually produced on our best land in good seasons1 and yet it is four times as much as is contained in an equal weight of the subsoil4 ,the average prairie land of the ,corn ,belt contains only #ejjj pounds of nitrogen in the plowed soil of an acre #f-b_/c inches deep1 whereas a #ajj-;bushel crop of corn removes #aej pounds of nitrogen from the soil4 ,a simple computation shows the supply in the plowed soil to be sufficient for only #cc such crops4 ,even the #ajj-;bushel crop of corn per acre is known to have been produced in many places on exceptionally rich land1 and yet the ten-year average yield in the ,united ,states is only #be bushels to the acre4 #bjj ,per ,cent for ,nitrogen ,on ,broadbalk ,field at ,rothamsted1 ,england1 wheat has been grown on the same land every year for about two-thirds of a century4 ,as an average of the sixty years1 #aheb to #aiaa the yield was #ab4f bushels an acre on unfertilized land1 #ad4f where mineral plant food was annually applied1 #bj4c where nitrogen salts alone were used1 and #cg where both nitrogen and mineral plant food were applied4 ,during the thirty years1 #ahhb to #aiaa the average yields were #aa4g bushels an acre on the unfertilized land1 #ad with minerals1 #ah4g where only nitrogen salts were used1 and #ch where both nitrogen and minerals were regularly supplied4 ,these absolute data from the oldest agricultural experiment station in the world should help us to understand why the ten-year average yield of wheat is #cc bushels an acre for all of ,great ,britain1 #cg-a_/b for ,england alone1 and only #ad for the ,united ,states4 ,the application of nitrogen increased the yield of wheat by #bd bushels an acre--from #ad to #ch bushels--as an average of the last thirty years1 following an average increase of #bf4c for the nitrogen applied during the previous thirty years4 ,it is true that the cost of the fertilizers used exceeded the value of the increase in yield2 but let us bear in mind that this truth does not destroy the other truth4 ,prove all things1 and hold fast that which is good4 ,it is a good fact that #abah bushels of wheat were produced by the application of nitrogen to an acre of land during a period of sixty years1 over and above the produce of another acre which differed only by not receiving nitrogen2 whereas the total produce from an acre of unfertilized land was only #gef bushels during the same sixty years4 ,it is a good fact that the increase alone from the nitrogen applied is more than twice the total yield of the unfertilized land during the last thirty years1 and he does well who holds fast this fact4 ,it is also a good fact that as an average of sixty years the yield of barley was increased by #ba4f bushels an acre by nitrogen2 that nitrogen increased the yield of hay on permanent meadow land at ,rothamsted by #a-a_/b tons an acre as a fifty-year average2 and that nitrogen increased the average yield of potatoes by #hh bushels as an average of twenty-six years2 while the average of the unfertilized land was only #ea bushels an acre1 these increases in barley1 bay1 and potatoes being obtained over and above the yields where minerals alone were used4 ,where ,is ,nitrogen8 ,if nitrogen has such enormous power to increase the yield of our great staple farm crops then we may well inquire1 ,where is nitrogen1 and how can it be secured economically and utilized profitably in practical agriculture8 ,the weight of the atmosphere is #ae pounds to the square inch4 ,this means that a column of air #a inch square taken to the full height of the terrestrial atmosphere weighs #ae pounds4 ,more than three fourths of the air is nitrogen4 ,since there are #dc1efj square feet in one acre1 it follows that the nitrogen in the air above each acre of the earth's surface amounts to #gj1jjj1jjj pounds1 or nearly #ejj1jjj times the #aej pounds of nitrogen required for a hundred-bushel crop of corn4 ,the leaves of the corn plant are blown about by the wind carrying #ge-a_/b per cent of nitrogen1 but cannot utilize an ounce of this supply4 ,many people know that clover and other legumes have power1 through the bacteria which inhabit their root tubercles1 to feed upon the inexhaustible supply of atmospheric nitrogen which freely enters the pores of the soil2 but who knows how much nitrogen is taken from the air by a given crop of clover8 ,not one in a thousand can answer this question2 and meanwhile our continued agricultural and national prosperity depends in large part upon the possibility of wide dissemination and practical application of a quantitative knowledge of the nitrogen problem4 ,as a rule the so-called practical farmer is a theorist4 ,he first believes that the virgin soil is inexhaustible1 even though cropped continuously4 ,later he clings to the popular theory that the rotation of crops will maintain the productive capacity of the land2 and it is safe to say that a large majority of the farmers of the ,united ,states gladly hold to the erroneous theory that clover grown once every three to five years will increase and permanently maintain the fertility of the soil4 ,the fact that clover was grown for generations on the lands of the older ,eastern states until the clover crop itself finally failed on millions of acres now agriculturally abandoned is overlooked or forgotten by present-day farmers1 especially by the descendants of those who have gone ,west and settled on new1 rich lands4 ,six ,facts and a ,question ,the following six facts will furnish a comprehensive basis for the solution of the nitrogen problem in practical general agriculture3 7#a7 ,to produce #ajj pounds of grain requires about #c pounds of nitrogen1 of which #b pounds are deposited in the grain itself and #a pound in the straw or stalks4 7#b7 ,in live-stock farming one-fourth of the nitrogen in the food consumed is retained in the animal products--meat1 milk1 wool1 and so on--and three-fourths may be returned to the land in the excrements if saved without loss4 7#c7 ,when grown on soils of normal productive capacity legumes secure about two-thirds of their total nitrogen from the air and one-third from the soil4 7#d7 ,clover and other biennial or perennial legumes have about two-thirds of their total nitrogen in the tops and one-third in the roots1 while the roots of cowpeas and other annual legumes contain only about one-tenth of their total nitrogen4 7#e7 ,hay made from our common legumes contains about #dj pounds of nitrogen per ton4 7#f7 ,average farm manure contains #af pounds of nitrogen per ton4 ,question3 ,how many tons of average farm manure must be applied to a #dj-;acre field in order to provide as much nitrogen as would be added to the soil by plowing under #b-a_/b tons of clover per acre8 ,answer3 #djj tons4 ,either method will furnish about as much nitrogen as would be taken from the soil by a #ej-;bushel crop of wheat1 a #ge-;bushel crop of corn or a #ajj-;bushel crop of oats per acre4 ,the decision by the individual between live-stock farming and grain farming should be based upon preference and profit rather than upon the erroneous teaching that farm manure is either essential or sufficient for the maintenance of soil fertility in this country4 ,bread is the staff of life1 and many must sell grain4 ,i do not advise all grain farmers to become live-stock farmers2 but ,i do advise both grain farmers and live-stock farmers to enrich their soils by practical1 profitable and permanent methods4 ,both classes of farmers may secure new nitrogen--that is1 they can positively increase their nitrogen supply by sufficient use of legume crops4 ,how to ,supply ,nitrogen ,the cotton-grower who sells cotton lint at #aj cents a pound and the market gardener who sells from #ajj to #cjj worth of fruits and vegetables from one acre may well make liberal use of commercial nitrogen at #ae or #bj cents a pound2 but if after deducting the cost of harvesting1 threshing1 storing and marketing the average farmer receives only #a cent a pound for his grain and if #dj per cent of the commercial nitrogen applied is lost by leaching1 then the total crop of grain would bring only enough money to pay for the nitrogen required to produce it1 at #bj cents a pound4 ,we may sometimes advise the ,american grain-grower to buy water with which to irrigate his crop1 but not to buy nitrogen with which to fertilize it4 ,if the grain farmer grows #dj bushels of wheat to the acre1 clover having been seeded on the same land in order to plow under the equivalent of #a-a_/b tons of hay as green manure the following spring1 and follows this by a #fj-;bushel crop of corn and a #ej-;bushel crop of oats1 and this the fourth year by two crops of clover aggregating #c tons an acre1 including #b bushels of seed1 he can thus secure from the air about #ahj pounds of nitrogen in the #d-a_/b tons of clover4 ,moreover1 if the first cutting of clover the fourth year is left on the land and the threshed clover straw from the seed crop and likewise all straw and stalks are returned to the soil1 only #aed pounds of nitrogen an acre would leave the farm if the total grain and clover seed were sold4 ,with #hj cents a bushel for wheat1 #ej cents for corn1 #dj cents for oats and #h for clover seed1 the total returns from the four acres would amount to #ih4 ,on the other hand the live-stock farmer may grow two #fj-;bushel crops of corn1 followed by #ej bushels of oats and then #c tons of clover hay containing #abj pounds of new nitrogen4 ,the four crops would contain #cej pounds of nitrogen2 and if the grain and hay and half the corn-stalks are used for feed1 with the straw and the remainder of the stalks for bedding1 it is likewise possible to replace the #bcj pounds of nitrogen required for the grain crops1 provided not more than one-seventh of the manure is lost before being returned to the land4 ,the important weakness on the common live-stock farm lies in the enormous waste of manure4 ,if #aj pounds of feed produce #a pound increase in the live-weight of the animals fed1 and if they bring #f cents a pound on the hoof1 the gross returns aggregate #ajg4ej from the four acres1 barring losses from accidents1 animal diseases1 and so on4 ,thus1 with a few established facts in mind1 one can easily determine how to maintain or even to increase the supply of nitrogen in the soil1 and without the purchase of nitrogen in any form2 and it is just as possible and just as necessary thus to provide the nitrogen needed in grain farming as in livestock farming4 ,when we consider that animals destroy two-thirds of the organic matter in the food consumed we find that as between the two systems above described the organic matter or humus of the soil will be better maintained in the grain system outlined4 ,live-,stock or ,grain ,farming ,for those who believe that live-stock farming must be adopted for the maintenance of fertility on all farms1 attention should be called to the fact that there are #ijj1jjj1jjj acres of farm-land in the ,united ,states and only #ij1jjj1jjj head of live-stock equivalent to cows1 including all farm animals4 ,will the manure from one cow serve to enrich #aj acres of land8 ,it should also be known that a hundred bushels of grain will support five times as many people as could live for the same length of time on the meat and milk that could be made by feeding the grain to domestic animals4 ,it is because of this fact that the consumer may sometimes boycott meat or other animal products1 while he never boycotts bread2 but let us hope that permanent systems will become generally adopted in ,america1 for the production of both grain and live stock1 so that high standards of living may be maintained for all classes of people in this country4 ,the oldest direct comparison between these two systems of farming1 so far as the writer has learned1 is on the experiment fields of the ,university of ,illinois1 where as an average of six years the yield of corn has been #hg bushels an acre in grain farming and #ij bushels in live-stock farming1 the same crop rotation being practiced4 ,where wheat was introduced the average yield for six years was #dc4a bushels in grain farming and #dc4e in live-stock farming4 ,no nitrogen was purchased in any form in either of these systems2 but clover is grown in the rotation to secure nitrogen from the air and then the crop residues or farm manure is returned to the soil to provide sufficient nitrogen for the grain crops4 ,in all cases phosphorus was used for these yields4 ,even more encouraging than these six-year average results from ,illinois are the results of sixty years from ,agdell ,field at ,rothamsted4 ,where mineral plant food was regularly applied1 and where all the manure produced by feeding the turnips was returned to the soil1 in a four-year rotation of turnips1 barley1 clover 7or beans7 and wheat1 with no other provision made for supplying nitrogen1 the yields per acre were as follows3 ,turnips1 #bd1gbd lbs4 in #ahdh1 and #bf1daj in #aijh4 ,barley1 #db4h bushels in #ahdi and #bb4a in #aiji ,clover1 #eehf pounds in #ahej and #gaij in #aiaj4 ,wheat1 #cb bushels in #ahea and #cg4h in #aiaa4 ,here we have data which span a period of sixty years and which show that where mineral plant food has been provided the clover in rotation and the manure produced by the feeding of only one of the four crops have maintained the yield of all crops except the barley-the third crop after clover-and without the application of nitrogen in any other form4 ,if the clover and straw had been returned to the land either directly or in farm manure the additional nitrogen thus provided would have been sufficient both to maintain the yield of barley and to prevent the moderate decrease which has occurred in the nitrogen content of the soil4 ,,chapter ,,iii ,,phosphorus3 ,,the ,,master ,,key ,,to ,,permanent ,,agriculture ,,the greatest economic loss that ,america has ever sustained has been the loss of energy and profit in farming with an inadequate supply of phosphorus4 ,phosphorus is a ,greek word which signifies light-bringer2 but it is a light which few ,americans have yet seen1 else we should not permit the annual exportation of more than a million tons of our best phosphate rock1 for which we receive at the mines the paltry sum of five million dollars1 carrying away from the ,united ,states an amount of the one element of plant food we shall always need to buy1 which if retained in this country and applied to our own soils would be worth not five million but a thousand million dollars for the production of food for the oncoming generations of ,americans4 ,for five million dollars we export to ,europe each year enough phosphorus for #a1djj1jjj1jjj bushels of wheat1 or twice the average crop of the entire ,united ,states4 ,meanwhile our ten-year-average yield of wheat is #ad bushels an acre1 while ,germany's yield has gone up to #bi1 ,great ,britain's to #cc1 ,england's to #cg-a_/b and ,denmark's to more than #dj as the average for a decade4 ,potato ,yield ,twice ,doubled ,there is only one place in the world where we can go for the results of soil improvement for more than a quarter of a century in connection with the growing of potatoes4 ,of course this place is ,rothamsted1 ,england1 where as an average for twenty-six years the yield of potatoes was #ea bushels an acre on unfertilized land and exactly #ajb bushels where only a phosphate fertilizer was applied4 ,where the same amount of phosphorus--#bi pounds of the element per acre per annum--was used in connection with other minerals--#cjj pounds of potassium sulfate and #ajj pounds each of the sulfates of magnesium and sodium--the average yield of potatoes was #aji bushels4 ,where #hf pounds of nitrogen was applied in sodium nitrate the average yield was #gi bushels2 but where the nitrogen1 phosphorus and other minerals were all applied the average yield for the twenty-six years was #bjc bushels4 ,at #ej cents a bushel for potatoes1 the investment in phosphorus alone paid #fjj per cent net profit2 and even the complete fertilizer1 including #cib pounds of acid phosphate1 #eej pounds of sodium nitrate and #ejj pounds of alkali salts1 aggregating #addb pounds1 and costing at moderate prices #bd4bh an acre per annum1 paid back #gf a year as a twenty-six year average1 thus making #cjj per cent even on an investment of nearly #be an acre a year4 ,phosphorus ,helps ,good ,farming ,there is also but one place in the world where we can learn the results secured from the application of phosphorus for a period of thirty-six years in a good system of farming2 and again this place is ,rothamsted4 ,in #ahdh ,sir ,john ,lawes and ,sir ,henry ,gilbert began investigations on ,agdell ,field4 ,the ,norfolk rotation1 already known at that time as one of the best rotation systems1 was turnips1 barley1 clover1 and wheat2 and in these practical field experiments the turnips were fed on the land and the animal fertilizer thus produced was returned to the soil1 which was well supplied with limestone4 ,during the next thirty-six years #bi4eb worth of phosphorus per acre was applied to one part of the field2 and in comparison with another part of the same field cropped and managed similarly1 except that no phosphorus was applied1 the #bi4eb worth of phosphorus produced #ih4jb increase in the value of the turnips1 #cg4de in barley1 #dh4ic in clover 7and beans7 and #de4ii in wheat4 ,the total value of the crops grown on the land not receiving phosphorus during the thirty-six years was #dcb4dc an acre1 while on the phosphated land the crop values amounted to #ffb4hb1 an increase of #bcj4ci from an investment of #bi4eb1 the turnips being figured at #a4dj a ton1 barley at #ej cents a bushel1 clover hay at #f a ton1 beans at #a4be a bushel1 wheat at #gj cents a bushel1 and phosphorus at #ab cents a pound4 ,as a general average at these conservative prices1 the investment of #c4bh an acre every four years paid back #be4fj in the four crops4 ,in most states the legal rate of interest is #f per cent but here is an investment that paid the principal and #fhj per cent interest every four years4 ,and these investigations show that the phosphorus was used with profit for the production of markedly different crops1 including potatoes and turnips1 barley and wheat1 clover and beans4 ,but the soil at ,rothamsted is no poorer in phosphorus than is the average soil of the ,united ,states2 and these results are given here not only because they are the oldest and most trustworthy the world affords1 but because they are strictly applicable to the production of common crops on vast areas of agricultural land in our own country4 ,the ,form of ,phosphorus to ,use ,the unfertilized soil at the ,rothamsted station contains1 in #b1jjj1jjj pounds--corresponding to about #f-b_/c inches to the acre--#ajjj pounds of phosphorus and #ce1jjj of potassium1 while an acre of plowed soil of the same weight at ,state ,college1 ,pennsylvania1 contains #aajj pounds of phosphorus and #ej1gjj of potassium4 ,in a word1 normal soils are deficient in phosphorus1 and the application of phosphorus in good systems of farming produces marked and profitable increases in crop yields4 ,but what form of phosphorus shall we apply8 ,this is a very important question in agricultural economics1 for we have many different kinds of fertilizing materials that contain phosphorus1 and one may cost ten times as much as another as a source of phosphorus4 ,thus #bej pounds of phosphorus in a ton of finely ground natural rock phosphate can be purchased at the mines in ,tennessee and delivered at the farmer's railway station in the heart of the ,corn ,belt for #h4 ,or the ton of raw phosphate may be mixed with a ton of sulfuric acid in the fertilizer factory1 and the two tons of acid phosphate may be sold to the same farmer for #cb4 ,or the fertilizer manufacturer may mix the two tons of acid phosphate with two tons of filler1 containing a little nitrogen and potassium1 and then sell the same farmer the four tons of so-called complete fertilizer for #hj2 and the farmer gets no more phosphorus in the four tons of complete fertilizer for #hj than in the one ton of natural phosphate for #h4 ,the ,pennsylvania ,state ,college conducted an experiment for twelve years--#ahhd to #ahie--;in which #a4je an acre was invested in ground raw rock phosphate with a rotation of corn1 oats1 wheat and hay 7clover and timothy71 and the value of the increase produced by the phosphorus amounted to #e4he as an average for the twelve years1 and to #h4da as an average for the last four years4 ,thus the profit was from about #efj to #hjj per cent on the investment1 counting corn at #ce cents a bushel1 oats at #cj cents1 wheat at #gj cents1 and hay at #f a ton4 ,these figures represent the increase produced by phosphorus over and above the value of the crops grown without phosphorus fertilizer4 ,in this case no farm manure was used on either part of the field2 but commercial nitrogen and potassium were applied alike on both parts1 and clover was grown in the rotation4 ,acid phosphate was also used in direct comparison2 and1 in answer to the question whether the general farmer should apply liberal amounts of finely ground natural rock phosphate1 or whether he should pay four times as much for phosphorus after the fertilizer manufacturer has mixed one part of the raw rock with one of sulfuric acid and thus produced two parts of acid phosphate1 these ,pennsylvania experiments tell us that the yearly average for the twelve years gave a gain per year of #b4de from the raw phosphate and #dh cents from the acid phosphate1 at the prices used by the ,pennsylvania ,experiment ,station4 ,but we must not draw general conclusions from this one experiment1 even though it covers twelve years4 ,in #ahie the ,maryland ,experiment ,station began field experiments with different forms of phosphorus2 and1 as an average of six tests every year for twelve years1 #a4ife invested in ground raw rock phosphate produced increases in corn1 wheat and hay that were worth #bb4aa1 at #ce cents a bushel for corn1 #gj cents for wheat1 #f a ton for hay1 and #c cents a pound for phosphorus in the ground natural phosphate4 ,how would you like #ajjj per cent profit as the result of mixing brain with brawn1 in connection with the improvement of your own business1 thus keeping the investment under your own control8 ,mind you1 this does not prove that farming is profitable1 but only that the intelligent use of phosphorus in farming is profitable4 ,in other words the admixture--brains--is profitable4 ,in commenting upon his investigations the director of the ,maryland ,agricultural ,experiment ,station states that the raw phosphate produced a higher total average yield than acid phosphate1 and at less than half the cost4 ,the ,rhode ,island ,experiment ,station began a series of experiments with different forms of phosphorus in #ahid4 ,if we add together all the hay and grain crops grown during the decade following the first year of these experiments1 we find that the increases per acre were #ad1ehj pounds for raw phosphate and #ad1eej pounds for acid phosphate1 on unlimed land2 while lime and raw phosphate produced #bg1jcj pounds1 and lime and acid phosphate #bi1fij pounds1 of increase2 and the acid phosphate cost three times as much as the raw phosphate4 ,in commenting upon these investigations the director of the ,rhode ,island ,experiment ,station states that the raw phosphate gave very good results with such farm crops as oats1 peas1 crimson clover1 millet1 soy beans1 and so forth1 but very poor results with such garden crops as turnips1 rutabagas1 cabbage1 beets1 lettuce1 squash1 and so forth1 and its use for these garden crops is not advised4 ,in #ahij the ,massachusetts ,experiment ,station began investigations with different phosphates applied in equal money value1 and in his report for #aijj the director states that the raw rock phosphate ranks above the acid phosphate both as an average for the entire period and as an average between #ahie and #aijj1 during which time the land to which no phosphorus was applied produced only #ee per cent as much as where raw phosphate was used--a result worth every farmer's consideration4 ,more ,bushels and ,tons ,the ,ohio ,agricultural ,experiment ,station has reported investigations covering sixteen years in which raw phosphate was compared with acid phosphate costing twice as much per acre4 ,as an average of all results secured1 #cbj pounds of raw phosphate applied with manure on clover sod produced #h4d bushels more corn1 #d4g bushels more wheat1 and #j4di ton more hay per acre than where manure alone was used1 and #cbj pounds of acid phosphate1 costing twice as much money but containing only half as much phosphorus1 applied with the same amount of manure1 produced #g4e bushels more corn1 #e4a bushels more wheat1 and #j4df ton more hay than where the manure alone was used4 ,now ,i have presented the averages or summaries of all investigations that have been reported covering ten years or more where equal money values of raw phosphate and acid phosphate have been used1 or where any apparent provision was made to supply some organic manure1 whether as farm manure1 green manure or merely as clover grown in the rotation2 and ,i invite the reader to mix his own brains with these data and not to expect me to state whether he should use the relatively cheap ground natural phosphate rock or the more costly manufactured acidulated phosphate in the improvement of his own soil in systems of permanent profitable agriculture4 ,making ,phosphate ,available ,if the natural rock is used it should be ground so that at least #ij per cent will pass through a sieve with #aj1jjj meshes to the square inch1 and of course its content of phosphorus 7from #ab to #ae per cent7 or of so-called phosphoric acid 7from #bg to #cd per cent7 should also be guaranteed4 ,moreover it should be used liberally and in connection with plenty of decaying organic matter4 ,people sometimes ask1 ,how much of the phosphorus in raw phosphate is available8 ,the best answer to this question is1 ,none of it2 and1 if you are not going to make it available1 don't use it4 ,on my own farm ,i use about one ton per acre of raw phosphate once every six years1 thus adding at least #bej pounds of phosphorus at a cost of less than #h2 whereas #bjj pounds of the common complete fertilizer per acre yearly would cost #ab every six years1 and would supply only #dj pounds of phosphorus4 ,i do not use complete fertilizers1 because there is plenty of nitrogen in the air and plenty of potassium in the soil2 and because1 by growing and plowing under plenty of clover1 ,i not only secure nitrogen from the air and liberate potassium from the soil but also liberate the phosphorus from the raw rock phosphate applied to the soil4 ,in beginning the use of raw phosphate where the supply of organic manures is limited1 ,i apply one ton of phosphate and #fjj pounds of kainit in intimate connection1 turn them under1 preferably with organic matter1 then add ground limestone if needed1 and thus prepare to grow clover4 ,by far the most important agencies under the farmer's control for the liberation of plant food are the decomposition products of fermenting or decaying organic matter1 such as green manures1 crop residues and ordinary farm manures4 ,in the decomposition of these organic materials sour or acid products are formed4 ,thus vinegar1 containing acetic acid1 is formed from the fermentation of apple juice1 hard cider being an intermediate product4 ,sweet1 chopped1 immature field corn becomes sour silage in the silo1 lactic1 acetic1 carbonic and other acids being formed4 ,by a similar process cabbage is turned into sauerkraut4 ,likewise sweet milk becomes sour1 with the formation of lactic acid4 ,oxalic1 citric1 tartaric1 succinic1 malic1 gallic and tannic are other well-known organic acids4 ,some of these are contained in the sap or juice of certain plants1 and these or others are formed when crop residues are decomposed in the soil4 ,in the ultimate decomposition of organic matter the carbon appears in the form of carbon dioxid which when combined with water forms carbonic acid4 ,though this is a very weak acid1 its solvent action is very important4 ,but1 in addition to the various organic acids and carbonic acid1 we have also to consider the formation of nitric acid in connection with the decomposition of organic manures4 ,nitric acid is one of the strongest known1 and in solvent power it is excelled by no single acid4 ,the nitrogen contained in crop residues and other organic manures is chiefly in chemical combination with carbon1 oxygen and hydrogen1 much of it in insoluble protein compounds4 ,normally this organic nitrogen is transformed in the soil1 first into ammonia nitrogen1 next into nitrite nitrogen1 and lastly into nitrate nitrogen1 these three transformations being effected by biochemical action produced by different kinds of living microscopic organisms called bacteria4 ,though detectable amounts of free nitric acid do not accumulate during this process of nitrification1 the soluble nitrate or final product is formed by the action of nitric acid upon a mineral base1 such as calcium1 magnesium1 or potassium1 which may have been in the soil in insoluble form1 so that the nitrogen must pass through the form of nitric acid in the transformation into nitrates4 ,while the organic matter applied to the soil contains about twenty times as much carbon as nitrogen1 and while corresponding amounts of carbonic acid and important amounts of intermediate organic acids must be formed1 it is of much interest to know that even the nitric acid formed in the transformation of organic nitrogen to nitrate nitrogen in sufficient quantity for a given crop is seven times as much acid as would be required to convert raw rock phosphate into soluble phosphate to furnish the phosphorus required for the same crop4 ,a knowledge of this definite quantitative relationship should help us to appreciate the possibilities of decaying organic manures in the important matter of making plant food available1 including potassium1 calcium and magnesium as well as phosphorus and nitrogen4 ,the value of rye1 rape1 buckwheat and other non-legumes when used as green manures is very largely due to the liberation of plant food by their decomposition in contact with the natural phosphates1 potash and other minerals contained in the soil4 ,the farmer has no more important business than that of making plant food available1 especially by supplying liberal amounts of decaying organic matter4 ,the following suggestions are offered to the land owner3 ,to enrich the soil apply liberal amounts of limestone1 organic manures and phosphorus4 ,to enrich the seller apply small amounts of high-priced complete commercial fertilizers4 ,thus the average of seventy-three ,cooperative ,fertilizer ,tests on ,clay and ,loam ,soils1 extending into thirty-eight different counties in ,indiana 7,bulletin #aee71 shows #ac cents as the farmer's profit from each dollar spent for complete fertilizers used for corn1 oats1 wheat1 timothy1 and potatoes1 if valued in the field at #dj cents a bushel for corn1 #cj cents for oats1 #hj cents for wheat1 #ej cents for potatoes1 and at #aj a ton for hay1 over and above the extra expense for harvesting and marketing the increase1 and of course the soil grows poorer1 because the crops harvested removed much more plant food than the fertilizers supplied4 ,,chapter ,,iv ,,permanent ,,soil ,,fertility ,its ,relation to ,profits and ,future ,values ,,though intelligent soil improvement is the most profitable business in which an honest man can engage1 ordinary farming is not a highly remunerative occupation1 and to a large extent the fortune of the farmer is bound up with the increase or depreciation in the market value of his land4 ,there are at least three important factors of influence which induce people to continue farming3 ,first1 the farmer is his own employer4 ,he controls his own job1 is his own boss and has no superior officer to lay him off because of disagreement1 dull business or political preferment4 ,farmers constitute by far the largest class of citizens who own their own business1 and are thus independent4 ,second1 the farmer is able as a rule to make some sort of a living for his family very largely out of the produce of the farm1 so that he gets some return for his labor in terms of food1 even when there is no profit in farming as a business2 whereas the wage-earner of the city1 as soon as his wages stop and his savings and credit are exhausted1 must see his family supported by charity or starve4 ,this is not fiction1 but fact4 ,third1 land is usually considered a safe investment1 in which one may hold a perfect and undivided title to his property2 and people will retain possession of a farm even when it pays a low rate of interest1 rather than sell and invest the proceeds in some other enterprise which they cannot control as individuals or which may suddenly depreciate in earning power1 fail or be utterly destroyed4 ,is ,land a ,safe ,investment8 ,though it is true that farm land does not pass out of existence in a day1 nevertheless it is by no means a safe investment1 as witness the numerous abandoned farms in the older agricultural sections of this new country4 ,it is easily possible for one of means to become land-poor--to have investments in land which will not pay the taxes and upkeep of buildings1 fences and so forth4 ,at prevailing prices for farm produce and labor there are vast areas of land in the older states far past the point of possible self-redemption2 and1 as a matter of business1 one might better burn his money and save his energy than to expend all his resources in half-paying for such depleted land1 depending upon the immediate income from it to raise a mortgage covering the unpaid balance4 ,intelligent optimism is admirable1 but fact is better than fiction2 and blind bigotry paraded as optimism is dangerous and condemnable4 ,some one has said that such a bigot is not an optimist but a cheerful idiot4 ,to purchase rich1 well-watered land at a low price and become wealthy by merely waiting till the land increases in value tenfold1 while making a living by taking fertility from the soil1 has been easy and common in the great agricultural states during the last half-century4 ,but1 paradoxical as it may seem1 land values have increased while fertility and productiveness have decreased and1 with shorter days for higher priced and less efficient farm labor1 with more middlemen absorbing the profits between the producer and the consumer1 it is now difficult indeed to buy land with borrowed money and pay for it from subsequent farm profits4 ,if continued soil depletion is practiced1 ultimate failure is the only future for such investments4 ,that vast areas of land once cultivated with profit in the original thirteen states now lie agriculturally abandoned is common knowledge2 and that the farm lands of the great ,corn ,belt and ,wheat ,belt of the ,north-,central states are even now undergoing the most rapid soil depletion ever witnessed is known to all who possess the facts4 ,unless this tendency is checked these lands will go the way of the abandoned farms4 ,some ,broad ,facts ,the ,united ,states ,bureau of the ,census reports that the total production of our five great grain crops--corn1 wheat1 oats1 barley and rye--amounted to #d1dad1jjj1jjj bushels in #ahii1 and to #d1dde1jjj1jjj bushels in #aiji1 an increase of less than one per cent4 ,furthermore1 if we assume the average production reported by the ,united ,states ,department of ,agriculture for the three-year periods #ahih to #aijj and #aijh to #aiaj as the normal for #ahii1 and #aiji1 respectively1 and compare these averages with the production actually reported by that department for #ahii and #aiji1 we find that as an average of all these crops #aiji was a slightly more favorable season than #ahii1 which indicates that with strictly comparable seasons the increase from #ahii to #aiji was less than #a_/b per cent in the production of these five great grain crops of the ,united ,states4 ,on the other hand1 the ,bureau of ,census reports that during the same decade the acreage of farm land in the ,united ,states increased by #d4h per cent1 and that the acreage of improved farm land-that is1 farmed land-increased by #aed per cent4 ,thus the census data plainly show reduced yield per acre4 ,in addition we have actual records which show that during the decade our wheat exports decreased from #baj1jjj1jjj to #ajh1jjj1jjj bushels1 and that our corn exports decreased from #aif1jjj1jjj to #di1jjj1jjj bushels1 in order to help feed the increase of #ba per cent in our population4 ,and yet the people complained of the high cost of plain living and many have been forced to adopt lower standards for the table4 ,meanwhile the value of the farm land in the ,united ,states increased by #aah per cent during the ten years--from #ac1jjj1jjj1jjj to #bh1ejj1jjj1jjj--;as reported by the ,bureau of ,census4 ,the ,value of ,land ,the great primary reason why land values have increased so markedly during the last thirty years is that ,america has no more free land of good quality in humid sections4 ,civilized man is characterized by hunger for the ownership of land4 ,our population continues to increase by more than #bj per cent each decade1 but all future possible additions to the farm lands of the ,united ,states amount to only #i per cent of the present acreage1 and most of this small addition requires expensive irrigation or drainage4 ,if it cost #d an acre to raise corn1 #e cents a bushel to harvest and market the crop1 #i cents a bushel to maintain the fertility of the soil1 and #a_/b per cent on the value of the land for taxes1 then1 if money is worth #e per cent1 land that produces #bj bushels of #dj-;cent corn is worth #ba4ha an acre4 ,on the same basis1 what would land be worth that produces #dj bushels of corn and equivalent values of other crops8 ,at first thought one might say1 #dc4fb2 but this answer would be far from the correct one1 which is #aaf4cf4 ,and1 if we again double the yield1 making it #hj bushels an acre1 the value of the land becomes not #hg4bd1 and not #bcb4gb2 but easy computation will show that the gross receipts from an #hj-;bushel crop will pay #g4bj an acre for soil enrichment1 #d for raising the crop1 #d for harvesting and marketing1 #a4ec for taxes and #e per cent interest on a valuation of #cje4de an acre4 ,the average yield of corn in the ,united ,states is only #be bushels an acre1 and the average net returns even from the farms of the ,corn ,belt will not pay #d per cent interest on their present market value4 ,but the intelligent investment of #b an acre annually in positive soil enrichment will increase the crop yield by two bushels of corn each year--or by equivalent amounts of other crops grown in the rotation--and will maintain this increase for at least a dozen years on the average land now under cultivation in the ,united ,states2 and no other safe investment can be named that will pay so great returns4 ,of course1 the cost is #a a bushel for the first year's increase1 and even the second year the #d bushels of corn cost #b2 but what is the cost per bushel of the increase the tenth year8 ,it is #aj cents2 and the twelfth year the #bd bushels of increase cost only #h-a_/c cents a bushel1 with a return of nearly #ejj per cent on the annual investment in soil improvement4 ,and this is not based on mere theoretical considerations4 ,the average ,corn-,belt land is producing only #dj bushels of corn to the acre2 while a six-year average yield of #ij bushels has been produced on the common ,corn-,belt land with proper and profitable soil treatment4 ,thus is it too much for any farmer to adopt a definite system based upon established practical scientific information which makes it possible for his yield to increase from #dj bushels to an average of #fd bushels an acre8 ,but let him make sure that the system he adopts is cumulative and truly permanent1 and not merely stimulating and temporary4 ,what ,phosphorus ,did on ,one ,farm ,on his #ejj-;acre farm near ,gilman1 in the heart of the ,illinois ,corn ,belt1 ,mr4 ,frank ,i4 ,mann has produced a #gj-;bushel average yield of corn for a five-year period1 and with #bjj acres of land in corn annually4 ,it cost him only #a an acre a year in fine-ground natural rock phosphate to produce increased yields of #af bushels more corn1 #bc bushels more oats and #a ton more clover than the average yields secured without adding phosphorus4 ,but this progressive1 practical farmer is only putting into profitable practice the results of the long-continued careful investigations with raw phosphate conducted by such public-service institutions as the agricultural experiment stations of ,pennsylvania1 ,maryland1 ,rhode ,island1 ,massachusetts1 ,ohio and ,illinois4 ,he knows also that on four different fields of typical ,corn-,belt land in ,mc,lean county1 ,illinois1 the total crop values per acre for a period of ten years were #adh4ge #aea-cj1 #adi4dc and #adi4if1 respectively1 and that on four other adjoining or intervening fields1 which differed only by two liberal additions of phosphorus during the ten years1 the respective crop values for the same time were #bbi1cg1 #bba4cj1 #bbi4bj and #bbe4eg4 ,of course1 ,mr4 ,mann does not buy nitrogen1 but he takes it from the inexhaustible supply in the air by means of clover and alfalfa or other legumes4 ,he does not buy potassium because he knows how to liberate it from the inexhaustible supply contained in the soil1 and because he knows that in the ,illinois investigation just cited the crop values from four different fields not receiving potassium were #adh4ge1 #aea4cj1 #bbi4cg and #bba4cj2 while four other adjoining fields1 which differed only by liberal applications of potassium1 produced during the same ten years #adi4dc1 #adi4if1 #bbi4bj and #bbe4eg1 respectively4 ,thus1 as a general average1 phosphorus increased the crop values by #gf4ej an acre1 which amounts to more than #cjj per cent on the investment1 and at the end of the ten years the soil on the best treated and highest yielding land was #aj per cent richer in phosphorus than at the beginning2 while the crops from the unfertilized land removed an amount of phosphorus equal to nearly one-tenth of the total supply in the plowed soil4 ,but a similar general average shows that potassium produced increased crop values worth only #hf cents1 or #c per cent of its cost4 ,what other results should be expected from land containing in the plowed soil of an acre less than #abjj pounds of phosphorus and more than #cf1jjj pounds of potassium8 ,working the ,land ,if there is one agricultural fact that needs to be impressed upon the ,american people it is that the farmers of this country have been living1 not upon the interest from their investments1 but upon their principal2 and whatever measure of apparent prosperity they have had has been taken from their capital stock4 ,the boastful statement sometimes made1 that the ,american landowner has become a scientific farmer1 is as erroneous as it is optimistic4 ,such statements are based upon a few selected examples or rare illustrations1 and not upon any adequate knowledge of general farm practice4 ,even to this date almost every effort put forth by the mass of ,american farmers has resulted in decreasing the fertility of the soil4 ,the productive power of normal land in humid climates depends almost wholly upon the power of the soil to feed the crop2 but the ,american farmer does everything except to restore to the soil the plant food required to maintain permanently its crop-producing power4 ,these ought be to have done1 but not to leave the other undone4 ,thus1 tile drainage adds nothing to the soil out of which crops are made1 but only permits the removal of more fertility in the larger crops produced on the well-drained land4 ,more thorough tillage with our improved implements of cultivation is merely working the land for all that's in it4 ,the use of better seed produces larger crops1 but only at the expense of the soil4 ,even the farm manure is so limited and is spread so thinly with manure-spreaders made for the purpose that it adds but little to the soil in comparison with the crops removed and sold in grain and hay as well as in meat and milk4 ,clover1 as commonly produced and harvested1 adds little or no nitrogen to the soil4 ,the ordinary high-priced1 manufactured1 acidulated1 so-called complete commercial fertilizers1 in the small amounts that farmers can afford to use1 and do use quite generally in the older states1 serve in part as soil-stimulants and commonly leave the land poorer year by year2 and if the farmers of the great ,corn and ,wheat ,belts are ever to adopt systems of permanent agriculture1 it must be done in the near future1 or they too will awake to find their lands impoverished beyond self-redemption4 ,even in the state of ,massachusetts1 where a most active campaign has been waged for forty years by the mixed commercial fertilizer interests1 urging and persuading many farmers to use their high-priced artificial soil stimulants1 very large areas of land are being agriculturally abandoned4 ,thus the following statement appears in the report of the ,united ,states ,bureau of ,census in regard to the farm land of ,massachusetts3 ,the area of improved land decreased without interruption until in #aiaj it was only about one-half what it was in #ahhj4 ,it should not be forgotten1 however1 that market gardeners often sell from #ajj to #cjj worth of produce from an acre and they can well afford to use large amounts of soluble commercial plant food 7acid phosphate1 nitrates1 etc47 as well as animal manures from the cities4 ,is the ,soil ,inexhaustible8 ,it is not the fault of the farmer alone that soil-robbing and land ruin have followed his work in ,america4 ,neither the average farmer of today nor any of his ancestors received any agricultural instruction in the schools2 and the greedy fertilizer agent has persuaded him to buy his patent soil medicine and has taken #ajj of the farmer's money and given him in return only #aj worth of what he really needs to buy2 and even the ,bureau of ,soils of the ,federal ,government has for several years promulgated the erroneous and condemnable theory expressed in the following quotations3 ,from the modern conception of the nature and purpose of the soil it is evident that it cannot wear out2 that1 so far as the mineral food is concerned1 it will continue automatically to supply adequate quantities of the mineral plant foods for crops4 7,united ,states ,bureau of ,soils1 ,bulletin ,no4 #ee1 p4 #gi47 ,there is another way in which the fertility of the soil can be maintained3 namely1 by arranging a system of rotation and growing each year a crop that is not injured by the excreta of the preceding crop3 then when the time comes round for the first crop to be planted again1 the soil has had ample time to dispose of the sewage resulting from the growth of the plant two or three years before4 7,united ,states ,farmers' ,bulletin ,no4 #beg1 p4 #ba47 ,the soil is the one indestructible1 immutable asset that the nation possesses4 ,it is the one resource that cannot be exhausted2 that cannot be used up4 7,united ,states ,bureau of ,soils1 ,bulletin ,no4 #ee1 p4 #ff47 ,and these are only samples of the false teaching spread abroad by this bureau of theorists1 even though the congressmen of the ,united ,states can not enter the capitol of the nation from any direction without passing depleted and agriculturally abandoned lands4 ,is it not in order to ask the ,congress or the president of the ,united ,states how long the ,american farmer is to be burdened with these pernicious1 disproved and condemnable doctrines poured forth and spread abroad by the ,federal ,bureau of ,soils8 ,it is true that these erroneous teachings have been opposed or ridiculed in ,europe2 they have been denounced by the ,association of ,official ,agricultural ,chemists of the ,united ,states1 and rejected by every land-grant college and agricultural experiment station that has been heard from1 including those in forty-seven states2 and yet this doctrine1 emanating from what should be the position of highest authority1 is the most potent of all existing influences to prevent the proper care of our soils4 ,the ,values in ,land ,it was ,baron von ,liebig who taught1 both in ,germany and in ,england1 that--it is not the land itself that constitutes the farmer's wealth1 but it is in the constituents of the soil1 which serve for the nutrition of plants1 that this wealth truly consists4 ,and it is in the application of this teaching1 completely verified by sixty years of investigation and demonstration by ,lawes and ,gilbert at ,rothamsted1 that ,england has been able to raise her #aj-year average yield of wheat to #cg-a_/b bushels an acre1 while the average for the ,united ,states stands at #ad bushels4 ,in ,illinois1 where the agricultural college and experiment station1 the state farmers' institute and the agricultural press have been working in perfect co-operation in teaching and demonstrating the need and value of soil enrichment as well as of seed selection and proper tillage1 the #aj-year average yield of wheat is already #c bushels higher and the #aj-year average yield of corn is #g-a_/b bushels higher than the averages for the #be-year period ending with #ahij1 before the definite information from ,illinois investigations began to be widely disseminated2 and yet it must be confessed that on the average ,illinois is producing only #af bushels of wheat and #cf bushels of corn to the acre1 which is less than half a crop1 measured by the possibilities of our soil and climate4 ,but what shall we say of ,georgia1 both an older and a larger state1 and with far better climatic conditions for corn1 yet with a #aj-year average yield of less than #ab bushels of corn to the acre1 notwithstanding the yearly expenditure of #bj1jjj1jjj for more than #bjjj different brands of commercial fertilizers that have been bought by ,georgia farmers8 ,the facts are that while some profit can be secured from the use of high-priced mixed commercial fertilizers for cotton with lint at #aj cents a pound1 they scarcely pay their cost when used for corn1 even at ,georgia prices4 ,working ,mind and ,muscle ,but ,georgia spends money enough for fertilizers to double the average crop yields of the entire state within a decade if wisely invested in positive soil enrichment in rational permanent systems of agriculture4 ,why should not the farmers of ,georgia and other ,southern states be brought to understand and to apply the results of those most valuable investigations conducted by the ,louisiana ,experiment ,station on typical worn upland soil of the ,south1 which show that the use of organic manures produced upon the farm-farm manure1 legume cover-crops and cottonseed meal--re-enforced by liberal additions of phosphorus1 increased the crop yields from #dff to #aead pounds per acre of seed cotton1 from #i4d to #ca4d bushels of corn1 and from #af4d to #da4h bushels of oats1 as the averages for nineteen years8 ,this experiment occupied #f acres of land1 but when the results are applied to a #fj-;acre farm it is found that the gross returns from the untreated land would amount to #eie4gf1 while the net returns from the soil treatment amount to #ief4jh annually1 both the value of produce and the cost of fertilizer being computed at the prices that were used by the ,louisiana ,experiment ,station4 ,thus the combined gross earning power of both land and labor is less than #fjj a year2 while the brain work applied to the improvement of the soil on the same farm brings a net return of more than #iej4 ,once in three years #ej pounds an acre of kainit was also applied4 ,this would contain only #e pounds of potassium1 or less than would be required for one #g-;bushel crop of corn4 ,these are the oldest experiments in the ,united ,states in which organic manures have been re-enforced with phosphorus1 and the only addition suggested for the profitable improvement of this system is ground limestone on acid soils4 ,these results only emphasize the fact that the average farm yields small returns upon the capital and labor invested1 but the statement may well be repeated that the intelligent improvement of his soil1 in systems of permanent agriculture1 is the most profitable business in which the farmer and land owner can engage4 ,,author',s ,,note ,the following generous statements are quoted here only because of the hope and earnest desire that those who have read the preceding pages may continue their study of the soil--the foundation of all agriculture--until they master the subject1 and make their own the existing knowledge of the fundamental principles of permanent soil fertility4 ,another ,great ,sermon ,have you read it8 ,it is ,the ,story of the ,soil1 by ,doctor ,cyril ,g4 ,hopkins1 and not since the publication of ,uncle ,tom's ,cabin has any writer in the world produced a book of such tremendous importance to present and future generations4 ,this sermon is in harmony with #bjth century ideals4 ,h4 ,a4 ,mc,k,e,e,n,e1 ,secretary ,illinois ,state ,farmers ,institute4 ,the ,story of the ,soil3 from the basis of absolute science and real life4 ,this is an odd book4 ,it has a love story running through it1 and it has an index1 not a usual appendix to a novel4 ,and yet it is not really a novel1 but a scientific book on agriculture4 ,there is just enough story to entice the less willing reader to absorb some of the latest results of soil analysis4 ,the young man of the story visits ,virginia and ,new ,england1 with a view to purchasing a worn-out farm and building it up4 ,he finally buys such a farm1 and by the methods carefully explained restores it to fertility and profit4 ,this requires dialogs and letters on scientific husbandry1 even in the love-making1 and one who reads and digests it will make a better farmer4--,the ,independent1 ,new ,york4 ,the ,story of the ,soil has proven an inspiration to many of our ,california farmers4 ,we wish for the book a widespread circulation4--,california ,cultivator4 ,i doubt if a dozen people in the country would believe that it is possible to write a novel about the soil--these big soil problems handled so ably1 so plainly that any person can understand4 ,here is a book that certainly every man in the land should read4--,editor ,,charles ,w4 ,,burkett1 of ,american ,agriculturist and of ,ginn ,company's ,country ,life ,education ,series4 ,i must say that ,i think the book is destined to do more good1 stir more thought1 encourage more upward effort among the farmers of this country1 than any other publication that has yet appeared4 ,it was a happy thought making a human story of it4--,ex-,gov4 ,w4 ,d4 ,,hoard1 ,editor of ,hoard's ,dairyman1 ,fort ,atkinson1 ,wis4 ,when ,dr4 ,cyril ,hopkins sets out to write a book we know we are in for something unconventional1 but this time he has excelled himself in unconventionality1 and has essayed a task that no author has attempted for the last sixty years1--to tell the story of the soil in the form of a chronicle4 ,the result is remarkable2 a clear account is given of the soil in relation to the crop1 and the interest of the subject is broadened by skillfully weaving in the threads of a mild novel4 ,light reading the book certainly is1 as the author intended1 but it has depth and permanent value4--,,dr4 ,e4,j4 ,russell1 ,director of the ,rothamsted ,experiment ,station1 ,england1--from ,nature4 ,in this book ,dr4 ,hopkins has embodied in the shape of an interesting story1 dealing with life on a farm1 the science of soil fertility and permanent agriculture4 ,he has demonstrated how the most badly run-down soil can be restored to more than virgin fertility1 and with profit in the doing of the work4--,editor ,j4 ,f4 ,,jackson1 of the ,southern ,planter1 ,richmond1 ,va4 ,i wish that every farmer and farmer's family in the land could read ,the ,story of the ,soil1 for it gives in a nutshell the results of years of patient study and investigation upon the most vital question that now confronts the farmer3 ,how shall he conserve his soil8 ,i have read it with great pleasure and profit4--,,fred ,l4 ,,hatch1 ,farmer1 ,spring ,grove1 ,ill4 ,in the form of a story--a real1 live1 interesting story--the book develops a very large number of highly important facts in connection with soils and farm fertility4 ,we have not seen anything like it before and owing to the hold it gets upon the reader it will be a power in carrying soil and fertility facts to many who would not read the purely scientific works4 ,the author is a leading authority and the statements in the book are reliable4--,ohio ,farmer4 ,the ,story of the ,soil1 by ,cyril ,g4 ,hopkins1 ,professor of ,soils and ,crops1 ,university of ,illinois1 a practical farmer and a scientific soil investigator2 a book of #cfj pages printed on heavy wove white paper1 in strong and durable binding2 illustrated with photographic reproductions of actual results secured in profitable systems of permanent soil improvement2 with comprehensive index and glossary4 ,price #a4jj ,can also be obtained from the publisher for #a4ab postpaid4