eetegee ole teres er ete 0488 8 8 wpe - > ! { de yA te \ = - Ki Ge ¢ =.) Yipee Led | if f ‘ii a wy ‘. Rate te: Be NOVE? ASHE A\ ition a" a. - 4 a wih [Pe ry of > LIBRARY OF CONGRESS. | ce] Chap.” } [URN ta Shelf. | i's UNITED STATES OF AMERICA. FERTILIZERS FERTILIZERS THE SOURCE, CHARACTER AND COMPOSITION OF NATURAL, HOME-MADE AND MANUFACTURED FERTILIZERS; AND SUGGESTIONS AS TO THEIR USE FOR DIFFERENT CROPS AND CONDITIONS v / 135'6 EDWARD B. VOORHEES, A.M. Director of the New Jersey Agricultural Experiment Stations, and Professor of Agriculture in Rutgers College New Vork THE MACMILLAN COMPANY LONDON: MACMILLAN & CO., Lrp. 1898 All rights reserved 1897! COPYRIGHT, 1898 By EDWARD B. VOORHEES Mount Pleasant Priniery J. Horace McFarland Company Harrisburg, Pa. CLOUT Sep. 30 ha ts PREFACE THERE is no question as to the desirability of the use of commercial fertilizers on most farms, though the methods now generally practiced are such as to indicate the very great need of a better under- standing of what the functions of a fertilizer are, of the terms used to express their composition and value, of the kind that shall be used, and the time and method of application for the different crops under the varying conditions that exist. In the preparation of this book, therefore, it has been the aim of the author to point out the under- lying principles and to discuss, in the light of our present knowledge of the subject, some of the important problems connected with the use of fer- tilizer materials. The subject is a large one when considered in all its bearings, and much must nec- essarily be omitted in a book intended for the general reader as well as the student. The author- appreciates keenly his _ limitations, owing to the lack of definite knowledge on many vital points; yet it seems that at this time, when (v) vl PREFACE the investigations of the experiment stations are beginning to be regarded as important educational factors, and when these institutions are more than ever prepared to study the fundamental principles which underlie the various processes involved in plant nutrition, the practical man should have a clear understanding of what is now known, in order that he may be prepared to accept and use that better knowledge which will undoubtedly be _ pro- vided for him in the near future. Kk Bee New BRUNSWICK, N. J., September 20, 1898. CONTENTS CHAPTER I THE NATURAL FERTILITY OF THE SOIL, AND SOURCES OF LOSS OF THE ELEMENTS OF FERTILITY .....-0.2-2--0> Soi1L FERTILITy—Chemical elements needed in plant growth—Fertility as influenced by water, climate and season—The influence of physical character of soil— Location of soil qualifies the term “fertility ” — Practical fertility is usable potential fertility ..............-.eeeees SourRcES oF NaTuRAL Loss or NITROGEN—Importance of careful culture—Loss of nitrogen by drainage— Escape of BEroren IGto the aAbLMOSPHEPO:5 oes sjic dsp dswas oe oe aid anes nds THE NATURAL LOSS OF .THE MINERAL ELEMENTS— Losses MueuLO MEChANiCal MCAS: ;ar,clarsseeiee aie alates Aa ayes wVee/Ses ARTIFICIAL LOSSES OF FERTILITY—A comparison of the prices received for the fertility elements in different crops—Fertility content of cereals and vegetables-— Irra- tional farm practice—Losses in ManureS.............eeees CHAPTER II THE FUNCTION OF MANURES AND FERTILIZERS, AND THE NEED OF ARTIFICIAL FERTILIZERS .....2.....sss000- THE ESSENTIAL ELEMENTS OF FERTILIZERS .......-. wisieieaie's NATURAL MANURES AND ARTIFICIAL FERTILIZERS ...cesecess (vii) PAGES 1-20 2-7 7-8 8-12 12-14 14-20 21-37 21 22 Vill CONTENTS PAGES DIRECT AND INDIRECT EFFECT OF MANURES....cccccccescees 23 UNAVAILABLE AND AVAILABLE PLANT-FOOD ..... Shamruoa ues 24-26 DANGER OF LOSS FROM THE USE OF SOLUBLE PLANT-FOOD.. 26 THE USEFULNESS OF A FERTILIZER CONSTITUENT DOES NOT DEPEND UPON ITs ORIGINAL SOURCE...... Stacie p's viniahawontt 27 Ust oF FERTILIZERS. 2.5.0.6. amtaaie s Sad aha deme Sees pm emee 28, 29 THE NEED OF ARTIFICIAL FERTILIZERS—The cost of produc- tion per unit of income is increased—A greater demand for special crops—Farm manures are inadequate—The growing importance of fruit-growing............ i oh ane me oes Seno 30-35 WILL It Pay TO USE FERTILIZERS? ......... i Sate an ee eae ea 35-37 CHAPTER III NITROGENOUS FERTILIZERS ....-..-0000. eima jedeintn st ateleteaate ~ B8-57 Waat Is MEANT BY FORM OF NITROGEN ? ....0ccccenscscecns 39 DRIED, WSDOOD sa. creche cclecsle clears cere siaeinls oratelerare sicher Goketae cyelbiisrerate 40, 41 DRIED MEAT OR MEAL, AZOTIN, AMMONITE, OR ANIMAL EAT TIES sce apie armremie) nals mn a eniareirt Wen Meee «sie Sipand aincaia aera 41 IGOR MBAti. oes iacewes ceed wa elas ee cae waela cen nina enstd - 42 DRIED AND GROUND FISH, OR FISH GUANO...... aa Rtas acl 42 PWG CRAB cizvisin eles xiaiai uae w acaleintcungaceeeheis aeaaiarnae wa iat'y. bisidlald ape toners 43 PB AICA GTS |. o/o:35,0.0,0 a: 3 aieis e nimyviane aciasein eiaiats aie cena ene iata eat otals 43, 44 GARBAGE 'TANKAGE «'o. «<9,0s.cq cael cemnaee eee Sees ane 44 LOW-GRADE NITROGENOUS PRoDuUcTS—Leather meal— Wool ged: We WASEO. sc. one St ee GUARANTEE ON BASIS OF ACTUAL CONSTITUENTS Nitrogen Chota): 0 Ye. pie ue 23 2 eee ee Phosphorie acid (available) Ni MAG ee aie ee 8.00 to 10.00 % Potash (actual). . 2. 21 1 ee ee ee 5.50 to 6.50% INTERPRETATION OF GUARANTEES 137 The guarantees of the raw materials mean prac- tically the same in the first as in the second case. In the first, the percentages given indicate the purity of the chemical salt; while in the second, the figures given indicate the actual content of the constituent contained in the chemical salt. In large commercial transactions, the sales are frequently made on the basis of certain purity percentages; as, for example, muriate of potash is sold at so much per ton on the basis of 80 per cent muriate. If the analysis shows it to contain less than 80 per cent, then the price paid per ton is less in proportion to such deficiency. If it is shown to contain more than 80 per cent, the purchaser pays for the excess at the same rate. In round numbers, a ton of muriate on the 80 per cent basis contains 1,000 pounds of actual potash; if the price is $40 per ton, the cost per pound is 4 cents. If analysis shows but 900 pounds instead of 1,000, the price paid per ton, at 4 cents per pound, is $36. If, on the other hand, it is shown te contain 1,100 pounds, the price paid per ton is $44. Purchase made when this method of guaranteeing is used is practically equivalent to the “unit” basis, though, as already stated, unless it is thoroughly understood, it is likely to be misleading. What has been said of the different statements of guarantees of the raw materials, is also true in the case of the mixed goods. In the first, the per- centages of the elements that are given represent the amounts when they exist in combination with other elements: nitrogen, as ammonia; phosphoric acid, 1388 FERTILIZERS as bone phosphate, and potash, as sulfate. While in the other, the percentages given indicate the con- tent of the actual constituents: namely, nitrogen, phosphorie acid and potash. The Advantages and Disadvantages of Purchasing Raw Materials and Mixed Fertilizers In the purchase of fertilizers, therefore, two meth- ods may be adopted: First, the buying of fertiliz- ing materials, as distinct from fertilizers, which fur- nish single constituents like the standard high-grade products, or which furnish one or two of the con- stituents, like ground bone, tankage, fish, and the mis- eellaneous products; these are called “incomplete,” because they do not furnish all of the three essential constituents. Second, the purchase of the mixed manufactured brands, which contain all of the three essential constituents, nitrogen, phosphoric acid, and potash, which are prepared to meet the demands of different soils and crops, and are called “complete,” because containing all of the essential manurial con- stituents, or those liable to be lacking in any soil. The relative advantage of these different methods of purchase depends, first, upon the cost of the con- stituents, and second, upon the use that is to be made of them. It may be urged that, on theoretical grounds, there are no good reasons why nitrate of soda, sulfate of ammonia, dried blood, superphosphates and potash compounds should be mixed, as the manufacture of DIFFERENT METHODS OF PURCHASE 139 these does not improve or change the quality of the constituents—it consists chiefly in simply grinding, mixing and bagging. There are, however, advan- tages and disadvantages in both methods of purchase, the chief of which are stated below. The advantages in the purchase and use of raw materials are :* 1. A better knowledge of the kind and quality of plant-food obtained. That is, these products as a rule possess characteristics which distinguish them from others and from each other, and they are more likely to be uniform in composition than mixtures. 2. It enables the use of one or more of the con- stituents as may be found necessary, thus avoiding the expense of purchasing and applying those not required for the particular crop or soil. The farmer is also enabled to adjust the forms and proportions of the various ingredients to suit what he has found to answer the needs of his soil or crop. 3. A saving in the cost of plant-food, since in their concentrated form, the expenses of handling, mixing and rebagging are avoided. The chief disadvantages are : 1. The materials are not generally distributed among dealers, and thus not so readily obtained. 2. It is difficult to spread evenly and thinly pro- ducts of so concentrated a character, particularly the chemical salts, which, unless great care is used, may ee ** First Principles of Agriculture.” 140 FERTILIZERS injure by coming in immediate contact with the roots of plants. 3. The mechanical condition or degree of fineness is less perfect than in the manufactured products. The advantages in the purchase and use of com- plete manures are: 1. They are generally distributed, and can be pur- chased in such amounts and at such times as are con- venient. 2. The different materials may be well propor- tioned, both as to form of the constituents and their relative amount for the various crops. 3. The products are, as a rule, finely ground and well-prepared for immediate use. The chief disadvantages are : 1. That it is impossible to detect in a mixture whether the materials are what they are claimed to be. 2. That without a true knowledge of what consti- tutes value, many are led to purchase on the ton basis, without regard to the quantity and quality of the plant-food offered. } There is no question that the actual cost of the constituent is less when purchased in the fertiliz- ing material than in the manufactured brand, as not only the expenses of mixing and bagging are saved, but the cost of handling the product per unit of plant-food is much less in the highly concentrated materials than in mixtures made up of both classes of fertilizing materials. In the purchase of fertilizers by the second method, the cost of the constituents is not only higher on the HOME MIXING 141 average, but the variations in their cost are very much greater, due to the differences in the charges made by the different manufacturers for handling and selling their products. HOME MIXTURES The fact that fertilizing materials are a regular article of trade, and may be purchased as such, and the fact that a complete fertilizer, so-called, is really only a mixture of the various manufactured fertilizing materials, has suggested the use of what are called “home mixtures,”—that is, their mixing by the farmer himself. This has proved to be very satisfac- tory under proper conditions, since, as already stated, the cost of the constituents is much less than if secured in the average manufactured brand (often from 25 to 50 per cent), and the mixing can be per- formed by the regular labor of the farm, and thus not add directly to the cost of the constituent. This matter of home mixtures has been carefully studied by a number of the experiment stations, notably Connecticut, Rhode Island and New Jersey. The results of their studies are published in their regular reports, and show that the materials can be evenly mixed on the farm, that the mechanical con- dition is good, and that the results obtained from their use are entirely satisfactory. It must be remem- bered, however, that whatever method of purchase is used, the object should be to obtain the kind and form of constituent best suited to the conditions 142 FERTILIZERS under which they shall be used, at the lowest price per pound. In any method of purchase which contemplates the use of a mixture, care should be taken in the selection of the brand or of the formula, since in mixtures as well as in the raw materials, there are two grades, the high-grade and the low-grade— high-grade in the sense that in quality the con- stituents are all good, and in the sense that maxi- mum quantities are contained; and_ second, high- grade only in that constituents of good quality are furnished. They may be low-grade in the sense that both the’ quality and amount of constituents contained are low, and also in the sense that only the quality of the constituents is low, the quan- tity being sufficiently high. Formulas The following formulas are used for the sole pur- pose of illustrating the differences that may exist between high-grade and low-grade mixtures, and not as indicating what should be used to make a good or poor mixture: ForRMULA No. 1 Nitrate of soda . . 500 lbs. furnishing 80 lbs. nitrogen High-grade super- phosphate ..1,100 ‘‘ : 180 ‘‘ phos. acid avail. Muriate of potash, 400 ‘‘ a 200 ‘* potash Totsha ys. 2,000 ‘' rr 460 ‘* total plant-food FORMULAS 143 With a guaranteed eomposition of : Nitrogen .. . OF ay eee pee ey) Phosphoric acid available) a ere, eae aan ere, se ses potash. hs ae haaa iets rohae 10% « FoRMULA No. 2 Nitrate of soda... 250 lbs. furnishing 40 lbs. nitrogen High-grade super- phosphate . .1,000 ‘‘ 7 160 ‘* phos. acid avail. Muriate of potash, 80 ‘‘ = 40 ‘* potash Make-weight . . . 670 ‘‘ Hi oo i Se 2,000 ** 2 240 ‘‘ total plant-food With a guaranteed composition of : ret hee gaa daa ane Phosphorie acid tecnitable) as eee Pease 07 PND eye oa ee 2 yt ote =," Ooms oes FoRMULA No. 3 wee 30 lbs. nitrogen WeEGSO os ss. 600 Ibs. furnishing | da"! - phosphono adil Mageaees =... 400 f ue 50 ‘* potash (actual) Make-weight . . .1,000 ‘‘ . J a 2,000 “* =« 170 ‘‘ total plant-food With a guaranteed composition of : EAE BSS Saeco a le re Oe RGMMOnG AGG 0. 66 gs ls 2 este ce 4.5 % EceateCbIA |) 6.5. ae 8 oles er Re ForRMULA No. 4 EO 60 lbs. nitrogen Mankaee ./. 3! : ankage 1,200 Ibs furnishing |) lations iis nied Le are B00,“ a 100 ‘‘ potash (actual) Motals) jie. 2.000 ** 340 ‘‘ total plant-food 144 FERTILIZERS With a guaranteed composition of : TRRGReRE eS en, he Ce a Oe 3% PROppHONG BCIG... 20. a ss a Ee ee 9% Piuaale. oe ah, ee. el he ke ee a ee 5 % Formula No. 1 shows a high-grade product, both in respect to quality of plant-food and concentration, while No. 2 is high-grade only in respect to quality. In order that the plant-food may be distributed throughout a ton of material, it is necessary to add what is called “make-weight,” or a diluent. These usu- ally consist of substances that possess no direct fer- tilizing value. High-grade mixtures cannot be made from low-grade materials, and low-grade mixtures cannot be made from high-grade materials without adding “make-weight.” The advantages of high- grade products are concentration and high quality of plant-food. It will be observed that formula No. 1 contains nearly twice as much plant-food as No. 2, or, in other words, it will require about two tons of a fer- tilizer made according to formula No. 2 to secure the same total amount of plant-food as is contained in one ton of No. 1. Now, the material in No. 2, other than the actual plant-food, is of no direct ferti- lizing value,—it is of no more value as a fertilizer than the soil to which it is applied,—but the actual cost of the constituents is considerably in- creased, because the expenses of handling, bagging and shipping are just double what they would be ror Nor a. DISCUSSION OF FORMULAS 145 Formula No. 3 illustrates a low-grade fertilizer in the sense that it contains the poorer forms of the con- stituents, and furnishes a comparatively small total amount of plant-food. The nitrogen is all in the organic form, and is derived from tankage, which, while not the poorest, is poorer than other forms of organic nitrogen. The phosphoric acid is also in organic combination, and, while useful under many conditions, is less useful for certain other conditions than the soluble in Nos. 1 and 2. The potash, while soluble, is derived from kainit, which, because of its large content of chlorin, is regarded as less desirable for certain crops than the more concentrated materials, muriate, or the high-grade sulfate, which is free from chlorids. It would require more than 2% tons of a mixture made according to this formula to furnish as much total plant-food as would be contained in a mixture made according to formula No. 1, besides the disadvantage of the lower quality of the constituents. Formula No. 4 illustrates a mixture which, while rich in total constituents, is not high-grade in its quality. All of these considerations should, therefore, be carefully observed in the purchase of mixtures, or even in the purchase of raw materials for home mixtures, and the analysis, if properly made, will give positive evidence on these points. The expensiveness of low-grade fertilizers, as repre- sented by formulas Nos. 2 and 38, is not fully appre- ciated by the purchaser in all cases. He does not stop to think that it is quite as expensive to handle the J 146 FERTILIZERS material which contains no plant-food as 1b as) ae handle material which is rich in plant-food. The Cost of Handling “ Make-weight” A comparison of the advantages of low-grade and high-grade mixtures in this sense of total quantity of plant-food may be illustrated as follows: : It has been shown by continued studies at the New Jersey Experiment Station that the charges of the manufacturers and dealers for mixing, bagging, ship- ping and other expenses are, on the average, $8.50 per ton; and also that the average manufactured fertilizer contains about three hundred pounds of actual fer- tilizing constituents per ton. A careful study of the fertilizer trade indicates that these conditions are also practically true for other states in which large quanti- ties of commercial fertilizers are used. A mixture of formula No. 1 would contain 460 pounds of actual available fertilizing constituents per ton—160 pounds, or over 50 per cent more than is contained in the average manufactured brand. That is, a farmer purchasing a brand similar to formula No. 1 would secure in 2 tons as much plant-food as would be contained in 3 tons of the average man- ufactured brand. Assuming that the charges per pound of plant-food at the factory, and the expense charges, are the same in each ease, and also that the quality of plant-food in the one is as good as in the other, the consumer would save $8.50 by purchasing two tons of the former instead of three tons of the CONCENTRATED FERTILIZERS 147 latter. In a few states the consumption of fertilizers reaches nearly 100,000 tons annually, while in many it ranges from 30,000 to 50,000 tons. Thus is shown the very great saving that may be effected in the matter of the purchase of fertilizers from the standpoint of concentration alone, or, in other words, the importance of a definite knowledge of what constitutes value in a fertilizer. This saving may be accomplished, too, without any detriment to the manufacturer, since the difference to him between making high-grade or low-grade goods, in reference to concentration, is largely a matter of unskilled labor. The manufacturers are in the business to cater to the demands of the trade. If consumers are intelligent, high-grade rather than low-grade goods will be pro- vided by the manufacturers. Furthermore, as already indicated, high-grade in the matter of concentration means high-grade in quality, for high-grade mixtures cannot be made from low-grade products. GENERAL ADVICE As farmers understand more fully the question of fertilization, and as intensive methods of practice are adopted, the tendency in the purchase of fertilizers will undoubtedly be toward the first method, or the purchase of fertilizing materials, rather than mixtures, or at any rate, of high-grade special mixtures, rather than what are now termed “standard brands,” which are, aS a rule, low-grade in the concentrated sense. ‘This tendency will come, first, because intensive prac- 148 FERTILIZERS tice requires a larger use of all of the constituents, and second, a greater need in the growth of certain crops of specific or dominant elements, and thus better results are obtained from the application of single constituents, or the use of special formulas, than in “extensive” practice, in which the object is more to supplement the soil supplies than to fully provide for all the needs of the plants for food. | The tendency toward codperative buying on the part of small farmers will increase as it has done in those countries in which there is a larger use of fertilizers than here, though the method is already in suecesstul operation in certain sections of the country, and with very gratifying results. In this method of direct purehase, the manufacturer and the consumer are brought into closer relations with each other. Transactions are based upon the transfer of a definite number of pounds of a specific kind and form of plant-food, rather than upon some mysteriously re- markable qualities that are claimed, and are by many supposed to be inherent in certain mixtures. CHAPTER VIII CHEMICAL ANALYSES OF FERTILIZERS A COMPLETE chemical analysis of a fertilizer shows not only the total amount of the different constituents contained in a brand, but the form in which they exist, and in most cases, the source of the materials used is also indicated. THE INTERPRETATION OF AN ANALYSIS An analysis may show simply the total amount of the constituents. This is not a sufficient guide as to the value of a mixture, for while it is not possible to indicate absolutely by analysis whether the organic nitrogen, for example, is derived from blood (which is one of the best forms), or from horn meal (one of the poorer forms), it is possible to show whether the nitro- ven is derived from nitrate or from ammonia, whether the phosphoric acid is derived from a superphosphate or a phosphate, and whether the potash present is in the form of a sulfate or of a muriate. A high-grade or a low-grade fertilizer, for example, may be distinctly indicated by the analysis, since it is of a high-grade if the three forms of nitrogen are present, if the total phosphoric acid is chiefly soluble in water, and if the potash has been derived from a sulfate or from a (149) 150 FERTILIZERS muriate. On the other hand, if the analysis shows that the nitrogen is all in the organic form, that only a minimum percentage of the phosphoric aeid is available, though not soluble, and that a high econ- tent of chlorin accompanies the potash, it is a low- erade product, in so far as the form of the constituents is concerned. The following statements of analyses of two brands, showing the same total content of constituents, illustrate this point: ANALYSIS No. 1 Nitrogen, -as-nitrate .. 5 is. .04 nS sie SUEY TISASINI a Se 3 YS, yo os ** organic mater... 6 de Ail: wh so sce. 4-5 ok a ee Oe ee Phosphoric acid, soluble. . . . .. .8% on Re cei) Ee Reren rs RL? sib A eG UTE we ieee, 5 Oe Topalcayaileabie leo. 54 Stee eee Peabimes eS ee hl oes otk ae Rs Ce CST SS ae ATT eee ee A eS ANALYsIS No. 2 Nitrogen, as nitrate . (6 ce ammonia . Ai eh DIS ae ‘organise mather ..2° .-4 4.88 Aik] 1 aes ey Lee ae re ee. eae Phosphorie acid, soluble. . sak eet ee Me 35 iS SERVES 5 oe eee is Pe. Gaoha bbe: oie el ee ee Total avilable << 5% es aS Bee PeGtaBh cP so. 7e park Boe me cack he oe Ohilorig: --.5- 0 a TAS ee ae ee A study of these two statements of analyses shows that the total contents of the constituents are identical, VALUE OF A CHEMICAL ANALYSIS 151 3, 10 and 5, respectively, in each case. That is, so far as the total amounts are concerned, one brand furnishes as much as the other, and from that stand- point alone it is as good as the other; but it has been already shown that the value of a fertilizer depends not only upon the total content of its constituents, but upon the form in which they exist. In the first brand it is found that two-thirds of the total nitrogen exists in the soluble form, equally divided between nitrate and ammonia; the remaining third is in the organic form, and may be derived from blood, or from some low-grade materials. It is to be fairly presumed, however, that when thus associated with so high a proportion of soluble nitrogen, it is in a good form, as the manufacturer has given evidence of his intent by his liberal use of other good forms. In the ease of the phosphoric acid, it is shown that of every 100 pounds of the total, 80 pounds are soluble, 10 reverted, or nine-tenths of the whole is available; 10 pounds of every hundred only are in- soluble, which is not only an indication, but positive’ proof, that the phosphoric acid is derived from a superphosphate. In the ease of potash, the chlorin associated with it is but % per cent, indicating that it has been drawn from high-grade sulfate, since kainit and muriate are rich in echlorin, while in a high-grade sulfate no appreciable amounts of chlorin are present. In the second statement, all of the nitrogen is shown to be in the form of organic matter. It may be derived from blood, though it is not likely to have 152 FERTILIZERS been drawn from this source, since of the total phosphoric acid but 20 pounds per hundred, or one- fifth, is available, and that is reverted rather than soluble, indicating that the phosphoric acid must have been drawn from tankage or from bone, or other ma- terials which contain reverted but no soluble phos- phorie acid, and which also contain a considerable percentage of nitrogen. The phosphoric acid was cer- tainly not drawn from a superphosphate, or it would have shown a higher percentage of available, a cer- tain proportion of which would have been soluble, and the percentage of insoluble would have been very much less. In the ease of potash, it is quite evident that it was drawn from kainit, inasmuch as the percentage of chlorin exceeds the percentage of the potash, as would be the ease if the potash had ip drawn from that source. Thus it is that a complete chemical analysis of a fertilizer indicates very clearly the source of the materials by the form in which the constituents exist in the mixture. THE AGRICULTURAL VALUE OF A FERTILIZER It is obvious, from what has already been pointed out, that the value of a fertilizer to the farmer _ depends not so much upon what is paid for it as upon the character of the materials used to make it. This value is termed the “agricultural value,” and it is measured by the value of the increased crop produced by its use. It is, therefore, a variable factor, depend- AGRICULTURAL VALUE OF A FERTILIZER 153 ing first, upon the availability of its constituents, and second, upon the value of the increased crop produced. For example, in the first place, the agricultural value of a pound of soluble phosphoric acid is likely to be greater than that of a pound of insoluble when applied under the same conditions as to soil and crop, because in the one case the element is in its most available form, while in the other it is least available. In the second place, the soluble phosphoric acid may exert its full effect and cause a greatly increased yield on a certain crop, and still not cause an increase in its value sufficient to pay the cost of the application, while for another crop the same application may result in a very great increase in the value of the erop. The character or form of the materials used in a mixture, as well as their suitability for the crop must, therefore, be carefully considered in the pur- chase of fertilizers. Slow-acting materials cannot be expected to give profitable returns, particularly upon quick-growing crops, nor expensive materials such profitable returns, when used for crops of relatively low value, as for crops of relatively high value. THE COMMERCIAL VALUE OF A FERTILIZER This agricultural value is, however, separate and distinct from what is termed “commercial value,” or cost in market. This value is determined by market and trade conditions, as the cost of production of the erude materials and the cost of their manufacture and sale. Since there is no strict relation between 154 FERTILIZERS agricultural and commercial or market value of a fer- terlizer constituent, it frequently happens that an element in its most available form, and under ordi- nary conditions of high agricultural value, costs less in market than the same element in less available forms and of a lower agricultural value. The cost of production in the one ease is lower than in the other, though the returns in the field are far superior. It is manifestly impossible to fix an agricultural value for any of the constituents that will be true under the varying conditions of soil, crop and season, and method of use, though the relative value of the different forms under uniform conditions of use may be fairly indicated, and the analysis is the guide as to their form. The commercial value of the different constituents in their various forms may, too, be fairly indicated, and will vary according to variations in trade conditions. If the wholesale jobbing price of nitrogen as nitrate is 15 cents per pound, available phosphorie acid 5 cents per pound, and potash 4 cents per pound, these are the prices which the manufacturers pay. Their increased cost in manufactured brands, therefore, is In proportion to the cost of this work ; hence their cost to the consumer at factory should vary within reasonably narrow limits, due to varia-— tions in cost of manufacturing in different localities. An illustration of the commercial value is shown by the following example: Suppose that nitrate of soda costs or can be purchased at retail, in ton lots, for $48 per ton, which is, then, its commercial value. The commercial or trade value of the nitrogen is, COMMERCIAL VALUE OF A FERTILIZER 155 therefore, 15 cents per pound, since a ton contains on the average 320 pounds of nitrogen. Or, suppose that the retail price of available phosphorie acid in superphosphates is $1 per unit; this is its commercial value, and hence the commercial or trade value of the available phosphoric acid would be 5 cents per pound, since a unit contains 20 pounds. It does not follow that the application of a pound of nitrogen, costing 15 cents, and, therefore, having a commercial value of 15 cents, will result in an increased crop worth 15 cents, or that the application of a pound of phosphorie acid costing 5 cents per pound will result in an increased crop worth 5 cents. The increased returns in crop from their use may be very much greater or much less than the cost of the constituents, depending upon the kind of crop and the skill of the user. In the purchase of materials, however, a com- mercial valuation is a guide as to the cost of the con- stituents from different manufacturers or dealers; and in many states a system of commercial values for mixed fertilizers has been fixed, which, when properly understood, is a useful method of comparison of the different brands. This method is based upon the fact that at points of supply a pound of nitrogen, in the form of nitrate, of ammonia, or of definite organic compounds, or a pound of available phosphoric acid, or of potash in the form of muriate or sulfate, is practically the same to all manufacturers. That is, these cost prices, or trade values, when applied to the constituents in the mixture, represent their commercial value before they 156 FERTILIZERS are mixed to form complete fertilizers. Hence, the difference between the valuation of a brand on this basis and the cost to the consumer represents the charges, including profit, for mixing, bagging, ship- ping and selling the goods. The commercial or trade value for each of these constituents is obtained, as already indicated, by simply calculating the cost, using two factors, — the wholesale prices for the different materials con- taining them, and their average composition. To this cost is added a certain percentage, to represent the cost of handling and distribution in small lots. Thus the trade value corresponds as nearly as may be with the cost of the constituents to the farmer. That is, the price fixed represents what the farmer would have to pay the manufacturer for the con- stituents in the material before it is mixed. For example, suppose the wholesale price per ton of nitrate of soda for the six months preceding’ March 1 is shown to be $40; the wholesale cost of nitrogen in this form is, therefore, 12.5 cents per pound. To this wholesale price may be added a certain sum to cover the expenses of handling, usually 20 per cent, thus making the retail price per ton $48, and the _ trade or commercial value of the nitrogen 15 cents per pound. That is, the $48 per ton, or 15 cents per pound, represents the retail cost per pound of nitrate nitrogen. This, if applied to the nitrogen as nitrate, in the mixed fertilizer, will show what it could have been bought for as nitrate in the unmixed fertilizer. The values for the other constituents are SCHEDULE OF TRADE VALUES $57 derived in the same way. These; together, make the schedule of trade or commercial values of the con- stituents which are used in the computing of the commercial values of mixed fertilizers. The schedule of values is revised annually, and, as nearly as pos- sible, at the same time in the year. The following schedule, used as an illustration of this point, was adopted for 1898 by the states of New York, Con- necticut, Rhode Island, Massachusetts, Vermont and New Jersey: SCHEDULE OF TRADE VALUES ADOPTED BY EXPERIMENT STATIONS FOR 1898 Cts. per lb. tomo das Miirahes . 6.6 Se ee atcha ts, eee a ammonia salts wo... . Vike gel aur ameter Organic nitrogen, in dried and fine- cand fish, meat and blood, and in mixed fertilizers... . Beak «Oe Organic nitrogen, in fine-ground bone and fahkaze* om cen eeees = a ‘‘ eoarse bone and tankaget .... . . 10.0 Phosphoric acid, soluble in water. ..... i Bb Denar cs & hee i 2 **) ammonium aioe. so ian BS ‘* insoluble, in fine bone and ee scan sage = o ns ‘* coarse bone and tankageft. . 3.5 4) 2 ‘* mixed fertilizers . ..°. 2.0 - eS ps ‘* fine-ground fish, cotton- abd meal, castor pomace and wood ashes... ....... . 4.0 omaha Muriahe.... 2. 6 6 J Se hes ay, agelee, p as Men ae ened - je emlfahe, and in. forms fea from muriates (or UTA et AES oT ok ig, a, Spe od BEG oy eV emtat gees ta Ce * Finer than 1-50 inch. 7 Coarser than 1-50 inch. tIn New Jersey, the price for the soluble and reverted is identical; viz., 4.5 cents, owing to the different method used in the determination of the “reverted.” 158 FERTILIZERS It will be observed that the schedule gives the cost per pound of the different forms of nitrogen, and of high-grade organic nitrogenous materials; of nitrogen and phosphoric acid in ground bone and tankage; of available phosphoric acid in superphos- phates, and of actual potash in the potash salts, and is a useful guide also in showing that the nitro- gen, phosphoric acid and potash contained iu these materials can be purchased in ton lots for the prices mentioned. The valuations of mixed fertilizers, obtained by the use of this schedule, are entirely commercial; they are not intended to indicate even a possible agricultural value. This point needs to be emphasized, aS many are inclined to interpret them as not only guides as to agricultural value, but as positive statements of such value. It can be said, however, that those who do so do not familarize themselves with the discussions that usually aeccom- pany reports of analyses. The different trade values given for the nitrogen and phosphoric acid in the two grades of bone represent their value in the form of ground bone and of bone meal, products which are distinctly recognized in the market, and which are quoted at different prices. The coarser ground bone is lower in price than the finer bone meal. The accuracy of the schedule of values can be shown by comparing it with the actual prices paid for the constituents in the different materials, and such comparisons as have been made from year to year, by a number of the institutions exercising an analysis control, show that manufacturers and dealers OBJECTIONS TO COMMERCIAL VALUES 159 are willing to sell to farmers at prices corresponding very closely with the schedule.* A value is placed upon the insoluble phosphoric acid in mixed fertilizers, not because all insoluble costs the price given, but because in mixtures it is assumed that the phosphoric acid is drawn from organic sources, which do cost, at least, the price given. There are arguments both in favor of and in oppo- sition to this method of comparing the commercial values of mixed fertilizers. The chief arguments in opposition may be stated as follows: ‘ First, that the prices of these materials vary, and hence in order to represent the actual commercial value at the time the sales are made, they should be changed as the markets change. . Second, the valuations are misleading, because the farmer does not clearly understand their meaning, and is thus guided in his judgment of the usefulness or agricultural value of a fertilizer by the stated com- mercial value, as shown by this method, rather than by the kind, form and proportion of constituents that may be contained in it, and upon which its agricultural value should be based. Third, the chemical analysis does: not show abso- lutely the sources of the materials, and thus it is difficult to place a true commercial value upon a mix- ture. This is especially true of organic nitrogen, since because it is impossible to separate the amounts that may be derived from different materials, a uniform *See Bulletins Connecticut and New Jersey Experiment Stations. 160 FERTILIZERS value is placed upon the total nitrogen found, whether it is derived from the best forms, as dried blood and dried meat, or whether derived from horn meal, ground leather, or other low-grade forms of nitrogenous material. This encourages the use of low-grade products by unscrupulous manufacturers, to the real detriment of the trade as a whole. Fourth, that the commercial value so fixed mili- tates against the use of certain kinds of good materials, and in favor of certain kinds of poorer materials. That is, a valuation of 2 cents per pound for insoluble phosphoric acid in complete fertilizers, for example, is a direct encouragement to include in the mixture a considerable proportion of the insoluble phosphoric acid from South Carolina, and other rock phosphates, the value of which is ignored in commercial transac- tions; while that price (2 cents) does not give a fair value to the phosphoric acid contained in bone, tankage and natural guanos, products in which the commercial value of the insoluble is recognized,—that is, mixtures which contain bone and tankage, and which furnish phosphoric acid largely in an insoluble form. The valuation fixed for this form is too low to fully represent the commercial value of these goods. It is also said that the trade value for available phos- phoric acid in the mixtures encourages the use of superphosphates from the rock phosphates, and dis- courages the use of superphosphates from bone-black, bone-ash and dissolved bone, because the trade or commercial values represent the average cost of availa- ble phosphoric acid in the superphosphates from all THE ADVANTAGES OF VALUATIONS 161 of these, while the latter materials, because of actual commercial conditions, cost more than the superphos- phates from the former. The chief arguments in favor are: First, that it is not asserted that the system shows absolutely the commercial value of each brand at the time the sales are made, but the comparative com- mercial value. Second. They are not misleading. The commercial valuations are not intended to be a guide as to the agricultural value of a fertilizer. It is distinctly stated in the reports of analyses that the comparative values are purely commercial. Third. It is a system which more nearly approaches perfection than any other that has been devised, is educative in its tendency, and is a safe guide, in the majority of instances, as to the charges made for mixing, handling and selling plant-food contained in the different brands. If the analysis is properly in- terpreted, as already indicated, it is the purchaser’s fault if he buys poor forms of plant-food at a high price. It is certainly a safer guide than mere name of brand, and does not encourage the use of poor materials. Fourth. Any system of comparison of brands must leave a great deal to the judgment of the purchaser. He must interpret for himself whether he would rather that his phosphorie acid were derived from one source or another, whether he would prefer to pay a higher price for insoluble phosphoric acid in acid phosphate, and have the remainder soluble, than to pay the same K 162 FERTILIZERS or a greater price for the insoluble phosphoric acid in bone, and have the remainder of it in the reverted form. These conditions are again indicated by the analysis which accompanies the valuation; the valua- tions are, therefore, not to be used in total disregard of the composition. If they are so used, it is not the fault of the system. That it militates against the use of high-priced superphosphates, if they are no better than the lower-priced ones, is no argument against the system, but rather for it, since it tends toward a readjustment of the prices, a condition that must be met in all competitive trades. Furthermore, the valua- tion system has been effective in driving out materials that are either fraudulent in their character or of very low-grade. It is impossible to obtain a high valuation on poor materials, and in the majority of eases de- pendence upon valuations alone would be a safe guide as to the comparative agricultural value of brands of the same general composition. CALCULATION OF COMMERCIAL VALUES The following examples illustrate how commercial values of complete fertilizers and of ground bone are caleulated. The mixed, or complete fertilizer, contains the three forms of nitrogen, three of phosphoric acid, and the two forms of potash. In the -bone, it is assumed that 50 per cent of the meal is finer than 1-50 inch, and is, therefore, regarded as fine, and that 50 per cent is coarser than 1-50 inch, and is, therefore, regarded as coarse; and it is also assumed that the CALCULATION OF COMMERCIAL VALUES 163 proportions of the nitrogen and phosphoric acid in the fine and coarse is the same; also, that the analysis shows the bone to contain 4 per cent of nitrogen and 20 per cent of phosphoric acid. A Complete Fertilizer it 2 3 4 Value Estimated value % or lbs. Lbs. per lb. per ton of each per 100 per ton cts. constituent-— Maworen, AS nitrates... . . .1* 20= 20.K 13.0 = $2 60 - mmmoma salts . 1 < 20= 20 x 14.0 = 2 80 se erence matter. <= 20 « 14:00 = 2 80 Piigspnorie acid, soluble. . . 8 >< 20=160. < 4.5 = 7 20 = — Teavertot,... 1K 30 2=- 90. << Asa 90 oh oe SSeS. 6) 1 Ok Br OK Oa 40 Potash, as muriate 5 ee nO Ke ee 4 25 - Rm@@ipnae. 5~. 32 25 R201 5 = 5 00 Total estimated value per ton. ....... . $25 95 The first column shows the per cent of the con- stituents contained, which, multiplied by 20, gives the pounds per ton in the second column, which, multiplied by the schedule prices per pound, gives the valuation per ton, as shown in the fourth column. Ground Bone 1 2 3 4 5 6 : % or lbs. .% of Value Estimated per _ fine- % or lbs. ‘Lbs. per lb. value 100 Ness per 100 per ton cts. per ton , fe Re in ee. = 20== 40°. 15 = ee 49 Nit : eee | ft X50: Bin coarse 6 20 =: 40. K--10.0 “= * 4°00 Phosphoric (20 K 50=10infine. * 20—200 K 4.0 = 800 acid . (20 K 50—10 in coarse. xX 20—=200 K 3.5 = 700 otal estimated value per ton... .... 03 8. - .- 1 $2440 164 FERTILIZERS The first column of figures shows the per cent, or pounds per hundred, of the constituents, which is multiplied by the percentage of fineness, which gives the percentage or pounds per hundred of fine or coarse in the third column. The calculation is then finished as in the case of complete fertilizers. THE UNIFORMITY OF MANUFACTURED BRANDS Another point which consumers of fertilizers are interested in is the reliability of the various brands. That is, they desire to know whether a brand that shows good forms of nitrogen, of phosphoric acid, and of potash in one year may be depended upon to fur- nish approximately the same the following year, or whether the manufacturers change their formulas from year to year to conform to the relative cost of the different materials: that is, whether when nitrogen is relatively expensive and phosphoric acid is rela- tively cheap, they introduce a larger proportion of phosphoric acid and a smaller percentage of nitrogen; whether when organic nitrogen is cheap and nitrate and ammonia nitrogen are dear, they change the pro- portions of these to correspond with the difference in price, in order to retain the same selling price. This is an important point, since after a certain brand has been shown to be better suited than another to their conditions of soil, to change the formula, both in reference to the character and pro- portions, may mean to the purchaser the difference between profit and loss. UNIFORMITY OF MANUFACTURED BRANDS 165 Evidence on this point can be obtained from the reports showing the results of the analyses of the dif- ferent brands from year to year, and a careful study of these shows that genuine manufacturers of fertilizers,—those who make it their sole business, rather than a side issue or an adjunct to another busi- ness,—can be fully depended upon in this respect. They know that the farmer’s interest is their interest, and that their sales will depend, other things being equal, upon the increased crop results that the farmer secures; that the permanency and success of their business will depend upon the successful and profitable use of their product; and that they cannot afford to and do not change their formulas from year to year, either in proportion or quality of constituents, to cor- respond with the changes in price of the materials. Their brands can be depended upon to furnish prac- tically the same amount, kind and proportion of plant-food from year to year. The value of a fertilizer depends upon the kind, quality and form of plant-food, as shown by the analysis. Value does not depend upon who the manu- facturer is, or what the statements may be concerning the usefulness of special manipulation, nor to any great extent upon special formulas, unless the farmer has positive knowledge of the character of his own conditions. Formulas derived both in kind and pro- portion from the same materials will do equally well under the same conditions. So far as the matter has been investigated, there is no specific virtue added by what is claimed to be the “blending” of the materials. 166 FERTILIZERS In the whole matter of the purchase of fertilizers, no guide, however good, can take the place of intel- ligence on the part of the purchaser. This intelli- gence must be exercised in the selection of forms of plant-food, in the preparation of formulas, in the interpretation of guarantees and of commercial values, and in the method of using the fertilizer. CHAPTER IX METHODS OF USE OF FERTILIZERS THE primary object in the use of a commercial fer- tilizer is to receive a profit from the increase in the yield of crops from the land to which it is applied; and this may be derived either from the immediate crop, or from the larger yield of a number of crops. That the greatest immediate or prospective profit may be gained, a wide knowledge of conditions which have either a direct or indirect bearing upon the result is ~ essential. CONDITIONS WHICH MODIFY THE USEFULNESS OF FERTILIZERS In fact, the controlling conditions surrounding the matter are so numerous and so various that it is im- possible, with our present knowledge, to lay down positive rules for our guidance. At best, only sug- gestions can be offered. We may possess a full knowledge of both the kind and form of existing fertilizer supplies, their cost and the action under known conditions of the constituents contained in each, as well as their maximum capability for increasing the crop, but together with this knowl- edge, it is essential that we should know how these (167) 168 FERTILIZERS facts and principles must be applied to each individual crop, soil and condition, and yet even with this, abso- lute certainty of profit is not guaranteed. A few of the more important conditions which control the profitable use of fertilizers are, therefore, briefly dis- cussed, in order to arrive at a better understanding of the practical suggestions and conerete examples given in subsequent chapters. | Derivation of Soil a Guide as to its Possible Deficiencies The first consideration is the soil itself, and its influence. It is well known that a wide difference exists in soils, both in reference to their chemical character or composition, and to their physical proper- ties, each having a direct influence in determining the effect of any specific application of fertilizers. These differences in soils are due to changes which were wrought in the surface of the earth during its forma- tion, and which are continuing in a small way at the present time. It is believed that the original earth crust contained all the minerals now found in it, but that in the beginning they were distributed more uni- fromly throughout its mass, and that the soils as they exist at the present time, and as a result of the direct disintegration of the original rock, represent a very small area of the earth’s surface. They are not now . constant, but variable in their character. The various changes that have taken place during geologic time have resulted in the breaking up of the original rocks, SOILS DIFFER IN CHEMICAL COMPOSITION 169 a part having been separated mechanically and being represented by various sizes of particles, and a part rendered soluble. The fragments and the soluble por- tions thus separated have not been deposited again in the same proportions as they existed in the original rock, which has caused a very wide variation in the chemical composition of the different soil deposits. The process and its results may be shown at the present time in the wearing away of rocks. The harder, sandy particles separate mechanically, and because of the difference in the size of the particles, the coarser are deposited as gravel or sand, in one place, and the finer particles are deposited in another, making the clay. The lime enters partly into solution and is de- posited in another place, and so on, thus giving us sandy soils, clayey soils and limy soils, all differing - from each other in their amount and proportion of the essential fertilizing constituents, as well as in their physical qualities,—the sandy and gravelly making the poorest soils because the particles consist very largely of quartz, and the remainder being poor in phosphoric acid or potash. The clay soils are frequently rich in minerals containing potash, and poor in those con- taining lime and phosphoric acid; and the limestone soils are poor in potash and rich in lime, and fre- quently in phosphates. In addition to these soils, there are those that are made up largely of vegetable matter, due to the accumulation of decaying growths. These are frequently rich in nitrogen and poor in all of the essential mineral constituents. Hence it is that in the use of a commercial fertilizer, 170 FERTILIZERS at least for certain crops, a knowledge of the nature of soils in respect to the possible deficient element is important, in order that those which exist in abun- dance may not be added to, but that they may be sup- plemented by such an abundance of the deficient ele- ments as to permit the acquirement by the crops of those necessary for a maximum growth. As a rule, potash is a very essential constituent of manures for sandy soils, not only because all crops require potash, but because they require it in relatively large amounts, and because in sandy soils it is lable to exist in minimum amounts. Potash fertilization, therefore, is especially useful on sandy soils. On the other hand, in clay soils, which, as a rule, contain a very con- siderable proportion of potash as compared with sandy soils, the deficient element may be either phosphoric acid or lime; and if these are supplied in abundanee, the plant will be able to secure the necessary potash. In a limy soil, the lime and phosphoric acid, and per- haps the potash, may be in sufficient abundance to cause a normal growth of plant, yet the nitrogen may be so deficient as to prevent a normal growth. Physical Imperfections of Sandy Soils If it were possible to distinctly classify soils in respect to their lack of one or more of the essential constituents, it would be an easy matter to formulate rules for our guidance in the fertilization of these soils; but such is not the ease. Even sandy soils vary widely in their chemical composition, as well as in SOILS DIFFER IN PHYSICAL CHARACTER 171 their mechanical or physical properties, and certain of them possess such a physical character as to make it impossible to grow maximum crops even though the essential elements are all supplied in sufficient abundance. The constituent particles are too coarse, and thus make the soils so open and porous that they too freely admit the air, water and warmth, and thus results a very rapid drying and heating of the soil, with a premature ripening and burning of the crops. The phosphates or the potash compounds ap- plied are not readily fixed, and suffer an immediate loss as soon as rain falls in such amounts as to cause a leaching from them. Physical Imperfections of Clay Soils In elay soils, the physical conditions are quite the reverse. All clay soils do not have the same general composition, and they differ widely in their physical qualities. Certain of them possess a reasonably good texture, and permit the absorption of the food applied, as well as its gradual distribution throughout the mass by the percolation of the water through them; while certain others are so compact, owing to the finely divided particles, that even though they were abundantly supplied with all or the necessary mineral constituents, profitable crops could not be grown because the roots could not readily penetrate, and because the water falling upon the land would not readily pass through, but remain upon the surface. In the ease of soils with an abundance of lime, 172 FERTILIZERS physical qualities also exercise a very considerable influence, even though there is a sufficient supply of all of the fertility elements. Certain of them are too cold, others are too dry, and the mechanical condition is such as to prevent the proper and uniform growth of plants. It must be remembered, then, that only gen- eral rules apply in the use of fertilizers upon soils of the different classes, and that they are modified by both the chemical composition and the mechanical con- dition of the soils. The best use of a fertilizer,—that is, the greatest proportionate return of plant-food in the erop, all things considered,—is obtained from its ap- plication upon soils that possess “condition,” or that are well cultivated or managed. Full returns cannot be expected when they are applied upon soils that are too wet or too dry, too porous or too compact, or too coarse or too fine. It is important that even the best soils should be properly prepared, and it is infinitely more important that those which possess poor mechan- ical condition should be improved in this respect, before large expenditures are made for fertilizers. The Influence of Previous Treatment and Cropping In the next place, the previous treatment and cropping of soils should guide in the use of fer- tilizers, since soils of the same natural character, located equally well, will not always show the same results from the application of fertilizers, because in the one case the eropping has been such as to result in the rapid exhaustion of one, rather than the three INFLUENCE OF PREVIOUS CROPPING 173 specific fertilizer elements; while in the other, the eropping may have been quite as severe, but has been helpful because judicious rotations have been used and improved methods practiced. It may be that in the one ease, there may have been a continuous cropping of wheat, for example, and only the grain sold from the farm, in which ease there would be a much more rapid exhaustion of the nitrogen and _ phosphoric acid than of the potash; and if this continuous wheat-cropping has been continued for a long time, an application of the phosphates only may result in quite as large an increase in crop as if both phos- phates and potash salts were applied, because the potash exhaustion has been less rapid than _ that of the phosphoric acid, and the addition of potash would simply add to the probably abundant quantities already there. On the other hand, if the cropping has been timothy hay, the removal of the potash would have been greatly in excess of the phosphoric acid, and consequently a fertilization with a greater proportion of potash, or even this element alone, of the minerals, may result in quite as large returns as if the fertilization had consisted of both phosphorie acid and potash. In fact, if the land had been cropped continuously with tobacco, cotton, potatoes, or other crop, there is likely to be a much larger removal proportionately of some one element, rather than proportionate amounts of all. This _ practice results in a disproportionate removal of the constitu- ents, and in order to bring the land back to its eapacity for maximum production, or to equalize 174 FERTILIZERS matters in this respect, it is necessary to add to the soil the constituents removed in amounts in excess of the others. On the other hand, the cropping may have been such as to be fully as exhaustive in the sense that the total quantity of constituents removed is quite as great, though since they are removed in more uniform proportions, the period of profitable cropping is extended, and the fertility needed ineludes all the essential elements, rather than one or two. That is, the grain, hay and potatoes may have been erown in rotation, each removing one or the other in greater proportion, but because they differ with each crop, no one is exhausted before the other; and thus when the land reaches the time when it would no longer profitably grow those crops, an application then of all of the constituent elements would result in a greater and more profitable increase in crop than if the fertilizer contained one constituent only. The previous treatment and cropping of soils, therefore, is an important guide in determining the most economical method of fertilization. Furthermore, in this matter of cropping as a guide to possible need of fertilization, it must be remem- bered that a continuous one-crop practice is more productive of total loss of constituents than a prac- tice which includes such renovating crops as clover, or one which permits of a more constant occupation of the land, since in the former, the introduction of clover reduces the need for nitrogen fertilization, and in the latter, the vegetable matter is not so rapidly used up, and the loss of mineral constituents by INFLUENCE OF CHARACTER OF CROP 175 mechanical and other means is very much reduced, because of the constant occupation of the land. The Influence of Character of Crop The financial result from the application of fer- tilizers is also influenced in a very large degree by the character of the crop itself, whether the value of an increase in crop as great as can be expected from a definite application is high or low; and on this basis, crops may be elassified into two general groups: first, those which possess a high fertility, and which, as a rule, possess a relatively low commercial value; and second, those which possess a low fertility value and a relatively high commercial value. In the first class are included the cereal and forage crops, as corn, oats, wheat, hay, buckwheat, cotton and tobacco, and in the second are included the various vegetable and fruit crops. This classification, and its importance, may be illustrated by the following examples : A ton of wheat, at $1 per bushel, will bring $33.33. Its sale removes from the farm 388 pounds of nitrogen, 19 of phosphoric acid, and 13 of potash. At prevailing prices for these constituents, it would cost $6.50 to return them to the farm. A ton of asparagus shoots, at 10 cents per pound bunch, will bring $200. Its sale removes from the farm 6 pounds of nitrogen, 2 of phosphoric acid and 6 of potash, which could be returned for but little more than $1. 176 FERTILIZERS A ton of timothy hay will bring $10. Its sale removes from the farm 18 pounds of nitrogen, 7 of phosphorie acid and 28 of potash, amounts that would cost $4. A ton of apples will bring in an ordinary season $20. It removes less than 3 pounds of nitrogen, 1 of phosphoric acid and 4 of potash, which would cost less than 60 cents to return to the land. It is thus shown that crops lke wheat and hay possess a relatively low commercial value, and yet carry away, when sold, a very considerable amount of the fertilizing constituents, while vegetables and fruits, as illustrated by the asparagus and the apples, have a high commercial or market value, and carry away but minimum amounts of the fertilizing con- stituents. This distinctive character of crops, while not an absolute guide as to the profits that may be obtained from the use of fertilizers,—since the cost of production varies widely for each class,—is instruc- tive in showing that those of a low commercial value are more exhaustive than the other class, or those of a high market value, and is certainly suggestive, pointing out the necessity for judgment in the ap- plication of fertilizers that shall be made in the ease of crops of the different groups. The Kind of Farming, Whether “ Extensive or Intensive” Another very important consideration, and one which exercises an influence, is whether the farming engaged in is “extensive” in its character, or “intensive;” CHARACTERISTICS OF GROWTH Ti whether the purpose or idea is to simply supplement the stores of plant-food in the soil, or whether the object is to ensure an abundance of all forms of constituents under all reasonable conditions, in order that a maximum production may be secured. PLANTS VARY IN THEIR POWER OF ACQUIRING FOOD In the next place, the character or feeding capacity of the plant and its season of growth should be con- sidered, that systematic methods may be adopted, and thus not only that waste of fertilizing materials may be avoided, but that the applications may be made at such times and in such amounts as will, other things being equal, promote the greatest increase per unit of applied food. While each plant possesses individual characteristics which distinguish it from all others, for our purpose they may again be classified into general groups which possess somewhat similar characteristics, particularly as to their method and time of growth and their capacity for acquiring food from soil sources. Characteristics of the Cereal Group The cereals possess distinct characteristics of growth. The roots branch just below the surface, and each shoot produces feeding roots, which distribute themselves in every direction, and thus absorb food from the lower layers of the soil as the plant grows older. Because of their wide root system, and because L 178 FERTILIZERS of the character of their feeding rootlets, they are able readily to acquire food from the insoluble phos- phates and potash compounds of the soil, though they are unable to feed to any extent upon the insoluble nitrogen. Furthermore, inasmuch as the most rapid development of many of these crops takes place early in the summer, before the conditions are favorable for the rapid changing of organic nitrogen into nitrates, they are, with the exception of Indian corn (maize), specifically benefited by early applications of nitrogen in the form of nitrate. The corn, on the other hand, which makes its most rapid growth after the other cereals are harvested,—in July or August,— when the conditions are particularly favorable for the de- velopment of nitrates, do not usually require as large proportions of nitrogen as of the mineral constituents, particularly the phosphates. That is, wheat, rye, oats and barley are specifically benefited by the early appli- eation of quickly available nitrogen. Characteristics of Grasses and Clovers Forage crops, including both the grasses and clovers, constitute another group, in so far as their use is con- cerned, though possessing marked distinguishing char- acteristics. Of the grasses, nearly all species are perennial, though their length of life depends upon the method of cropping and upon the character of the soil. They send their fibrous roots into the sur- face soil in the same manner as the cereals, though they differ from them in forming a set of buds which CHARACTERISTICS OF GROWTH 179 become active in the late summer and develop new roots and shoots. They resemble the cereals in their power of acquiring mineral food, and are even more benefited by the application of nitrogen, since the chief object in their use is to obtain the nitrogenous substances contained in leaf and stem in the form of pasture, forage or hay, rather than the matured grain. Hence, nitrogen, which promotes this form of growth, is an important constituent, and under any conditions there should be a liberal supply provided. The clovers, on the other hand, are not perennial, with the partial exception of “white” or ‘Dutch” clover, and with this exception they all possess a tap- root, which penetrates downward, and as it descends, throws out fibrous roots into the various layers of soil. They are capable of readily acquiring their mineral food, both because of their large root systems and because of the character of the roots. They, how- ever, differ in one very important particular from the cereals and grasses, in that under proper conditions, as already pointed out (p. 118), they are capable of acquiring their nitrogen from the air. Thus with liberal dressing of only phosphoric acid and potash, maximum crops may be secured. They are “nitrogen gatherers,” and the tendency of their growth is to im- prove the soil for the nitrogen consumers, or for those that obtain their nitrogen only from soil sources. Root Crops Another class of plants, differing from those already described, includes the root crops, as beets, mangels, 180 FERTILIZERS turnips and carrots. These plants cannot make ready use of the insoluble mineral constituents of the soil. Hence, in order to insure full crops, they must be liberally supplied with available food. Of the three classes of fertilizing constituents, the phosphates are especially useful for turnips, while the slower- growing beets and earrots require that the nitrogen shall be in quickly available forms. The proper fertilization of sugar beets, for example, is of great importance, since not only is the yield affected by fertilization, but the quality of the beet for the production of sugar. White potatoes and sweet potatoes, the one a tuber, the other an enlarged root, constitute another class which does not possess strong foraging powers. They require their food in soluble and available forms, and with suitable soils potash is the ingredient that is especially useful in the manures applied. Market-garden Crops Another group of crops is distinguished as a class, not so much because of their peculiar habits of growth as beeause of the objects of their growth, though this latter fact has a very important bearing upon economical methods of fertilization. This class in- eludes what are called “market-garden crops,” as lettuce, beets, asparagus, celery, turnips, cucumbers, melons, sweet corn, beans, peas, radishes, and various others. The particular object in raising these is to secure rapidity in growth, and thus to insure high quality, which is measured by the element of succu- FRUIT CROPS A DISTINCT CLASS 181 lence. In order that this may be accomplished, they must be supplied with an abundance of available plant-food, and since nitrogen is the one element which more than any other encourages and stimulates leaf and stem growth, its use is especially beneficial to all of these crops. They must not lack for this element in any period of their growth, though, of course, a sufficiency of minerals must be supplied in order that the nitrogen may be properly utilized. Because of their high commercial value, the quantity of plant-food applied may be greatly in excess of that for any other of the groups, and profits, as a rule, are measured by this excess rather than by the proportion of the elements. Fruit Crops Another distinct class of crops, though differing materially in their individual characteristics, as well as in their time and period of growth, are the fruits. These differ from most other crops, in that a longer season of preparation is required, in which the growth may be so directed as to prepare the plant or tree for the proper development of a different kind of product, namely, fruit, as distinct from grain or seed in the cereals, or succulence in the vegetable crops. The fruit differs in its characteristics from the ordinary farm crops, in that its growth and development require a little different treatment, since it is necessary that there shall be a constant transfer of nitrogen from the tree to the fruit throughout the entire growing season. The growth of each succeeding year of tree and fruit 182 FERTILIZERS is dependent, not altogether upon the food acquired during the year, but as well upon that acquired in the previous year, and which has been stored up in bud and branches. A knowledge of the habits of growth, the period of growth and the object of the growth of this class is, therefore, useful as a guide to the eco- nomical supply of the essential elements of growth. These crops must be provided with food that will en- courage a slow and continuous rather than a quick growth and development. SYSTEMS OF FERTILIZING SUGGESTED A careful review of the foregoing facts furnishes abundant evidence of the impracticability of attempts to give information concerning the use of fertilizers that will apply equally well under all of the conditions of farming that may occur. Nevertheless, there have been a number of methods or systems of fertilization suggested, each of which gg one or more points of advantage. A System Based Upon the Specific Influence of a Single Hlement The one which has perhaps received the most atten- tion, doubtless largely because one of the first pre- sented, and in a very attractive manner, is the system advocated by the celebrated French scientist, George Ville. This system, while not to be depended upon absolutely, suggests lines of practice which, under SYSTEMS OF FERTILIZING 183 proper restrictions, may be of very great service. In brief, this method assumes that plants may be, so far as their fertilization is concerned, divided into three distinct groups. One group is specifically benefited by nitrogenous fertilization, the second by phosphatie, and the third by potassic. That is, in each class or group, one element more than any other rules or dominates the growth of that group, and hence each particular element should be applied in excess to the class of plants for which it is a dominant. In this system it is asserted that nitrogen is the dominant ingredient for wheat, rye, oats, barley, meadow grass, - and beet crops. Phosphoric acid is the dominant fer- tilizer ingredient for turnips, Swedes, Indian corn (maize), sorghum and sugar cane; and potash is the dominant or ruling element for peas, beans, clover, vetches, flax and potatoes. It must not be understood that this system advoeates only single elements, for the others are quite as important up to a certain point, beyond which they do not exercise a _ controlling influence in the manures for the crops of the three classes. This special or dominating element is used in greater proportion than the others, and if soils are in a high state of cultivation, or have been manured with natural products, as stable manure, they may be used singly to force a maximum growth of the crop. Thus, a specific fertilization is arranged for the various rotations, the crop receiving that which is the most useful. There is no doubt that there is a good scien- tific basis for this system, and that it will work well, particularly where there is a reasonable abundance 184 FERTILIZERS of all of the plant-food constituents, and where the mechanical and physical qualities of soil are good, though its best use is in “intensive” systems of prac- tice. It cannot be depended upon to give good results where the land is naturally poor, or run down, and where the physical character also needs improvement. A System Based Upon the Necessity of an Abundant Supply of the Minerals Another system which has been urged, notably by German scientists, is based upon the fact that the mineral constituents, phosphoric acid and_ potash, form fixed compounds in the soil, and are, therefore, not likely to be leached out, provided the land is con- tinuously cropped. They remain in the soil until used by growing plants, while the nitrogen, on the other hand, since it forms no fixed compounds and is perfectly soluble when in a form useful to plants, is hable to loss from leaching. Furthermore, the mineral elements are relatively cheap, while the nitro- gen is relatively expensive, and thus that the eco- nomical use of this expensive element, nitrogen, is dependent to a large degree upon the abundance of the mineral elements in the soil. It is, therefore, advocated that for all crops and for all soils that are in a good state of cultivation, a reasonable excess of phosphoric acid and potash shall be applied, sufficient to more than satisfy the maximum needs of any crop, and that the nitrogen be applied in active forms, as nitrate or ammonia, and in such quantities and at MINERAL SUPPLIES ADVANTAGEOUS 185 such times as will insure the minimum loss of the element and the maximum development of the plant. The supply of the mineral elements may be drawn from the cheaper materials, as ground bone, tankage, ground phosphates and iron phosphates, as_ their tendency is to improve in character; potash may come from the erude salts. Nitrogen should be applied chiefly as nitrate of soda, because in this form it is immediately useful, and thus may be applied in frac- tional amounts, and at such times as to best meet the needs of the plant at its different stages of growth, with a reasonable certainty of a maximum use by the plants. Thus no unknown conditions of availability are involved, and when the nitrogen is so applied, the danger of loss by leaching, which would exist if it were all applied at one time, is obviated. This method also possesses many advantages, par- ticularly where the “intensive” system is practiced, though it is also useful in quickly building up worn- out soils, or those naturally poor, because in any case these must be provided with liberal supplies of the minerals, and when these only are applied, the im- mediate outlay is far less than if the expensive ele- ment, nitrogen, were included; and a greater economy in the use of nitrogen is accomplished if it is added in small amounts when required. Besides, in the im- provement of soils, the liberal application of the minerals is conducive to an abundant growth of the legumes, which are able to acquire their nitrogen from the air, thus reducing to some extent the outlay for this expensive element. This system is strongly 186 FERTILIZERS recommended where cheap phosphatic and _ potassic materials are readily accessible, as is the case in those countries where it is successfully used. A System Based on the Needs of the Plants for the Different Elements as Shown by Chemical Analysis Another system of fertilization is based upon the theory that the different plants should be provided with the essential elements in the proportions in which they exist in the plants, as shown by chemical analysis. Different formulas are, therefore, recom- mended for each crop, the constituents of which are so proportioned as to meet its full needs. This method, if care is taken to supply an abundance of all the necessary constituents, may result in a com- plete though perhaps not an economical feeding of the plant, since it assumes that a plant which con- tains a larger amount of one constituent than of another requires more of that constituent in the fer- tilizer than of the others. It does not take into con- sideration the fact that the plant which contains a larger amount of one element than another may pos- sess a greater power of acquiring it than one which contains a smaller amount. Neither does this system take into consideration, as already pointed out (p. 178), that the period or time of growth of the plant also exercises a consider- able influence in indicating the capability of the plant to acquire its necessary food from the stores of the FERTILIZING POT-PLANTS 187 soil, as may be illustrated by wheat and Indian corn, which both contain a relatively high content of nitrogen. Under good conditions of soil, wheat is specifically benefited by heavy dressings of quickly available nitrogen. Corn is not, and one reason is, that they possess different powers of acquiring food, due, to a considerable extent, to the difference in their time of growth, as well as to the period or time of their most rapid growth. This method may, however, be applied with very ereat advantage in greenhouse work, or in growing market-garden crops, where the amounts in the soil are not regarded as of importance, and excessive amounts of all are added. The system has been elaborated to a great degree of nicety for the grow- ing of greenhouse crops, flowers, and foliage plants, so much so that now artificial manure cartridges are prepared, which contain the amounts and kinds of food shown by the analysis of the different plants to be needed for their growth and full development. “The manure has the form of a fine powder, enclosed within a metallic wrapper, and firmly compressed into the shape of a cartouche or capsule, cylindrical in form, about three-fourths inch across and one-half inch in depth. It is simply thrust into the soil of the pot to a depth of one-half or one inch, and allowed to remain. After a time it is found that the fertilizer gradually disappears, and at length nothing is left but the little pill-box-like wrapper, which originally contained the mixed fertilizing powder.” * *«The Gardener’s Chronicle,” London, England. 188 FERTILIZERS A System in Which the Fertilizer is Applied to the “Money Crop” in the Rotation Another system is also recommended, which is well adapted for “extensive” farming, where the ma- jority of crops which are grown in rotation possess a high fertility value and a low commercial value, and where one crop is regarded as the chief ‘ money- maker.” The system demands that to this crop shall be applied such an abundance of plant-food as to insure a continuous feeding, and a consequent max- imum production, even though adverse conditions intervene. Thus by a liberal supply of food, a money crop is secured which is as large as climate and sea- sonal conditions will permit, though which does not require all of the food applied. Hence the residue may be depended upon to fully nourish the remaining crops in the rotation, or at least the immediately suc- ceeeding ones, thus saving direct outlay for them. This system may be illustrated as follows: On soils in good physical condition, and naturally well adapted for growing potatoes, this crop is se- lected as the “money-maker” in the rotation, which consists of corn, potatoes, wheat, clover and hay. The potato crop is fertilized so liberally, say with 1,500 pounds per acre of a fertilizer containing — PION! 395), Cah bee agin OSes, ee emer ee 4% Phosphoric acid: .: 38ers ee ce eee 6% | ners wimee eres epee r kn see ot 10% as to insure its maximum growth under average con- ditions. The removal of a large crop would still IRRATIONAL SYSTEM OF FERTILIZING 189 leave a large residue of plant-food, which would pro- vide the following wheat crop with at least all of the mineral elements necessary to produce a maximum crop. If the wheat does not show vigorous growth in the spring, it is lightly top-dressed with nitrate of soda, which not only feeds it directly with nitrogen, but strengthens and invigorates the plant, enabling it to secure the minerals needed. The removal of a large crop still leaves an unused residue, upon which the clover crop following is also able to make a maxi- mum growth, and thus three crops are fertilized with the one application. The hay is either fertilized with both the minerals and nitrogen, or lightly top-dressed with nitrogen early in the spring. The yard manure, accumulated from the residue of straw, hay and corn, ‘is applied to the corn, which, being a gross feeder, is able to obtain from this an abundance. Thus, by the heavy application of fertilizer upon the ‘money erop,” all the crops in the rotation are benefited. This method possesses many valuable features, and is, perhaps, quite as well adapted as any other for this system of farm practice. An Irrational System The most expensive and irrational system of all, and one more commonly practiced than any other in general farming, may be termed the “hit or miss” system; if a “hit” is made, there is a profit, if a “miss,” the loss is trifling. In this system, no special thought is given to the character of the crop or its 190 FERTILIZERS needs. If the farmer can afford it, he purchases a fertilizer, without regard to its composition, and ap- plies it in very small amounts. If it happens to con- tain that element which is particularly needed for the plant to which it is applied, a profit is secured. In too many eases, however, the constituents added are already in abundance in the soil, or so little of the fertilizer is used as to preclude any profit. SUMMARY With the exception of this last system, there are good features in all of these suggested methods of use, and it rests with the farmer to select the best points from each, or rather to use the suggestions in each which are in his judgment more applicable to his con- ditions. They are all based upon underlying principles, and pre-suppose a knowledge of them on the part of the farmer. They are, at best, but guides or sign-posts pointing toward better methods in the use of fertil- izers, rather than absolute rules to be blindly followed. The suggestions here and in subsequent chapters, in reference to the use of fertilizers, are formulated from the best information obtainable by the writer, and mainly from two sources: First, the results of experimental inquiry, and, second, the results of the observation and experience of practical men. In no case can absolute rules be laid down. Farmers may safely rely on the well-established principles, but each must remember that the use of the principles must be modified according to his own conditions. CHAPTER X FERTILIZERS FOR CEREALS AND GRASSES Ir HAS already been pointed out (p. 175) that these crops are classed as possessing a relatively low commercial value and a relatively high fertility value, and that, from a practical standpoint, in any fertiliza- tion of them a possible profitable return should be borne in mind. This is, of course, necessary in all cases, but is particulary necessary where an increased yield, as great as can be expected from an application of proper fertilizing materials, cannot possibly result in an extraordinary profit, a result quite possible with certain crops of the opposite class. The possible in- crease in yield, too is, dependent on the conditions of soil and season, and if these latter are such as to forbid a maximum increased yield, the immediate profits from the application are considerably reduced. It has been shown, too, by careful experiments, that, on the average, at least one-third of the nitro- gen applied to these crops, though contained in the best forms, is not secured in the crop, even under the most favorable conditions; that is, in any case certain amounts are lost through drainage, the growth of weeds and denitrification; and, further, that the minerals must exist in the soil, or must be supplhed in sufficient excess, otherwise, the utilization of the (191) 192 FERTILIZERS nitrogen by the plant is still further reduced. The expense of fertilizer per unit of increase in these crops is, therefore, relatively greater, even under the best conditions of its use. A bushel of wheat, with its accompanying straw, will contain, for example: POP oo nk Ss is EN a ee 1% lbs. PRGEAMOLIG ROME 66.0 ia ion a ae ee Be Ba Paani A es 8 So eee se ee i Weare It will be observed that the amounts of fertilizer ingredients contained in the crop are such that, if the seasonal conditions are perfect, so that the maximum of the amounts applied are recovered in the crop, the cost of fertilizers per bushel of increase is still rela- tively high, thus showing that great care must be exercised in order that a direct and immediate profit may be secured. Nevertheless, since the cost of pre- paring the land and of harvesting the crop is but slightly greater for a large crop than for a small one, the larger returns for the labor very frequently pay well for the application of the material, even though the margin of money profit is small. In crops of this sort therefore, and especially when grown on the “extensive” plan, an important point to be de- termined is whether the land is deficient in all of the constituents for grain and hay growing, or whether only one or two are lacking, in order that in the ap- plications made, only those constituents are supplied that are necessary, and adding to an excess already present is thus avoided, with a consequent saving in the cost of the fertilizer. FARMERS SHOULD EXPERIMENT 193 EXPERIMENTS TO DETERMINE THE LACKING ELEMENT The lacking element cannot be fully determined, except by direct experiments by the farmer himself. That is, no general principle can be depended on as an absolute guide. He should learn whether his soil is deficient in any of the elements, and, if so, which ones should be applied to the different crops in his rotation. 202 FERTILIZERS Wheat For the wheat crop following oats, the rest of the farm manure on hand may be applied after plowing, well harrowed into the surface soil, and a fertilizer ap- plied which shall be rich in available phosphoric acid, and which shall contain only a sufficient amount of nitrogen in quickly available forms to insure a good fall growth. When the land has been well fertilized for previous crops, a dissolved animal bone super- phosphate is an excellent fertilizer for wheat, because containing the elements, phosphoric acid and nitrogen, in good forms and proportions. If more nitrogen is needed than is provided by 200 to 300 pounds of this fertilizer in order to mature the crop, which is fre- quently the case, particularly if the winter has been severe, or if the land is light, it may be applied in the spring, and preferably in the form of a nitrate, which distributes readily, and is immediately available, ad- vantages not possessed by other forms. At this period of its growth, the crops need to make a rapid appro- priation of nitrogenous food, though the conditions are not yet favorable for the change of nitrogenous organic compounds in the soil into the availabie nitrate. The top-dressings should be made as soon as the crop has been well started, and should range from 75 to 150 pounds per acre, according to the character of the soil and previous fertilization. The better the natural character of the soil and its treatment, the larger the dressing that may be applied with possible profit, though in no ease should it exceed the larger amount. FERTILIZERS FOR CLOVER AND TIMOTHY 203 Clover For the clover which follows the wheat, only the minerals, phosphorie acid and potash, need be applied. An inereased return is likely to follow such an application, as the clover is not able to utilize to the fullest extent the nitrogen from the air except when the soil is supplied with an abundance of mineral food. An appleation which will furnish 12 pounds of phos- phorie acid and 25 pounds of potash per acre marks the minimum dressing, and it may be applied with advantage immediately after the wheat is harvested. -Timothy The timothy, the next crop in the rotation, is a member of the grass family, and is especially benefited by nitrogenous fertilization, and top-dressings in the spring with nitrate of soda have proved of great value on soils well supplied with minerals, though experienced farmers have learned that better results are obtained if the minerals are applied with the nitrate, thus in- suring a better growth and development of plant. A mixture made up of 150 pounds of nitrate of soda, 100 of acid phosphate and 50 of muriate of potash, at the rate of 300 pounds per acre, is now used by many successful hay growers. The application should be made as soon as the crop has well started in the spring. The system of fertilization here outlined is not to be advocated except under circumstances where it is not 204 FERTILIZERS possible or practicable to supply such an abundance of plant-food as will guarantee a maximum production, as in “intensive” practice, in which the yield is measured by climatic and seasonal rather than soil conditions, but rather such additions as will return a profit and at the same time tend toward the improvement of soil. This system is economical in the use of nitrogen, the most expensive element. It provides a_ sufficient amount of available plant-food to insure a reasonable increase in crop, and it is well adapted to lead the farmer by easy steps from the “extensive” to the “intensive” system of farming. A Gain of Fertility by the Rotation System Assuming that the inereased yield of corn is 20 bushels, with accompanying stalks, of wheat 10 bushels per acre, of oats 15 bushels, of clover % ton, and of timothy % ton, the amounts applied will be practically sufficient to furnish all of the potash contained in this increase, and more than sufficient to meet the demands for phosphoric acid. That is, by this system, there has been applied in the materials 30 pounds of nitrogen, 64 of phosphoric acid and 80 of potash. While, if this increased crop was secured, the following amounts would be required: 71 pounds of nitrogen, 31 of phosphoric acid and 79 of potash. The considerable amounts of plant-food contained in the yard manure, and the gain from the roots and stubble of the clover, serve to supply the balance of nitrogen required, and to provide a store of unused residue for future crops. NECESSITY OF AN EXCESS OF FOOD 205 The method, if adopted, would be more rational, and likely to result in more satisfactory returns than the one now generally practiced, namely, to purchase with- out particular regard to the character of the materials furnishing the constituents, or their proportions, and to apply, on the average, even less per acre than is here recommended. Assuming that 200 pounds per acre of the average corn fertilizer, showing a composi- tion of 2.5 per cent nitrogen, 8 of phosphoric acid and 5 of potash, were applied only to the crops corn, oats and wheat, omitting both clover and timothy, there would have been added 15 pounds of nitrogen, 48 of phosphorie acid and 30 of potash, amounts of each too small to provide for a large increase in crop, provided all were needed. The Necessity of Adding More Plant-food than is Required by a Definite Increase in Crop It may be asked, why add more of the constituents than is necessary to provide for a definite increase in crop? Assuming that the average yield of the land is twenty bushels of wheat per acre, and the aim is to secure thirty bushels, why not add the constituents in the amounts and proportions necessary to provide for this extra increased yield, rather than any excess of these amounts? The answer is, that in order that such a result may be accomplished, the conditions would need to be absolutely perfect, so that the plant would have at its command the amount of food needed each day. If a period in the growth 206 FERTILIZERS of the plant should be so wet or so dry as to prevent the plants from acquiring the food necessary for their continuous growth, there would be no opportunity for them to gather food faster, when the better conditions followed the unfavorable conditions, and thus to over- come the ill effects of the period of partial starvation. In other words, if there were only sufficient food to supply the plant under normal conditions of season, the plant, after a period of time during which there was no growth, could not grow faster than it did before, hence it could not eatch up in its growth and make a full crop. Furthermore, the plan of applying only that needed for the increase must necessarily assume that the plant-food is in the best forms, and that the physical conditions of soil are so perfect as to cause it to absorb and retain all the food appled, and in such a manner as to permit it to be readily obtained by the plant. A further advantage is to enable the clover plant in the rotation to fully exercise its power of acquiring nitrogen from the air. Moreover, if properly carried out, it fulfils the idea of successful agriculture ; viz., the production of profitable crops, while at the same time not reducing, but increasing, the potential fertility of the soil. The System Should Be Modified if no Farm Manures are Used In this rotation, if no manures are available, as indicated, then the amounts and kinds of fertilizers should be somewhat changed. For example, if it was EXCLUSIVE USE OF FERTILIZERS 207 necessary to supply the corn crop with a sufficient abundance of all the elements in artificial forms, then the proportions of nitrogen should be somewhat greater and the total amounts of the constituents applied to the different crops considerably increased. For corn, a mixture consisting of 20 pounds of nitrogen, 30 of phosphorie acid and 50 of potash should be applied, and if grown upon raw ground rather than upon sod, it would be desirable to still further inerease the nitrogen. The oats could be fertilized, as before rec- ommended, while the wheat should have an increased supply of both nitrogen and phosphoric acid,—double the amounts recommended when used with manure,— besides an addition of at least 10 pounds per acre of potash. The fertilizing of the clover and timothy need not be changed. If, in a rotation of this character, barley were substituted for oats and rye for wheat, the fertilization need not be materially changed, though the rye possesses a slightly greater power of acquiring phosphorie acid than wheat, and the nitrogenous top- dressings may be omitted, unless the crop is grown primarily for straw rather than for grain. The barley is also less able to acquire its phosphoric acid than the oats, and is especially benefited by nitrogen, though eare should be exercised to regulate the amounts ap- plied in order to prevent lodging, which affects both the yield and quality of the grain. If in the rota- tion the timothy hay is omitted, then the fertilization for the corn may be reduced, as on good soils the yard manure, together with the plant-food stored in the surface in the clover sod, will furnish an abundance. 208 FERTILIZERS FERTILIZERS FOR A SINGLE CROP GROWN CONTINUOUSLY When it is desirable to grow any one or all of these crops continuously (and this practice may be followed with advantage, particularly when a legumi- nous catch-crop is seeded with the main crop, which insures a continuous occupation of the land and also provides vegetable matter and nitrogen), the fertiliza- tion would naturally be somewhat different, and, as a rule, would require more nearly even quantities of the different constituents. For corn, a fertilizer supplying 20 pounds of nitrogen, 40 each of phosphoric acid and potash, would provide for a liberal increase in the yield from year to year. The nitrogen should prefera- bly be in good organic forms, which would decay rap- idly enough to supply the needed available nitrogen during the growing season. The phosphoric acid may be drawn partly from superphosphates and partly from organic compounds, as ground bone and tankage, pro- vided these latter may be secured at as low a price as the superphosphate, and the potash applied in the form of a muriate or kainit. Fertilizers may be applied broadcast and well harrowed into the soil, or part may be distributed in the row at time of planting. If a catch crop were seeded to be used as green manure, as, for example, crimson clover, the applica- tion of nitrogen may be very materially reduced. This practice has been followed with advantage in the middle and southern states. For continuous wheat growing, a fertilizer may be FERTILIZERS FOR A CONTINUOUS CROP 209 used at time of seeding which supplies 10 pounds of nitrogen, 40 of phosphoric acid and 20 of potash. A small part of this nitrogen would better be in the form of a nitrate, which will encourage a good top-growth in the fall, as well as a deep root system; the phos- phoric acid should be soluble, in order to supply the immediate needs of the young plant, and the potash in the form of a muriate. Such an application would provide for a very considerable increase in crop, par- ticularly if followed in the spring by a top-dressing of 100 pounds per acre of nitrate of soda. The top-dressing with nitrate of soda is, however, not always advisable. The chief objection to its use is that it does not encourage, but frequently seems to retard, the growth of clover, though its very great advantage is that it encourages the deeper rooting of the wheat and the more rapid growth of grasses. If continuous cropping of wheat is practiced, clover should be seeded with it, in order that the ground may be constantly occupied, and thus prevent leaching, as well as mechanical losses of fertility, and also to supply vegetable matter containing nitrogen for the succeeding crop. When a system thus outlined has been continued for a few years, the nitrogen in the fertilizer may be largely omitted. The same considerations apply to rye as were in- dicated for wheat. Oats are seldom grown as a continuous crop, though if it should be desirable, a fertilizer furnishing at least 20 pounds of nitrogen, 25 of phosphorie acid and 10 of potash would be a good dressing, eare being taken that a large portion N 210 FERTILIZERS of the nitrogen exists as nitrate or as ammonia, in order to stimulate and strengthen the early growth of the plant. For the grass crop, or continuous mowing land, a fertilizer rich in nitrogen and potash should be applied. A good application in the spring may consist of 25 pounds of nitrogen, 15 of phosphoric acid and 25 of potash, and immediately after the hay is har- vested a further application of at least 20 pounds of nitrogen and 30 each of phosphoric acid and potash should be applied. The nitrogen in this case may consist partly of organic forms, though the soluble nitrogen is to be preferred as top-dressings where it can be procured at such a price as to make it compara- ble with other forms. The nitrogen of bone, tankage and other slower-acting forms is excellent for the grasses, though these should be preferably applied and well worked into the soil previous to seeding. The early spring application should consist largely of solu- ble nitrogen, both to encourage a rapid appropriation of this element by the plant early in the season, as well as a deeper root-system, and consequently a greater drought-resisting power, and also to provide the elements necessary for the increased crop. The sum- mer or later application stimulates and strengthens the roots for the coming season. If an aftermath crop is removed, or if it is pastured, a further application may be made, which may consist largely of the mineral elements. This fertilization of the hay crop will also result in a richer product, for an abundant supply of nitrogen encourages a larger proportion of leaf growth, and consequently a smaller proportion of stem, contain- FERTILIZERS FOR MEADOWS Pap ba A ing the less valuable woody matter. Lands that are well fertilized in this way, if properly seeded in the first place, may make profitable mowing crops for a long series of years, and good crops cannot be expected unless liberal fertilization is practiced. Fertilizers for Meadows For meadows used as pastures, a more liberal application of the mineral elements is recommended, since an abundance of these encourage the growth of the clovers, which make a richer herbage than the grasses. Heavy nitrogenous fertilization is expensive, and encourages the growth of the grasses rather than the clovers. Pasturing, while less exhaustive than - hay cropping, nevertheless results in the gradual depletion of fertility, and an abundant growth of rich pasturage can only be secured where there is an abundant supply of available plant-food. Mixtures made up of acid phosphate, ground bone and muriate of potash in equal proportions, make very good dressings, if applied in sufficient quantity, three hun- dred to five hundred pounds per acre annually. The ground bone is recommended because it decays slowly, and thus furnishes a continuous supply of nitrogen and of phosphoric acid. The application should preferably be made both in spring and in late summer, in order to secure a good growth, as well as to encourage the introduction of the clovers. In any system of continuous cropping, or in fact in any sys- tem of rotation-cropping, in which an abundance of 212 FERTILIZERS organic matter is introduced in the way of green erops, or in decaying vegetable matter contained in roots, the land should occasionally receive a dressing of lime, both to supply that which the plants need, as well as to correct possible acidity of soil. WILL THIS SYSTEM of FERTILIZING PAY? That fertilization will pay if carried out, as is pointed out here, and upon lands not now producing paying crops, depends, of course, very largely upon the price of the crops, the cost of the materials, and the method of farming practiced. At the prices which have prevailed in the recent past, for both crops and fertilizing materials, there is no doubt that this reasonable fertilization, together with a good system of practice in other respects,—that, is, good plowing good harrowing, good drainage and good cultivation, —will result in very satisfactory returns. In fact, it has been shown by repeated experiments (see bulletins and reports of New Jersey Experiment Station) that the yields on land which is capable of producing an average crop of 15 bushels of wheat per acre, 30 of eorn and 30 of oats, may be more than doubled by an abundant supply of fertilizing materials. Such an increase results in an actual direct gain, as well as in the saving of labor per unit of product, which is accomplished when the larger crop is secured. The main point in this whole matter of fertiliza- tion is to understand that a fertilizer is a fertilizer because of the kind and form of plant-food contained WILL FERTILIZING PAY? 213 in it; and that its best action, other things being equal, is accomplished when the soil possesses good physical qualities, when the management is also good, and when systematic methods are planned and adopted. “Hit or miss” fertilization, even for these crops, may pay, and doubtless, on the average does pay as well as some other things that farmers do, but does not pay as well as it might if better methods were used. CHAPTER XI POTATOES, SWEET POTATOES, TOMATOES AND SUGAR BEETS These crops differ from the cereals and grasses in that they are products of high commercial value, and are less exhaustive of plant-food constituents per unit of money value. As field crops they are usually grown in a rotation, and constitute one at least of the chief money crops. In sections near large markets these erops are, with the exception of sugar beets, divided into two classes, early and late, the early crop being regarded as the most profitable; hence greater efforts are made, both in the way of fertilization and of management, to secure a large and early crop, than — is the case with the late crop. For the early crop the natural supply of plant-food in the soil is not a prime consideration. In districts distant from markets, the late crop is the only one grown to any extent, and because it has the whole season for its growth, greater dependence is placed upon the natural resources of the soil. While, as already stated, these crops are not regarded as exhaustive of plant-food elements in the Same sense as the cereal crops are, because it fre- quently happens that a bushel of potatoes, or of sweet potatoes, or of tomatoes, will bring as much as a bushel of corn, or sometimes as a bushel of wheat, (214) FERTILIZERS FOR POTATOES 215 yet the amount removed in the entire crop may be quite as great as in the grain crop, because of the much larger number of bushels grown per acre. FERTILIZERS FOR POTATOES, EARLY CROP It has been demonstrated, both by experiment and practical experience, that good crops of early potatoes require an abundance of plant-food, and that on soils of good character a heavy fertilization is usually more profitable than a medium or light application. The plant-food removed by a fair crop— 200 bushels per acre of tubers—will, on the average, consist of 27 pounds of nitrogen, 12 pounds of phosphoric acid and 60 of potash. Even though the increase from the application of fertilizers is less than 100 bushels per acre, it is always advisable to add plant-food in considerable excess of these amounts: first, because the crop must be grown quickly; and second, because a large part of its growth must be made in the early season, before the natural conditions are favorable for soil activities. A study of the fertility composition of the potato shows that of the three essential constituents, the potash is contained in the greatest amount and the nitrogen next, while the amount of phosphoric acid contained in it is comparatively small. Most fertilizer formulas for potatoes are, therefore, pre- pared with the idea of furnishing a greater amount of potash than of nitrogen or phosphorie acid. A study recently made by the Geneva Experiment 216 FERTILIZERS Station* shows that the formulas prepared to con- tain the plant-food in nearly the proportions used by the entire potato plant, excepting that the phos- phorie acid is in considerable excess, were less useful than those containing very different proportions .of the constituents, and which were based upon the experience of observing growers. That is, a formula of the first class, furnishing — RIOT; Cg chu ode the Bs 6% % Available phosphoric acid. ........ 5 % Potashes oi sh ey a Sa tee Ce eee 10 % gave less satisfactory returns for the same amount applied than one furnishing — Mrmr sos patie FT) eh tees Saheet 4% Available phosphoric acid. ........ 8 % Pipher Sk aah | nd See Sins es eee 10 % This latter formula is very generally used in sections where early potatoes are an important crop. The Time and Method of Application These are matters of considerable importance. It has been urged, particularly by German experi- menters, that the potash salts, when used in such excess as seems desirable, should be applied more largely to the crop preceding, rather than directly to the potato crop. This method has not been adopted in this country to any extent, and it is believed that * Bulletin No. 137, N. Y. State Exp. Sta. THE AMOUNT OF FERTILIZER OG our climatic conditions are such as to cause a very general distribution of the salts throughout the soil, if applied, in part at least, just before planting and thoroughly distributed by cultivation. At any rate, very satisfactory returns are secured from the direct application to the crop of fertilizers of this composi-° tion. In reference to the method of application, while very good results are secured from the application of the fertilizers directly in the row, this is to some extent influenced by the character of the soil. Where the soil is somewhat heavy, and the circulation of water is not perfectly free, it is less desirable than where the soils are open and porous, and free circu- lation is not impeded; though where the amounts applied are considerable, it is recommended that at ‘least one-half of the fertilizer should be applied broadcast and worked into the soil, and the remainder placed in the row at the time of planting. Naturally, when the soils are poor, a concentration of the con- stituents is more desirable than when the surround- ing soil possesses reasonably abundant supplies of available food. The Amount to be Applied As already stated, the amount of the different con- stituents to be applied should be in considerable excess of that required by the actual increase in crop, ‘both for the reasons already given, and because it is desirable in crops of this sort to insure a continuous and abundant feeding of the plant. Where “intensive” 918 FERTILIZERS practice is general, the amounts applied very frequently reach a ton per acre of the high-grade fertilizer already mentioned, though the necessity for so large an application as this has been questioned, particularly if it is expected to give rise to a profitable return in the crop to which the application is made, and though it can be readily seen that if conditions should not be favorable the larger amounts would be preferable. The result of investigations of this point by the Geneva Experiment Station* showed that an addition of fer- tilizers above 1,000 pounds per acre, or 40 pounds of nitrogen, 80 of phosphoric acid and 100 of potash, was not as profitable as 1,000 pounds. It must be remembered, however, that these experiments were conducted upon light soils, and on these entire de- pendence must be placed upon added plant-food. In the best potato sections of New Jersey, the application of a fertilizer of this composition ranges from 1,000 to 2,000 pounds per acre, while the majority of the growers use the smaller rather than the greater quantity. Many use the larger, and are of the opinion that it is a profitable practice, because of the greater certainty of securing a good potato crop, and because the unused residue provides for large yields of the subsequent crop without further applications. The growers of potatoes in the vicinity of Norfolk, as well as farther south, also find it profitable to be generous in the use of fertilizer for this as well as for other crops of high commercial value, *Bulletins 93, 112, 137. N. Y. State Exp. Sta. FERTILIZERS SHOULD BE AVAILABLE 919 Form of the Constituents In the growing of potatoes, sulfate of potash is generally recommended in preference to the muriate, owing to the supposedly deleterious effect on the quality of the tubers resulting from the large quantities of chlorids contained in the muriate, though the dif- ferent forms, when properly applied, do not seem to materially influence the yield. That is, if muriate or kainit is applied previous to the planting of potatoes, the deleterious chlorids may be washed from the soil. There is no doubt that the sulfate improves the ap- pearance of the potatoes, making them more clean and uniform in size, though experiments that have been conducted do not show a material difference in the ‘chemical composition of the tubers grown with any of the forms. The tendency on the part of the mu- riate seems to be to diminish the amount of dry matter, and inasmuch as the dry matter is mostly starch, the latter is thereby slightly reduced, though it has not yet been demonstrated that the good quality of the potatoes is measured by the content of starch.* In reference to the form of nitrogen, both theoret- ical considerations and the experience of growers con- firm the belief that for the early crop, a portion of the nitrogen should exist in the form of nitrate or ammonia and the remainder in quickly available organic forms, although no definite experiments have been conducted to determine this point, nor the one * Bulletin No. 137, N. Y. State (Geneva) Exp. Sta. Bulletin No. 80, N. J. Exp. Sta. 990 FERTILIZERS as to whether all of the nitrogen in the form of nitrate should be applied at the time of planting. A top-dressing after the potatoes have come up is a very desirable method of practice on light soils which have been liberally supplied with the minerals. On good potato soils, therefore, a good fertiliza- tion would consist of 800 pounds per acre, as a mini- mum, of a mixture containing: Nitro @eN ate, a 2 ek oe 2 ae eee 3to 4% PROSPHOTIC: BEM. 5 5. 6) Sao k kg eee 6to 8% Potente oF SS ars 2s een tebe 8 to 10 % The nitrogen is to be in quickly available forms; the phosphoric acid, also, is to be available, and the potash to be derived from sulfate, particularly if fine quality of crop, as indicated by appearance, is desired. If only yield is considered, the muriate is quite as serviceable. LATE POTATOES For late potatoes, the considerations in reference to the form of the constituents and the amount of the application, as suggested for early potatoes, do not always hold good, since in many eases the crop is able to secure a larger proportion of its plant-food from soil sources,—due, first, to the longer period of growth of the plant, and second, to the fact that the crop is usually grown upon soils naturally richer in the plant-food elements, though the proportion of pot- ash, as in the formulas already indicated, should be relatively large. The nitrogen may be reduced, and FERTILIZERS FOR SWEET POTATOES yw the form of nitrogen may be derived largely from organic sources. Good formulas for late potatoes may consist of — PIR MIIE NA os i oe Fe nies (5) NT old 2 a 214 % UOTE WEI spr EE Paes 6 % WECM or co a EE han iw oe ~ oat 8% and the application may be from 600 to 800 pounds per acre. Where potatoes are grown in rotations with the cereal crops mentioned in Chapter X, the unused residue from the rather heavy application of fertil- izers to the potato crop is depended upon to very materially aid the growth of these, thus reducing the outlay for fertilizer for crops of a low commercial value. This practice is advantageous, though the prime object should be to feed the crop rather than the soil—that is, apply the fertilizer with the idea of securing a profit from it in the potato crop, rather than a possible profit in subsequent crops. SWEET POTATOES In the growing of sweet potatoes, the quality of the product is more important than in the ease of the white potato. The northern markets distinctly recog- nize quality in this crop, and it is measured by size, shape, and results in cooking. The potato that brings the best price in the different markets is small, about the size of a white potato; in shape round, rather than oblong, and is dry and mealy when cooked. pp FERTILIZERS This characteristic of the crop is influenced both by the character of the soil and of the manures and fertilizers applied. The soils best adapted are dry, sandy loams, and the most useful fertilizers are those which contain an abundance of minerals,—phosphorie acid and potash,—and not too large supplies of quickly available nitrogen. It is also true that the yields of sweet potatoes of this character are not as large as those that may be obtained when quality is not a prime consideration, and which are grown for the general market. Fertilizer Constituents Contained in an Average Crop This crop is very similar to the white potato in regard to food required. Two hundred bushels of sweet potatoes, not including vines, contain, on the average, 30 pounds of nitrogen, 10 of phosphoric acid and 45 of potash; and since the yield of the general erop is larger on the average than one of white potatoes, a liberal supply of the minerals must in all cases be provided. The studies made of this crop have not yet established the best proportions of the constituents in fertilizers, though such experiments as have been conducted show that those that contain a very considerable excess of potash over the other elements are preferable. While nitrogen is needed, too much, particularly in soluble forms, seems to encourage too large a growth of vine, which con- tributes to yield, but at the expense of quality, which is a very important consideration. The best growers PROFITABLE FERTILIZATION 993 use fertilizers containing a small percentage of nitro- gen and a high percentage of phosphoric acid and potash. Applications that furnish 20 pounds of nitro- gen, 50 of phosphoric acid and 80 of potash per acre have given excellent results in regions in New Jersey in which market quality up to a certain point is quite as important as increase in yield, though, of course, yield is also considered. Any excess of nitrogen over this amount seems to contribute toward a larger, rather oblong, rooty growth of tuber, and to injure cooking quality. In growing crops for the general market, however, larger applications of nitrogen are demanded, and experiments have shown that organic forms are preferable to soluble forms, though the climate and season largely influence this point. In northern sections, and in cold seasons, the soluble forms are more useful than in the warmer climate and longer seasons of the South. There is no question, however, that commercial fertilizers can be depended upon to produce maximum crops of sweet potatoes, and at much smaller cost than with yard manure.* Results reported by the Georgia Experiment Stationt indicate the following formula as an_ excellent one for sweet potatoes, though, as there stated, “the amounts that can be used vary considerably, depending upon the character of the soil—the richer the land in humus, the greater the quantity that can be safely used.” “Thin soils will, of course, only stand very moderate manuring, —_— ——_ * Bulletin P, New Jersey Exp. Sta. 7 Bulletin No. 25, Georgia Exp. Sta. 224 FERTILIZERS and necessarily produce a very small yield.” The formula consists of — GIG TORDHALO 2 OS ee ce ee ee ee 320 Ibs. Catt@n-ssea moal =... 2... eee 360. aa Fr. i te eee 040 «SS This formula will furnish about 25 pounds of nitro- gen, 50 of phosphoric acid and 80 of potash, and, according to the bulletin, will produce a yield of potatoes of from 200 to 400 bushels per acre, depend- ing upon the season and variety of potatoes planted. Experiments at the Georgia Station also show that organic nitrogen (cotton-seed meal) is preferable to nitrate of soda as a source of nitrogen. In making mixtures which furnish these propor- tions of plant-food, other nitrogenous organic ma- terials, furnishing an equivalent of nitrogen,—as blood or concentrated tankage,—may be substituted for the eotton-seed meal, if they can be purchased quite as cheaply; and muriate of potash, furnishing an equiva- lent of potash, may be substituted for the kainit, if it can be more readily obtained. As already stated, however, this fertilizer is too rich in nitrogen for the production of the best quality of potatoes, as for example “Vineland Sweets,” which command the highest prices in northern markets. The erowers in that district use a fertilizer richer in the minerals; one containing — Nitros. 6 i a ele eee eee 3% PhOpphorie-acid.s 6.5" Sa eee 7% Piao oe eS See ere 12% APPLICATION OF FERTILIZERS hag is very generally used, though reasonably heavy dressings of this are often further supplemented by applications of from 200 to 3800 pounds of acid phosphate and 100 to 150 pounds of muriate of potash per acre. The Application of the Fertilizers Owing to the fact that the sweet potato is grown from plants or slips, rather than from seed, and the fact that the best quality of potatoes is produced upon rather light, sandy land, it is desirable that the fer- tilizer should be applied some time before the putting out of the plants. The practice on this light land is to apply the fertilizer when making up the hills, which ~usually occurs from two to three weeks before the plants are set. “That is, in making up the hills, the soil is ridged, and during the preparation of the ridge the fertilizer may be distributed in it and well mixed with the soil. Where the land contains more clay and humus it is frequently advocated that the potash manures be applied broadcast the previous year, and only the nitrogenous fertilizer and superphosphate be applied immediately to the plant. On soils of this latter character, this is doubtless the best system. If kainit,—which has been found to be preferable to mu- riate in the Georgia experiments referred to,—is used as the source of potash, it is very necessary that it be well mixed with the soil before setting out the plants. Heavy applications of this salt in the spring proved injurious in the experiments conducted at the New O 996 FERTILIZERS Jersey Station.* The effect of fertilizers upon the chemical composition of the tuber was chiefly to reduce dry matter, and not apparently to affect edible quality, though the experiments were carried out upon the general crop rather than upon those grown for high quality. TOMATOES Tomatoes are largely grown as a field crop, and the object of their growth, whether for the early market or for the canneries, is a factor that must be considered in the adoption of systems of fertilization. Field Experiments with Fertilizers for Tomatoes The impression is very prevalent among growers that the tomato does not require heavy manuring. Studies made at a number of experiment stationst show, however, that the tomato is a plant that quickly and profitably responds to the use of manures or ferti- lizers, and that the maturity and yield are very largely influenced by the method of manuring and fertilizing. Experiments were conducted by the New Jersey Station upon three farms located in different parts of the state, and during four seasons, the object of which was to test the effect on maturity and yield of the early crop * Bulletin P, New Jersey Experiment Station. + Bulletins Nos. 21 and 32, Cornell Experiment Station (Ithaca). Bulletin No. 17, Georgia Experiment Station. Annual Report for 1891, Maryland Experi- ment Station. Bulletin No. 11, Virginia Experiment Station. Bulletins Nos. 63, 79 and O, and Report for 1892, New Jersey Experiment Station. THE NEW JERSEY EXPERIMENTS ae of the use of nitrate of soda in different quantities and at different times, both with and without the ad- dition of the mineral elements, phosphoric acid and potash, and to make a comparison of these with barn- yard manure. The results showed: First. That nitrate of soda was one of the best nitrogenous fertilizers for this crop, and that its use in small quantities (160 pounds per acre), or in large quantities (320 pounds per acre) in two applications, increased the yield materially, but not at the expense of maturity, and that this was equally true when used alone and when used in connection with phosphoric acid and potash. Second. That nitrate of soda, when used in large quantities (320 pounds per acre) in one application, in ' the presence of a sufficient excess of phosphoric acid and potash, did increase the yield, but at the expense of maturity. Third. That when properly used, nitrate of soda was a profitable fertilizer for the crop. It was shown, furthermore, that nitrate of soda was superior to both barnyard manure and mineral ferti- lizers alone, and on the whole, was but slightly less effective than the complete fertilizers. Fertilizers for the Early Crop for Different Conditions of Soil These results have been practically confirmed both by the experiments of the stations referred to, and also in actual practice on soils similar in character ; II8 FERTILIZERS namely, those which were well adapted for the early tomato — light, well-drained sandy loams—and which had been previously well manured for crops entering the rotation. The results do not apply in the case of very poor soils, or upon heavy elay soils, which are not adapted for the early crop. The statement that it pays to fertilize early toma- toes, and that nitrate of soda is one of the best ferti- lizers for the crop, must, therefore, be accompanied by statements regarding the condition of soil and the purpose of growth. With the conditions clearly under- stood, a scheme of fertilization for early tomatoes may be outlined which, when the conditions are observed, will be likely to give much better results than methods of fertilization which do not take into consideration the habits of the plant and the special object of its erowth. For example, on soils which have been well sup- plied with the mineral elements, phosphoric acid and potash, by previous manuring or fertilizing, a ferti- lizer very rich in nitrogen derived from nitrate of soda, or nitrate of soda alone, should be used; the application at the time of setting the plant to be equivalent in nitrogen to from 80 to 100 pounds of nitrate of soda, with a second application of an equiv- alent amount made from three to four weeks later. A single application of the amount here suggested at the time of setting the plants would, perhaps, under good seasonal conditions give results quite as good, though the heavier application of nitrate at one time may result, in certain cases, in the loss of nitrogen FERTILIZATION OF THE EARLY CROP II9 by leaching, since it is an extremely soluble salt. In this ease a deficiency of food would result, and thus prevent the normal development of both plant and fruit. On soils which possess only good mechanical con- dition, and are very poor in plant-food, a_ heavier application of both nitrogen and the mineral elements will be required, in which case the following fertiliza- tion is recommended : Previous to setting the plants, or at the time they are set, apply 50 pounds per acre of phosphorie acid, preferably derived from superphosphate, and 100 pounds of potash, derived from muriate, and thor- oughly harrow or cultivate into the soil; and at the time of setting apply around the hill 100 to 150 pounds per acre of nitrate of soda. Three to four weeks later, make another application of from 100 to 150 pounds per acre of nitrate of soda. Owing to the small bulk of nitrate, it should be mixed with dry soil or sawdust, in order to insure even distribution. The only precaution to be observed is to prevent. its immediate contact with the plant roots. If these methods are practiced, the plant secures its nitrogen in an immediately available form at a time when it is needed,—when it is set in the field. There is thus no delay in growth, and because of the presence of an abundance of the mineral elements no ex- cessive growth of vine is encouraged by the use of the nitrate, as would be the case were the mineral elements absent. Inasmuch as the nitrogen is ap- plied close to the plant, it is within the immediate 930 FERTILIZERS reach of its roots; and because it is all in an im- mediately available form, which is used up rapidly, the tendency to late plant growth, which would be caused by a continuous supply of nitrogen, is not en-. couraged, and a normal and rapid growth and de- velopment of fruit results. It is not stated that by this method of fertilization maturity is increased in the sense that the date of the first picking is earlier, but that a larger number of fruits is picked earlier. It was not shown in any of the experiments that the date of picking was made earlier by virtue of the nitrate, for, in fact, the earliest tomatoes were picked upon land where the minerals only had been applied. Here the yield was not satisfactory, but where the nitrate was applied, because of the larger crop, a larger proportion of early tomatoes was secured. It is obvious that, in- asmuch as the price of the fruit rapidly declines as the season advanees, receipts from the proportionately larger quantity of early fruit will be materially increased. The Use of Fertilizers with Yard Manures When it is desirable to use yard manures with fer- tilizers for tomatoes, because of the abundance and cheapness of the former,they should be applied broad- cast, and the nitrate applied at the time of planting, as already described, rather than both together in the hill. The tendency in the latter case will be to cause a loss of nitrogen from the nitrate, depending upon the FERTILIZATION OF THE LATE CROP 931 amount of organic matter in the manures. That is, experiments and experience have shown that under these circumstances more or less of the nitrogen in the nitrate may be lost. In the use of yard manures for early tomatoes, the application of excessive quantities should be avoided, as they are virtually nitrogenous manures, which, because of their organic character, feed the plant in proportion to their rate of decay. Hence, the presence of large quantities will encourage not only an undue growth of plant, but a late growth as well. The mineral fertilizers, as acid phosphate and muriate of potash, can be used with the yard manures with perfect - safety, in fact, with great advantage, because supple- menting their proportionate lack of the mineral con- stituents. It is also desirable, where it is the practice to use manure, particularly if it is coarse, to spread it during the winter, in order that the soluble portions may become thoroughly distributed throughout the soil. As soon as the land is ready to work in the spring, it should again be plowed shallow and then deeply tilled, in order both to thoroughly warm up the soil, and to incorporate with it coarser portions of the manure. Fertilizers for Late Tomatoes In manuring and fertilizing for the late crop, the character of the crop and the season of its growth should be remembered. In the first place, the plants for this crop are not put in the soil until summer, when the conditions are most favorable for the rapid change 939 FERTILIZERS of organic forms of nitrogen into nitrates. Thus, if the soil has been manured or is naturally rich in vege- table matter, the additional application of nitrogen in immediately available forms is not so important. In the second place, the object of the growth is not early maturity, but the largest yield of matured fruit; hence it is more desirable to grow a larger plant than in the ease of the early tomatoes. The fertilization should, therefore, be such as to furnish an abundance of all the elements of plant-food; and, inasmuch as the tomato belongs to the potash-consuming eclass.of plants, any fertilization should be particularly rich in this element. It is not to be understood, however, that it is not necessary to apply nitrogen, for frequently soils are used that are either not well adapted for the plant or are poor, not having been previously well supplied with vegetable matter containing nitrogen. On such soils, additional applications are very important, and nitrate of soda is one of the best forms to use, as it is absorbed freely by the roots, encouraging an early and vigor- ous growth of plant and a normal development of fruit. Slow-acting organic forms of nitrogen, on the other hand, frequently begin to feed the plant and cause its rapid growth when the energies should be concentrated in the growth and maturity of fruit. Fertilizers that have proved very excellent are those which contain a relatively smaller amount of nitrogen than is required for early tomatoes, and are richer in phosphorie acid and potash. A study of the composition of both the fruit and vine of the tomato will serve to guide us in ths COMPOSITION OF FRUIT AND VINE 933 respect, though the amounts and proportions of food removed by any crop are not absolute guides, inas- much as the soil may furnish more of one constituent than another, and because the plant may have the power of acquiring certain of its constituents more readily than others. The analyses of the fruit and vines of tomatoes show that one ton contains: ae Metied: Sh Acid sil eg Warrine ese 3.20 1.00 5.40 Vines (green). . . 6.40 1.40 10.00 Ten tons of the fruit, with the accompanying vines, which would probably reach four tons, would contain 57 pounds of nitrogen, 16 of phosphoric acid and 94 of potash. On a good soil, therefore, which -without manure would produce five or six tons, there should be added a_ sufficient excess of the constituents to provide for a maximum production, and the materials should be relatively richer in nitro- gen and potash than in phosphoric acid. A mixed fertilizer composed of : ieee ae ei 8 elle ie S88 400 lbs. rn Te on a etn ahs TOR. <** UE NOMBISEO co ooo. es cay Sc er bn ee 400 ‘ Mariate. Ge DOME . 6 eos me eae wes 500 ‘* would contain, approximately, 95 pounds of nitrogen, 144 of phosphoric acid and 250 of potash in each ton. An application of 500 pounds per acre of this mixture would furnish half as much nitrogen as is contained in a crop of ten tons, nearly as much immediately available phosphoric acid, and two-thirds as much 234 FERTILIZERS potash. Hence a dressing containing the amounts, kinds and proportions of plant-food here shown would be regarded as very desirable, since one-half of the nitrogen is in the form of a nitrate, which would contribute to the immediate growth of the plant. The amount of soluble and available phosphoric acid is sufficient to satisfy the needs of the crop throughout its entire growth, and such an abundance of potash as to contribute to the normal development of both plant and fruit. Formulas of this character have been used with good results, though the large pro- portion of salts sometimes make mixtures of this sort too moist to handle well, in which ease a part of the potash, or even of the nitrate, may be applied separately with advantage. On poorer soils, the arti- ficial supply of plant-food should be proportionately greater, or sufficient to provide for the entire needs of a fair-sized crop, since as a rule the relative power of the plant to acquire food is somewhat slighter on poor soils than on good soils; or, stated in another way, the results from the use of fertilizers are pro- portionately better upon soils in good condition than upon those not well cared for. A good formula for these may consist of: Witrate Gf Bodsiye 2320.45 eee eee 500 Ibs. Bone tanked) <> be) sh hy oa 500° Acid phiaphnte” .-1 es. aoud ers et oe 400 ‘S Murinte of potash. .s 0. <2 0-76 ee eee 600 ‘‘ One ton of this mixture would furnish, approximately, 105 pounds of nitrogen, 120 of phosphoric acid and 300 of potash. The application of 1,000 pounds, NEED FOR NITROGEN REDUCED Ja5 therefore, would furnish the food in sufficient abun- dance and in good proportions to meet the demands of a fair crop. The advantage of using so large a proportion of nitrogen in the form of nitrate of soda in this case is, that it is immediately available, inducing the im- mediate and rapid growth of plant, and preventing a too late growth by furnishing a minimum of organic nitrogen, which would become available late in the season. The cost of the fertilizer suggested in these eases is high, and the necessity of so expensive a dressing could be materially reduced by decreasing the need for nitrogen, particularly in organic forms, which may be accomplished by sowing crimson clo- ver with or after the previous crop of, say, corn or tomatoes. If weather conditions are favorable, crim- son clover may be sown in the tomato fields in August, after cultivation has ceased, or at the last cultivation, and a crop of clover grown which will provide nitrogen for the next year’s crop. This method is now practiced with advantage by many growers. The late crop, like potatoes and sweet pota- toes, is usually grown in rotations in which it is the chief money crop; hence the unused residue from fer- tilizers applied in large amounts, as here indicated, contributes largely to the economical growth of sub- sequent crops. SUGAR BEETS The purpose in the growth of sugar beets is to obtain the largest total yield of sugar per acre; and 936 FERTILIZERS inasmuch as the sugar content of the beet, as well as its ‘right growth and development, is very largely influenced by the character of the fertilization, this matter becomes of very considerable importance, in view of the promising development of the sugar beet industry in this country. Thus far, information con- cerning the use of fertilizers is derived largely from the results obtained in other countries, where it has been a prominent crop, and where great attention has been paid to this factor in its production. The Demands of the Crop for Plant-food The sugar beet draws heavily upon the soil for the nitrogen and potash constituents. A minimum yield of 10 tons of topped beets contains 44 pounds of nitrogen, 20 of phosphoric acid and 96 of potash. On medium loamy soils, which by their character are well adapted for the growth of the sugar beet, heavy fertilization with potash, however, has not been found to be de- sirable; while on light soils, which are also well adapted for the crop, liberal manuring with potash becomes absolutely necessary. As in this erop, the object of the growth is to se- cure not primarily beets, but sugar, and since the sugar formation is not perfected until the absorption of the necessary food from the soil has been in large part completed, any fertilization which promotes a too rapid or too long continued growth has a tendency to reduce the percentage of sugar; and inasmuch as the matu- ration takes place largely in the months of early fall, FERTILIZATION OF SUGAR BEETS 237 the growth must be forced early in the season. That is, it is essential that a large and rapid leaf growth be made early, in order that the food from the air may be acquired. It has been demonstrated that for this early and rapid growth of the beet, phosphoric acid is one of the most essential constituents, which explains the need for phosphoric acid in larger proportion than is indicated by the composition of the beet. The crop requires a considerably greater supply of phosphoric acid at this stage of its growth than other farm crops which are quite as exhaustive, and it is also evident that in order that the crop may obtain the phosphoric _acid at this period, it must be soluble and immediately available; hence the larger portion of this element applied should be derived from superphosphates. In the matter of fertilization with nitrogen, the object of the growth must also be kept in view. An application which would encourage steady and continuous growth, rather than an early and rapid growth, while contrib- uting to a large yield, causes a reduction in the sugar content of the beet. Hence it is strongly urged by those who are in a position to give sound advice, that the early nitrogen fertilization should consist of the quickly available forms, nitrate or ammonia, and that the organic or slower-acting forms should not be applied in such excess as to encourage a late growth. Hence it is, that upon medium and light lands the use of commercial fertilizers has proved of greater service in the growing of this crop than the exclusive use of yard manure, and in such quantities as to supply the entire needs of the plant. In the use of fertilizer, not 938 FERTILIZERS only the total supply of the constituents, but their form, may be regulated to the needs under different conditions, thus permitting a full feeding of the plant, and at a time most suitable to accomplish the object in view,— advantages which are not possessed by the natural manures. A fertilization which would meet the needs both in respect to quantity and kind of fertilizers, may be as follows: On good soils, the application or a fertilizer con- taining from 40 to 50 pounds of nitrogen, from 50 to 60 of phosphoric acid and from 40 to 50 of potash, would be sufficient to meet the demands of the plant. The nitrogen supplied should be derived largely from nitrates or ammonia, or both, and the phosphoric acid from a superphosphate, while the potash may be de- rived from sulfate or muriate of potash. The former is preferable if applied during the spring preceding the planting of the beets. While it is frequently desirable, for convenience and economy of labor in applying, that the fertilizer should be mixed, in order to prevent any waste of soluble nitrogen, it should be applied in fractional dressings. For example, a mix- ture of 250 to 300 pounds of nitrate of soda (or, the nitrogen may be derived partly from nitrate and partly from ammonia), 400 to 500 pounds superphosphate, and 80 to 100 of muriate or high-grade sulfate of potash, should be applied in two or three dressings. A part only should be applied previous to sowing, for both the nitrate and the potash salts have a depress- ing effect upon germination. They are preferably ap- ADVANTAGES OF DEEP CULTIVATION 939 plied, say, one-third of the mixture as soon as the plants have come up, another third immediately after or before the first cultivation, and the remainder immediately after or before the second cultivation. The application of the fertilizers in these forms and at the times indicated insures the rapid and early growth and development of the plant; and by reason of the solubility of the nitrates and ammonia salts, a late feeding of the plant with nitrogen is obviated. On light or medium soils, the amount of plant- food should be increased by at least one-third, though fractional applications should be made as _ previously recommended. On soils rich in vegetable matter, a part of the nitrogen may be omitted, though the phos- phorie acid should not be reduced. The Influence of Previous Deep Cultivation of Soil Another point to observe in the growing of beets for sugar,—and it also has an immediate bearing upon fertilization,—is the character of the previous cultiva- tion. If the soils have not been deeply and well eulti- vated, so large a dressing as is here recommended would be likely to be deleterious, as with a shallow and poorly prepared soil plants would have less op- portunity to penetrate deeply, and thus too great a growth above the surface of the ground would be encouraged, with a consequent lowering of sugar con- tent as well as yield. The best practice in our country will have to be developed by the experience of our own growers, 940 FERTILIZERS though in the absence of such experience, the recom- mendations here made may be relied upon. In many of the sections of this country in which the soils and climate are well adapted for the sugar beet industry, the needs as yet are quite as much for improved methods of cultivation as for added fertility. They have not been exhausted of their essential elements of fertility. An epitome of the soil conditions for sugar beet eulture will be found in the second edition of Roberts’ “Fertility of the Land,” p. 400. CHAPTER XII GREEN FORAGE CROPS A LARGE number of crops is included in this elass. In dairy districts they are grown for summer feeding, mainly to supplement or to entirely substitute pas- turage, as well as to provide a succulent ration of roughage in winter. Any crop which grows quickly, is palatable, and makes a reasonably large yield, is adapted for the purpose. For convenience of study, these crops may be further classified into three groups : 1. Cereals and grasses. 2. Clovers and _ other legumes. 3. Roots and tubers. In the case of those included in the first group, the purpose or object is to obtain as large a growth of leaf and stem as possible. Thus the character of the fertilization may differ from that recommended when the same crops are grown for the primary purpose of obtaining the. largest yield of seed or grain. These erops, too, may in all cases be considered as only well adapted for the “intensive” system of practice—that is, when the management is such as to encourage the largest yield possible per unit of area under the ex- isting conditions of climate and season. ‘I'he natural fertility of the soil thus becomes a less important factor; indeed it cannot be relied upon altogether, as P (241) OAS FERTILIZERS the largest yield of succulent food is dependent upon a rapid and continuous growth, and hence the supply of plant-food must be relatively much greater than is the ease when the cereals are grown for their seed. That is, forage crops, because suecculence is a factor influencing quality, must, as a rule, be grown quickly, and in order that large yields may be obtained in a short period of time a relatively greater abundance of plant-food must be at their disposal than when the growth is distributed through a longer period. Be- sides, larger amounts of all of the food constituents are required for the production of the same amount of dry matter per acre than when grown for the mature crop, because the dry matter of the mature crop is richer in the constituents derived from the air and poorer in those derived from the soil, than the dry matter of the immature crop. Maize (Corn) Forage A valuable forage crop of the first group is maize (Indian corn), because it grows quickly, is well adapted for a wide variety of soils and climates, is extremely palatable, and is capable of producing large yields. The fertilization which has been recommended for the field crop is less desirable than one which furnishes a greater proportion of nitrogen, because of the greater need of this element, and because it encourages a larger leaf and stalk growth; and the greater the pro- portion of these in a corn crop the richer will be the dry matter in the important compound protein, and FERTILIZERS FOR CORN FORAGE 943 nitrogen is the basic element in this group of nu- trients. When the crop is grown on good land on clover sod, which has been liberally manured, the fertilizers applied should be particularly rich in the mineral elements, phosphoric acid and potash. An application of 500 pounds of a mixture containing— LES 2 ce a I, ecees eet OOS aaa ae em ae 2% Available phosphoric acid ......... 6 % RMR Crs Ct eta eG hae eae Sa. ga: bs. te HOG 8 % would provide an abundance of food, even should unfavorable conditions intervene, but when grown on light, unmanured soil without sod, a larger amount of nitrogen should be used in connection with the min- erals. An application of 25 pounds of nitrogen, 35 of phosphoric acid and 50 of potash is as small a fer- tilization as should be recommended on soils of this character, since a yield of 10 tons per acre, containing 25 per cent of dry matter— which is only a fair crop —would remove 60 pounds of nitrogen, 25 of phosphoric acid and 70 of potash. Hence, very large increases in yield could not be expected from smaller dressings, unless conditions were absolutely favorable throughout the entire period of growth. The nitrogen, as in the ease of field corn, may be derived from organic sources, as the season of growth is the same—the summer—which is the most favorable for encouraging a rapid change of the organic nitrogen into the soluble nitrates. The phosphoric acid should be in large part derived from superphosphates, though since the season of growth 944 FERTILIZERS and the character of the crop and of its cultivation are conditions all of which favor a rapid change of in- soluble into available forms, a portion may be sup- plied by ground bone or tankage. The potash may be kainit or muriate, though if kainit is used, it should be broadeasted and well worked into the soil before planting. Silage Corn Corn grown for the silo, while distinctly a forage crop, is, in its management, very similar to the field erop, and is not planted so thickly as to prevent the formation of ears. The object in its growth is, how- ever, to obtain a large yield of dry matter, somewhat richer in nitrogenous substance and poorer in starch and woody fiber than field corn. Hence the fertilizers for the crop on medium soils should be richer in nitrogen than for the field corn, where the primary object is the grain, and where heavy fertilization with nitrogen would encourage a disproportionate stalk growth. An application of 30 pounds of nitrogen (equivalent to 250 pounds of dried blood or 450 of cot- ton-seed meal), 40 of phosphoric acid (equivalent to 300 pounds of acid phosphate), and 60 of potash (equivalent to 120 pounds of muriate of potash), would provide for a marked increase in yield. Wheat and Rye Forage In the growth of cereal grains, the object is to secure as large a yield of grain as is possible under WHEAT AND RYE FORAGE 245 the conditions of climate and season, and only such development of leaf and stem as will contribute to a maximum yield of grain. Hence a too liberal nitrog- enous fertilization which encourages this form of growth may result in too great a proportionate yield of straw. This objection becomes an advantage when the cereals are grown for forage. The cereal crops, wheat and rye, if seeded in the fall, should, therefore, receive a fertilizer which shall especially promote leaf and stem growth; and to ac- complish this purpose in the best manner, a rapid early fall growth, and a consequent deep rooting system, as well as an early and rapid spring growth, should be encouraged. Fertilizers most suitable are rich in nitrogen and phosphoric acid, and should contain potash also, if the land has not been previously well supplied with this element. The larger proportion of the nitrogen, however, should be applied in available forms as a top-dressing in the spring, rather than at time of seeding, thus reducing the possible loss of this element during the winter and early spring through _ leaching, besides providing the plant with it when most needed, and producing a crop richer in nitrog- enous substance. The ranker growth and somewhat coarser product resulting from this method of fertilization, while not desirable for grain crops, is not a detriment when the product is eut in its green stage for feeding, and the larger growth is accompanied by greater succulence. Where these cereal grains are sown mainly as eatch crops following a corn crop which has been 946 FERTILIZERS liberally fertilized with the minerals phosphoric acid and potash, the application at time of seeding may be light, and may consist only of nitrogen and phosphoric acid,—for example, from 200 to 400 pounds per acre of a dissolved bone; and the top-dressing in the spring need not exceed 100 pounds of nitrate of soda per acre for the wheat, and 75 pounds per acre for the rye. For lighter soils, or for those not previously well fer- tilized, much heavier applications not only are required, but all of the constituents should be ineluded, and the top-dressings should be made in spring, as already pointed out. Spring Rye For spring rye, an application of a fertilizer fur- nishing 10 pounds of nitrogen, 20 of phosphorie acid and 10 of potash per acre would be a sufficiently liberal dressing for the crop on good soils, sinee the plant possesses good foraging powers, though it is not so desirable a forage crop for northern climates as the winter rye. The nitrogen, in any. case, should be in quickly available forms. Oats Oats and millet are also suitable crops for forage purposes, and are largely grown; the first, because it is adapted for cool, moist weather, and makes a rapid early growth, and the second, because adapted for late spring seeding and for summer conditions. The oat crop for forage purposes is even more A PECULIARITY OF THE OAT CROP QA47 generally benefited by manuring than when grown for the grain, and the constituents particularly useful are nitrogen and phosphoric acid, though on sandy soils, and on those of medium fertility and not previously fertilized with potash, this element should also be added. A good dressing, keeping in mind the value of the possible increased yield, may consist of 12 pounds of nitrogen, 20 of phosphoric acid and 10 of potash,— the nitrogen largely in the form of a nitrate and the phos- phorie acid in soluble and available forms. The oat crop is peculiar in that shortly after the germination of the seed, there usually oceurs a period of a week or ten days during which the growth is ex- tremely slow, which experienced farmers call the ‘ pout- ing” period. While the exact cause of this well-known habit is not understood, it is believed to be due in part to the absence of available plant-food of the right sort early in the season, since liberal applications of nitrates and superphosphates seem to shorten the period of “pouting,” if not altogether preventing its occurrence. Its avoidance for grain crops, while im- portant, is not so important a matter as in the ease of forage crops, since an extension of the period of growth simply delays ripening, while in the latter, delays not only prevent maximum growth within a certain time, but seriously interfere with rotations. Winter oats, which are successfully grown in the southern sections of the country, should be fertilized at time of seeding practically in the same manner as wheat; that is, dressings furnishing small amounts of 248 FERTILIZERS nitrogen and considerable phosphoric acid, to be fol- lowed in spring with a top-dressing of nitrate of soda, not to exceed 100 pounds per acre. Oats and Peas Where oats are grown with field peas for the pur- pose of supporting the vines, as well as to obtain a larger yield than from either alone, the fertilizer should also contribute toward the inerease in the pea crop, and hence a greater abundance of the minerals should be applied, though it is very desir- able in this case, too, to encourage the rapid growth of the oats by reasonably liberal supplies of available nitrogen. Barley and Peas The growth of this combination of plants is a desirable one when late fall forage is needed, and as a crop is well adapted for fall conditions. The ferti- lization should be liberal, in order to encourage a rapid and large appropriation of food, which may be elaborated after light frosts oceur. An application of 200 pounds per acre of a mixture of 100 pounds of nitrate of soda, 175 of acid phosphate and 25 of muriate of potash, will furnish sufficient and good proportions of the plant-food constituents. Millet The various kinds of millet are eminently sur- face feeders, and are particularly benefited by lberal THE FERTILIZATION OF MILLET 949 applications of all the fertility elements. In fact, maximum forage crops of this plant cannot be ob- tained except when there is present in the soil such an abundance of all of the fertility elements as to enable a continuous and rapid growth. Both the nitrogen and phosphoric acid should be largely in immediately available forms; hence nitrates and super- phosphates are recommended. The potash may be in the form of muriate. A crop of ten tons per acre of millet forage, of any of the Japanese varieties, which are very suitable for this purpose, will remove 50 pounds of nitrogen, 25 of phosphorie acid, and 110 of potash, practically all of which food is absorbed from the immediate surface soil. Good crops fre- quently reach this assumed yield; hence, unless the Jand is in a high state of fertility, or has been pre- viously fertilized, it is necessary, in order to obtain a fair crop, to furnish by direct application at least one- half of the nitrogen and potash, and as much phos- phoric acid, as are contained in the crop. These amounts and kinds of plant-food could be practically supplied by a dressing of 450 pounds of a mixture made up of 150 pounds of nitrate of soda, 200 of acid phosphate, and 100 of muriate of potash, and such dressings have given excellent satisfaction in the New Jersey experiments with forage crops. CLOVERS AND OTHER LEGUMES These are among the most valuable of our summer forage crops: first, because of the time of their 950 FERTILIZERS growth, they furnish food before spring-sown erops are ready; second, because of their power of ac- quiring food from sources inaccessible to the cereals, they are less exhaustive; and third, they are espe- cially rich in the compound protein, the most useful substance contained in feeds. Since these crops gen- erally grow well on soils of medium fertility, many are inclined to regard them as able to subsist and make a good crop without liberal fertilization. It should be remembered, however, that the power which these plants possess of acquiring nitrogen from the air depends largely upon the supply at their command of the mineral elements, phosphoric acid, potash and lime; the presence of these is of primary importance, and good crops cannot be grown on land deficient in these elements. In any event, therefore, liberal sup- plies of the minerals should be provided, in order that maximum yields may be obtained. On soils of medium fertility which are fairly well supplied with vegetable matter, the need for nitrogen is not marked, even in the early growth of the plant. On lghter soils, how- ever, a nitrogenous fertilization is often serviceable, because supplying nitrogen before the plant has ac- quired the power of obtaining it from the air. This practice enables the plant to make an early start, and prevents the delay in growth which sometimes occurs, particularly on light soils, during the period imme- diately after germination, when the plant is unable to obtain its nitrogen from sources other than the soil. A green forage crop averaging 10 tons per acre re- quires, on the average, about 30 pounds of phosphoric FERTILIZERS FOR SUMMER LEGUMES 951 acid and 100 of potash, and the nitrogen which neces- sarily accompanies these amounts of minerals will reach, on the average, 100 pounds. If this element is drawn from the air, because provided with an abun- dance of minerals, it is manifestly economy to supply the full amount of these required, rather than omit them, and thus to limit the plant’s power of acquiring this expensive element, since the value of the 100 pounds of nitrogen gained is greater than the cost of both the phosphoric acid and potash required. Cow Pea and Soy Bean The clovers, which range in their length of life from annuals to perennials, are, too, able to obtain their necessary supplies of minerals more readily from soil sourees than the distinctly summer crops, as the cow pea and soy bean, because of the longer period of preparatory growth in the ease of the former. That is, clover or vetch, while it does make a very rapid growth through a short period, does not obtain all of its food during that period. In its preparatory stage of growth—fall and early spring—a very con- siderable amount of food, the larger proportion, in many instances, is obtained, which in its later stages of growth, is simply distributed throughout the entire plant; while the cow pea and soy bean, on the other hand, must obtain the entire amount of food needed for their growth and development during a short period, and these crops reach their best stage of development for forage in two and one-half to three 252 FERTILIZERS months from time of planting. Hence, these crops, which possess apparently greater foraging powers, and make their development during the season when con- ditions are most favorable for rapid change of in- soluble to soluble food in the soil, require, when the conditions of the land are the same in each ease, a relatively greater abundance of the mineral elements than do the clovers, which can acquire food through a longer period. An application of 3800 pounds per acre of a mixture of 200 pounds of acid phosphate and 100 of muriate of potash, which supplies 25 pounds of phosphoric acid and 50 of potash, would, on medium soils, be regarded as a sufficient annual dressing for clover crops; whereas, in the case of the purely summer crops, the application could be inereased one-half with profit. In the case of the summer erop, the phosphoric acid should. be in a soluble form, because it is not economy to depend upon the conditions of climate, soil and season to change insoluble forms rapidly enough to provide for the continuous feeding of the plant, while for the clovers, less available forms may be used with advantage. Alfalfa, or Lucerne This valuable crop, which was not formerly regarded as well adapted for the eastern states, can be success- fully and profitably grown if the soil is_ sufficiently deep and open and naturally well drained, and pro- vided it is supplied with an abundance of mineral ALFALFA OR LUCERNE 2060 food, consisting of phosphoric acid, potash and lime. Its habits of growth are such as to enable the harvest- ing of three or four green forage crops, and at least two hay crops annually. In order to meet the large plant-food demands thus made, the fertilization pre- vious to seeding must be not only liberal, but frequent top-dressings should be made. The phosphoric acid for these dressings should preferably be drawn from superphosphates, in order that ready distribution may be accomplished, while a large portion of that con- tained in the preparatory dressing may consist of the less soluble forms, as ground bone, natural phosphatic guanos, and fine ground rock phosphates. Twenty tons of alfalfa green forage, which may be regarded as a good annual yield for this plant from the two to four cuttings that may be made, will contain 250 pounds of nitrogen, 50 of phosphoric acid and 275 of potash. Assuming that the demands for soil nitrogen are confined to a short period immediately subsequent to the germination of the seed, the total required plant-food is still considerable, and is es- - pecially severe upon the potash compounds of the soil. Hence, the fertilizers supplied should be particularly rich in this element. For eastern conditions, where soils possess a medium rather than a high potential fertility, heavy dressings of the minerals should always be made. at eed II. THe YIELD WITH BARNYARD MANURE Baskets per acre 1884-1891, inclusive, 8 years, EreTaeY a your we Sh yr he near 169.5 1884-1893, ei 1 OR Sa Na aa MN Cale A aS ESAS Fe Y- 194.7 1887-1891, es (5 crop years), average per year .. . 271.3 1887-1893, rs fa Fe 5 = Ss). he IV. THE RELATIVE YIELD IN AN UNFAVORABLE SEASON Baskets per acre eter TeEITPEEREPIEB EMS ea SS eae AS ae Lee ahs: hale 10.9 Ere MRE IME MN Rareah Sect Ee ws a es Pa, oo Ey Re A ae ee et el mg 152.5 ToS Segal itl c/o ma pe oe aaann ede ee SEM Me atey SSE ey SMO US OL Same, oe 162.5 296 FERTILIZERS “The first point of importance and value observed is in reference to the number of crops that were secured. On the unmanured land, the crops secured after eight years were so small as to materially reduce the average for the whole period, while for the ma- nured land the average for the whole period was not only not reduced, but very materially increased; that is, the crops secured on these after the trees on the unmanured land had practically ceased to bear were greater proportionately than those secured previous to that time. This was true both for the fertilized and manured land. “In the next place, it is shown that the yield was very materially increased by the use of manures, either in the form of artificial or natural supplies, and the differences in yield derived from these two forms are very slight, indicating that very much smaller amounts of actual plant-food in quick-acting forms were quite as useful as larger amounts of the less available forms in which the food exists in natural manure products. “For the ten years, the fertilized plot received 250 pounds of nitrogen, 560 of phosphoric acid and 750 of potash, while the yard manure plot received — assum- ing the average composition of yard manure — 2,000 pounds of nitrogen, 2,000 of phosphoric acid and 1,600 of potash; yet with eight times as much nitrogen, nearly four times as much phosphoric acid and more than twice as much potash, the yield was but 113 baskets greater, or an average of 11 baskets per acre. FERTILIZERS FOR GOOD AND POOR SOILS Y97 “In the third place, it is interesting to observe— and it is a point of great importance—the effect of an abundance of food in overcoming unfavorable weather or seasonal conditions. The year 1889 was extremely unfavorable, and the crop throughout the state was small. In this experiment the unmanured plot yielded at the rate of 10.9 baskets per acre, while the manured and fertilized plots both showed a yleld exceeding 150 baskets per acre. The manure strengthened and stimulated the trees, and enabled them to successfully resist such conditions as were fatal to the crop on the unmanured land. “This point is one that is seldom considered in calculating the advantages to be derived from proper manuring, though it is of extreme value, since the expenses of cultivation, trimming, and interest on investment are quite as great in one case as in the other.” * Methods of Fertilization On soils of good natural character, the necessity for fertilizing peaches is seldom apparent until after the first or second year of growth. That is, good soils will provide sufficient food for a normal develop- ment of leaf and wood, and any additional fer- tilization would have the tendeney to unduly increase the tree growth. On medium and poor soils, the setting of the trees should be preceded by a fer- **Manuring Orchards.” Massachusetts Horticultural Society, 1896. 298 FERTILIZERS tilization with one or the other of the basic mix- tures (p. 288), on the better soils No. 2, and on the poorer No. 1, at the rate of 400 to 600 pounds per acre, which should be followed by the application of the more soluble fertilizers immediately the trees begin to bear. The need of nitrogen is often very marked, and is shown by a lack of vigor of the tree. The soluble nitrates have proved very valuable as a source of this element, since from these the nitrogen may be appropriated by the roots during the early season, and which, if a sufficient abundance of the minerals is present, enables a normal development of leaf and branch. If the quick-acting nitrogenous fertilizers are applied late, or if too large applications of the slower-acting nitrogenous materials are applied early, the tendency is to provide for a continuous feeding on nitrogen, and thus encourage an undue develop- ment of leaf and branch, which does not permit the ripening of the wood before the beginning of winter. Thus on these soils, in addition to an annual applica- tion of the basic formula, from 100 to 150 pounds of nitrate of soda, 200 pounds of acid phosphate and 100 of muriate of potash should be applied early in the season and carefully worked into the soil. For peach crops, too, green manuring with legumi- nous crops should be earefully carried out, since if too much nitrogen is added by this means, an abnormal growth of wood is encouraged, and a late ripening of the fruit occurs; and injury to the tree may follow if the manuring crop is not used at the proper time, as already indicated. CAREFUL USE OF NITROGEN 299 Many orchardists use much larger amounts of fer- tilizer than is here recommended, though if the sug- gestions concerning the method of use are carried out, the quantities named will be found sufficient to supply all the needs of maximum crops. PLUMS, CHERRIES AND APRICOTS The fertilization of these fruits, when grown on the different classes of soils, need not differ materially from that recommended for peaches under the same conditions, though cherries, particularly, require in addition to the essential constituents, nitrogen, phos- phorie acid and potash, a relatively greater supply of lime, and this substance should be applied in addition to the regular fertilization. Care should also be exercised in the application of nitrogen, in order to prevent a too great development of leaf and branch. Unless these trees show a decided need for nitrogen, a medium application of the second basic formula (p. 288) will furnish sufficient for their needs. CITROUS FRUITS These products—the oranges, lemons, and the like— belong to a distinct class of fruits, and the experience already gained in their fertilization is such as to make - applicable the suggestions concerning peaches, plums and apricots. On the lighter sandy soils of Florida, which are naturally well adapted for oranges, growers have found potash to be a specially important element | - 800 FERTILIZERS in manures. The nitrogen and phosphorie acid should be accompanied by a larger proportion of potash than is recommended for the stone fruits. Great care should be exercised in the use of nitrogen, though in the ease of these semi-tropical crops, the danger from immature growth, as in the case of fruits for the more northern climates, is not so marked. SMALL FRUITS IN GENERAL These crops do not differ from those already dis- cussed in reference to their needs for liberal fertiliza- tion, yet because of their different character of growth, the method of fertilization should be somewhat dif- ferent. They are, as a rule, crops which require a shorter preparatory season, and have a shorter period of bearing life. The strawberry, for example, does not advantageously bear more than two crops without re-setting, whereas the blackberry and raspberry may range in life from four to eight years, and the goose- berry and currant are relatively long-lived, provided they are supplied with an abundance of food. In respect to their general character, they correspond more nearly with the vegetable crops than with the cereal grains, in that they possess a relatively higher market value and a lower fertility value than these, and the period of growth and development of the fruit is much shorter. Therefore, natural sources of plant-food may be largely ignored in their growth, and the more quickly available — particularly nitrogenous and phosphatic — materials supplied. AVAILABLE PLANT-FOOD RECOMMENDED 301 STRAWBERRIES In the case of the strawberry, the preparatory period of growth of the plant before bearing is but one year, and the crop that may be obtained is largely dependent upon the strength and vigor of plant which has been acquired during this period. Hence, it is desirable that the soil in which the plants are set should be abundantly provided with the mineral elements, particularly with soluble and available phosphoric acid; hence an application of from 500 to 800 pounds per acre of basic formula No. 1 (p. 288) is recommended. The nitrogen should also be in quickly available forms, and should be supplied in sufficient quantities at time of setting the plant to enable it to mature, and thus to withstand the rigors of winter. Hence, an additional application of 100 pounds of dried blood, or its equiva- lent in nitrate of soda or ammonia, is advisable, par- ticularly on soils not previously well enriched with organic nitrogenous matter. In the spring of the sea- son during which the first crop is harvested, an appli- eation of a quick-acting fertilizer rich in nitrogen is desirable, since it not only provides for an early and strong growth of plant, but a better setting of fruit, if other conditions are favorable; and frequently, with a full setting, top-dressings with nitrate of soda are useful, in order to insure the full development of the crop. Many growers, therefore, who have supplied the soil liberally with minerals and nitrogen, both at time of setting the plants and in the following spring, make top-dressings of nitrate of soda (about 100 pounds per 302 FERTILIZERS acre), preferably after the plant has blossomed, in order to insure a sufficiency of this element. This should be applied at this time rather than later in the season, since later applications have a tendency to cause a soft growth of fruit, and thus injure shipping qualities. RASPBERRIES AND BLACKBERRIES Raspberries and blackberries also require a soil well enriched with the mineral elements, which insure an abundant and strong growth of canes. The need for nitrogen, while apparent, is less marked than in the case of the strawberries, and the slower-acting forms serve a good purpose, provided they are not applied in too great quantities, so as to encourage a late growth of plant, which does not fully mature. The main object is to obtain strong, well-ripened canes, and this can be accomplished with the slowly avail- able nitrogenous substances, provided an abundance of the minerals is present. An annual application in spring of 500 pounds per acre of basic formula No. 2 (p. 288) will furnish sufficient food on soils of good character, though on lighter soils additional nitrogen should be supplied, preferably in forms not too active. The practice of applying quick-acting nitrogen early in the spring, after plants have blos- somed, has been followed with great success, particu- larly upon the lighter soils, as it encourages a more complete development of fruit, though it should be used with caution, since the fruit canes of both the FERTILIZE FOR FRUIT, NOT WOOD 303 present year and those which provide the plant for the next year naturally grow in the same bed, and the young canes may not mature properly if too heavy applications of nitrogen are made. CURRANTS AND GOOSEBERRIES These are crops which, under average conditions, are seldom heavily fertilized, though fertilizing is usually followed with great profit. They are less likely to need nitrogen than the other crops men- tioned, and a too heavy fertilization with this element has a tendency to encourage the development of mil- dew, the disease so common to these crops. In com- mon with the other crops mentioned, they should be abundantly supplied with the minerals, phosphoric acid and potash, and the basic formula already rec- ommended (p. 288) may be used in all cases with profit at the rate of 500 to 1,000 pounds per acre. The additional nitrogen needed may be provided by the slow-acting materials. Many growers find such waste products as wool and hair of great advantage in the growing of these crops. GRAPES Grapes are more exhaustive as a crop than most of the fruit crops, largely because of the larger total crop harvested, and the special need is for phosphoric acid and potash. These elements may be supplied by the basic formula (p. 288), and very liberal dressings are 304 FERTILIZERS recommended,—from 1,000 to 2,000 pounds per acre annually,—after the bearing period begins. On light soils, an annual spring dressing of nitrate of soda, at the rate of 200 pounds per acre, is also desirable, in order to encourage rapid and large early growth of leaf and vine, though this dressing may be omitted if the growth of clover as a green manure is practicable. The latter, however, as when used in connection with the other fruits mentioned, should not be allowed to mature, but rather be plowed down early in the season. The main point in the fertilization of all fruits is to provide an abundance of the mineral elements, and to give particular attention to fertilization with nitrog- enous materials. It must be remembered that it is the fruit, not the wood, that constitutes the crop, and that all the energies should be directed toward the development of such a tree or vine as will best contribute toward this end. CHAPTER XV FERTILIZERS FOR VARIOUS SPECIAL CROPS IN ADDITION to the generally familiar crops already deseribed, there are certain special ones, not distinct from the others because they are of less importance, but rather because they are only grown in certain localities. COTTON Among these special crops, cotton takes first rank, because it is one of the leading crops of the country, occupying wide areas, and exercising fully as great an influence upon our agricultural prosperity as any other of our American staples. The climate suitable for the growing of cotton is confined to about one-quarter of the area of the coun- try, and in this area it occupies a more important position than any other crop grown there. In the earlier history of its cultivation, the methods employed were not such as to encourage the largest yield. In the first place, it was grown on the poorer soils rather than the more fertile, and after it had been grown consecutively upon the same lands for a number of years, and thus rapidly exhausting them, the planter, instead of attempting to improve the lands, T (305) 306 FERTILIZERS either by better methods of culture or by the use of manures, extended the areas under cultivation. After the civil war, when it became still more necessary to change methods, fertilizers were looked to as the main reliance, rather than the improvement of the character of the soil, either by judicious rotation or by manur- ing. The results secured from the use of fertilizers at this time were so generally satisfactory that their large and indiscriminate use was encouraged, and this, with- out proper attempts at the improvement of the soil in other respects, hastened the time when such use did not give profitable returns. The very great importance of the crop to the agriculture of the leading cotton states, and the necessity of better methods of culture, were so fully appreciated that a scientific study of the crop was then entered upon, and the states largely interested planned, through the aid of their colleges and ex- periment stations, a wide series of experiments, which were directed toward the solution of the problems connected with the feeding of the plant. The results of these experiments have been fruitful of such valuable information as to warrant practical and specific sug- gestions which have a wide application, and which, if followed, will result in the improvement of the soil and in the economical increase in crop. As already stated, the cotton crop is not an ex- haustive one in one sense, though the methods of practice used in its growth have been wasteful, and thus have given rise to that belief. That is, a large crop of cotton does not remove from the soil a very considerable amount of the fertilizer constituents. IMPORTANCE OF PHOSPHORIC ACID BUT The following amounts are contained in a crop yield- ing 300 pounds of lint per acre :* 2 UE, Sr ii EA Pir ne i aa 46 lbs. RONNSHISEIS RAG Fe is oe a) ee RT 12 lbs. RIED ers) SEN aT aia tacit ye tie BR Fertilizers for Cotton In regard to its need for fertilizing, cotton may be classed with the cereals rather than with the crops al- ready discussed; and like the cereals, its best growth is attained when properly introduced into a rotation with other crops, and the annual food supply arranged in such a manner as to contribute to the larger yield of the immediate crop, as well as to furnish an unused residue which will provide for an increase in the yield of the succeeding ones. Of the constituents, phos- phorie acid seems to exercise a greater influence upon the growth and development of the cotton plant than any other element, notwithstanding the fact that smaller amounts are contained in it than of either nitrogen or potash. That is, it appears that the plant must have an abundance of available phosphoric acid at its command in order that the other constituents necessary for a full crop may be freely absorbed, though on the soils adapted for the crop, which naturally vary widely both in their general and special physical char- acteristics, but are poor in the fertility elements, both nitrogen and potash must be applied, in order that maximum crops may be obtained. *Parmers’ Bulletin No. 14, Department of Agriculture. 308 FERTILIZERS On the whole, therefore, though the “intensive” system is not generally practiced, fertilizers furnishing all of the constituents are superior to those which fur- nish but one or two; -yet when proper rotations are — practiced and leguminous crops are grown for the pur- pose of improving the physical character of the soil, as well as increasing its content of nitrogen, the percent- age of this element introduced into the fertilizer may be very largely reduced. The conclusions that have been arrived at by the experiments conducted in the various states have been very fully set forth in various publications,* and the following statements drawn from these indicate what are believed to be the advantages derived from the right use of fertilizers, and the best methods to be observed: “The cotton plant responds promptly, liberally and | profitably to judicious fertilization. The maturation of the crop may be hastened, and the period of growth from germination to fruiting may be so short- ened as to increase the climatic area in which it may be profitably grown. It should be assigned to a place in a rotation system. One of small grain, corn (with peas) and cotton, is well suited for the con- ditions prevailing in the cotton belt, and, as with other crops, the results derived from the use of fertilizers for this crop are much enhanced by the proper preparation of the soil. It pays to bring * Farmers’ Bulletins, Nos. 14 and 48, Department of Agriculture. Office of Experiment Stations, Bulletin No. 33, Department of Agriculture. Various bulletins issued by the Georgia, South Carolina and Louisiana Experiment Stations. FORMULAS FOR COTTON 309 up the cotton lands by mechanical treatment, and especially by introducing organic matter. The renovating crops, especially the cow pea, are very profitably employed as adjuncts to the fertilization of the crop itself. On the majority of soils, too, it is advisable, and more generally proves profitable, to use a complete fertilizer, rather than one containing one or two of the constituents; and of the forms of nitro- gen, organic (vegetable and animal) is best suited to the cotton, if one form alone be used, although nitrate of soda is probably nearly, if not quite, of equal value. The relative advantages of various pro- portions of the different forms have, however, not yet been fully determined; hence the use of a mixture of the best is a safe plan, the proportions to be determined by their relative cost. In the case of phosphoric acid, superphosphate is to be preferred to to materials of an organic or mineral nature, which are not immediately available. Of the potash salts, no particular difference is observed in the use of the different forms. The form to be secured is to be based upon the price of the different forms.” Formulas for Cotton Fertilizers While the most judicious proportions of soluble phosphoric acid, of potash and of nitrogen in a com- plete fertilizer cannot be said to have been determined with entire accuracy, the carefully conducted experi- ments of both the Georgia and South Carolina sta- tions indicate that for general use 1 part of nitrogen, 310 FERTILIZERS 1 of potash, and 22% or 3 of phosphoric acid in- dicate the best proportions. The amount of fer- tilizer that may be profitably used very naturally varies widely, though medium rather than very large dressings are recommended, not so much because the plant under good soil conditions could not appropriate and use to advantage large amounts, but because on the whole, soils used for cotton are peculiarly lacking in those qualities which enable the proper distribu- tion and appropriation of the larger quantity. For those soils, then, the amounts per acre indicated by the Georgia Experiment Station are, annually — INFEVOROM 2a hod ct, a saan Be eee 20 Ibs. Available phosphoric acid. ....... 70: 3° POTS Bc go hearts aay 9's eee cas ats GL 20°. The South Carolina Experiment Station recom- mends an application per acre of — NRG REN:. Pc. id an a ase say ake we 20 lbs. Available phosphorie;seid .-.-. . 2+: <;% 50k nc 1g aa Arne Neg Not a RSG PE ats 10h are or, as suggested by the Georgia Experiment Station, perhaps a fertilizer containing — INDGROSEM SS aos We eee) whe nal a eae 3% Phosphoric acid: (soluble)... 2 oc ee ae 9 % Potash $2.2 hk 2 eS eS eee 3% applied at the rate of 700 pounds per acre, would be approximately the best amounts to use under ordinary circumstances. ADVANTAGES OF HOME MIXTURES ke Method of Application The fertilizer should be applied in the drill at the time of planting, and at the depth of not more than three inches, and well mixed with the soil. In most eases it is best to apply all of the fertilizer in one application rather than in fractional applications, though with lands in superior condition profitable applications may be made again at the second plow- ing. Owing to the nearness of the cotton belt to the supplies of superphosphate, and to the cheap sup- plies of cotton-seed meal, the only fertilizer neces- sary to import is potash. Hence it has become a practice in most sections for the planter to make his own formulas, using his own supplies of phosphoric acid and nitrogen; and home mixtures, made up of acid phosphate, cotton-seed meal and muriate of potash, or kainit, are largely used to supply the demands. The following formula is an example of a good mixture : CIA POS PEALG: os oe Kw sl es oe OS 1,200 lbs. Upison-seed meal... 9. 2s . 6 6 sss 0 i matcher oul ie boyy Oo oP le SP ake 200° ** The formula containing — EL RECOM Beep cd ee eS yh ca pie ge wel we a eee 3% PGB OTIO: RCO = se ahora. at oe ei aes 9% eat ced Fay GAN SAG ust ah od (2% ete a the 3 % is also recommended, since an application of 700 pounds per acre will furnish the amounts and propor- tions of the elements indicated as the maximum by 312 FERTILIZERS the Georgia station. This formula is also well suited for corn, if introduced into a rotation as previously suggested. TOBACCO Tobacco is another special crop grown only in cer- tain localities, favored either by reason of climate or character of soil, or both. It is, however, a_ very important crop in this country, and one which requires very careful attention in reference to the amounts and kinds of fertilizers applied, because the fertilization exercises an influence upon both the yield and quality of the crop. It is an exhaustive crop, drawing heavily upon both nitrogen and potash.