aa i Oo Fegned March 21, 1908, ° J - ¥ ' ; OF SOILS—BULLETIN No. 48. | ; fA Geran a { ft rah MILTON WHITNEY, Chief. 3 FERTILITY OF SOILS AS AFFECTED oe BY. MANURES. BY ; FRANK D. GARDNER. Re es if ay? WASHINGTON: GOVERNMENT PRINTING OFFICE. 1908. ' .. e Woncgraple v Issued March 21, 1908. eo perewn eee NP.OF. AGRICULTURE, BUREAU OF SOILS—BULLETIN No. 48. MILTON WHITNEY, Chief. FERTILITY OF SOILS AS AFFECTED BY MANURES. BY a ‘ \ a a Ah ie ti \ WASHINGTON: GOVERNMENT PRINTING OFFICE. 1908. vf APR 1 1968 D ot D, G oper 4/7/ 0 F se,” LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, BuREAU OF SOILS, Washington, D. C., June 24, 1907. Str: I have the honor to transmit a manuscript entitled Fertility of Soils as Affected by Manures, by Frank D. Gardner, in charge of Soil Management. It embodies the results of a uniform scheme of manurial treatments, as measured by the resulting increase in plant growth on soils collected from 220 fields in 23 States, located in the eastern half of the United States. The increasing use of manures, and especially of commercial fertilizers, by the farmers of the United States is sufficient justifica- tion for careful investigations as to the relative efficiency of various forms of manures on different soils. You will find here a vast amount of data, treated in a manner commensurate with the importance of the subject. It should be of great value to all who are interested in the use of manures. , The manuscript has been gone over carefully with Assistant Secre- tary Hays, who concurs in my recommendation for its publication as Bulletin No. 48 of the Bureau of Soils. Respectfully, Mitton WHITNEY, Chief of Bureau. Hon. James Witson, Secretary of Agriculture. CONTENTS. OSE THUY REE LOT ESE ABS Nes eee aa ge PSS 0 Ta a ee a a a LE eae a Obiect ‘of the investigations: .........-.......-:- ia 1 Meares ech a AE ce “PNG BOTS. CUA OBE GC SELES ae EAE a tp a Sp, iach ee ener ethodlc cece vcs.s4/ 210 = Eafe are Fee a Serre cnc oe Wigan dy Da POR OP ae Jey TASTES TIS Es (Nk Sc a ee hg Nope ae mormusemiont) sng taipulation Of resulis: 125... ..6..65 225-25. 2cc- 2a lone sess ss Comparative efficiency of salts used separately and in combination -.........-- iinee ol boas alone and with other salis...-....-..2.-2.2-.2..26.4----6---. Sulpbate of potash alone and with other salts..............--.--.--+---------- Aeid phosphate alone and with other salts................--.--2------..e-0/65 Per alanine with fertilizer salts’. ..:....60< os - os. o2- se es Beee se ce ae eee Relative efficiency of organic and chemical manures. : Relative efficiency of all salts and combinations, 5 ila are Pe eouped a ace a SMC IMRENIC UGE PHN of nor scs, os miei coe Su cine as gine e's aon diene 32 Bae E Relative efficiency of salts when used alone and in combination....- Hs ee ee Relation of fertilizer requirements to character of soils.......--.......-.-..-- Peiatye enicioncy of fertilizers by locality...2......26.... 002 -20-n.eeemecece Dee EDEN HOPEULG Or EGU. on eos eine clint Sa eee en eee chee codices beeen oie Relative response to fertilizers and expenditures for fertilizers...............-- Average efficiency of fertilizer salts, ac locality - iy telat ce oT ee Rak esa Ae Natural fertility as related to pa pense LORPCRUULAOES 22.0 A anne ose GN YE Nate Fertilizers and economy of water in plant growth .............--------------- EAU UN AN ane eee in, CON ULE ry Mere Ene sees ATs Ate ae os Aen mae me PELUSTRA TIONS. Fic. 1. Percentage increase in growth of plants, attributable to various ferti- lizer treatments of five principal soil types of the Waycross area, Georgia. ....-.-----++-++2+-+22---- ees See ries Mike Calta A orice . Percentage increase im growth of plants, attributable to various forti- lizer treatments for all soils of Waycross area, Georgia, and Escambia vcr OTLEY eS a as a ee RS ne a ae eee A ee ee 3. Percentage gain in plant growth attributable to each of the salts P, K, N, Peer erry ERR NO Ga 0. 08) een de etic oe Siac eto wet es ose 4e~ 4. Relative efficiency of fertilizer ingredients by soil series, when the ingre- ater aE WSS eyes! Scheie Sek eae ae Slee has wee cess oe 5. Percentage increase in growth of plants attributable to fertilizer and accompanying increase per unit of water transpired. Average of 20 Te Penk nt A SSR eGR Ou SEY Sieg Lina sais 'e deeb sacaae bo 48 44 . 5 . = “ = : . ‘ hy ‘ . ; ‘ i . ’ - ‘ ’ ? z . 2 r SF ’ i FERTILITY OF SOILS AS AFFECTED BY MANURES.’ INTRODUCTION. The use of manures as a means of increasing the growth of crops dates back to ancient times. At the time of the discovery of America, the North American Indians used dead fish as a manure for corn, The Peruvians have used guano since the beginning of their recorded history, and the Chinese have long recognized the value of all kinds of excrements as fertilizers. In the early part of the last century De Saussure established the existence of the mineral constituents of the soil in plants, and while he believed that they were essential to the life of plants, his contemporaries regarded them as nonessential, or at the best useful only as a kind of stimulant. Justus Von Liebig, as a result of his investigations, published in 1843 a new edition of his notable work, ‘‘Chemistry in its Application to Agriculture and Physiology,” in which it may be said he laid the foundation of the celebrated ‘‘ mineral theory” of agriculture. Prior to the time of Liebig the use of manures and fertilizers was purely an art, the beneficial results of which had not been satisfac- torily explained. Liebig’s mineral plant food theory, apparently so ample, and in time widely accepted, attributed the beneficial effect of fertilizers solely to the plant food constituents which were supplied to the growing plants, and thereby laid the foundation for the compounding of fertilizers to meet the needs of soils and crops. There soon sprang into existence a soil chemistry which had for its object an investigation of the stores of plant food in soils with a view to ascertaining the agricultural value of lands, as well as the character and amount of fertilizer, if any, that would give the largest net crop income per acre. It was soon learned that the soil con- stituents existed in various forms or compounds not all of which were available as plant food, and this led to a study of inexpensive methods of determining the available constituents, a study which has formed no small part of soil chemistry even down to the present aA comparative study of the fertility of the soils of the central and eastern United States, as influenced by manures and fertilizers and measured by the paraflin-pot method. 28220—Bull. 48—08 2 7 8 FERTILITY OF SOILS AS AFFECTED BY MANURES. time, with little indication that a method will ever be devised that will prove universally satisfactory for all soils and crops. So far as can be gleaned from the writings of soil investigators, only within recent years have any considerable number of them come to realize that there is no definite relation between the available plant food constituents of soils, as determined by mineral analysis, and their crop-yielding capacities. Neither had they arrived at that further realization that the crop-yielding capacity of a soil is dependent upon a complexity of factors, any one of which may be dominant, but all of which are concerned in large or small degree. Arable soils contain the organic remains of previous crops together with excretions produced during their growth and are also filled with living forms. Their bacterial flora is diversified and the activities and processes which take place within the soil, physical, chemical, and biological, are exceedingly complex, and at present but imper- fectly understood. It is the sum total of these activities and their products that determines largely the fitness of a soil for plants, rather than the variation in the character and composition of its mineral matter. While manure and fertilizers may often increase crop yields as a result of a direct supply of plant food or as a stimulant to the plants, there is now abundant evidence that their effect is rather the result of a direct action upon the soil, thereby changing its relation to plants. Complex and imperfectly under- stood as is this action, it is a more satisfactory explanation of the benefits derived from fertilizers than the idea that the inconsequential amounts of nitrogen, potash, and phosphorus applied, as compared with the larger stores of those elements already in the soil, should be directly responsible for such marked increase in growth as fre- quently follows the application of fertilizers. The prime object of manuring the soil, whether with stable manure, green manure, or commercial fertilizers, is to increase its crop- yielding capacity, and in order to justify the practice the resulting increase in product must be more than enough to offset the cost of the fertilizers applied. That is to say, the beneficial effect on the present and succeeding crops must be sufficient to compensate for the cost of the fertilizers and give a profit on the capital so invested. The first noteworthy use of commercial fertilizers in the United States was in 1848, during which year there was imported 1,000 tons. of guano. This was followed the succeeding year by twenty times that quantity, after which date the importation steadily increased until 1880, when it reached its maximum and began to fall off because of a failing supply. Other materials, notably sodium nitrate from Chile and the potash salts from Germany, have taken the place of the failing supply of guano, and these, together with the development of our phosphate mines, the use of cotton-seed meal, and the utilization OBJECT OF THE INVESTIGATION. 9 of slaughterhouse by-products, have met the continually increasing demand for commercial fertilizers by our farmers. According to our census reports, the expenditure for fertilizers in the United States in 1880 was $28,500,000. Ten years later it was $38,500,000, and in 1900 it reached the significant sum of $54,750,000. There seems little doubt that this rate of increase in the use of fertilizers will continue for some time to come, and the subject is one of sufficient national importance to justify careful investigations. OBJECT OF THE INVESTIGATION. The object of this investigation is not for the purpose of explaining how fertilizers act nor of studying the relation of the composition of the soil to the beneficial effect of the fertilizer when applied to it, but rather to compare the effects of several high-grade standard fertilizer ingredients, lime, stable manure, and cowpea vines when applied under like conditions to a large number of soils, collected from widely separated areas and representing a wide range in soil ' texture, type, origin, and crop adaptation. By making a comparative test of a large number of soils it was thought that there might be established a relation between the manurial requirements and the origin, formation, type, or crop adaptation of the soil. While there has been recorded in agricultural literature, in the ageregate, a large number of field tests of fertilizers on a great variety of soils, representing nearly every State in the eastern half of the United States, it is impossible to make a satisfactory comparison of the results obtained, because of the innumerable details in which the conditions of the tests do not agree. The variation in the amount, class, kind, and composition of the fertilizer used, the time and manner of its application, the test crop used, and the weather condi- tions which prevailed form such a wide range of possible combinations that it is rare to find two tests that are strictly comparable. In the present investigation the same variety of wheat was used throughout as the test crop, and all of the conditions for growth, excepting the manurial treatments to be tested, were maintained as nearly uniform as possible. With the same fertilizer ingredients, in like form and used in the same combinations, for a crop common to all, the results obtained from this large number of soils are strictly comparable, and far exceed in number any similar tests that can be brought together on such a basis. _ Mention should also be made of the fact that all tests reported in the following tables under areal surveys—and they constitute fully four-fifths of them—were made for the further purpose of gaining practical knowledge concerning the manurial requirements of the principal soil types as established by the soil survey parties and with 10 FERTILITY OF SOILS AS AFFECTED BY MANURES. the ultimate object of determining what manures or fertilizers would give best results on the soils. The results of all such tests are reported in general terms in the soil survey reports for the respective areas in which they occur. THE SOILS. The soils tested in this investigation, 220 in number, represent 90 types, half that number of soil series, and many geological forma- tions. The samples were taken from twenty-three States, extending from the Mississippi River to the Atlantic seaboard and from Rhode Island to Texas. With the exception of a limited number of mis- cellaneous samples, the greater number were collected from areas that were in process of being surveyed by the Bureau of Soils dur- ing the summer of 1905, and the following winter, and are representa- tive of the soils of those areas rather than the vast expanse of country included in the twenty-three States above mentioned. Each sample, being a composite, made up of fifteen or twenty small samples, taken from different parts of the same field, is representative of the field from which it is taken as well as the type which it represents. The sam- ples were placed in strong grain bags and shipped to the Bureau's headquarters; where they were at once transferred to covered gal- vanized iron cans for storage. In this way the original condition and original moisture content were, as far as practicable, maintained until they could be tested. This is important in relation to the test, for it has been found by experience that as a result of long storage and resulting air-dry condition soils become more productive and are usually less responsive to fertilizers than when such a change is prevented. THE METHOD. The paraffin-pot method, described in Circular No. 18 of this Bureau and in the appendix to Farmers’ Bulletin No. 257 of tho United States Department of Agriculture, was employed in these tests, and while it is not designed to supersede field tests, results obtained with it, when compared with results obtained on the same soils at the agricultural experiment stations in Rhode Island,? New York, Ohio,’ Iowa, Missouri, and North Carolina, show that it will indicate the manurial requirements of soils for general farm crops with a fair degree of accuracy. It is also admirably adapted to an investigation of the character described in the following pages. The soil to be tested is thoroughly pulverized by crushing all lumps, and if containing stone or gravel this is removed by sifting. The sample is then thoroughly mixed and equal amounts weighed into aSee Bul. 109 of the Rhode Island Expt. Sta. bSee Buls. Nos. 167 and 168 of the Ohio Agricultural Expt. Sta. THE METHOD. get granite-ware pans, where they receive their respective applications of manure or fertilizers and are made up to their optimum water content with distilled water. After remaining in the pans for about a week, being occasionally wet with distilled water, and frequently stirred in order to secure a thorough incorporation of the fertilizer and a good soil condition, it is ready to pot and plant. Five small wire-gauze pots are used for each treatment. About 350 grams of soil is then placed in each pot, uniformly packed, and planted with ' six selected germinated kernels of wheat, after which the pots are dipped in melted paraffin, which not only forms an intimate contact with the soil but makes the pot water tight. The soil is then cov- ered with a-thin layer of washed quartz sand and the pot and con- tents weighed and weight recorded. The pots are next placed in trays and given a favorable exposure in the greenhouse for three or four days or until the plants attain a height of about 14 inches, at which time the pots are sealed. The sealing consists of covering the tops with paraffined paper disks in which are slits through which the plants grow. The disks are sealed to the sides of the pots by means of melted paraffin. The loss of water by direct evaporation from the soil is in this way reduced to a negligible quantity. During the growing of the plants, which usually continues from eighteen to twenty-one days from the date of sealing, the pots are weighed at intervals of two or three days and watered with distilled water in order to retain a favorable moisture content for plant growth. By this method the loss of water or the amount transpired by the plants may be ascertained periodically, and at the end of the experiment the total amount of water given off through the plants of each pot obtained for comparison with the growth and green weight of the plants, which is ascertained by cutting and weighing the plants at the time the experiment is concluded. All conditions of the experiment are so carefully controlled that the average result of five pots rarely differs more than 5 per cent from the average result of any other five pots that have been treated throughout in precisely the same manner (see Table I). Differences which occur beyond this amount may therefore safely be attributed to the different manurial treatments which have been given. This method has several advantages over the growing of plants in open and porous pots. The method of coating the soil with paraffin prevents any accumulation of roots between the soil and the receptacle, a trouble which is common in pot experiments. The complete sealing up of the soil also enables the experimenter to determine the amount of water which the plant has actually used and transpired in its process of growth, and this, together with the small size of the pots, enables the moisture content and its fluctuations to be carefully controlled. Ie FERTILITY OF SOILS AS AFFECTED BY MANURES. On good soils, or as a result of favorable treatment, plants are produced in the little pots in twenty-five days or less time, the green weight of which sometimes equals or exceeds 1 per cent of the weight of the soil in which they grew. Such plants are approximately 85 per cent water; they have transpired about 100 units of water for each unit of green matter produced, and their dry matter is relatively richer in mineral constituents and nitrogen than that of mature plants. On this basis, an acre foot of soil, weighing 3,500,000 pounds, would produce 35,000 pounds of green matter, requiring for its pro- duction the equivalent of 174 inches of rainfall. This green matter would be equivalent to 5,900 pounds of air-dry material, or about 50 bushels of wheat and 14 tons of straw to an acre. While the removal of green matter equal to 1 per cent of the soil in the little pots is somewhat above the average, it serves as an illustration of the heavy draft made upon the soil in a very short time, a draft, as regards moisture and mineral constituents, although part of the latter comes from the seed, greater than that which takes place under field conditions by the removal of a large mature crop, assuming that the removal takes place to a depth not greater than 1 foot, which for wheat and similar crops would be approximately correct, and providing also the movement of plant food by capillarity from below 1 foot be ignored. TasBLE I.—Actual transpiration in grams for each of twenty pots, on three soils, under uniform treatment, and the percentage variation from the average for each pot, also average percentage variation of each group of five pots. Leonardtown loam. Corn. Cecil clay—poor. Leonardtown loam. HOF Variation Seales Variation Transpl Variation ration. ag ; ration. ; ; ration. ; = - 7 a | (aa ae an) | i For each! Foreach| For5 || Foreach|Foreach| For5 || Foreach|Foreach| For 5 pot. pot. pots. pot. pot. pots. || pot. pot. pots. Grams. | Per cent.| Per cent.|| Grams. | Per cent. | Per cent. | Grams. | Per cent.| Per cent. 60:9) | "Bab: lags" | aoa" | Si | eae Niece erase. 5) D571 «28,0 | 90.5 | + 3.9 58.7 || —20.1 —0.9 37.7 + 5.6 |} —2.8 89. 1 +. 2.2 +3.3 83.5 +12.8 34.8 — 2.9 | 98. 4 +12. 9 76.5 + 3.3 395. 9 ae WH || 84.8 | — 2.6 59. 1 —20. 2 35.8 + 0.3 | 89.9 + 3.2 | 72.1 — 2.6 37.3 +44 | 99. 2 +13. 9 79.2 + 7.0 —3.0 38. 6 One es a 87.7 ON atl 73.9 | — 0.2 35.4 | —0.8 | 80255. 706! + 74.1 | + 0.8 38.9 + 8:9 85. 2 ae || 8203 0 a | 38.8 | + 8.6 | 79.8 | — 8.4 66.8 | — 9.8 33.6 — 5.9 | 79.5 = 8:74 70.6 | — 46 |- +2.2 7.8 + 5.9 |- +0.8 86. 1 = 1.1 |p =2:7 68.9 | — 6.9 | 38.1 | + 6.7 | S8.8)1) 5 hood 89.9 | 421.4 31.7 —11.2 89. 5 + 2.7 84.3 +13.8 | 34.7 — 2.8 82. 4 — 5.4 79.0 | + 6.7 | 32.0 |) — 9.5 83.0 — 47 16.40) 352) 1 250 39.8 +11.2 | —2.5 94. 3 + 8.2 —2.1 683575) iol 0 36.9 + 3.4 | 87.4 + 0.3 69. 7 — 5.8 | 31.2 —12.6 79.3 | — 8.9 | FERTILIZERS USED. 13 FERTILIZERS USED. In this investigation the tests were confined to the use of high-grade, standard fertilizing materials, consisting of nitrate of soda, sulphate of potash, and acid phosphate, together with air-slaked lime, well- decomposed stable manure, and green cowpea vines. These ingredi- ents were applied to the soil separately and in various combinations as follows: Treatment and rate per acre. 1. Untreated. 2. Manure, 10 tons. 3. Lime, 1 ton. 4. Nitrate of soda, 200 pounds. 5. Sulphate of potash, 200 pounds. 6. Acid phosphate, 200 pounds. 7. Nitrate of soda and sulphate of potash, 200 pounds each. 8. Nitrate of soda and acid phosphate, 200 pounds each. 9. Sulphate of potash and acid phosphate, 200 pounds each. 10. Nitrate of soda, sulphate of potash, and acid phosphate, 200 pounds each. 11. Same, plus lime, 2,000 pounds. 12. Cowpea vines 5 tons, lime 2,000 pounds. The rate of application is based on the weight of an acre of soil to the depth of 7 inches, which is approximately 2,000,000 pounds. The fer- tilizers were applied in solution, and the lime, manure, and cowpea vines in bulk, each being finely ground. CALCULATION OF RESULTS. While this report combines the results of more than 13,000 pots, individual record of which has been made, the results were reported on forms, of which the following is a sample: [Can 101.] Actual transpiration and green weight and relative transpiration and green weight of 30 wheat plants on the basis of 100 for the untreated soil. Soil: Norfolk Sandy Loam. Siermme® Waycross, Ga. Planted: April5. Sealed April10. Disctd.: April 28. Basket Nos.: 2066-2125. Hels tive vere 2 Transpira- lon by— en Treatment and parts per million.¢ * tion, BS 5 18 days. 1got- | Pranspi-| Green ration. | weight. MW UNbTeA edie een ee= nfo sa ao 8 dice ccien stent k's 757.6 | 7.0 190 100 2) Mantra 100005. sacs cnc oo cc ec 1295, 2 14.2 171 203 12 | Cowpeas 5,000, lime 1,000 1135.7 13.6 150 194 10 | Nitrate of soda, potassium sulphate, and acid phos- PHASER CM ea A cain acess. eacisccine ode eae ne eS 1160.3 15 153 164 DS eames Q0ONsse eek yee stake cu ccksccsicaened 1090. 1 11.0 144 157 7 | Nitrate of soda and potassium sulphate 100 each. --. 1047. 2 10.8 139 154 8 | Nitrate of soda and acid phosphate 100 each.......-- 997.6 9.6 132 137 AW MNTaLe OMSOUR MOU ses me anee ss cc cncciees camctaweascuss 1053. 0 9.5 139 136 a) |pEOrasslimsmphateb0Olos «<2 c-ccece sce ceces cae ese< 925.9 8.0 122 114 9 | Potassium sulphate and acid phosphate 100 each. ... 833. 6 8.0 110 114 53 (ARSE) TI. 0) Be tae ae DAC Aa ER SEE Ea 803. 0 7.0 106 100 Gli PACiopHOspharemO0s nes. ce oc 5 coealndce seis cinctnes = lec 651.9 6.5 86 93 2 Parts per million multiplied by 2 equals the pound rate per acre on the basis of 2,000,000 pounds as the weight of an acre of soil 7 inches deep. 14 FERTILITY OF SOILS AS AFFECTED BY MANURES. On this form are given the total transpiration and total weight of ereen plants for each treatment, consisting of five pots. The trans- piration and the green weight of plants for each treatment are entered in the third and fourth columns, respectively, while the relative transpiration and weight, based on 100 for the untreated soil, are given in the fifth and sixth columns and are merely com- puted from the actual transpiration and weight in order to convert the comparison to a percentage basis and make it more simple. The variation by transpiration, while a good indication of the relative growth and effect of the treatments, frequently gives a range of lesser magnitude than the actual growth of plants. Plants that have made a marked increase in growth as a result of soil treatment usually contain a higher percentage of water than untreated ones and therefore show a slightly lesser variation by dry, or water-free, weight than by green weight. See Table II, which follows. The increase in growth is also accompanied by an improvement in con- dition which can only be measured by appearance, but which will usually prove an advantage to the better plants if grown to maturity. The results given in this bulletin are all based on the actual green weight of plants, the weighings being made immediately upon cutting the plants and under uniform conditions. Tasie I].—Percentage gain or loss attributable to various fertilizer treatments on four soils. [P=acid phosphate. K=sulphate of potash. N=nitrate of soda. L=lime. M=stable manure.] A.—BASED ON GREEN WEIGHT OF PLANTS GROWN ON UNTREATED SOILS. Percentage gain or loss attributable to— Green weight ; | | of plants | | Soil. grown | } on un- les ess ING) PAKS | PIN. [OKON EPIKENE || KON a va treated soils. Grams. Ceciliclay; coodese sc -ssen- 8.8 O24 Sa een 9 14) — 4 il eee oe 9 Cecil clay, poor........... 8.8 | — 1 1 OU See — 6 7 5 Giles. So —14 Leonardtown loam, good. 8.3 16 di Ags [ee Maes 41 AT 46 AO Wee akeoeeee 17 Leonardtown loam, poor.. 6.5 | — 7 15 Sule wee 0 12 22 iL ilsca eee 24 verdes ce eae. TSE (PhO ee SR St eae Tg ee) eg | Hl aL we 2 9 Soil. weight | of plants grown Percentage gain or loss attributable to— P. N. | PK. | PN. | KN. Cecil clay, good Cecil clay, poor Leonardtown loam, good. Leonardtown loam, poor.. Average. ,, a ee ARRANGEMENT AND TABULATION OF RESULTS. : 15 ARRANGEMENT AND TABULATION OF RESULTS. Table III, which follows, gives the actual green weight of plants grown on the untreated soils and the percentage increase or decrease in growth, the latter indicated by the minus (—) sign, resulting from th® various fertilizer ingredients and combinations. The data are arranged by States, areas, and types and averages are given for areas and for types within areas. The symbols at the head of the columns are used for the sake of brevity. P stands for acid phosphate; K for sulphate of potash; N for nitrate of soda; L for air-slaked lime; M for well-rotted stable manure, and Cv for green cowpea vines. The ingre- dients and rate of application are given in the preceding form. All data resulting from the tests are embodied in Table III. Marked variations from the general trend are exceptional and most. frequently occur with manure or cowpea vines. These substances have occa- sionally given negative results apparently as a result of decomposition products from which the soil did not have sufficient time to recover prior to the planting of the seed. The blanks in the table indicate no tests for the ingredients or combinations heading the columns in which they occur. Practically all such omissions occurred in miscellaneous samples which were tested by the Bureau parties at several of the State experiment stations. Table III gives the results for 220 soils and from these results many tabulations were made, parts of which are given on subsequent pages. The arrangement and segregation of data in subsequent tables are for the purpose of a further compara- tive study of the facts as well as to enable the reader to verify state- ments that may follow in the text, although a number of facts are given from tabulations other than those which follow. TaBLE II1.—Percentage increase in growth attributable to the various fertilizer appli- cations. Weight Gain or loss attributable to— of | | | | plants | Soil type and locality. grown | onun-| P. | K.| N. | PK.) PN.| KN. PKN.| L. | PKNL.| M. |CvlL. treated | soil. ; WISCONSIN. Portage County: NGNOM Se) (Pre Cla) kon ChE. Copa Ct, be. ClslkaCL.\. bra) Cbe \EnaCt.|) 2a Chs VPs Che Ct Miami stony sand..... 9.9 6 13 11 |— 3 | |} 21 22 |— 3 19) 47 8 Miami sand........... 6.0 Te | Alani od 5 | 24) 29 39 7 AS | 80) — 4 Miami sandy loam..... 9.0 4 8 2.2 a SOL ee 3 4 21 | 29 12 Marshall gravelly loam M0); —1)/— 2) 14 2 3] 16 4 2 3 | 36 14 Marshall sand.-........ 8.4 7 9] 31) 13) 23) 32 35] 11 8| 34 3 Portage silt loam....-.. 10.0 | —11 9 6 1 |=—10 |—'3 3 5 10 |, 21 | 10 Portage silt loam...... 8.7 2 |—16 |— 2 5|— 9} 10 1 9 —14) 42| —14 Average for area .... 9.0 Seat our Ben | ete 15| 5 13 | 41 | 4 MISSOURI. | Crawford County: Clarksville silt loam... 6.6 26ND Needy ee eon) do Te 14 1| 43 32 Wabash silt loam...... 7.6 | —11 1 |— 3 |-— 2 3/—5| —1 0 2| 23 24 Clarksville stony loam. 14.6 4 3|—2\|-—9 ie wk 3 |— 3 — 2 |-—10 13 Average for area .... 9.6 6 6 4 5] 10 ii 3 4 0; 19] 23 ——— SaaS SSS \—— ———— 28220—Bull. 48—08-——3 16 FERTILITY OF SOILS AS AFFECTED BY MANURES. TasBLe III1.—Percentage increase in growth attributable to the various fertilizer appli- cations—Continued. Weight Gain or loss attributable to— of plants Soil type and locality. grown | onun-| P. | K.| N. | PK.) PN.| KN. PKN.| L. | PKNL.| M.«CvL. treated | soil | —_.———————____——_- eee s PUA oS | ES ee ee eee MISSOURI—Ccontinued. Scotland County: Grams. | P. ct.|P.ct.|P.ct.|P.ct.\P.ct.|P.ct.) P.ct.|P.ct.| P.ct. |\P.ct.| P. ct. Shelby silt loam......-. 9.6 TN 24) AAD 225) 17 32 28 11 28 | 69 30 Miscellaneous: Loess, McBain County Ti Sae) 1Si\P 22) |e neSaln 220) |) 26u)) 147 SO! 19) | oder state 23 35 Clay loam, Salem...-..- (WUE) Raspes Gaecd bocce 25 | 50} 60 68 | 25 50 | 57 35 Silt loam, Columbia. - . BNO eyed ese aia ais 29 | 54) 44 61 if 66 | 34 50 INDIANA. | Newton County: Marshall fine sandy | loamir: seat ese 6.3 5] 12 9 0 5} 12] — 4/—12 — 1) 60]; —2 Marshall loam......--.- 7.6 LT 22a Le 2On as et 16 | 22 PA Ne 7ir/ 34 Clyde fine sand...-....- 12.6 | —21 |— 2 |—14 |— 8 |+23 | 13| —17 |—12 —7| 32) —4 Average for area - | 8.8 OF ad 4 4/—1] 15|.—2)/—1 4| 56 9 Tippecanoe County: | Marshall silt loam..... der? 4 1 GP LOs ener 3 12 |—7 6 |—.2 4 Marshall loam.......-- | 7.5/| — 3 2 CN 4/ 18 6 |— 3 7| 42) —2 Miami silt loam...---- 5.6 | 30] 21] 28] 26] 58 | 46 58] 17 35 | 71 30 Average for area.-...| 6.8 10 8) 4 | 10") 3) 22 25 2 16 | 37 1 OHIO. | Westerville area: | Miami black clay loam. 8.3 | —11 6 |— 2 9] 13 tf 8 1 LD 22 5 Miami clay loam ..-.... | 6.1 11 5} 15 Sileeeh | ake 13 7 bale ates 45 Miamioamece esse eee. | 8.6} —8| ,3|—2)\- 3 1 8| —5 2 2| 48 15 Average for area -... 7.8 | — 3 5 4 3 | 14 9 5 3 8 |. 28 22 Miscellaneous: Volusia silt loam, WiOOsternatscsese once 5.8 | Our el aoer | 14) 47) 46 62} 21 Onlh. bap seers ore Miami clay loam, Ger- | | | | mantown .........-- (eal Tae gee eee 6| 24) 30 27 9 47 | 10 22 Miami clay loam, Strongsville......... ee ett 2 = | a I = OSD seocsiece TY ee NEW YORK. | Tompkins County: | Dunkirk clay loam... . 9.0 0 9; 13 )/—1 6| 23 11 |—14 12168 | — 5 Dunkirk clay loam... -| 4.5 | —18 4) 55/— 5) 27) 47 42/5 20) ogee ee 33 54 Average for type.... FCA ERR ST al Wk 9 9) a Ss Dr RE OF eles ees 51 25 Dunkirk loam.......-- 8.4|— 4 2) 15 |= 1 | 46) 20 12 |— 7 11 | 46 0 Miami stony loam....-. 9.6 4 1 1;—4\|-—8} 6 ll 0 Wai noo 26 Average for area .... 7.9] — 5 4) 21/— 3] 10)| 24 19 2 10 | 46 19 Binghamton area: Dunkirk gravelly sandy loam ........- 6.6 4 iy att 4; 20| 16 1} 26 27 | 29 69 Dunkirk gravelly loam | 10.6 9 9 1|— 8 0 9 7 \|-— 3 —11; 20) —9 Wabash loam......... | 10.6 | — 1 11 5| 16 12 | 22 26 10 157} 38h 10 Averageforarea..... 9.3| 4] 7| 6]. 4| 11| 16| ul w 10| 27| 2 Other localities in State: Volusia silt loam. ....-| 5.4 2/ 15) 13) 11 8} 38 20 9 32) 51 29 Volusia silt loam..-..- 48) —2] 15} 34) 15] 21) 583 35] 15 623) sel) eeeeee Volusia silt loam....-. 6.6 AWS 22i\ 0 LON sue 4) 19 23 8 15 | 77 13 Dunkirk clay loam... .| 8.9 16 | 29) 20; 31) 10) 21 28 | 19 22 Li 28 Dunkirk clay loam...-. 10. 2 ee Ss on 6 5 8 OF a1 21 ARRANGEMENT AND TABULATION OF RESULTS. LW ¢ Tape II1.—Percentage increase in growth attributable to the various fertilizer appli- cattons—Continued. Weight Gain or loss attributable to— of Te = cre as as plants | Soil type and locality. grown onun=} Po | K. | N. | PK.| PN.| KN.) PKN.| L. | PKENL.| M. |Cvl. treated ‘ soil. | ,PENNSYLVANIA. Montgomery County: Grams. | P. ct.|P.ct.|P.ct.|P.ct.|P.ct.\P.ct.) P.ct.|P.ct.| P.ct. |P.ct. P. ct. Hagerstown loam....-.. 10.3 13 |— 2 1a a Be fa as 3 6 9 6 23 | 20 29 Penn silt loam-......-- 12.3 8] 12 8) Dt pede) 24 13 |— 8 4] 24 36 Lansdale silt loam .... 9.9 0} 23 L | 27 |—=:7 |, 31 7} 19 17 9 30 Chester loam.......... 7.8 0 9 NT ATES) emia at ona 9 27 4 33] 18 8 Average for area ...- 10.1 | 5] 10 4; 18 9| 19 ED ast is eae HY 24 RHODE ISLAND. | The State: Miami silt loam, King- 1G 5 at 5 On a Se 3.6 | — 8 |—19 |—14| 28] 22] 22 31 | 133 2B es 2 le ee Miami stony loam, | j , Middleton:.......... CET We Ve oS | ts se Lda 18 9 CU eee | ee Miami stony loam, Jamestown.........- Sa Fikase | Le Pe abl (eee eee (ire ee See [See ae 24) 60 eee eee Miami stony loam, Curtis Corners. ...... (AYP Ic eeterel leseet el Nt Ael eee Se Sees 7 5 ES 5% SNe SSS Miami stony loam, Woonsocket......... SMB Stra tats Net cll ara ee fick Seen PRES 10 | 10 Dial \sseas Miami stony loam, Little Compton ..... 10 See Pe coed Dm al Hea a (ee 5 0 | Oui eR eames Miami stony loam, | Ashaway..-....--.... OMe 5 tae Cee [oer oe eared) Benes sr ocie 4) 21 5 1)| PerseaedSl Ue geee Average for type .... Sag [ep ye rel eee | ER eae [Oc 1D ts AQ tA RS Gloucester stony loam, ‘ East Greenwich. ...- Cp | eye ey (ae Tae a Se eat he ve Be elo 2 By ( 4 eeooe! bees Gloucester stony loam, Chepachet....... Sat toy | SRS a eed SR) Ae ON at bn Pea 4 9 Pate eel a Gloucester stony loam, iene hat ab Ae Ma ee AL See a ey ee 3 0 We crate see Gloucester stony loam, | IMO SRenee = seh fs ee oe Pej Wee ete hs Secs eae i ee |» De 2} 25 Me eS ae Gloucester stony loam, Gresteie nes. 62-222 ee (BR ep ae See BL ees —22 8 5 0 en ee eae Average for type. . SNOU lee met weeds | eee. |e amet ue ibaa 0; 9 BOPP Rac Alton stony loam, | Hope Valley......... Sor ee ge ee Ree ae he ie 34| 38 Bale wet Alton stony loam, Wickiord) 2.228525... aia peters | pent (eegpcetie ae = t 51 |— 2 DL Rees] ese Average for type. Seeley ee eee |e le cue Peg ssh Td WE 43 | 18 53 4| ee ee ee ‘| = | SS Warwick sandy loam, OUR eee ae eee CLI) aes Sel eet eee | Meese ee 8 eee 41 |\— 8 42 | PF ealsenaare Warwick sandy loam, Barrington. -........ Tete ae ee Se ee |oaeus|---4'- 23 | 28 BON ee Al Lee Average for type. - BB era rae eee ei eae IIe bees >. 32} 10 YOUN eee ae eB Average for area .. Tee | Ae ee | es | cae | ee eek 15 | 14 Bile, Sahota aes VIRGINIA. Louisa County: Cecil sandy loam...... 7.2 24 5 Weyl) yahl Sid) Sea 30 bay 39 | 25 Dh Geerlloamier ae S22 3c: 4.6 36 | 47] 75) 26] 75 | 100 102 | 71 153 | 63 158 j Average for area.... 5.9 30 | 26 | 44| 28); 44] 64 66 | 38 96 44 108 Hanover County: i | ' Wickham sandy loam. 7.5 | — 3 Sey LU ST LON) 1G 36 9 35 | 31; —i2 Norfolk sandy loam... ao 3 11 20; 16 fal SS 30 |— 1) 47 | 44 — 8 Average for area .... oa LO (acs | ra eo ie 9 ae ys |.-9g-)s 6 18 FERTILITY OF SOILS AS AFFECTED BY MANURES. . TasLe Il1.—Percentage increase in growth attributable to the various fertilizer appli- cations—Continued. Weight Gain or loss attributable to— of plants Soil type and locality. grown onun-| P. | K. | N. | PK.) PN.| KN.) PKN.| L. | PKNL.| M. |CvL. treated soil. VIRGINIA—continued. Appomattox County: Gramss|| (PO CLP ch Pech enh. Gb. Po aCt.|| sere Cha Eo«Gl.| > ele Che ocr een OLe Gecillelaiyies = 8s: ese--te EO a tere eee 6 |—13 4] 12 2\/— 1 2\— 3 24 Cecil clay, Pocahontas C1 Ge eres cine tee ee 1.7 | = 3 A ye Sia) aoe alee ree 9i— 6 7|-— 2 7 Cecil clay, Mitchell ClO Re Shi ace eee I A ieee ie eae 4 SY ees alas 6 5 — 4 2 6 NORTH CAROLINA. New Hanover County: | Noriolk'sand)=-22. 2.2. 4.1 37 | 41 | 122] 61 | 124 | 131 151 66 154 | 241 144 Norfolk fine sand... ..- 6.4 3 95) 37 |) 20/0 455) 63 | 16 70 | 94 37 Norfolk fine sandy LOA ea ee eee ee 7.3 3 3 | 22 3} 20) 33 29 8 BL ion 34 Portsmouth fine sand - 3.0 DSH BON ite) 2 40nd mala 110 | 70 173 | 130 230 Average for area ...-. 5.2 141)" 21) | (657) 311/769" 83 88 | 40 107 | 131 111 Miscellaneous: Cecil clay (good), Statesvilles 22 =. 8.8 O|}— 2 |— 4)..... 9 14 — 4 Oe Ae 1 ad PE SA Cecil clay (poor), Statesville........... 8.8} —1 1 Op eee — 6 i 5 Ohl eee —14 3 Cecil clay, Iredell test UD TMN Peo she ra'a = steicrarats 4.5 86 34; 42 99 97 35 105 45 105 90) ea Cecil sandy loam, | Raleighie.-- 5-55 252s. aol 20} 31] 30} 29) 23 39 49) 52 103 | 53 54 Iredell clay loam, | Statesville........... er it \) Pal 16] 19 9 | 28 34 |— 1 28) \ootlleenoee Norfolk fine sandy loam, Edgecombe . - - 4.8 AA 4263.) 383) |e pei) ail 561 625 Ge) \OOn| hee eee Norfolk fine sandy loam, Tarboro. -...._. 3.9 25.) 22°) 42 | 29) 51) 59 63 1 70 | 38 78 Porters clay, Asheville. 5.8 | —6|— 2] 29 |—-14| 24] 40 19 | 10 53 8 15 Porters clay, Biltmore. 12.4 ll Ta] LS 5 eG) e260 to skss! 20 || 73 26} 61 24 Porters sandy loam, Blantyre. 2... oss2 4.5 4) 44} 20} 31] 20; S51 24) 43 22 | 61 31 Portsmouth sand, . Rinehunstac= ee. e 4.8 42) 26) 42] 35] 43] 38 56 | 26 46 | 41 45 Portsmouth silt loam, Chowan County..... 4.5 PI) sks) GE Gs I) PRI Ge 62 | 19 57 | 46 74 Silt loam, Union } CountyAa eee 4.6| — 4 0} 32] 19] 19) 21 42 4 SIG M28 nites Tobacco soil, Wake OUND oss ote eee 4.7 Oy A) 284) 20s RL | 22 30} 11 LO" Meee ales SOUTH CAROLINA. York County: Cecil'sande a: esac seek 3.9} —15 |— 8 | 26] 28 8 | 20 54 8 71! 90 60 Cecil sandy loam... ... 7.0 40 3| 28/—9] 0; 40 34 | 33 41) 76 58 Iredell clay loam...... avd, 0 6] 19 1 6 16 18 3 7 | wo 19 Average for area .... 6.2 | 8 OF rea entero: | 25 35) 15 43 | 72 46 | | Cherokee County: | | | Ceciltelaiveee se ence 7.4) = 4 1—="6.1 (361.25! 268)" 7389 35 4 | 44 | 42 12 Cecil silt loam.....-..- 6.6 2 1S x2 9| 47} 52 48 | 39 | 56} 81 74 Cecil fine sandy loam. . 5.9 | — 3 7| 46|/— 1); 46) 46 52 | 29) 68 | 88 128 Cecil sandy loam ..._.- 6.9 | —12] 28] 35 Si 335160 58 4 Ga! aa 5 Iredell clay loam... .. 91)— 3 To\ere, 1 27| 46 27 14 | 42] 36 Hf Average for area .._. |) NS 2 Wh By) Ba eS) 44| 18 | 55 | 64 44 Lancaster County: | Cecil silt loam... .-. al BGS ae © 75| 15| 63| 61 NS GS) 73) AON arti Miscellaneous: | | | Orangeburg sandy | | loam, St. Matthews. . 11.8 0\/— 2; 15 5| 16] 14 26} 19'| 28 | 25 17 Portsmouth sandy | : loam, Darlington. -.. Bagels oe Babe 133] 9! 35] 26! 301 40! 1051 441 138 : ARRANGEMENT AND TABULATION OF RESULTS. 19 TasLe II1I.—Percentage increase in growth attributable to the various fertilizer appli- Soil type and locality. TENNESSEE. Henderson County: Lexington silt loam... . KENTUCKY. McCracken County: Memphis silt loam..--. GEORGIA. Waycross area: Norfolk sand, 12 miles west Waycross...... Norfolk sand, 43 miles SE. Waycross.....-_. Norfolk sand, 3} miles NW. Waltertown ... Average for type ree Norfolk fine sand, 3 miles W. Waycross. . Norfolk fine sand, 8 miles SE. Waycross - Norfolk fine sand, 2 miles W. Waycross... Average for type . rt Norfolk Sandy loam, 23 miles N. Way- Norfolk sandy loam, 3 miles NW. Way- Norfolk sandy loam, 2; miles SW. Elsie. .-. Average for type... Norfolk fine sandy loam, 54 miles W. WIRY CrOSS%o2 2.525.055 Norfolk fine sandy loam, 3 miles E. NVI GRONSo: ya. 8 eo) Norfolk fine sandy loam, 4 miles N. MManonmece ssa 22 Average for type. . Portsmouth fine sand, 53 miles SE. Way- Portsmouth ine sand, lmileS. Needham.... Portsmouth fine sand, 1mileS. Glenmore. .. Average for type. -| Average for area... FLORIDA. | Escambia County: Portsmouth sand... ._- Norfolk sand.......... | Norfolk sand.........- | Norfolk sand ........-- cations—Continued. Weight Gain or loss attributable to— of ST ET Gene oe plants | | | grown onun-| P. | K.| N. | PK.) PN.|KN.) PKN.| L. | PKNL.| M. |CvL treated soil. Grams. | P. ct.|P.ct.|P.ct.|\P.ct.|P.ct.\P. ct.) P.ct.|P.ct.| P.ct. |Poct.\P. ct. 7.5 rl) SST Re) Ma ea allows 36| 5 57 | 72 17 5.0/—3| 3] 39) 8] 25! 42 42| 18 48| 70) —2 | 5.5 | — 9} 241) 45 | 27) 491 65 72,1 64 109 | 124] 118 | | 5.6|—4 | 30/ 61] 18] 45] 50 57! 20 121} 114} 132 Got Ora 8G) Bile one vay 24 | 34 55| 77 65 Sele |e Lor |e aan) Le [Sn | aoe 51 | 39 95 | 105 105 6.1 7| 15| 55] 23] 49] 69 74| 34 84| 102 | 107 6.0 Bell Sie san—=eo |e sh a38 50 | 27 Bebe e| aay 7.4|/—9|—8|—3/—6|-12| 0 i a, 25 | 928 36 6.5 ON Pagel sul tele-36 46 | 22 47| 81 83 7.00) ef |) T4136) O04 | 87 54 64 0 57 | 103 94 6.5 | 11] 15] 54] 15] 77 | 102 85 | 35 100 | 109. ~—-109 | 5.0 0| 16) 20] 31-15) 42 25 | —9 43| 54| 42 a2) 1) i5|-az|}-m| 4|'e6| sel 9 67 | 89 fare | = | | | 7.5| 171 28] 60| 23] 63] 83 73 | 40 s9 | 113 | 113 7.9 Tall 3b. 29M e ey gte| 038 24| 29 35 | 961. 67 3.9} ° it) 29) 74 | 35). 51). 79 86 | 64 1051150! 176 6.4| 10] 21! 54] 21] 45) 67 61| 42 76 | 120! 119 5.2 6| 21] 73] 31]| 92] 104 77 | 29 | 117] 150 | 148 | 5.2 1| 15] 50] 26] 75]! 80 90 | 92 153 | 219 | 175 5.5 2 18h" 33) | 24 | 338i) 29 71'| 20 75 | 64} 109 5.3 STM isi sonora a 79 | 47 115} 144) 144 6.0 2/ 15) 45] 16] 42] 59 59 | 32 80} 108 | 107 a3 Dicer ph oadoal ae 5e | etSe\) «Til 11] 48 43 | 47) 35 5.4] 16| 18| 131 1] n| 13 | 4 74| 83| 107 5.9 5| 32] 45| 15] 20] 84 46 | 24 55| 94] 97 7.2 Ae tOnleessu | couleaey|) 41 22 | 29 | 23| 66| 65 6.2 8| 231 30] 12] 16] 46 26)| 438 51 | st 90 20 FERTILITY OF SOILS AS AFFECTED BY MANURES. TaBLE III.—Percentage increase in growth attributable to the various fertilizer appli- cations—Continued. Weight Gain or loss attributable to— of == ss ; = ; oS piants | | Soil type and locality. grown onun-| P K. | N. |,PK.| PN.| KN.] PKN.; L.|PKNL.| M. | CvL. treated soil. FLORIDA—continued. Escambia County—Cont’d. Norfolk fine sandy | Grams. |P.ct.| P.ct.|P.ct.\P.ct.'P.ct.|P.ct.| P. ct.\P.ct.| P.ct. |P.ct.| P. et. loamilss 24a ce secs se BA 2 aE IS Sha Pay Pn 35 14] 32 51 Norfolk fine sandy s losimpas ee cce ee eee 5.5 10 12} —5| 32 39 | 30) 32 45 82 32 85 Norfolk fine sandy | oho a eeramess cise Shem EP axon AN BRL ci) ale) 48 | 136 130 | 90 136 Average for type - - 5.7 | Sh) urAl 12| 24] 25 13 | 30 | 72 75 | 51 91 Average for area .. 6.3 | So FLO Te 20) LG ZO ano, 26 | 52 61} 63 82 ALABAMA. Lee County: | Cecil sandy loam... .-- 8.6 1 9| 14|— 2 8| 31 Gy 3) 28) ie soee 58° Cecil sandy loam... --- One Sp leSiyy Tey si Zeyh SB} 5D) /| 4a eee Average for type. - . - Tel i=" 5 Te > eee Me nee 29 | 12 40 Maa wane ae INoriolkisandless. 22 5he- 6.8 9|/ 10] 40 By Ry | ch 62 | 57 103 | 107 | 160 Norfolk sand..--......- | 4.77} — 1 ae a ace esi eal | el) 35 | 50 135 | 108 143 Average for type... - | 5.8 4| 4] 35 0} 42) 58 | 48 | 53 119 | 108 | 151 Norfolk sandy loam. -- 6 ae | 42) 15) 37) -43) 46 | 11 64] 42| 104 Norfolk sandy loam. --| Cai 12} 19) 55) 20) 50) 53 | 63 | 19 87 | 61 164 Average for type- --- 6.9 | — 1 12 | 48 | 18| 43} 48 | 54) 15 75} 52 134 Norfolk coarse sand. -- Bodh obs] 4s) eg Saag 50 5 70 | 59 101 Norfolk coarse sand. -- 6.4 | —12 0| 20 |— 2 3) 13a 25 | 22 23 | 33 41 Average for type... . 5S | Ou nazalie SAuen Sula Samo By |e 46 | 46 71 Average for area... - 6.4 | — 3 6) 35 3} 28) 40] 42 | 23 70 | 65 110 Miscellaneous: | | Clarksville clay loam, IWIOLENCO Renee eee OMe eee 6 |— 4/— 4 3 19 |= 1 10 |-15 | —13 Clarksville silt loam, | Wlorenctesss-oee. eee i RG | aanctoe ae 2) |) alia eles eeskiat 20; 4 15 |— 3} 30 Orangeburg clay, | Kangs farm)-2 2 2S. 10.3 3 ly aly 6| 40} 19 19 | 16 3D) ) 32h | 26 Orangeburg clay, Hord’smiarmes- -a225 9.1 QO DANS VAD ST. li Aon | eos. 67 | 20 55 | 49 35 Orangeburg sandy loam, Rawl’s farm. . - 8.1 6/— 5 4 <5 9 Ps 127) 21 sty a) ea 77 20 Orangeburg sandy loam, Marion........ 4.8 14 7) 255) 19 | 59.) 28 69 | 12 69 37 60 MISSISSIPPI. | ‘i Pontotoc County: | | Ibuikiml clave Saeacec os Orangeburg fine sandy Oats eee os ess 6.5 3 3 0 On tO er 15 a 15; 20 26 Orangeburg fine sandy LOSS eaeeeeen oe 5.0 0 6; 10} 22) 20] 30 32 0 44| 34 96 ayeruee foptype. 21) 8.7.1 2) 5) 5] 11} 15] 49| 24]. 4 30] 27| 61 Average for area... 6.3 Pele Se 201-6 |) a5: 24| 15 | 45| 54| 74 ARKANSAS. | Prairie County: Calhoun clay......._.. 8.3 DO EZ ek 195)" 16+\) 16 26) 18 27 4 13 Crowley silt loam...... Peo 9 s(n oe] 9 7| 36 60/ 19| 38 Crowley silt loam. .___. 10.1} — 1 3 0|— 6 |— 5| -2 3 2 5 7 9 Crowley silt loam... ... 7.0 0; 10) 43|—6/ 22] 26 PAN) 28} 71 | 64 80 Crowley silt loam... __. 8.1 9| 14 2\/— 3! 7} 18 0] 46) 33 | 18 42 Average fortype.....| 81/ 0| 7| 14/-1| 6| 9 9| 32 42| 27) 42 JP, FERTILITY OF SOILS AS AFFECTED BY MANURES. Tasue III.—Percentage increase in growth attributable in the ‘various fertilizer appli- cations—Continued. \ Gain or loss attributable to— Weight of | plants Soil type and locality. grown onun-} P. | K. | N. | PK.| PN.|KN.| PKN.| L. | PKNL.| M. |CvL. | treated soil. ARKANSAS—Continued. Prairie County—Cont’d. Gramss)|\Pach | Pcl VPs ch: E.sCl.VE> Chel Ers Che Che|' Ea Che | eee Chans| Eeneraieeatets Morse clays 222 -/---=- refs} =) 8 1 2| il 6 Ons: —7 6 22 Morse claiy..3..-.=.-.2 10.8 4|/- 3 2\/—7 2 6| —3 2 4 4 9 Morseiclays.2 2-6 2-sa2 11.1 5] 13 |— 3 4 3 9) -—11|—7 —1 5 4 Average fortype....| 10.2 Os ReN colle LO See yelne= Bale. 0 STs 12 | — ad } Acadia silt loam.....-. ie 0 Ze Pas) Salat 25 | 24 20 12 33 | 46 27 Acadia silt loam..----- (68) 1 Cel Kay a ele a) 15 | 14 37 i 16 Acadia silt loam...._-- 7.4 22))| - 20%\) 295) Sli 308) ||) 22 41 | 23 48; 31 38 Acadia silt loam.....-- 9.0 0; ll Gye sin 26 18 |—11 41 | 32 21 Average for type.... 8.7 6] 11] 19| 16] 19] 21 25 | 10 40| 29| 26 Waverly silt loam. --. 6.5 LOO 20) |) 2S ZT Neale st 38 | 61 55 | 38 54 Waverly silt loam. -.. 7.8| —7 9|— 7|— 3 |— 4 4} — 3] 37 40; 18 41 Waverly silt loam..__ | 5.0 28 | 20'} 18°) 23+)) 227), 29 28 | 104 150 | 10 132 Average for type... | eee Fae |) UII TGS |) ay) at ee 21| 67 SD |G Se, 76 Average for area. 8.3 See 10) 12 Salle mals 14] 26 40| 21| + 36 TEXAS. | i San Marcos area: | : | Blanco loam... .-..-- | St WAN eer « LOW 2 23] 10 33 | 20 21 28 37 Crawiord silt clay... 9.2| 20] 21| 31| 20| 40/ 29| 22] 20 42| 40| 52 Crawford silt clay - - - 9.2] —7 2) W/—1 8 | 19 23 4 Ses, 34 Crawford silt clay - -- 8.8 13'} 25/30") 18°) 29%) 30 42 | 24 46 | 56 11 Average for type. . - 9.1 OF | Os ee ea eb t26 29 | 16 40 | 37 32 Houston black clay. -- 7.9 8 Sapa 8.) 2335)". 79 SO pals 21} 30 42 Houston black clay --. 8.9 0 gi aN ali 4° - 9 17 5 23 8 23 Houston black clay- - 7.0 20) -21 | pl 250 3a|) 35 35 17 42 | 10 38 Houston black clay. - 8.1) —4/—5]| 21 fp Be) Al 19 6 26 | 25 32 Average for type... | 8.0 6 fe 22) a) 21s) || 19 PAs era til 28] 18 34 Average for area -_- 8.5 8] 12) 23) 14) 22] 20 28 | 14 | 32 | 26 34 Rusk County: Caddo fine sandy loam 8.2 6 PA aS} iy | eal) GB 47 7 47 | 61 57 Caddo fine sandy loam | 8.1 TQ 5) Le AO) ls ae eedes | 35 34] 17 36 | 62 40° Average for type... Baily “Gills cyl Sage] 40, haa aia [ena eae 42) 62| 49 Norfolk fine sand... .- 8.5 14 16 | 41 16 | 29| 54 49 | 21 55 | 86 48 Norfolk fine sand__._- 7.8); — 4 Sif 21 65 Ue 28 28 3 60 | 103 69 Norfolk fine sand..____, 8.6 5 6| 19j— 3] 21] 36 36} 10 26| 61 | 37 Average for type... .| 8.3 DO) LOO 27 el 22 [09 38 11 47) 83 51 Norfolk fine sandy | OBIS Se Fo Cee Ee feo 20 | 28 38 41 42 62 65 21 64 | 105 62 Norfolk fine sandy (Oyshodl AOE = Se ia | 6.1 31 31 ‘48 48 52 56 48 40 41 48 80 Average for type... 6.8] 26| 30) 48] 45] 47] 59 57 | 31 53 | 76 7 Orangeburg fine sandy . Qa =) See; aes 9.2 | —12 — 6 14 |— 9 |— 6 14 36 13 39 | 68 53 Orangeburg fine sandy | OBEY. ao Nees aes 9.2 0 | 2| 34\/-—1 26 | 26 26 12 37 | 37 66 Orangeburg fine sand. . Cao —atigh P20 SSL 2a DT eSso 40 8 60 80 68 Susquehanna fine | sandy loam.......... | 7.0}—3] O}| 9i/—3] 3) 3 9 |—11 26 | 29, 36 Average for area. ....| 8.0 6 ll 32 13) 28 | 37 38) 13 45 | 67 54 ARRANGEMENT AND TABULATION OF RESULTS. 23 TaBLe II11.—Percentage increase in growth attributable to the various fertilizer appli- cations—Continued. © Weight Gain or loss attributable to— 0 | | | hid i Wi at © plants Soil type and locality. grown uJ “ ‘ on un- Poss. | IN. | PKS PN. EEN. || PEN:| 12.) PEN. | M..) CvL. treated 1 | soil. | Fs ee RG ae | aa | or ail TEXAS—continued. Miscellaneous: } : Galveston clay, | Grams. | P. ct.|P.ct.\P.ct.'P.ct.. P.ct.|\P.ct.| P.ct.|P.ct.| P.ct. |P.ct.| P. ct. Gallyestont = see. ae 11.2 | —14 |-—12 3 |—23 Pe 4} —20 |— 2 —8 4 3L Houston black clay loam, San Antonio... 5.8 8 1/— 3; 14); 12] 35 LO; }) Th 19|°°19} —7 Orangeburgclay, | | . Maroney’s farm...... 8.6 | — 3 ¥ | 17 |\— 3 |. 12 7 14 4 5 | 29 is Orangeburg fine sandy | loam, Crockett....... (5078 eee eee 67 17 | 60| 67 92 24 93 19 58 Orangeburg fine sandy | | loam, Palestine. ..... ee ae Meese 30 |— 7 | 37.| 31 21 7 32-|—14 | 40 Orangeburg fine sandy loam, Nagadoches... 8.8 1 Otol. LOU Lok 43 24 16 24| 56 15 Orangeburg fine sandy loam, Palestine... ... Mabe rte Aly odd 18.) 10 | 9 34 14 |—15 9| 37] 483 IOWA. | Miscellaneous: | Wisconsin drift (good) 9.6} —10} 15] 30 /—-13)| 34 Wisconsin drift (poor) | Tell 19} 34] 53). 30) 49 Lowen drift’ 2es ts. 9.0 16°} 25] 28°) 257) 47 Missouri loess......... 11.6 0 DAN (ai Mayet ae a Pe South Iowan loess. .... Gey | eeeieeae SR iets 35 | 32 Kansan till... 2...-.-- 5.9 7 15%) 4851) 02.1) 57 ILLINOIS. | | Marion silt loam........... 7.7 | —13 fs 8/— 38 -ll —4 9} — § |—13 — 4] 48) —12 Red siltloam: 3 ooo... 2k. 7.0 3 8] 19 8| 17] 24 22 | 16 38 | 26 45 NEW JERSEY. | Miscellaneous: Norfolk sandy loam, | | Woodbine. . 0.3222. : 6.0 12 5 | 20 |— 2 16 | 34} 20) a 17} 25) 14 Norfolk fine sandy | : loam, Woodbine..... | 6.5 1 1 9 9} 22) 385 32 7 31 28 42 CONNECTICUT. Connecticut Valley area: | Hartford sandy loam... She al Means eee 18 3/— 6) 18 3}. 10 20) | ee 58 MARYLAND. | Miscellaneous: | Leonardtown loam | E (a o(s) eae ee | BATH Vel@ tho tia van Risk: 41 | 47 AB est ON Ley fe, 17) eke: Leonardtown loam | | (neon) esaece ae st | 6.5 | — 7 15 ts fh teers oO} 12 22 1h 2 pai eet 24 | 25°89 Muck, peat, and swamp soils: Hiingiges yee ee ee 9.4 16 49 4 39 14 40 25 7 33 45 51 MOMs: Sere Ne Le. 15.0 24 | 26) 21 ll |— 4 15 20) dS 3k. a Gas eae Wisconsin, Portage = } : . Countivys 22 es oe 7.2 42')} 25 | 21 51 39 | 39 47 | 23 41 51 16 _ Indiana, Newton WOOUNE Vestas eet 4.4) —25| 61 14| 66 —7 41 100 14 70 40 18 Virginia, Portsmouth . 3.2 53 | 112] 69| 69} 84] 75 GO|) 275i ng = OMe > Ar 72 Average for type... 7.8 |.- 22) 55], 26 | '47| 25.) 42 52 |: 21 60.| 49 | 39 28220—Bull. 48—08——4 24 FERTILITY OF SOILS AS AFFECTED BY MANURES. COMPARATIVE EFFICIENCY OF SALTS USED SEPARATELY AND IN COMBINATION. Table IV, which follows, is primarily for the purpose of showing the wide variation in the aggregate effect of the three fertilizer in- gredients when used separately as compared with their efficiency when used together. This table gives the percentage increase or decrease in growth (the latter indicated by the minus sign) produced by acid phosphate, sulphate of potash, and nitrate of soda used separately; the aggregate increase attributable to these three ingredients; the increase when the three ingredients were combined and the difference between the aggregate and that observed when the same ingredients were used in combination. All soils having complete data for these observations are included, the total number being 190, and the data are arranged in a descending series, beginning with the greatest difference in favor of the sum of the ingredients, until the difference becomes zero, after which the series is ascending and the differences are in favor of the combination. A wide varia- tion is shown in the last column, the difference ranging from a max- imum of 165 per cent in favor of the sum of the ingredients to zero and then increasing to a maximum of 72 per cent at the other extreme in favor of the combination. Of the total number of comparisons (190) there are 71 soils in which the efficiency of the combination exceeded the aggregate of the separate ingredients, 117 soils in which the aggregate of the individual effects exceeds that of the combination, and 2 solis in which the aggregate effect of the single ingredients exactly equals the increase in growth when those ingredients were used in com- bination. The number of soils that show very wide differences in respect to the aggregate efficiency of the ingredients as compared with the effect when the same ingredients are combined is small, the number increasing greatly as the lesser differences are approached. For exampie, 60 soils show differences of 9 per cent or less, while for 115 soils the difference is within the limit of 19 per cent. Within this limit of 19 per cent there are 51 soils in which the difference is in favor of the combination and 62 in which it is in favor of the aggregate increase for the same ingredients used separately. (See Table V following.) As a result of averages within these limits, acid phosphate gives an increase of 0.64 per cent, sulphate of potash 6.68 per cent, and nitrate of soda 19 per cent, or a total of 26.32 per cent, as compared with 24.5 per cent as a mean effect of the same ingre- dients used in combination on the same soils. Within these limits, which includes 60 per cent of the soils, the average efficiency of the ingredients as measured by the growth of the plants is nearly the same whether used separately or in combination. It therefore ap- COMPARATIVE EFFICIENCY OF SALTS. 25 pears that each ingredient has performed special functions which differ from and are independent of those performed by the others, whether the ingredients are applied separately or in combination. - Of the soils in which the effect of the ingredients in combination differs from the aggregate effect of the same ingredients used sepa- _ rately by 20 per cent or more, 55 are in favor of the ingredients used separately and 20 in favor of their combination. ‘Within the former group of soils there are 15 instances in which the aggregate increase of the ingredients when used separately is more than three times as great as when the same ingredients were used in combination, and 12 instances where the aggregate is less than three times but more than two times as great as when used in combination. Within this group, therefore, the function of the several ingredients is to a considerable degree identical, at least so far as they effect an increase in the growth of plants, and one may be substituted for another to a considerable extent. Of the soils in which the efficiency of the combination exceeds that of the same ingredients used separately by 20 per cent or more there are only 20./ In this group the function of each ingredient is not only different from that of the others, but each is dependent upon the presence of others in order that it may have the greatest effect. There is no apparent relation either by soil type or locality with this grouping of the soils; neither do the soils of one group appear to be particularly more responsive to the complete fertilizer than those of another. Of 190 observations on each, the individual ingredients give negative results as follows: Acid prosphate 66 times, sulphate of potash 31 times, and nitrate of soda 22 times. The combination of all three ingredients gives a negative result only 9 times, while the aggregate effect of the individual ingredients becomes negative 21 times. . Table V shows the average increase produced by each ingredient, the aggregate increase, and the actual increase when the ingredients were combined for soils in which the aggregate increase from indi- vidual ingredients differs within certain limits from that obtained when the same ingredients were combined. There are ten soils in which each of the three ingredients when used separately gave a greater increase in growth than when all were com- bined and ten others in which two of the three each equaled or exceeded the gain produced by the three combined. (See Tables VI and VII.) These soils are not confined to particular localities or types, neither are they associated with high or low degree of natural fertility, as may be seen by the wide range in weight of plants on the untreated soils. 26 EF ERTILITY OF SOILS AS AFFECTED BY MANURES. Taste 1LV.—Percentage increase in growth attributable to P, K, and N, and the sum of the same, as compared with the observed increase when a mixture of the three Sertilizers was ap pli ed. [Results arranged in descending series, beginning with the greatest actual difference in favor of the sum of the ingredients.] State. Virginia. . North Carolina. Mississippi... -. Louisiana... ... Louisiana... ... North Carolina. Mirginiias 2 teas Louisiana. .-... North Carolina. Missouri North Carolina. North Carolina. Indiana Ste hee che Arkansas Texas Se South Carolina. | New York. North Carolina. Mississippi... -- Arkansas Indians). 222s: Texas (Nee a Georgia ....-.. North Carolina.| Texasi sho. see Arkansas.....-.. * Louisiana....._. Arkansas---.. .,2 lo wasiscsee aes Arkansas...-..- TCXas: 2.2.85 2522 Maryland....... Georgia. -2se22 ee Alabama......- Louisiana..-..-- | .| Waycross area . -. Locality. Portsmouth... .__. Edgecombe. .-..-- Pontotoe County - Caddo Parish....-. Rusk County....- Caddo Parish... _- dredell test farm.) Louisa County ... Caddo Parish....-| Pinehurst - Crawford County. Ames San Marcos.....-.- New Hanover County. Blantyre - ... - Poe Manito Caddo Parish... - Caddo Parish... - Newton County -- Montgomery County. EscambiaCounty. Prairie County - - - San Marcos area-.- Geneseo. 2h 25% aa | EscambiaCounty. EscambiaCounty. Genesee County... EsecambiaCounty. Waycross area ... Rialeighe yeh se. ; Montgomery County. Prairie County ..-. Newton County . - Waycross area ..- Rusk County....- Parporos sss 533 San Marcos area. - Prairie County..-..| Prairie County..-. Caddo Parish..-..- Prairie County-..- TAIMOS Sine ncls. sat Prairie County .--- San Marcos...-..--| Leonardtown... - | Waycross area --- sLee County......-.| Caddo Parish....- Soil. TRGaG ete ta hte g Norfolk fine sandy loam. Lufkin silt loam... Caddo fine sandy loam. Norfolk fine sandy loam. Norfolk fine sand -- Cecil clay Cecil oame irk Miller fine sand-_-- Portsmouth sand.. Clarksville silt loam. Pedite- hes aces pete Crawford silt clay... Norfolk sand loam. Mick: seat fo ee Miller fine sand - . -- Caddo fine sandy loam. Orangeburg fine sandy loam. Norfolk fine sandy loam. Waverly silt loam. Houston black clay. Cecil sandy loam. . Dunkirk clay loam. Norfolk sand Norfolk sand _...-. Dunkirk clay loam. Norfolk sand ..._-- Norfolk fine sandy loam. Cecil sandy loam... Lintonia loam Acadia silt loam... Marshall fine sandy loam. Norfolk sand Caddo fine sandy loam. Norfolk fine sandy loam. Norfolk fine sandy loam. Crawford silt clay... Crowley silt a Morse clay Norfolk fine sand-. Crowley silt loam.. Wisconsin drift | (pocr). : W aeaaly silt loam.| Blanco loam-.- | Leonardtown loam (good). Povteinouih fine sand. | Norfolk sandy loam. Caddo fine sandy | loam, Weight Increase at- In- of _ tributable to—| 5UM | groase |... pacrrera (plea tease We Pc tee | Pye (0) | Dif plants Pp. Kk | attrib-| 4o7- on un- ae utable | 7 treated | P. | K.| N. | O° |. tos one soil. oe 5 «fh Grams: |\ Pict 4P..ct.\Pict:\ Pet. | P.cts VPack: 3.2 | 53.112 | 69 | 234 69 | 165 4.8 | 44] 42) 63 | 149 56 | 93 | | Far eee YD 50) 9387 4.4] 18| 18] 86] 122 36) " 86 Bele RST Mesh uns sine lO 48 62 SoU On| ied |i62el wat LO 51 |. 59 4.5} 86] 34] 42| 162 105 | 57 4.6) 36| 47] 75 | 158 102 56 TB (21). 264) 10h BT Gel has. 3) 4.8| 42] 26] 42] 110 56 54 6.6 | 26] 15] 17] 58 7 51 15.0] 24] 26] 21 71 20! 51 IS POUT fe wails] Pei 72 92) emi aO 4.1] 37 | 41] 122] 200 151.| 49 45| 4| 44|' 20]. 68 94 | mda 9.4] 16] 49}: 4] 69 25| 44 58. |) 12) 2) 88,4" 62 19| 48 6.0| 6] 17] 26] 49 Sui LOR powaaa|s Cle] (eee 47 41 WO: | let pealiea | oe HG 16 40 7.5 | 24] 20) 43] 87 48 29 | | 3.3.) 24). 36 [27 |" -87 48 | 39 5.0 | 28| 20] 18] 66 28 | 38 720) |) 320s Oie |, 30 72 S5 m8, 750) 2405 Bel C2Ra a 34| 37 8.9 | 16] 29| 20] | 65 98-137 Be Ory Perini 32 |e Abeer 8D 46 |» 36 Bad. (16 |b Asal 47 alban pete TOD) NT Hee tts mS 5} 85 Te) vad) 001 83) B56 Boil Gd TeO\l LT 128) | ynOOn| eeLOS 73 32 | | AML 2-20) rsdn neaOnlnanel 49} 32 SH5i [yoni elie oe2OR ews 22. 31 TaAs| 122)) WOO QOH at aa 41 |». 30 6. Sele Bal ee k2: ee Oh eae BP RU) 5.6 |— 4| 301) 61 87 57 t . 80 Sa |eoe Diy le chs OI G3 34 nee | SE Oilwell meu eir4al| uth 86| 28 5.3| 25| 22] 42] 89 63} 26 8) Sele 3ul e255 SO ean68 AD nog 7.0 |*. 0.1! 10°} 43 | °53 27 26 tials Re sts | Bp NES) 15s\tn ell 26 Bi4clh Luh 219) eat St 56 25 SisLil oe Wy ep chy 2 | 5 0 25 7.7.\ 19\|' 344) 53°l) 106 ayia SON 6.5| 15| 20| 27] 62 38} 24 Se weie Oy || melee 330 \ea 9B RB MWe TGs 17s joe Aveta tO 46; 24 | Be Gale O1 |, 738i 1, 000 77 | 23 Tale Loe |e 104 | Santee 8G 63) 28 OF) =210'4 eas ese Perey 4 23 COMPARATIVE EFFICIENCY OF SALTS. 27 Tasie IV.—Percentage increase in growth attributable to P, K, and N, and the sum of the same, etc.—Continued. State. Locality. (5.0 ae Alabama WOXAG. 3552.2. 50% indigna.22-.222 Louisiana....... North Carolina North Carolina Louisiana.....-- OG oo tte Mississippi-...... New Jersey. ... Missouri.......- Pennsylvania... Georgia2.0... - Wisconsin... . -- Mississippi.....- Mississippi-.... - Pennsylvania... Louisiana Menai cases ot. =', TOROS cc tcce. . 3 | New York...... TOWais.--'25----5 New York...... Wisconsin... .- < Wirginia as. 2: Arkansas....... New York...... Georgia......... Hlorida..5.0.5 22. Louisiana......- Wisconsin Geéorgia2t 3:22. North Carolina. North Carolina. if bee (7 ee New York.....- Alabama Ohio Wiens See Florida-. South Carolina. South Carolina. Wisconsin---___- Ford’s farm Rusk County... .-- Tippecanoe County. Caddo Parish...-. Biltmore farm....- Wake County....-! Caddo Parish..... Westerville area.) Pontotoe County., Woodbine.........- Scotland County. Montgomery County. W Sy Cross: 22. -22. Portage County... Pontotoe County Montgomery County. Montgomery County. Binghamton area. Caddo Parish..... | Rusk County Nagadoches....-... Portage County... Louisa County ... Prairie County... Binghamton area. Waycross area... . Escambia County Tompkins County Caddo Parish..... Portage County... Waycross area... . New Hanover County. Statesville........- Rusk County Cherokee County. Lee County Strongsville.....-. Pulaski Portage County -. Escambia County. Cherokee County . San Marcos King’s farm York County... . - Portage County .-.- Lee County Prairie County ...! Weight | Increase at- | gym! 12> : of tributable to—| of | Cease | pir P plants attrib- Soil. PK; fer- on un- ; aud utable Enea treated 5 - to : Pe Hise le Ne hy NFS - soil. 7 e PKN Grams. |P.ct.|P.ct.|P.ct.| P.ct.| P.ct. | P. ct. Norfolk fine sand. 85] 14) 16] 41 71 49 22 Orangeburg clay... Quik BO 2a bea 88 67 21 Norfolk fine sandy De | 20. 2S cos 86 65 21 loam. Miami silt loam... 5.6 | 30) 215) 228) 79 58 21 Norfolk fine sandy 5.6 |— 3 20; 35 52 33 19 loam. Porters clay-...-...- 12.4} 11} 15) 18 44 25 19 Tobacco soil......- 47 9| 11{| 28 48 30 18 Orangeburg fine 7.4 8} 10] 21 39 21 18 sand. | Miamiclay loam... (eG ee fe 5} 15 31 13 18 Orangeburg sandy 7.6| 17 —2)| 28) 4 26 17 | loam. | Norfolk sandy | 6.0} 12 5| 20 37 20 17 loam. Shelby silt loam.... 9.6 7 | 24) 14 45 28 17 Lansdale silt loam. 9.9 0 | 23 1 24 7 17 Norfolk fine sand. 6.0 5 8) 53 66 50 16 Miami sand........ 6.0 7 15} 33 55 39 16 Lufkin clay..-..... 6.4 8 8] 28 44 28 16 Memphis silt loam. 7.0 7 9| 14 30 14 16 Penn silt loam.... 12.3 J oe 64 8 28 13 15 Dunkirk gravelly 6.6 4 LijeeLe 16 1 15 sandy loam. Noriolk fine sandy 9.6 |— 8 9| 13 14 —1 15 loam. Caddo fine sandy 8.2 6 2] 53 61 47 14 loam. Orangeburg fine 8.8 1 6] 31 38 24 14 sandy loam. Volusia silt loam. . 6.6 4; 22) 10 36 | 23 13 Iowan drift.......-. 9.0) 16}; 25] 28 69 57 12 Volusia silt loam. . 4.8/— 2) 15] 34 47 35 12 Marshall sand..... 8.4 if 9} 31 47 35 12 Cecil sandy loam.. - Gs2o aieks) +0) ede 42 30 12 Calhoun clay....-... 83°) 12°) 120), 114 3 26 12 Dunkirk gravelly 10.6 9; 9 1 19 7 12 loam. | Norfolk fine sandy 7.9 1 5] .29 35 24 11 loam. ; Norfolk fine sandy 84/—7 14) 15 22 11 oa! loam. Dunkirk clay loam; 9.0 0 9} 13 22 11 il Norfolk fine sandy | 8.7 4 9 7 20 9 11 loam. Miami sandy loam 9.0 4 8 2 14 3 11 Norfolk sandy 5.0 0) 1651720: 36 25 11 loam. | Penecoe fine 3.0} 13 30}. 77 | 120 110 10 sand. Tredell clay loam...) 5.2 Tike, bol 44 34 10 Orangeburg fine 9.2 0 2] 34 36 26 10 sandy loam. Volusia silt loam. . 5.4 2) 15) 18 30 20 Norfolk fine sand. . ERS Mar 1 Sep PA as 3 68 59 Iredell clay loam. . 9.1 |— 3 (ie? 36 27 Cecil sandy loam... 8.6 1 9| 14 24 15 Miami clay loam...]......... —4\)—5)| 12 3 — 6 Red silt loam.....- 7.0 3 8| 19 30 22 Miami stony sand. 9.9 6] 138]. IL 30 22 Portsmouth sand. . & 3 2 Gale. 19 | Cecil silt loam... .. 6.6 2 1\), 52 55 48 Houston black clay 7.9 Be eSn| eo 37 30 Orangeburg clay - . 10. 3 3 6| 17 26 19 Iredell clay loam... Gua 0 6| 19 25 18 Marshall gravelly 11.0|/—1|— 2] 14 il 4 loam. Norfolk coarse 5.3 |— 7} 15) 48 56 50 sand. Acadia silt loam... 11,2 0 4! 29 33 27 ray ao 2 NINNNNWWOOUCoCoOS 28 FERTILITY OF SOILS AS AFFECTED BY MANURES. TABLE IV.—Percentage increase in growth attributable to P, K, and N, and the sum of the same, etc.—Continued. | Weight | Increase at- Su In- of | tributable to— of | crease Dit- State. Locality. Soil. plants | bP re, | ae aor: on un- | atl utable ¢ ence, treated |) p ay aN N to BOD sich i ‘ > PENT Grams. \P.ct.|P.ct.|P.ct.| P.ct.| P.ct. | P.ct. Arkansas.....-- Prairie County ...) Morse clay......... 10.8 4|— 3 PA 3| —3 6 Georgia.....-.- Waycross area...) Norfolk sand...-... 6.1/—2\/—5| 36 29 24 | 5 MEXGS Sx28. 055-4 Rusk County-.--- Cuiueebure fine 7.5/— 7} 20] 31 44 40 4 sand. | Virginia. ....... | Hanover County.. —— sandy Resa eae All aN DOR ae 30 4 oam. | Georgia..-....- Waycross area....| Norfolk fine sand. . 6.1 Wall aleve eae 77 74 3 Arkansas.......| Prairie County ...| Acadia silt loam... 13 1 Tel otO 18 15 3 Pennsylvania... xe ntgomery | Hagerstown loam. LOSS Meo reg oI 12 9 3 ounty. | | Tennessee... ..- Henderson) Lexington silt | Reon nella} le (ero 38 36 | 2 County. | loam. North Carolina | Asheville..... ... | Porters clay....... 5.8 |— 6/— 2| 29] 21} 19 | 2 Mexaae 2. fe 217) San Marcos area... Houston blackclay | 839) O 4 15 19 | 17a 2 Missouri... ...-- | Crawford County.) Cee stony TASB ea Sen | 5 3 | 2 | oam. | | | | | ROXAS Scasce oe. Maroney’s farm...| Orangeburg clay . .| 86/—3]| 1] 17 15 | 14 1 New York..... Tompkins County, Dunkirk loam..._. | 84/— 4); 2) 15 13 12 1 Imdisina)es os oe Tippecanoe | Marshall loam..... 7.5 —3 2 vf 6 6 0 ; County. Arkansas......- Prairie County ...| Morse clay. ......-- 88 —9)| 8 1 0 0} 0 Arkansas? 4- Prairie County ...| Crowley silt loam -- 10.1 —1 | 3 0 2 3 1 rdians =.=. -? Tippecanoe) Marshall silt loam. %2 4 1 6 11 12 | 1 County. | | | Arkansas.....- Prairie County...) Acadia silt loam...! 9.0 0 | 11 6 17 18 | 1 North Carolina... New Hanover | Norfolk fine sandy | 7.3 3 3 | 22 28 | 29 | 1 County. | loam. | ‘ New York. .... | Tompkins County | Dunkirk clay loam | 4.5 j—18| 4] 55) 41 42 | 1 OM02 Faces e8 Westerville area... Miami loam......- 86 —8) 3|/—2|—7 =—a 2 Arkansas...... Prairie County - .| Waverly silt loam. 7.8 —7 9i\—-7/—5| —8 2 South Carolina.) Cherokee County..| tell fine sandy 5.9 |— 3) 7] 46) 50} 52 2 | loam. | } North Carolina.) Statesville......_. Cecil clay (good) - -| 8.8 0|—2|—4)/—6| —4| 2 exas doo7 (ote | Galveston...-.-.. | Galveston clay..-.- 11.2 —14/|-12| 3 -23) —20 3 Texrag Che so 7 3s Rusk County..--- | Susquehanna fine 7.0 —3| 0 9 6 9 | 3 | sandy loam. Mextisg7 © eee Rusk County...-- Norfolk fine sand... 7.8 —4 Co pa Ie Nia 28 | 3 Kentucky ...... McCracken /| Memphis silt loam. 5.0 — 3 3| 39) 39 42 | 3 | _ County. Alabama ...... Lee County....... Norfolk sand ....-. 6.8 ON 10) (e40 59 62 2 TOW eee as MeO: 2h aS Kansan till ......- 5.9 Tel lah 48 70 73 3 Louisiana... -.. Caddo Parish. ..-. caade fine sandy 8&8 —7 5 7 5 9 4 oam. : Wexas Secon s San Antonio. ..... Hioueter blsek clay) 5.8 8 1 |—3 | 6 10 4 oam. | } | North Carolina.’ Statesville......-- Cecil clay (poor). ..| &8 —1 1 0 0 OG By New York. Tompkins | Miami stony loam. 9. 6 4 1 1 6 11 | 5 County. Georgia......-- Wiayeross:; 2-=5-- ny eee sandy | 6.5.| 112} 15) 54 80 85 5 oam. Arkansas...... Prairie County .. | Crowley silt loam... 7.1 —8 0 9 1 7 6 Maryland...... Leonardtown. ...- oe eee 6.5 — 7} 15 8 16 22 6 | oor). Texas nese Rusk County-~..-. Notfolk fine sand.. 8.6 5); 6) 19 30 | 36 6 Alabama....... | Rawles’s farm.. -- SRE PUNe sandy 8.1 6/— 5 4| 5] 12 7 oam. | TEXais Lote ees San Marcos area..| Houston blackclay 8.1 —4 —5| 21 12 19 | mil Alabama....... Lee County.....-- Norfolk sand...... 4.77 —1/\—1}] 30 28 35: | 7 South Carolina.| Cherokee County -| Cecil sandy loam. - - 6.9 —12| 28] 35 51 58 7 Mississippi- -.-- Montgomery | Memphis silt loam.) 8.6 —13; 6] 12 5 | 13 8 County. Louisiana... .... Caddo Parish..... Orangeburg fine 655 3 3 0 6 | 15 9 sandy loam. Pexases ess San Marcos area..| Crawford silt clay- 9.2 —7 2) 19 14 23 | 9 South Carolina.| Cherokee County.| Cecil clay.......... 7.4 —4 — 6) °36 26 35 | 9 Virginia-2 2 2 Pocahontas field..| Cecil clay.......... 11.7 /— 3) 4/—3]—-— 2) 9 | 11 Mississippi. -- - - Pontotoc County.) Monroe silt loam... 80 i\— 4/— 6), 13)" 3 14 | 11 New York ..... Binghamton arei.| Wabash loam ..... 10.6 — 1) il 5 15 26 | 11 Missounriss. 2225 Crawford County-.| Wabash silt loam. - el Owes pana ses ek eee 12 Georgia.......- IWiaiViGlOSSe ces. or Norfolk sand. ..... 5.5 — 9] 24] 45 60 72\| 12 South Carolina.| St. Matthews..-.. Onmeebure, sandy 11.8; O|— 2) 15 13 26 | 13 oam. ! IPREXAS en wet toe Palestine... .....- Orangeburg fine 11.4—-7/— 4] ll 0 14 14 sandy loam. COMPARATIVE EFFICIENCY OF SALTS. 29 Taste 1V.—Percentage increase in growth attributable to P, K, and N, and the sum of the same, etc.—Continued. State. Area. . Pennsylvania... Montgomery County. North Carolina.| Union County. -.. Alabama. .....-. Lee County....-... North Carolina.; New Hanover County. Whig! s Joe e2< - Westerville area. . WMlorida. =... = Escambia County MUIMOIS Scions ot ec senses oe e's ere oe Louisiana... .:.. Caddo Parish. .... Wisconsin...... Portage County. . Alabama......- Lee County....... LID Ds oS ae A MERE ees Georgia. .-..--- WWeyeross:) = 225). Mississippi. - - - - | Mont gomery County. Indiana. ....... Newton County .. Mississippi. - - - - Montgomery | County. New Jersey... -- Woodbine. ....... Georgia- <<... WiaiyCross: 2.2225. | Virginia........ Hanover County.. Alabama. ...... MATION. oo... 222 2- Georgia. . -. / juz | WS ¥CTOSR Ss = s5/=- North Carolina. Chowan County. | Wisconsin... -.- Portage County. . Mississippi. - - - - Montgomery County. Alabama... =. - Lee County. ...... Mississippi. -.- - Pontotoc County. Georgia.......- WiBYCTOSS--...¢-=- Mississippi. . - - - Montgomery County. MOXaGesstcoce=c| Rusk County. ...- Louisiana...... _ Caddo Parish... -. Indiaman 22... 2 | Newton County .. South Carolina.) York County..... Louisiana... ....! Caddo Parish. .... Rhode Island... Kingston......... Weight | Increase at- In- of. tributable to— ere crease | pis Soil plants | pK, attrib-| so, ; OTE ar, sean rand utable Fics treated | p | kK. | N N to soil. bell trea : 7 EON Grams..\P.ct.|P:ct.|P.ct.\(P-(ct.|| Pct. |.P. ct. Chester loam... .-.. 7.8 0 9 4 13 27 14 Sultdoames. <= =.~2- 4.6 — 4 0| 32 28 42 14 Norfolk sandy 6.1 |—14 4| 42 32 46 14 loam. Norfolk fine sand. . 6.4 3 9| 37 49 63 14 Miami black clay 8.3 |—11 6|-2|)-—7 8 15 loam. Norfolk fine sandy 5.5] 10] 12 |— 5 17 32 15 oam. : Marion silt loam... 7.7 |—13 |— 8 |— 3 | —24 —8 16 Orangeburg fine 5.0 0 6/10 16 32 16 sandy loam. Portage silt loam. . 8.7) 2 |—16 '— 2| —16 1 17 Norfolk cqarse 6.4 |—12 0| 20 8 25 17 sand. Wisconsin = drift 9.6 |—10 | 15] 30 35 52 17 (good). | Portsmouth fine 5.5 2} 18) 33 53 71 18 sand. Memphis silt loam- 10.6 |—13 |— 3 |— 2} —18 1 19 Clyde fine sand .... 12.6 |—21 |— 2 |—14 | —37 —17 20 Memphis silt loam. 9.5 |—16 |— 9 0 | —25 —5 20 Norfolk fine sandy 6.5 if 1 9 11 32 21 loam. Norfolk sandy 7.0 |— 7| 14] 36 43 64 21 ‘oam. Wickham = sandy 7.5 |— 3 a) Tt 13 36 23 loam. Orangeburg sandy 4.8] 14 7| 25 46 69 23 loam. ee fine 5.2 it | etor |= 50 66 90 24 sand. Portsmcuth silt 4.5 2} 19} 14 35 62 27 loam. Portage silt loam. . 10.0 —11 |— 9 |— 6 | —26 3 29 Memphis silt loam. 10.2 |— 3 |— 2 |—15 | —20 12 32 | Cecil sandy loam. - . 5.6 |—-1l1 — 7]| 29 il 43 32 Orangeburg clay-.. 6.6 — 9 3 | 18 12 45 33 Norfolk fine sand. . 7.4|— 9 — 8 |— 3 | —20 14 34 Memphis silt loam. 11.2 |—-10 — 7 |—11 | —28 8 36 Orangeburg fine 9.2 |-12 — 6) 141-4 36 40 sandy loam. | Norfolk fine sandy 7.9; 1 — 5 |—10 |] —14 35 49 loam. Mieke: ae Bet ae 4.4 |-25| 61] 14 50 100 50 Cecil sand: = <2 <2. 3.9 |-15 — 8| 26 3 54 51 Orangeburg fine 5.0 |=22 —10 |—10 | —42 28 70 sand. Miami silt loam... . 3.6 — 8 19 \—14 | —41 31 72 30 FERTILITY OF SOILS AS AFFECTED BY MANURES. TaBLE V.—Average percentage increase in growth attributable to P, K, and N and the aggregate increase of the same salts used individually as compared with the actual increase when the same salts were used together, averages being for the soils in which the difference between the aggregate and actual increase is within limits indicated in the first column. io Sa = 7 oe aA Se 7 Increase attributable to— | Increase Range of Green Sum of + attribu- a difter- | Namher) weight PK | table to) Die ence. oes OES Alot plants. Pe Ke. N. and N. | mixture pee of PKN. Per cent Grams. | Per cent.| Per cent.| Per cent. | Per cent. Per cent.| Per cent. 60+ 5 4.8 37 49 64 150 52 98 50-59 8 7.0 31 31 38 100 46 54 40-49 7 6.4 19 30 35 84 41 43 30-39 16 6.7 16 22 31 69 34 35 20-29 19 (63 13 19 38 70 46 24 10-19 35 7.6 6 12 22 40 26 14 0-9 28 8.3 1 5 22 28 23 5 fae 9-0 32 7.6 — 2 4 17 19 23 —4 19-10 20 7.9 —5 4 14 13 28 —15 29-20 9 ee —4 4 14 14 7 —23 39-30 5 8.2 == 4 —5 1 —9 24 —33 49-40 2 8.6 — 6 | —5 2 —9 36 | —45 50+ 4 4.2 —18 | 6 4 —§ 53 —61 if =} Taste VI.—Ten. soils in which percentage increase attributable to each ingredient is- greater than that produced when all are combined. | ‘ Increase - | Weight | attributable = of plants Agee ete i i once Sum | attrib-| Dif- State. Locality. Soil type. = “pe - areal Ot utable | fer- iieated ee PKN. | to mix-| ence 7 eat IPS Rea PING ture of . | PKN. Grams. |P.ct.|P.ct.|P.ct.| P:ct. | P.ct. | P.ct. Louisiana... --! Caddo Parish. .... Miller fine sand .-- Hrdem alate 20 lasekO 57 1 56 LOW aes ee Ames ee Saas ak Peat fs 2a een een 15.0: | 24) 26) 21 71 20 } 51 Missouri... --- Crawford County.| Clarksville silt 6.6 | 26) 15 | 17 58 7 51 loam. | idvangeese~ ase Newton County -.| Marshall loam....- CA es 7 eI ty 56 16 | 40 Blonidaresc-. 2-2 Escambia County.) Norfolk sand. ..-- 5.4] 16) 18) 13 47 11 | 36 New York... ..- Geneseoieea ss). Dunkirk clay aOR (ae) righ i 40 5 35 loam. Indianars.2--- Newton County -.| Marshall fine 6.3 vey [pent 27 9 26 —4 30 sandy loam. Arkansas. ..--- Prairie County -..| Morse clay......-.- UT: Cg eal IS Sere} 15 —ll 26 Arkansas. ....-| Prairie County -..| Crowley silt loam. 8.1 9] 14 2 25 Of 25 New York... ...| Binghamton area.| Dunkirk gravelly 6.6 4 Tle Sat 16 1 15 sandy loam. AWORARC Soret BA nade BE Se ted feel OT Way) ob § 41 5 36 NITRATE OF SODA ALONE AND WITH OTHER SALTS. 31 TasBLe VII.—Ten soils in which two of the three ingredients each produced a greater increase than when all three were combined. aeons Inferease | Tas | | Weight | attributable | crease | Sr glants to— Sum |attrib-| Dif : F rown a ay State. Locality. Soil type. eased q= =|... of; | utable | .fer- treaied PKN.| to mix- ence. Seal |, eSNG ture of - | PKN. | | | | Grams. |P.ct.|P.ct.|P.ct.| P.ct. | P.ct. | P. ct. Virginiaje.:.. | Portsmouth... .. REA ee one Se nc: See |. 53.) PL2)) 69 234 69 165 Louisiana... ... Caddo Parish. .... Norfolk fine sand. 320 ft 3) “Ob | 162 110 51 59 Louisiana...... | Caddo Parish. .... | Caddo fine sandy 6.0 6| 17) 26 49 8 41 | loam. Louisiana...... Caddo Parish. .... Caddo fine sandy | 5.0 —1lo0 | ie 4 oe 27 4 23 | loam. Louisiana... ... Caddo Parish. .... Norfolk fine sandy | 9.6 |— 8 9:43 14 —1 15 loam. | New York.. ... Binghamton area.| Dunkirk gravelly 10.6| 9 9 11 19 7 12 ; loam. Florida.. ......; Escambia County., Norfolk fine sandy 8.4/— 7} 14] 15 22 ll 11 | loam. 3 Wisconsin... .. Portage County...| Miamisandyloam.! 9.0 4 8 2 14 3 11 Arkansas ......| Prairie County -..| Morse clay........ 10.8 4|— 3 2 3 — 3 6 Missouri. ...__- | Crawford County. Clarksville stony 14.6 4 3 \|— 2 5 3 2 | | loam. — | AVOCAPO LS ne SI) ee ee ES 8.1 5 |. 23) 22 50 15 35 NITRATE OF SODA ALONE AND WITH OTHER SALTS. A study of Table IV shows that in 66 per cent of the instances nitrate of soda when used alone has produced an increase of growth which equals or exceeds that produced by either sulphate of potash or acid phosphate. A tabulation of the data for nitrate of soda and of combinations ip which it enters shows that the nitrate of soda has a marked bene- ficial effect on the majority of soils which on an average is not increased by the addition of acid phosphate. A comparison of the nitrate with the nitrate-phosphate column shows a difference in favor of the former in shghtly more than half of the comparisons. The average of these two columns shows a difference of less than one- tenth of 1 per cent. Nitrate of soda when supplemented with sulphate of potash gives an increase in growth which in 74 per cent of the instances equals or exceeds that produced by nitrate of soda alone, the average result being 8.5 per cent in favor of the combination. When this nitrogen- potash combination is still further supplemented by acid phosphate there is on an average no additional increase in growth. In fact the instances in which the nitrogen-potash combination equals or exceeds that of the complete fertilizer are slightly in the majority. The tabulation above mentioned is not published, but the same facts may be gathered by careful study of those columns in Table III, which give the results for nitrogen and all combinations into which “it enters. 32 FERTILITY OF SOILS AS AFFECTED BY MANURES. SULPHATE OF POTASH ALONE AND WITH OTHER SALTS. Sulphate of potash when supplemented by acid phosphate pro- duced an increase in growth, which in 50 per cent of the soils exceeded that produced by potash alone, the average increase being one- tenth of 1 per cent in favor of the combination. When the potash salt is combined with nitrate of soda there is a marked increase in growth over that produced by potash alone, which, on the average, is not further increased by the addition of acid phosphate. In 86 per cent of the soils the effect of potash combined with nitrogen has equaled or exceeded the effect of potash alone. These facts are brought out by a study of the columns in Table III, in which potash occurs, omitting all soils for which the data for this salt and all its combinations are incomplete. ACID PHOSPHATE ALONE AND WITH OTHER SALTS. Referring to Table IV, the striking fact is the large number of instances in which acid phosphate gives a small or negative effect. The efficiency is quite regularly increased (see all columns of Table III in which phosphate enters) as each fertilizer salt is added, the exceptions to this being mostly for those soils in which the efficiency of the complete fertilizer as a whole becomes quite small or is negative. In the life and economy of the plant, phosphates are generally recognized to be instrumental chiefly in the production of seed or fruit, and have a tendency to hasten maturity, and may influence the color and quality of the fruit. It is also known that plants do not absorb extraneous phosphates during the very early stages of growth. From the standpoint of the requirements of the plant, no response would be expected from the phosphates, and it is, there- fore, not strange that in many instances a small or negative effect has resulted from their application. It should be borne in mind, however, that this is not a study of the plant’s requirements, but a study of the fertility of the soil as affected by fertilizers and that the plants have been used merely as the indicator of the degree to which fertility has been affected by the various applications. It is now contended that aside from the direct action that various salts have on the growth and economy of the plant, they may also act directly on the soil, thereby increasing its fertility in a way not fully under- stood. An inspection of the tables will show that while small and negative effects have often resulted from the phosphate, there are 55 soils in which the increase in growth attributable to this salt when used alone has ranged from 10 to 50 per cent and in two instances even more. . LIME ALONE AND WITH FERTILIZER SALTS. as LIME ALONE AND WITH FERTILIZER SALTS. Table VIII shows the increase in growth attributable to lime, to a complete fertilizer with and without lime, to manure, and to cowpea vines with lime. The soils are arranged in a descending series as determined by the efficiency of the complete fertilizer without lime. Lime alone shows quite a marked effect in the majority of the soils, and while its efficiency corresponds in a general way with that of a complete fertilizer there are numerous exceptions to this. The lime may have little or no effect where the fertilizer is markedly beneficial. For example, in the upper portion of the table where the figures for the complete fertilizer range from 50 to 75 per cent increase in growth there are 8 soils on which lime gives less than 10 per cent increase, while in the lower portion of the table where the complete fertilizer does not exceed 11 per cent there are 7 instances where the increase in growth attributable to lime exceeds 30 per cent. As a rule, the efficiency of the complete fertilizer has been appreciably increased by the addition of lime. There seems to be little evidence in support of the contention sometimes made that the benefits due to lime are attributable to its favorable action on nitrification. A study of Table IX, which summarizes the results of Table VIII and all data for the same soils in Table III—i. e., gives the mean per- centage increase in growth attributable to the several fertilizer salts and combinations for groups of soils in which the efficiency of a complete fertilizer falls within certain limits as given in the second column—shows that as the efficiency of a complete fertilizer declines there is a corresponding decline in the effect of practically all ingre- dients and combinations. This is equally as true for manure or for potash and phosphate as it is for nitrate of soda and lime, so that the parallel decline in the lime and nitrate columns in the table loses significance. Of the soils in Table VIII, where the efficiency of a com- plete fertilizer is not less than 25 nor more than 75 per cent, there are 17 in which the efficiency of lime exceeds 35 per cent and 31 in which it is 10 per cent or less. As a result of averages of these two groups of soils, we get the following results: Seventeen soils (lime ‘giving increase of 35 per cent or more) average efficiency, lime 63, N 35, NKP 49; 31 soils (lime giving increase of 10 per cent or less) lime 4, N 24, NKP 40. The effect 6f nitrogen is obtained from Table ITI. The difference in the efficiency of lime is here very marked, drop- ping from an average of 63 per cent for the 17 soils to only 4 per cent for the 31 soils. The relative decline in the effect of nitrate of soda and the complete fertilizer, however, is small, being from 35 to 24 for the former and 49 to 40 for the latter. 34 FERTILITY OF SOILS AS AFFECTED BY MANURES. Tasxe VIII.— Weight of plants on the untreated soil and the percentage increase in arowth produced by lime, a complete fertilizer with lime, a complete fer tilizer, manwre, and cow- pea vines with lime. Increase attributable to— Weight of State. Locality. Soil. pianye, / erested| L. | NPKL.| NPK.| M. | CvL. soil Grams. | P.ct.| P.ct Picts: Pct ace North Carolina... Now Hanover | Norfolk sand......-. 4.1 66 154 151 | 254 144 ounty. North Carolina... New Hanover] Portsmouth 3.0 70 173 110 | 130 230 County. fine sand. North Carolina. .| Iredell test farm...| Cecil clay............ 4.5 45 105 105%); 90n) esas Virginia. 22s. Louisa County....| Cevilloam.......--. 4.6 71 153 102 | 63 158 Indianaa-* =... Newton County. -.| Peat............-..- 4.4 14 70 100 | 40. 18 Georgia..........., Waycross area....| Portsmouth fine 5.2 92 153 90 | 219 175 sand. Georgians <2. Waycross area....| Norfolk fine sandy 3.9 64 105 86 | 150 176 loam. Georgia...........| Waycross area... .| Norfolk sandy loam 6.5 35 100 > 85 | 109 109 LOWS acc oe- =. 5s cee PAINS AS. oR Wisconsin drift dork Pl eect eee S2 [es SO wee oa (poor). Georgia...........,; Waycross area....| Portsmouth fine |* 5. 2 29 117} 77 | 150 148 sand. . Georgia...........| Waycross area... .| Norfolk fine sand... - 6.1 34 84 74 | 102 107 Georgia... Waycross area... - hou fine sandy 7.5 40 89 73 | 113 113 oam. WOW aeeseee corre eel ae Ollnery tom eee Kansamitile 2252252 5.9 6 42 Wie 244 | (3 eee Georgia...........) Waycross area__..| Norfolk sand.. 5.5 64 109 72.) 124 118 Georgia...........| Waycross area... -| Portsmouth fine 5.5 20 75 71 | 64 109 sand. Alabama......... Marion ae. ecice Orangeburg sandy 4.8 12 69 69 | 37 60 loam. Virginia S205 3. Portsmouth. ....-. Peate sees aich aecet 3.2 75 97 69 | 47 72 JAE) of nose ee Sep oee Marion v2 si.gseace Orangeburg Clay . - - 9.1 20 55 67 | 49 35 Texas aj oo. Rusk County.....- Norfolk fine sandy 7.5 21 64 65 105 62 loam. Georgia... ..| Waycross area....| Norfolk sandy loam. 7.0 0 57 64 | 103 94 North Carolina. - Nev Hanover | Norfolk fine sand... - 6.4 16 70 63 | 94 37 ounty.. | North Carolina...) Tarboro:.....---2.. Norfolk fine sandy 3.0 1 70 63 | 38 78 loam Alabama... -....-- Lee County....-.- Norfolk sandy loam. Teh 19 87 63 | 61 164 North Carolina... Chowan County-..} Portsmouth silt 4.5 19 57 62 | 46 74 loam. Alabama.......-- | Lee County --.-.-- Norfolk sand....-..-- 6.8 57 103 62 | 107 160 Louisiana........., Caddo Parish..... Norfolk fine sand ... 5.3 9 74 59; 28 80 Tndiamns. 622 = ee 7 | | | | State. Locality. Soil. Paes) | trentea| LU: |NPKL.|NPK.| M. | CvL. soil | Grams.|P.ct.| P.ct. | P.ct. |P.ct.| P.ct. Louisiana. ...-.- Caddo Parish..... eee fine sandy 6:05 21g 16 8| 79 | 23 oam. | MISSOUE = =< 5 =. Crawford County.| Clarksville silt loam 6.6 | 14 1 wn, 43 32 Pennsylvania..... Montgomery | Lansdale silt loam. - 9'9 le 39 17 7 9 30 County. New) York>.....- Binghamton | Dunkirk gravelly 10.6 | — 3! —l11 (AN PAU ee) area. loam. Arkansas........ Prairie County .-.| Crowley silt loam... 71} | 36! 60 dake Oa! 38 Waidiania iss SoG Tippecanoe | Marshallloam...... 7.5 | —3 7 6| 42} —2 County. j New, Or .-2-. . Geneseo . --| Dunkirk cla; loam... 10:2) 5038 0 Die Egat S21 Wisconsin. ....-. Portage County ..| Marshall gravelly 11.0 2 3 4] 36 | 14 ; } too m. Louisiana....... Caddo Parish..... eae fine sandy DOM 8 72 4| 44] 148 : oam. Wisconsin. ...-. Portage County... Miami sand; loam. . 9.0 | 4 21 3 | 29 12 Wisconsin......-. Portage County.. Portage silt loam..-| 10.0 | 5 10 3 | 21 | 10 Missouri........ Crawiord County. Oh rksville stony 14.6 | — 3 —2 3 |—10 13 oam. Arkansas.......- Prairie County. .-., Crowle silt loam... 10.1 | 2 5 3 7 9 Wisconsin. ....-- Portage County. -., Portage silt loam... 8.7 | 9 —14 1 42 —14 New York....... Binghamton area.| Dunkirk gravelly | 6.6 | . 26 27 1| 29 69 sandy loam. Mississippi. - - - - - Montgomery Co..| Memphis silt loam. - 10.6 | —1 16 1|— 4 6 Louisiana....... Caddo Parish ....) Miller fine sand..... tea 14 16 1.) 343 36 Arkansas... .-.- Prairie County...) Crowley silt loam...| 8.1 46 33 0; 18 42 Arkansas........ Prairie County...| Morse clay....-.--. 8.8 6 —7 0 6 22 Missouri........- Crawford County.| Wabash silt loam... 7.6 0 PN tsi) ( BBR oe BY Louisiana......- rate Parish .... eee fine sandy 9.6 6 19} —1]| 22 1 oam. } Arkansas........ Prairie County --.| Morse clay....--..-- 10.8 2 4| —3 4 9 Arkansas........ Prairie County .-.| Waverly silt loam. -| 7.8 37 40' — 3] 18 41 PWGATIOS Soe ee Newton County. . Mereeall fine sandy 6.3 | —12 —1|! —4] 60| —2 oam. North Carolina...) Statesville........ Cecil clay (good)... - 8.8 FP ease eae —4 ON See ORIOS aeons Westerville area..| Miami loam.......-. 8.6 2 2/ —5| 48 15 Mississippi- ----- Montgomery | Memphis silt loam.. 9.5 | — 5 3); —5|—5 11 County. OHIO scene 2s Strongsville.....- Miami clay loam...-|.......-- SOM etek ae | —6 0 seers HMInOIs: 4200823 Clinton County...| Marion silt loam... . 7.7 | —13 —4| —8]| 48] —12 Arkansas.....-.. Prairie County ..-| Morse clay..--..--- 111|/—7 —1 —i1 3 4 imdiana: = 2222252 Newton County. .| Clyde fine sand...-- 12.6 | —12 — 7) -—17} 32} —4 ROHS Wc ek ae Galveston.2 > :.-% Galveston clay...-. 11.2 | — 2 —8| —2 4 31 RELATIVE EFFICIENCY OF ORGANIC AND CHEMICAL MANURES. An examination of Table VIII shows further the efficiency of manure and cowpea vines with lime as compared with a complete fertilizer with and without lime. In the majority of instances the manure or cowpea vines with lime, or both, have proved superior to the mineral fertilizers. A careful analysis of the results shows that manure and cowpea vines with lime nearly tie for first rank, while the complete fertilizer with lime ranks third, and without lime becomes fourth, or last. The relative number of times that each treatment ranks first on the basis of 100 for the whole is: Manure, 39; cowpea vines with lime, 39; complete fertilizer with lime, 16, aad complete fertilizer alone, 6. 38 FERTILITY OF SOILS AS AFFECTED BY MANURES. > RELATIVE EFFICIENCY OF ALL SALTS AND COMBINATIONS WHEN SOILS ARE GROUPED ACCORDING TO EFFICIENCY OF PKN. Table LX is an aggregation of the results in Table VIII and the results for the same soils in Table III and gives the average per- centage increase in growth attributable to each ingredient and com- bination of ingredients for groups of soils in which the efficiency of a combination of nitrate, potash, and phosphate was within certain limits as given in the second column of the table. It also gives the average green weight of plants grown on the untreated soil for each of the groups as well as the weight produced by a complete fertilizer and the weight produced by the best average treatment for each group which in eight instances is attributable to cowpea vines with lime and in three instances to manure. The efficiency of the single fertilizers, phosphate, potash, lime and nitrate, with a few exceptions increase in the order named, the phos- phate being least effective and the nitrate most effective. In the group of soils for which the efficiency of a complete fertilizer is 60 to 69 per cent, potash outranks lime by 1 per cent, and in the fol- lowing group it becomes identical with lime. In the last two groups in the table lime outranks the nitrate as well as potash and phosphate. A comparison of the efficiency of the several combinations of fer- tilizer salts and lime gives the order of efficiency that would be expected from a study of the relative efficiency of the same salts used separately. With a few exceptions, however, the efficiency of the various combinations is a little less than the aggregate efficiency of the same salts when used separately. These exceptions are mostly with the combination of potash and nitrate (KN), which in six out of eleven groups gives a larger percentage increase in growth than the aggregate of the same ingredients used separately. The efficiency order of the combinations, beginning with the smallest, is phosphate-potash (PK), phosphate-nitrate (PN), potash-nitrate (KN), phosphate-potash-nitrate (PKN), and phosphate-potash- nitrate-lime (PKNL). In the four lowest groups of the table, how- ever, the potash-nitrate (KN) combination outranks the complete fertilizer without lime. A comparison of the most efficient fertilizer treatment, viz, that of the three fertilizing salts and lime, with the results obtained with manure and with cowpea vines and lime shows only four groups in which the fertilizer with lime outranks the manure and no instances in which the cowpea vines with lime have failed to outrank the fertilizer with lime. Of the eleven groups, cowpea vines with lime rank first eight times and manure three times. In the last three columns is given the.average green weight of plants on the untreated soil, with a complete fertilizer, and with the best average treatment, for each of the eleven groups of soil. It is EFFICIENCY OF SALTS ALONE AND IN COMBINATION. 39 noticeable that as there is a regular decrease in the efficiency of the fertilizers there is a corresponding regular increase in the weight of plants produced on the untreated soil. In other words, the lower the producing capacity of the soils the greater their response to fer- tilizers. The decrease in the efficiency of a complete fertilizer with- out lime is nearly inversely proportional to the increase in the weight of plants so that the weight of plants produced by the same fertilizer for any group of soils approaches a constant. The same is essentially true for the best average treatment with a tendency toward the largest plants on the poorer soils, as shown by the maximum weights of plants for the second and third groups from the top of the table under heading of best treatment. TABLE LX.—Average effect of fertilizer salts and combinations by groups according to the efficiency of PK N, also average weight of plants on untreated soil, average weight when treated with PK N, and average weight with best fertilizer treatment. Increase attributable to— Weight of plants. Num-| Range | | eS | peel et: | | Cow- ' B of | eff- | p =} - 2 5 - Ma~ | pea |) Un | | best Soilsvicioncv| oe | K. | N. | L. | PK.| PN.| KN.) PKN.| LPKN. nure.| Vines} treated) PKN. |treat- ene 2) | | | and || soil. ment. | | lime. ai bead ene Gbs| E-Cbs| Pye Coopes.Cr.) by Cb. EeO0s| Pre Gbe || Lee Choma lh. Cory. Ce. |) (Gms. «| Gms. || me. 5; 100+ |} 29| 43) 66] 53] 58] 75] 85 113 131 115 | 187 || 4.1 toHd | Our 4} 80-99] 10| 23] 58/] 52] 26]. 63] 85 86 119 | 141] 158 5.8 | 10.8} 14.7 6 | 70-79 5} 20] 53] 32] 23) 57] 72 73 86 96 | 119 || §.9)| 10.2) 1279 10 | 60-69 |} 15] 26) 40} 25) 27] 50] 55 ‘65 73 69 84 | 6.0 O59" USO 15 | 50-59 | 11] 23); 43] 23) 20| 40] 48 54 68 69 83 || 5.8 8.9 | 10.6 18 | 40-49 Ree won ak te 27) AS hois2n a0 45 59 i [620 6.3 9.1 10.2 26 | 30-30 i 8} 23] 20} 13} 21) 33 34 48 46 56 |) 6.6 8.8 10.3 35 | 20-29 5|/ 12] 21 MGI) cLOs) eye) e277, 25 35 45 41 8.0; 10.0} 11.9 29 | 10-19 2 yee 9 4] 11] 16 14 23 31 29 8.2 9.3 | 10.7 25; 0-9 1 5 6 8 2 6} 12 5 15 24 26 9.0 9.5} 11.3 —1 to ‘ 7 ‘ 134) a \_7 ee Me ey ae DW a ol aa 9.3] 8.7| 11.2 RELATIVE EFFICIENCY OF SALTS WHEN USED ALONE AND IN COMBINATION. In these tests as shown in Table III, beginning on page 15, each of the three salts, acid phosphate, sulphate of potash, and nitrate of soda, has been used separately and in three combinations, thus giving four observations relative to the increase in growth pro-- duced by each. For lime there are two observations, while for manure and cowpea vines and lime there is only one observation each. While it is disputed ground as to whether the efficiency of a fertilizer salt should be measured by using it alone or by combining it with all other elements in which the soil may be deficient, many experimenters have adopted the combination as the most reliable means. It seems probable, however, that theoretical considerations, rather than observed results, have led to the adoption of such a system, the idea being that if the soil is deficient in two or more Uy 40 FERTILITY OF SOILS AS AFFECTED BY MANURES. ingredients the full benefits of any one of them can not be obtained in the absence of a sufficiency of the others. While such reasoning seems logical it is not always supported by facts, as may be seen by a study of Table IV. Here there are only 20 soils out of 190 in which this seems to be noticeably true, while there is a much larger number, viz, 50 soils, in which the efficiency of the ingredients used separately is much more marked than when used in combination, and this in spite of the fact that all three of them produce quite marked results. Indeed, when we calculate the average efficiency of the ingredients for all soils we find that each is shghtly more efficient when used alone than when in combination with one or more other ingredients. As an average of many field tests on various crops and in numerous localities the conclusion is that the efficiency of a fertilizer ingredient is about equally as marked whether used alone or in combination with one or more other ingredients. On the less productive soils the tendency is toward a better effect from the ingredient when in com- bination with other ingredients which are also beneficial. On better soils the tendency is in the other direction.¢ For many individual soils this tendency is as marked under field conditions as it is in the pots. Numerous bulletins of the Alabama agricultural experiment station report the results of fertilizer tests that were conducted at intervals during the years 1889 to 1900. Of such tests 156 were cooperative experiments with cotton and were carried on in 53 of the 67 counties of the State. The fertilizer materials used per acre consisted of nitro- gen derived from 90 pounds of sulphate of ammonia or 96 pounds of nitrate of soda or 200 pounds of cotton-seed meal, potash derived from 150 or 200 pounds of kainit or 64 pounds of muriate of potash, and phosphorus derived from 195 or 200 pounds of dissolved bone- black or 240 pounds of acid phosphate. The three classes of fertilizer were used separately and the three were also combined, each ingre- dient entering into the combination in the same amount as when used alone. The results are reported in pounds of seed cotton per acre over and above that produced when no fertilizer was used, and the data for each of the three fertilizers when used alone and in com- bination are complete for 134 tests. The aggregate increase attrib- uted to the three fertilizers when used separately was 443.2 pounds of seed cotton per acre, as compared with an average of 444.7 pounds increase per acre when the same ingredients were combined. Table X shows the percentage increase in growth attributable to each ingredient when used separately, as compared with the calcu- 4 See tabulated results on corn in ‘ Results in Field Experiments with Various Fertilizers,’’ by Prof. W. O. Atwater, Ph. D., U. S. Dept. Agr., 1883. EFFICIENCY OF SALTS ALONE AND IN COMBINATION. 41 lated increase where it occurs in the several combinations. The results are for each of the four ingredients, lime, nitrate, potash, and phosphate, and are the averages for each of the 25 areas given in Table III. As an illustration of how the results are calculated, take the average results of the five soils from Cherokee County,S.C. Nitrate alone gave an increase of 40 per cent. Nitrate and phosphate pro- duced an increase of 36 per cent, or 40 per cent more than phosphate alone, while nitrate and potash produced 49 per cent, or 42 per cent more than potash alone. The average effect for nitrogen in these two combinations is therefore 41 per cent and is entered in the second column under nitrogen. As NP=36 and NK=49, by addition (2N)PK=85. However, PK =3, so by difference we have 2N =82 or N=41, which is entered in the third column under nitrogen. NPK = 44 and since PK =3, N in the NPK combination produced an increase of 41 per cent. The four values each for potash and phos- phate and the two values for lime are obtained in the same manner. For this area the efficiency of the several ingredients is very uniform, the range of variation for nitrate, potash, and phosphate being only 1 per cent, while for lime the difference between the two observations is7 percent. Since the results in Table X are based upon the average of all soils from each area the variation in the efficiency of the ingre- dients as they occur in the various combinations is not marked. By _making the same calculations for each of the soils, however, many of them show a marked variation in the efficiency of the ingredients as they occur in the several combinations, a difference far too great to be attributable to error of observation, which by actual test has been found not to exceed plus or minus 5 per cent. Where the variation in the efficiency of a fertilizer ingredient, as it occurs alone and in several combinations, exceeds the limit of error in observatious as above stated, such portion of the variation as exceeds that limit must be attributable to its association with the other ingredients. Just as in a solution of several salts the presence of one may increase or decrease the solubility of others, so in the soil the addition of one ingredient may increase or decrease the effectiveness of another. It has already been shown that for quite a number of soils the effect of three ingredients combined is no better than for one of them and that one ingredient may be substituted for another with equally good effect. See Table VI, page 30. On the other hand, there are many soils in which the effect attributable to a combination of three ferti- lizer ingredients is two or three times greater than the aggregate effect of the same ingredients when used separately. See latter portion of Table IV, page 26. The variation in the efficiency of a fertilizer ingredient as used sep- arately and in several combinations bears no consistent relation to the 49 FERTILITY OF SOILS AS AFFECTED BY’ MANURES. efficiency of the ingredients with which it is associated or to the effi- ciency of the combination as a whole. If nitrate of soda produces an increase in growth which equals or exceeds that produced when it is associated with potash and phosphate, as is frequently shown in Table IV, page 26, we would theoretically expect little or no effect from either potash or phosphate when used alone on the same soils. Con- trary to this theory, however, we find that, with an occasional excep- tion, both potash and phosphate are markedly efficient on these soils. On the other hand, if nitrate of soda produces little or no increase as compared with a fair to good increase obtained when it is combined with potash and phosphate, as is frequently shown in the latter por- tion of Table IV, we should expect to obtain fair to,good results from potash or phosphate when used alone on the same soils. But what do we find? Usually little or no effect from. potash, and a negative effect from the phosphate. Table V, page 30, which is a condensation of the results in Table IV, shows up this relationship in a striking man- ner. In that table is given the average percentage increase in growth attributable to each of three ingredients and their combination for groups of soils in which the aggregate effect of the ingredients dif- fers within certain limits from that obtained when they are used in combination. It will be noticed that there is a more or less regular and parallel decline in the efficiency of each of the ingredients when used separately, from a maximum of 37, 49, and 64 per cent for phosphate, potash, and nitrate to a minimum of — 18, —5, and 2 for the same ingredients, respectively. Notwithstanding this marked de- cline in the efficiency of the ingredients when used separately, the efficiency for the three ingredients combined is essentially as marked at the end of the series as at the beginning, the average effect for the first and last groups being 52 and 53 per cent, respectively. The aggregate effect of the three ingredients used separately is 150 and—8 per cent for the same groups. (See Table V, p. 30.) EFFICIENCY OF SALTS ALONE AND IN COMBINATION. 43 TABLE X.— Percentage increase in growth attributable to each fertilizer salt and lime, when used alone und when used in various combinations, as calculated by the difference method. Average, by areas. State. Locality. LSet Who oe eS Sea Newton County... ......5.5 4: Missouriss: 9 2.%2/0. Crawford County............. Win Oe eee wae Westerville area..........-...- | New York.....-..- Tompkins County........-..-- WISCONSIN 2.3.2. =/5 Portare County 2. -2 22-5: 32 2- « New York........- Binghamton area..........-.- Mississippi-.....-..- Montgomery County.....-.--- Pennsylvania.-..... Montgomery County.......---. Indiana Tippecanoe County .....-.--.- Missouri Scotland County. 2s ..s2-.<-- Virginia Hanover County...---...-.00-. OKAGie- sot sec lees San Marcos area......--..---- Arkansas PTAC GOUMUGY.) 2 senses > Mississippi. .....--- Pontotoc County.......-.-.--- | South Carolina. .... Work County ss. ------ even eae WOWISIANa. <5... 5.5%: Caddo Parishes ..- 3: 2-002 22... Wexdgtes seh tl. 7s Rusk County... .. SES eat Tennessee: ......-.. Henderson County...........- Kentucky: ....:-- McCracken County..........-.- South Carolina... .. Cherokee County..........---- PUB DEING Je. 5 coos MpeiCounlbyters > acatsen- elo. LORI dania fe Nos oe Escambia County....-....-.-- | Georrigs: <2-225-.2 WSYCTOSS A168... <. <....02 +2 == Wireiiia 522). os. 22] ouisa (County... s-ss----=+--- North Carolina. ... New Hanover County Increase with | Increase with phosphoric acid. lime. Z Z A Z 4 ~ ee ; A Sail ioem nel 8 (oa G FS - FS “4 a “ | = Z < +| | &% 3 LS 3s Md rn \ : 4 vis Mi | ) oe A sy ay 4 Per Ph Ps Ch. Pet. Piven: Peter: il 6 0 SNE RG) Th alee 4 a) 6 24 4 a4. 3 3 aa 4 4 ane 2 = 9 EB) SON) eee Bile ees 5 = 7: 2 SOR: abo gy ay 11 Sil 4 1 | 0 = 5) 8 4 al ee A 5 | 5 5 64 4 aa Ol ee 10 9h 9 | 3 11 0 7 0 3 =i 4 8 0 t 2 7 14 4 8 0 8 8 26 26 5 =i 2 1 16 6 10 ae 2 6 15 8 | 8 —6 =e 10 15 21 | 3 0 1 alii 13 7 6 =i 2 1 5 21 1 =e =i = 8 18 6 3 4 4 | 0 18 11 = 4 eva Lae FF fee en see 23 28 a) i Ey i! 2 52 35 8 5! 4 a 32 21 2) =e 0 0 38 30 | 30 re} 4 2 40 19 14 7 | 9 | 5 Increase with potash. Increase with nitrogen. i "i | Z eh bd ha | State. ‘Locality. MI 1a Z, 4 +) ] | a Ny} | oy a | a Z Ay 3 pS t M4 I hd |n | fs Ay VA | 1 Bald Uae WN Ny = (tay 0 sill oe | at es y, Bae patieces i=. =) (Zp | |e A Z | gbat wat | P. ct.| P. ct.| P. ct.| PB. ct.| P. ct.| P. ct.| P. ct.| P. ct. nWininitee sees eos. Newton'County..< -.-- 22-5222... Heel 74 10}—1 14 on —6 MissOUnIae- 2002 2: | Crawford County........-.... 6 il 1|/—7 4 23 61s ORI Oe ee nee Westerville area.........-.-2.- 5 54, —1)}— 9 4 103; 10 2 New Mork. .5%..0%. Tompkins, Countiy<-.-- 22.252. 4 23! 6 9 21 174; 18 22 Wisconsin. ........ Rortage County. <6... 8n a2. 3 3 63 8 12 93 104 12 New wonle.- =. 2. 8) Binghamton area.........-.... 7 5 5 0 6 8 12 7 IMISSISSIPPl ies cemeee Montgomery County........-- 3 53! 5 5 8 124; 13 14 Pennsylvania......|...... Gp eee ee ee ee 0 14| 14 by 4 63 oul po—e MAGIA asso one Tippecanoe County.......-.... 8 4 | 0; —6 14 173) 21 15 Missouric. See... Scotland County.< ... 2222.25. 24 165) 18) 14 9 13 6 Wireiniase tesco oe Hanover County; ..-.-.-...--- eres 9 10}, 19 16 16 16 25 ANG CCI aera ae ati San Mareosiarea. 2.2 2.0 5... 12 1}! 6 6 23 11 14 14 ARICAMISASS ot ceee te Prairie, County. 4.5. 65.5 2. 10 3 6 3 12 4 9 6 Mississippi. ........ BRontotoc! County. i. 2. 5.4242. 9! —13 6 10 28 144! 20 23 South Carolina... .. MOMRKCOUMUV Ee a1. cases tease 0 0 13 30 24 21 12 28 Pouisiant;.. 225.452 CiddoruPamish: - ese. 30a ce = 13 9 9|— 2 24 22h 25 14 eecriisi> Sp, wee ee RMS COUNTY G:422 2545s ae 11 6 11 10 32 24 26 25 Tennessee.........- Henderson County...-.....-.- 1 6| 16 20 36 29 28 31 Kentucky.........- McCracken County. ..-.......-- 3 7 13 i 39 333} 30 34 South Carolina. .... Cherokee County...-.....--.-- if 8 8 8 40 41 41 41 ALAIN Sm eat ee Count ys. - 2-42.47 822 6 53 | 6 14 35 323; 32 39 (Rlowmidap ere ates Escambia County..........--- 19 Ta 12 6 20 10 15 10 Georeiae $3.0. 2en: WiRVCrOss areae ac hs. fen ke 15 14 16 17 45 42 42 43 WAby jbo ie emer ee Homsa, County- + s-.-- sess 6 - 26 9 24 22 44 26 40 38 North Carolina ....| New Hanover County.......-. 21 174) 22 19 65 583} 60 57 | 44 FERTILITY OF SOILS AS AFFECTED BY MANURES. RELATION OF FERTILIZER REQUIREMENTS TO CHARACTER OF SOILS. That soils vary greatly in their crop-producing capacity and in the degree to which they respond to fertilizers under field conditions has long been known as a result of experience and also as a result of care- fully recorded field tests. This marked difference in the degree to which various soils respond to fertilizer treatments is the most strik- Pe K N iL a Se a | KN PKN PKNLM CVL 150 140 130 120 110 100 INCREASE IN GROWTH PERIGEE NTs PORTSMOUTH FINE SAND *xx=xxxx xx NORFOLK FINE SANOY LOAM ——————_+—_ WK) Te MONS SO) NORFOLK FINE SANO---——-—-~— NORFOLK SANDY LOAM —-—-—-—-— Fig. 1.—Percentage increase in growth of plants attributable to various fertilizer treatments of five principal soil types of the Waycross area, Georgia. ing feature manifested in the results recorded in the preceding tables. It has also been long contended that there is a relation between the origin and the character of the soil and the character of the fertilizer that would be required to produce good results. It is doubtful, how- ever, if such a claim can be substantiated by observed facts over a large territory. It certainly is not borne out by the results obtained on the 220 soils here reported, except in case of the muck soils which uniformly respond to potash. In fact, the character of the fertilizer RELATION OF FERTILIZER REQUIREMENT TO SOILS. 45 required for the same types or series of soils, as found in widely sep- arated areas or localities, and as shown by these results, varies more than that required for different types and series when they occur in the same area or locality. In illustration of this point, five soils from Waycross, Ga., tested in triplicate, show a marked uniformity in the character of their manurial requirements, regardless of the fact that they represent five types and two soil series. The same soils in Escambia County, Fla., show manurial requirements of a very differ- ent character. (See Table III, p. 15, and figs. 1 and 2.) In the Waycross area nitrate of soda is much more effective than sulphate of potash, and while lime is decidedly beneficial it is not P K N L PK PN KN PKN PKNLM CYL PERCENT INCREASE IN GROWTH ee ta Oh ee Os 0" '676:.0:- 0-6-6 —- © W [eo Wael 2 Ee ees © | WAYIGROSS AREA: GEOR GIA =e ESCAME/IA COUNTY, FLORIOA=—-7---=-- Fic. 2.—Percentage increase in growth of plants, attributable to various fertilizer treatments for soil of the Waycross area, Georgia, and Escambia County, Fla. equal to nitrate of soda. In Escambia County sulphate of potash is nearly as efficient as nitrate of soda, and lime is about twice as effect- ive as the three fertilizer ingredients combined. These differences are based on average results for the two areas, and notwithstanding that the soils are of the same type, series, and formation, they show as marked differences in the character of fertilizer required as will be found between any of the areas, even when the soil types are entirely different. A Cecil sandy loam from Raleigh, N. C., was markedly improved by each of the three fertilizer salts, and also by lime, the increased growth of plants obtained when all of these ingredients were com- 46 FERTILITY OF SOILS AS AFFECTED BY MANURES. bined being 103 per cent. The same soil type from Lee County, Ala., as a result of tests on two samples, gave no response to either potash or phosphate, but produced a fair increase in growth as a result of nitrate of soda and also for lime, the maximum increase being 40 per cent where all three fertilizer salts were used in conjunction with lime. (See Table III, p. 15.) RELATIVE EFFICIENCY OF FERTILIZERS BY LOCALITY. In comparing the relative efficiency of the fertilizer ingredients, it is found that in the vast majority of instances nitrate of soda ranks first and lime second. This is especially true in the southern areas, where fertilizers are most extensively used. In the Central and North- ern States, where the efficiency is less marked, there are quite a num- ber of instances in which potash or phosphate outranks the lime or nitrate, although on an average the nitrate holds first rank and lime second. Sulphate of potash ranks next to lime, while acid phosphate having the lowest value, has in numerous instances shown a slightly negative effect. With soils from the States of Wisconsin, Jowa, Missouri, Illinois, Indiana, Ohio, New York, and Pennsylvania the response to commer- cial fertilizers has been moderate, slight, or in many instances almost imperceptible. On those soils, also, organic manures, in the form of cowpea vines or stable manure, have been very much more effective than the chemical ones, the mean relative increase attributable to manure being nearly three times that for a complete fertilizer with lime, i. e., barnyard manure gave an average increase of 38 per cent, while the complete fertilizer with lime gave an average increase of only 13\;per cent. (See Table XI, from which the averages were com- puted.) In these States lime alone seldom showed a marked effect. While the tests for these States are insufficient in number to represent all soil types and conditions, yet the results are in conformity with the general practices of the vast majority of farmers of these sections, who as a rule do not purchase commercial fertilizers for use in the growing of general farm crops, but who for the most part recognize the high value of barnyard manure and generally utilize all that is pro- duced on the farm. In the Atlantic and Gulf Coast States, including Kentucky, Tennes- see, and Arkansas, for which a larger number of observations have been made and where most of the important soil types have been tested, the soils, with few exceptions, respond in a marked degree to commercial fertilizers and lime, and while cowpea vines and stable manure are on an average somewhat superior to commercial fertilizers, the differences between the relative value of these materials is small, being 54.7 and 58.6 per cent increase in growth for commercial fertil- izers and manure, respectively, as compared with 13 and 388 per cent for the same materials in the former group of States. (See Table XI, COMPARATIVE FERTILITY OF SOILS. 47 from which these averages were computed.) In other words, the commercial fertilizers and lime are more than four times as effective on soils of the Altantic and Gulf Coast States as they are on those of the North Central States, including New York and: Pennsylvania, while manure, when compared on the same soils, is only a half better on the soils from the former States. In this respect the results are again in conformity with the practices in the Atlantic and Gulf Coast States, where the bulk of the commercial fertilizers are used. COMPARATIVE FERTILITY OF SOILS. Another point brought out in the tables is the relative fertility or crop-ylelding capacity of the untreated soils. Under the prevailing - condition of crops and climate in the field, marked differences in this respect exist, some of the better soils showing a crop-producing capacity four or five times as great as that of the poorer ones. In these tests, where all soils are put into excellent physical condition and where moisture and temperature are always favorable, these dif- ferences are less marked but nevertheless exist to a considerable degree, as may be seen by comparing the actual weight of plants grown on-the untreated soils. The average growth of plants on untreated soils from the North-Central States, including New York and Pennsylvania, is 28 per cent greater than the average of those from the Atlantic and Gulf Coast States. This difference in the initial crop-producing capacity of the soils from the two sections as indicated in the pots is sufficient to make the actual increase in growth from the stable manure nearly as great from one section as from the other. TasiEe XI.—Jncrease in growth attributable to complete fertilizer with lime and manure; and proportionate cost of fertilizer to value of crops as obtained from Census, 1900. Cost of Weight | Increase ii ai of plants,| from fer- nerease | fertilizer Ptate. Locality. untreat-| tilizer AB 8 to value ed soil. | and lime. *| of crop. m Grams. | Per cent.) Per cent.| ‘Per cent. IMASSOUTIC.s = 2222-5 Crawtord, County sc. 2.52 2oseecs ses tsc ce 9.6 0 | 19 0.23 lonel phat: eee see eee INGwOnuGOunby << amc: eiese ase ae pele vices 8.8 4 56 03 NO 2a oes Sos 4 Wiesterville aren. 5.0.25 sco see ee 7.8 8 28 62 ING We ORK = sc 'siee 22 Bin en amibom Sak. coe =< kee eee ae = 9.3 10 27 ieshe Wisconsin... -...:.- Rortars County... 3) 2-5-2 52.2cceees ss] 9.0 13 41 32 1a Itenut: aoe eee Pippecanoe Countys--~ 5.552. seca =e 6.8 16 37 39 Mississippi-...--.-- Monteomery County = 5. .2-- = Wom = eter — = aes od Ind, Tippeconoe Co. — Tenn, Henderson Co SecenaEnEEEEaE SC, York Co meee soe Ark, Prairie Co a rin La, Caddo Parish cre Mo, Scotland Co. al cinema catenin a —— iconenaseeaemtenmn ma Saerermentnnite cena ron tire Tex , Son Marcos Area Ay. Me Crocken Co S.C. Cherokee Co. Alo. Lee Co. Tex, Rusk Co. Miss, Pontotoc Co, Ga. Woycross Area Fla, Escambia Ceo. Va. Louisa Co N C.. New Hanover Co P mam A sss VW oo L coz Fig. 3.—Percentage gain in plant growth attributable to each of the salts P, K, N, and L when used alone. however, besides the comparative response to fertilizers which are concerned in their profitable use. Low value of land, long distance from markets and seat of supplies, including fertilizer, would all tend 50 FERTILITY OF SOILS AS AFFECTED BY MANURES. toward the unprofitable use of fertilizers. In Rusk County, Tex., and Caddo Parish, La., a few farmers have begun the use of commercial fertilizers and find them profitable. AVERAGE EFFICIENCY OF FERTILIZER SALTS, BY LOCALITY. Figure 3 shows graphically the percentage increase in growth attributable to each of the fertilizer salts and lime when used sepa- rately, and is based on the average for all soils of each area as given in Table X on page 43. The areas are arranged in an ascending series according to the aggregate increase from all ingredients, which ranges from a minimum of only 9 per cent for the Westerville area, Ohio, to a “maximum of 140 per cent for New Hanover County, N.C. The range in the efficiency of the individual salts is also marked, the increase attributable to nitrate of soda varying from 4 per cent in several of the areas in the upper part of the diagram to 65 per cent in New Han- over County, N. C., and that for lime varying from a slightly negative result for Newton County, Ind., to an increase of 52 per cent for Escambia County, Fla., with somewhat lesser variations for potash and phosphorus. In the majority of the areas the efficiency of the three fertilizer ingredients and lime assume the same order. In 16 of the 25 areas, nitrate of soda was the dominant salt, while lime was dominant in 3 and potash in 3 of the areas. In 14 areas out of 25 lime ranks second in efficiency. In the States of Indiana, Missouri, Pennsylvania, and Virginia potash seems to have been relatively more effective than elsewhere. In the Arkansas and Florida areas lime is largely responsible for their position in the series, and in both of them nitrate of soda holds a relatively low rank. TaBLeE XII.—Average percentage increase in growth for all fertilizers and combinations, by soil series. Weight Increase in growth attributable to— N of plants, | sae Soil series. oN eatantee | =) 2 hyn soils. | treated | ; ea eae Wea We 9) Si | soil. | a | M | 4 | | | MM | A | Der hele at aa | ae a ale | Grams. | P.ct. P.ct.|P.ct.|P.ct.| Pct. Ptehs| Pe Gb. WP Ch E~ch.WP- Crs Es. Ce. Rortsmouthy sso. .e = sane. 7 5.2} 10] 19) 43] 25] 53 | 63 | 68 | 43) 96); 100) 117 Norfolk see seen fanaa 45 6.3 6| 16) 35| 16; 34] 47) 45| 28) 64) 76 83 Cecile are ROY aa eae 12 6.0} 14} 12 )- 36) 17| 32 | 46] 52) 26) 69) 62) 65 Orangeburg: +20... .2-<2625 - 18 8.0 2 | 4) 20; 8] 23] 23); 31 THR SHO oe ce Miaamilie toe Santos nee cers 8 eG) | aahall = =e) ie ati oc! | 15 18} 19 | 4| 19| 44 17 Marshall 22) 1 Pe Lk peeeleane 5 TO. Si, PAS LG HS Os ON) 20) 2 | a Sed 8 Muck 252 shades sercene | 4 | 6.0 | 21 | §2 | 27 | 56 | 33) 49 | 60 | 30] 60} 46) 39 | | | | | | | | . EFFICIENCY OF FERTILIZERS, BY SOIL SERIES. 51 Taste XIII.—Percentage increase in growth attributable to each fertilizer salt and to lime when used alone, as compared with its calculated effect when used in various com- binations. Averages for each of six serves and Muck. 1 P K. N | | Z| Al | al | | bel ! | eal al esi aaa fas Z catia | a Soil series. G | By) g : bay ee a) | ‘a anit Ay 7 | + _ J q sf ar rs) x Z real tay | 4 ei) b) 8 (8 aR | Ba) (Bel |e 8) leis 7 | re | ; | + | a Z ae. a 4 Be dhe + Z ue BeM alien 4 ieee |e | mall ay | 4 4 > |i i x ~ [ol | il vi | 4 a ou S| | A ao | fH 1Cl pe Sabet ee Me Tha Zz “ Lasts eoslmaea eects eee eee Portsmouth../ 43} 28 | 10 8 7H S| 19) 17a) ATR 18] ) 48 433, 453| 48 Norfolk ...... Naraei| at Cy aay a 2 | te Ta AMA aT SAB oll BOR] BBR tS BD Rolly eee ee Pipl) ilrale ave! Aertel er. 12 6s} 6-154, 20 | 36.) 26| 308 35 Orangeburg 11 Gi a2 3a} 4 8 4| 43 2 Sh 20 a oO 19 peers ree ee ee ghee eg | og beg gh at aah Cagh fal a5 Marshall ..... fe ee | 15 ae: Gy ae ee 8 Se 8) 8/16 SH oe 6 Muck. ........ | 30 O{ 21} 0} 2) 11) 62} 283 36) 27) 2) —4 18 4 | ‘COMPARATIVE EFFICIENCY OF FERTILIZERS, BY SOIL SERIES. Table XII gives the average percentage increase in growth attribu- - table to each fertilizer salt and combination of salts, by soil series, using only those in which the treatments were uniform and complete. No series were used where less than 5 samples were available, except in the case of Muck, in which only 4 samples were used. Table XIII gives the percentage increase in growth attributable to each of the three fertilizer ingredients and lime, as compared with their effect when used in the combinations, the efficiency in the com- binations being calculated by the difference method previously explained. These two tables show that the relative efficiency of the three salts and lime is essentially the same for all the soil series except the Muck. The range of efficiency of the complete fertilizer with lime is very marked, varying from a maximum of 96 per cent for the Portsmouth series to only 8 per cent for the Marshall series. It is noticeable that barnyard manure is relatively much more efficient _ for the Marshall and Miami series than for the others. Figure 4 shows graphically the average relative percentage effect- iveness of the three fertilizer ingredients and lime by series when used separately, as given in Table XIII. The variation in the aggregate effectiveness of the three salts and lime for the several series is nearly as great as when the soils were grouped by localities. It is evident, however, that the serial grouping is, to some extent, a locality group- ing also, the Marshall and Miami series, which are the least responsive to the commercial fertilizers, occurring only in those States in which fertilizers are but little used, while the Portsmouth and Norfolk series are confined wholly to the Atlantic seaboard, where fertilizers are most extensively used. While there is a marked difference in the aggregate effectiveness of the three salts and lime on different series, 52 FERTILITY OF SOILS AS AFFECTED BY MANURES. ranging from a minimum of 29 per cent for the Miami series to a maximum of 115 per cent for the Portsmouth series, broadly speaking the relation between the value of the individual ingredients in the several series is remarkably uniform, even more so than occurs when the soils are considered by areas. The Muck, represented by only 4 samples, is exceptional, and shows the characteristic importance of potash, that ingredient being on the average about as effective as the total of lime, nitrogen, and phosphate. This fact is alsoin conformity with our field knowledge of Muck and Peat, which are greatly bene- fited by applications of potash salts. ban ey Portsmouth Cees! Norfolk Orange bur g Marshal/ safeties Moms semioisin Muck sors Q 40 Pom A ws NV oo lL cz Fia. 4.—Relative efficiency of fertilizer ingredients by soil series, when the ingredients are used alone. TasLeE XIV.—Average percentage increase in growth attributable to each fertilizer salt and lime for soils of the Norfolk, Portsmouth, Orangeburg, and Cecil series when classified by texture. Ts, *) ie K. N. | zZ Z | | ‘| : Ei ea icra 0 3 3 ler Pini =a | Ss eS Soil class. | & | a zt A al < Zz vy : hes | se tia] | 4 _ | tie sy | a . tie a ey Selo l eS) Em T Ble) (eT Tela) [Zio lh ES g = “= Ay B28) = el [gl S/S teh lal (el Siay fel je am VT = feet me a O71 Ye Se ba | PS a i us % tea es os ies | Coarse sand........... Di ae eco4 90) |= 40 he Saale 7 eee S 8| 19) 34] 26 | 24] 35 Sanda0-- 6s a oko 12 | 43 | 33 Paes 2 |-1 | 16 | 10 16 | 13 | 42| 325] 35] 32 Fine sindtt.s 1s 17 | 33.) 21 5 | 2.5 3] 3|15|135| ‘15 | 15 | 37 | 35 36 | 36 Sandy loam........... C7 joerg. ee Acca Osh dal el aia | At) feral ora 27 | a Fine sandy loam..-...| 25 | 22 | 13 pels} 5 | 0) 13) 85 | 10 | 6 | 27 | 23.5 26), 222 | | | ! EFFICIENCY OF FERTILIZER AND SOIL TEXTURE. 53 EFFICIENCY OF FERTILIZER AS RELATED TO SOIL TEXTURE. Table XIV gives the response to each of the three salts and lime when used alone and when in the various combinations for soils of the Norfolk, Portsmouth, Cecil, and Orangeburg series when grouped by the variation in texture. This grouping of the soil fails to bring out any variations in the character of the fertilizer required for the differ- ent textures, but it does show in general that the finer the texture of the soil, the less marked is the effect of the various fertilizer salts or the aggregate effect of them all. NATURAL FERTILITY AS RELATED TO RESPONSIVENESS TO FERTILIZERS. Another comparison brought out in the general tables is the rela- tion between the crop-producing capacity of the untreated soils in the pots and their response to fertilizers. In general, the lower the crop capacity, the greater the response to fertilizers or manure, and vice versa. Table XV shows the average effectiveness of a complete fertilizer and lime on soils arranged in groups according to the weight of plants grown when untreated, and it is shown that there is a gradual and consistent decrease in the effect of the treatment, as the untreated soils are capable of producing larger plants. TaBLe XV.—Showing decreasing effect of fertilizers with increasing productiveness in untreated samples. areata Average Jeight o gain at- ae plants on tributable - |untreated soil.| to fertil- izers. ‘ Grams. Per cent. 23 3to 49 87.9 35 5to 5.9 68.3 25 6to 6.9 41.8 46 | 7to 7.9 40.1 33 8to 8.9 23.9 19 9to 9.9 26.8 9 10 to 10.9 13.0 9 11 to 11.9 8.4 it 12 and over 3.9 It is significant that the sandy soils of the Norfolk and Portsmouth series, collected from the Southern States where wheat is seldom grown, have produced on an average larger and more thrifty wheat plants by the application of a complete fertilizer and lime, than have been produced by the same or other treatments on soils of the Mar- shall or Miami series from Wisconsin, Ohio, Indiana, and New York, where wheat does well. This fact is in harmony with the view now gaining prevalence, that the variation in the character and composi- tion of the mineral matter of soils is of minor importance as regards crop adaptation and yielding capacity, except so far as character of 54 FERTILITY OF SOILS AS AFFECTED BY MANURES. material influences condition of the soil in its relation to soil moisture and permeability to air, water, and the roots of plants. In other words, crop adaptation and crop-producing power depend more upon climatic environment and physical condition of the soil than upon soil type or the geological formation from which it is derived. The best wheat soils or those best suited to peaches or to truck crops are not so solely by virtue of the character of the mineral matter of which they are composed, but because there are present climatic and soil conditions that enable those classes of plants to attain perfection. The poorest soils, by proper ntanipulation and the addition of suit- able manure or fertilizer, can be made to produce as large yields in the pots as can be procured by the same or other treatments on the best soils that occur, and yet such applications have but slightly altered the composition of the soil. Such. improvement does not involve any considerable length of time, but may be brought about in a few days or at most a few weeks. This does not mean that it would be either feasible or practical to attempt such a radical change under field conditions in so short a time. The expense involved would not justify the procedure, neither would the soil be able to maintain such an ideal condition under the adverse climatic condi- tions which might prevail or against the poor systems of farming in vogue. The improvement of soil conditions in the field becomes a purely business proposition in which the expense involved must not exceed probable returns. Important in this connection is the assembling and association of all those factors that will work together for the good of the soil, such as the selection of suitable crops, the use of a proper rotation, the adoption of catch and winter cover crops, and cultivation of such character that erosion will be reduced to a minimum and the rainfall absorbed and retained in ample supply. By such procedure the con- dition of a soil will in time become greatly modified and its fertility improved. So-called soil robbery is, after all, more properly soil mutilation, brought about by the carelessness of man. FERTILIZERS AND ECONOMY OF WATER IN PLANT GROWTH. It has been stated that no attempt will be made to explain how fertilizers effect an increase in plant growth, yet there is one point which has been established as a result of this investigation of which mention should be made. It is the relation between growth, as effected by fertilizers, and water transpired by the plants or used in the process of their growth. In all of the tests a careful record has been kept of the water transpired for each of the 13,000 or more pots. As a result of such observations, it has been found that as fertilizers increase plant growth, there is a marked diminution in the water transpired per unit of growth; or, putting it im the reverse order, FERTILIZERS AND WATER IN PLANT GROWTH. 55 there is a marked increase in growth for a unit of water used, and such increase becomes greater as the fertilizers are more effective. As a result of computations for twenty soils taken at random, it was found that the percentage increase in growth for a unit of water used’ equaled, approximately, one-half of the total increase in growth resulting from the fertilizer treatments. Figure 5 gives the average results for 20 soils and shows not only the gain in growth following the fertilizer treatments, but also shows the associated increase in growth per unit of water transpired. Relative | Relative growth \transpira PEP unet \tion per Transpiration Green weight Fig. 5.—Percentage increase in growth of plants attributable to fertilizer and accompanying increase per unit of water transpired. Average of 20 soils. Excepting lime, in the presence of which transpiration remains nearly normal, the different fertilizer constituents show no marked variation in respect to this phenomenon. Lime frequently produces an increase in growth and yet the plants maintain practically the same rate of transpiration per unit of growth as that observed for the untreated soil. In a few miscellaneous tests, where the different forms of potash were tried, it was found that kainit and muriate of potash decreased the rate of transpiration per unit of growth, as compared with sul- phate of potash. 56 FERTILITY OF SOILS AS AFFECTED BY MANURES. While these observations have no economic significance in the pots where moisture content is always ample, they may be of con- siderable importance in relation to the use of fertilizers in the field and explain, in part, the benefits derived therefrom. It frequently happens, owing to scanty rainfall, or a low water-holding capacity of the soil, that the available water supply is the limiting factor in crop yields. Where such conditions exist, and they occur frequently in all parts of the country, the presence of a fertilizer which would enable the crop to economize in its water consumption would be of considerable importance and might, as pointed out above, enable the crop to make a marked increase in growth despite the limited water supply. i SUMMARY. The paraffin-pot method of testing the manurial requirements of soils, used in these investigations, while not designed to supersede field tests, is admirably adapted to an investigation of this kind and is very useful as a method of indicating what fertilizers should be used in the field. The results obtained in the pots with the various ingredients are relatively the same as those obtained in the field, but may differ in degree. This is true of all ingredients commonly used except the phosphates, which give a relatively lower effect in the pots than the others. The absolute effect is usually greater in the field than in the pots and phosphates may frequently be economically used where their benefits are not indicated by the pots. The results obtained in the pots generally agree with the fertilizer practices in the various sections from which the soils were secured. In the North Central States, where but little commercial fertilizer is used, and where the main dependence is placed upon barnyard manure, the pot tests show manure to be three times as efficient as the fertilizer. Inthe Atlantic seaboard and Gulf Coast States, where but little manure is available, and where the main dependence is upon com- mercial fertilizers, the manure as tested in the pots has been only slightly superior to the fertilizers. Muck, quite generally recognized as in need of potash in the field, has shown that ingredient to be nearly as efficient as lime, nitrate, and phosphate combined, as deter- mined by the pot tests. Transpiration, while a good indicator of the relative growth of plants when under like conditions, usually gives a range of lesser magnitude than the variation by green weights. The green weight of plants grown for about twenty-five days in the pots occasionally equals or exceeds 1 per cent of the weight of the soil in which they grew. Such plants contain about 85 per cent of water and transpire approximately 100 grams of water for each gram of SUMMARY. Ae green matter produced. The dry matter of such plants is richer in mineral constituents and nitrogen than that of the same plants if matured. The draft on the water and mineral constituents of the soil under these conditions is greater than that occasioned by the removal of a large and matured crop under field conditions. As an average of all tests, the organic manures have outranked the _ chemical ones. Barnyard manure and cowpea vines with lime tie for first rank. The three chemical salts with lime rank third and the same salts without lime rank fourth. Of the combinations of chemical salts the order of efficiency is as follows: The three salts with lime, first; three salts alone, second; potash and nitrate, third; phosphate and nitrate, fourth, and phos- phate and potash, fifth. Of the salts used individually the order is nitrate, lime, potash, and phosphate; nitrate being the most efficient and phosphate the least efficient. As an average result of all tests, nitrate of soda has produced a marked increase in growth which has not been further increased by the addition of acid phosphate. Potash has produced a moderate increase in growth and when supplemented by nitrate the effect has been slightly less than the aggregate of these two ingredients when used separately. The efficiency of the combination of nitrate and potash has not been appreciably improved by the addition of phos- phate. Lime alone has generally produced a marked increase in growth and has usually increased the efficiency of a complete fertilizer. There is but little evidence that the benefits derived from lime are due to beneficial action on nitrification. Soils vary greatly in crop-producing capacity as found under field conditions. Part of such variation is due to physical condition and consequent relation to water, and is largely overcome in the pots. After these conditions are largely equalized in the pots marked differ- ences in crop-yielding capacity still exist to such an extent that good soils may produce four or five times as large a growth as that produced on very poor soils under the same conditions. By the application of suitable manures or fertilizers these differences are overcome, and in the pots the poorest soils when treated with suitable substances become as productive as the best ones. Soils vary greatly in the degree to which they respond to commer- cial fertilizers, lime, manure, and green manure. In general, the degree of response varies inversely as the crop-yielding capacity and ranges from zero to several hundred per cent. The soils of the At- lantic and Gulf Coast States are much more responsive than those of the Central and Northern States. 58 FERTILITY OF SOILS AS AFFECTED BY MANURES. In 60 per cent of the soils here tested, each fertilizer salt appears to have a special function, so far as it influences the growth of plants, which is not materially modified by the addition or withholding of the other salts. In 29 per cent of the soils the functions of the several salts, as affecting the growth of plants, are more or less inter- changeable, there being quite a number of instances when each salt used alone gave as large an increase in growth as was secured by com- bining three of them. In 11 per cent of the soils each salt not only has a distinct function, but it is dependent upon the presence of others for its fullest effect as shown by a much greater efficiency when used in combination than when used alone. There is no ap- parent relation either by soil type or by locality to this grouping of the soils. The variation in the efficiency of a fertilizer salt as used alone and in combination with various other salts bears no consistent relation to the efficiency of the associated salts or to the efficiency of the combination as a whole. In the pots, as an average of all tests, the aggregate efficiency of the several salts when used separately is slightly greater than when the same salts are used in combination. Under field conditions, as an average of many tests, the aggregate of individuals is the same as when used in combination. Individual soils show wide variation in respect to this point. The character of fertilizer indicated for a specific soil type as it occurs in widely separated localities usually varies more than that for very different types when in the same locality and subjected to similar environment. The character of fertilizer indicated for various soil series is essen- tially the same, although the response to such a fertilizer varies greatly. In general, the finer the texture of soils the less responsive are they to fertilizers, although the character of fertilizer indicated remains the same. With few exceptions the character of fertilizer required for soils depends more upon local conditions and practices than it does upon the type of soil or the geological formation to which it belongs. The Muck soils are an exception and show a universal response to potash salts. The condition of the soil is of greater importance than its chemical composition. Without materially changing the composition of the soil, poor soils by proper manipulation and suitable applications can be made to produce as large crops in the pots as can be grown on the best soils by the same or other treatments. SUMMARY. 59 Fertilizers when effective aid plants to economize in the use of water. In conclusion it may be said that the crop-yielding capacity of soils is increased by improving their physical condition and by sup- plying manures or fertilizers. Frequently both are necessary, and the latter may assist the former. By the employment of both meth- ods poor soils may become as productive as the best ones. There is but little to indicate any relation between the formation and char acter of the soil and character of fertilizer to which it will respond. Usually soils of a limited locality, where climatic condition and farm practices are uniform, show but little difference in the character of fertilizer required, although the degree of response may vary greatly for different fields, making their use profitable in some instances and unprofitable in others. Except in the most general way, the ferti- lizer requirement of soils becomes a problem for each farm or for each class of farms under like conditions of soil, climate, and system of cropping and fertilization. The indications are that fertilizers containing relatively more potash and nitrogen than do those now in general use would prove more effective. This conclusion (to which exception might be taken by some because of the fact that phosphates are known to be economically used on some soils that fail to respond to that salt in the pots) is not based alone on the result of this investigation, but upon the tendency of the more pro- gressive planters to use a higher grade fertilizer, i. e., one containing relatively more nitrogen and potash than that used in the past. Lime has proved quite generally beneficial, being on an average more effective than both potash and phosphate. O LIBRARY OF CONGRESS 0002755414 : a Kd Hf af ot A is 4 a4 au Pi e