INVESTIGATIONS IN SOIL MANAGEMENT BEING THREE OF SIX PAPERS ON THE Influence of Soil Management UPON THE Water-Soluble Salts in Soils AND THE Yield of Crops BY F. H. KING Amounts of Plant Food Readily Recoverable from Field Soils by Distilled Water. Relations of Crop Yields to Amounts of Water-Soluble Plant-Food Materials Recovered from Soils. "D" Absorption of Water-So'.uble Salts by Different Soil Types. "E" Influence of Farm Yard Manure upon the Water-Soluble Salts of Soils. "F" Movement of Water-Soluble Saits in Soils. "G" Relations of Differences of Yield on Eight Soil Types to Difference of Climato- logical Environment. The six papers constitute the Report of the Chief of the Division of Soil Management, for 1902 and 1903, but the three here printed have been refused Departmental publication by the Chief of the Bureau of Soils. MADISON, WIS.: Published by the author, with permission of the Secretary of Agriculture. 1904. •': '•'.: PREFACE. The three papers here presented form but portions of a single investigation systematically planned to throw new light upon important problems in soil management, and the full signifi- cance of them,, as parts of a whole, can only be seen by consid- ering them in connection with the three papers from which they have been severed in that they were not allowed to appear as Departmental publications. It is believed that the subjects of the six papers, and the data presented in them, merit adequate discussion but this was with- held to avoid, as far as possible, antagonizing the published views of the Bureau and the three papers are presented here as they were originally submitted. In addition to these statements it is due the writer and his associates in this investigation to say that the data presented have lost very much of fullness and value through changes in plan, made in. the midst of the investigation but over which we had no control. F. H. KIXG. Madison, Wis., Aug. 18, 1901. LETTERS OF SUMITTAL WASIIIXGTOX, D. C., June 20, 1904. SIR: In order to test, in an adequate manner, the field methods which had been, devised for the determination of sol- uble salts in soils, and in order to be able to study the same soil under conditions where the yields were certain to be meas- urably different, it was decided to develop systematic differ- ences in each of the eight soils, chosen for the investigations of 1903, by the application of definite quantities of manure in multiple amounts upon different portions of the areas where crops were to be grown. Manure was chosen to develop these differences because it is acknowledged to be the best general fertilizer known, and be- cause it is a universal by-product of the farm whose most eco- nomical use demands much fuller knowledge than is yet avail- able. The quantities of manure chosen, were small — 5, 10, and 15 tons per acre — in order better to test the sensitiveness and reliability of the methods, by not developing too large differ- ences ini the soluble salt content of the soil, and in order to gain more definite knowledge of the relative and absolute efficiencies of manure when applied broadcast to soil in different amounts. The results herewith submitted are those which relate to the influence of different amounts of manure upon the water-soluble salts1 which may be recovered from: soils with distilled water; and those which show the absolute and relative efficiencies, the first season, of different amounts of manure when applied broadcast to soils and well plowed under. The fitting1 of the soils, application of manure, planting and general care of the crops, were under the immediate charge of W. O. Palmier, J. W. Xelson, J. O. Belz and A. H, Snyder; 646J279 IV LETTERS OF SUBMITTAL. and the chemical determinations were made by them and by ~F. R. Pember and J. C. Hogenson. F. H. KING, Chief of the Division of Soil Management. PROF. MILTON WHITNEY, Chief of the Bureau of Soil*. WASHINGTON, D. C., June 27, 1904. SIR: In our earlier investigations, relating to the influence of tillage, and especially to that of deep and shallow cultivation, upon the yields of crops, there were relations observed which made it appear that such tillage exerts an influence upon, yield other than that due simply to the effect it may have upon soil moisture. Moreover, in investigating the causes of the rela- tively low fertility of so many of the Southern soils, it was felt, on account of the excessive surface washing which is char- acteristic of the region in question, that if notable amounts of readily water-soluble plant food materials are brought by capil- larity to the surface during drying times, the carrying of these away in the surface drainage may he one of the causes of their low productive capacity. It appeared very important, therefore, from the practical standpoint, to investigate the movements of plant food mater- ials, as influenced by capillarity, in these Southern! soils. The paper which is submitted herewith gives the results of investi- gations; relating to this subject, carried on during the seasons of 1902 and 1903. This paper, like the other four which have been, submitted, is the result of co-operative and concerted effort on the part of most of the men of this Division and credit is due J. O. Belz, W. C. Palmer, A. H. Snyder, J. W. Xelson, Dr. Oswald Schreiner, J. C. Hogenson, F. D. Stevens, H. L. Belden, A. T. Strahorn, F. R. Pember, Jay F. Warner, F. C. Schroeder and W. S. Lyman. F. BO. KING, Chief of the Division of Soil Management. PROF. MILTON WHITNEY. Chief of the Bureau of Soils. II i I KKS • >! sriSMlTTAI.. WASHINGTON, ]>. C., June 20, 1004. SIB: In conducing invoii^ninns along the lines of those reported in the bulletins 011 "The Amounts of Plant Food Re- coverable from Field Soils with Distilled \V:it<-r," and on the "Relation of Crop Yields to the Amounts of Water-Soluble Plant Food Materials Recovered from Soils/' the power of soils to absorb plant food materials from, solutions, when brought in contact with them, could not be omitted from con- sideration ; neither could the re-solution of such absorbed mater- ials be ignored. Moreover, since it has been long (recognized that the influence of both good soil management and bad soil management is cumulative in its effects upon, soils to a marked degree, while the reasons for these tendencies are not suffi.- ciently understood, it is of fundamental importance to ascertain whether the productive capacities of soils are, in. any essential way, related to their absorptive and retentive powers over the essential plant food materials ; and whether good soil manage- ment may not result in clothing the soil skeleton with heavier and heavier accumulations of these miaterials while the reverse tendency may not be associated with poor soil management. The absorption studies submitted herewith, were made chiefly upon the 8 soil types which have contributed a large share of the data of the two former investigations whose results have been submitted, and they have, therefore, a value they would not otherwise possess. We have also incorporated so much of the results of investigations along these lines, made between. 1845 and 1865, as will serve to indicate the nature of the results and the importance attached to this subject at that time. The determinations for this work have been made chiefly by Mr. J. O. Belz, A. H. Snyder, J. W. kelson, WT. C. Palmer, F. R. Pember, and J. C. Hogenson, and the solutions used were prepared by Dr. Schreinr r. F. H. KING, Chief of the Division of Soil Management. PROF. MILTON WHITNEY, Chief of the Bureau of Soils. TABLE OF CONTENTS. BULLETIN "E." INFLUENCE OF FARM YARD MANURE UPON YIELD AND UPON THE WATER- SOLUBLE SALTS OF SOILS. PAGE Conditions under which the observations were made 1 Application of the manure 3 Seed, planting and care of crop .* 3 Relation of yields to fertilizations 4 Yields of corn 4 Increase of yield due to fertilization 6 Yields of potatoes ; 14 Increase in yield due to fertilization 17 Mean increase in yields on 8 soil types due to fertilization 18 Influence of farm yard manure on the water-soluble salts of soils. 20 Effect of 5, 10 and 15 tons of manure per acre upon the water- soluble salts of soils . , 20 Influence of 25, 50, 100 and 200 tons of manure per acre upon the water-soluble salts of soils 23 Potash absorbed from manure by eight soils 25 Influence of manure on the water-soluble lime in 8 soils ... 26 Influence of manure on the water-soluble magnesia in 8 soils. 27 Influence of 5, 10, and 15 tons of stable manure on the amounts of nitric acid in field soils 28 Influence of large amounts of manure upon the nitric acid in soils 31 Influence of manure upon the water-soluble phosphates in soils 32 Influence of farm yard manure upon the amounts of water- soluble sulphates in soils 34 Influence of manure upon the amounts of water-soluble bi- carbonates, chlorine and silica in soils 35 Amounts of salts recovered from manured soils by continuous percolation 36 Amounts of water-soluble salts added to the 8 soil types with the different quantities of manure applied 39 Amounts of salts added to the soils with the manure which were not recovered by washing in distilled water 41 Influence of lime and stable manure on water-soluble salts in soils . 44 CONTENTS. Vll PAGE Influence of manure upon the water-soluble salts recovered from plants... * 49 Influence of manure upon the amounts of potash recovered from soils by plants 53 Influence of manure upon the amounts of lime and magnesia recovered from soils by plants 56 Influence of manure upon the amounts of nitric and phosphoric acids recovered from soils by plants 58 Largest returns from stable manure 60 BULLETIN "F." MOVEMENTS OF WATER-SOLUBLE SALTS IN SOILS. Capillary movement of soluble salts in soils 62 Capillary movement in 6 soil types 62 Capillary concentration of salts under field conditions 69 In a coarse sandy soil 69 In a medium clay loam — 70 In Norfolk Sandy Soil 71 On Goldsboro Compact Sandy Loam and Selma Silt Loam.. 73 Capillary movement of sallts in 8 soil types 74 Method of treatment 74 Amount of capillary movement. 76 Duration of capillary movement 76 Water-soluble salts recovered after capillary movement 77 Movement of potash by capillarity 82 Movement of lime by capillarity 85 Movement of magnesia by capillarity 86 Movement of phosphates by capillarity 88 Movement of sulphates by capillarity 90 Movement of chlorides by capillarity 93 Recovery of absorbed nitric acid 94 Retention, of nitrates by clean sand . . .w 97 Influence of earth mulches upon the movement and distribution of water-soluble salts in soils 98 Conditions of the experiment 98 Distribution of salts in mulched and unmulched soils after capillary movement of 70 days 100 Influence of capillary movement in soils under naked fallow treatment upon the amounts of water-soluble salts in soils. 105 Influence of 3-inch earth mulches on the distribution of nitrates, sulphates and chlorides in soils 107 Influence of 3-inch earth mulches on the distribution of phos- phates, silica and bicarbonates 108 Bearing of capillary movement of salts upon soil management. . . 110 Cultivation to make water-soluble plant food materials more available 110 Loss of plant food in surface drainage 113 VI 11 CONTENTS. BULLETIN "D." ABSORPTION OF WATER-SOLUBLE SALTS BY DIFFERENT TYPES. PAGE On the extent of the power of soils to absorb ammonia 114 Observations of Way 114 Observations of Voelcker 115 The power of soils to retain ammonia 117 Observations of O. Kullenberg 118 Absorption of potash by soils 120 Observations of Voelcker 120 Observations of Way 122 Observations of E. Peters 123 Recovery of absorbed potash 125 Observations of O. Kullenberg 130 The absorption of soda, lime and magnesia from solutions by soils 132 Absorption of soda 132 Observations of Voelcker 132 Observations of Kullenberg 133 Absorption of lime and magnesia 134 Absorptive power of soils for phosphoric acid 136 Observations of O. Kullenberg 136 Observations of Voelcker 137 Absorption by soils of sulphuric and nitric acids and of chlorine. . 138 Comparative study of the absortive power of 8 soil types 139 Methods of observation 140 Absorption of salts by the Janesville Loam 140 Absorption of salts by the Hagerstown Loam 144 Absorption of salts by washed sands 149 Absorption of salts by 8 soil types from dilute manure solution. 153 Comparison of yields with the amounts of absorbed and dis- solved salts 157 Absorption of salts by 8 soil types from a solution of acme guano 158 Absorption of salts from a prepared chemical solution by 8 soil types after having been 11-times washed in distilled water. 161 Absorption of salts by black marsh soil 163 BULLETIN "E. Influence of Farm Yard Manure Upon Yield and Upon the Water- Soluble Salts of Soils. In the comparative study, the results of which are here re- ported, an effort was made to measure the effect of three very moderate dressings of stable manure both upon the yield of crops and upon the water-soluble salts which could be recovered readily from the soils so treated. The amounts of manure applied were at the rates of 5, 10 and 15 tons per acre, and these quantities were applied to 8 soil types upon 2-aere areas, subdivided in the manner indi- cated in Fig. 1. The soils selected were the Norfolk Sandy Soil and Selma Silt Loam at Goldsboro, 1ST. O. ; the Norfolk Sand and Sassa- fras Sandy Loam at Upper Marlboro, Ml. ; the Hagerstown Clay Loam and Hagerstown Loam at Lancaster, Penn. ; and the Janesville Loam and Miami Loam at Janesville, Wis. These soils are fully described in the Second and Fourth Re- ports of this Bureau. The areas here considered were chosen primarily for a com- parative study of the water-soluble salts of soils and their rela- tions to yields, and the treatments here referred to were given in order to secure differences of yield within the samei soil type. These phases of the study are reported in Bulletins "B"* and "C". As there stated, the soils were specially chosen with the view to having those strongly contrasted in their native productive capacities, in order thatj well marked differences might be dealt with. Such selection, too, is quite as satisfactory for the purposes of the study here made. *Bureau of Soils. "B," Amounts of Plant Food Readily Recoverable from Field Soils with Distilled Water. "C," Relation of Crop Yields to the Amounts of Water-Soluble Plant Food Materials Recovered from Soils. POTATOES 0 H< FALLOW thing applied. CORK 0 .5, Tiye tons of stable mam re per acre. 5 10 Teu tons of stable mam re per acre 10 15 Fifteen torn of stable mam re per acre. 15 F 300 Ibs. of acme guano per acre. F 0 K< thing applied. 0 5 Five tens of stable manux e per acre. 5 10 Ten tons of stable manur 5 per acre. 10 15 Fifteen tor 3 of stable man ire per acre!5 F SCO Ibs. of acme guano aer acre. F 0 i othing applied. 0 5 Five toss of stable manur s per acre. 5 16 Ten tons of stable manur s per acre. 10 15 Fifteen tons of stable manu re per acre 15 F 300 Ibs. of acme guano per acre F 0 He thing applied. 0 5 Five tons of stable manur 5 per aere. 6 10 Ten tons of stable manui 6 per acre. 10 15 Fifteen' tor 9 of stable man ire per acrelS F 300 Ibs, of acme guano per acre. F FIG. 1. — Showing arrangement of plots to study effects of fertilization upon yield and upon the water-soluble salts in soil. The sub-plots had the width of six rows and were not separated by paths. MAM UK. YIELD AND SOLUBLE SALTS IN SOILS. 3 We shall have, therefore, for comparis n, four naturally strong soils and four others which, in native capacity, are weak. The Janesville and Lancaster soils constitute the stronger group, while the Goldsboro and Marlboro soils form the weaker group. APPLICATION OF THE MANURE. In order to secure a uniform quality of manure for the two soil types in each locality and for the different amounts ap- plied, the manure to be used was first brought together into a single pile, spreading each load evenly over it until the required amount had been collected. Then, when applying the manure to the field, each load was distributed crosswise of the sub-plots in such a manner that proper aliquot portions fell upon each, sub-plot treated. It happened at Janesville that the manure of the previous winter from a dairy herd could be taken direct from the yard where it had been piled. That used at Lancas- ter was taken from roofed stock yards, but that for Goldsboro and Marlboro had to be collected from various places about the city. Composite samples of the manures had been carefully taken for analyses but these have not been made. The acme gtnano* used was purchased in one lot and sub- divided for the four localities, so that this fertilizer was the same for the 8 soil types. The manure and fertilizer were ap- plied broadcast and plowed under on all soils to a depth of 6 to 8 inches, about 3 weeks before planting. SEED, PLANTING, AXD CARE OF CROP. The corn and potatoes used for seed were purchased of' Nbrthrup, King & Company, Minneapolis, Minnesota, Iowa Gold Mine being used for corn and Rural !N"ew Yorkers for potatoes. The planting was in hills 42 inches each way for corn, and 42 inches one way by 21 inches the other for pota- toes. The planting of both corn and potatoes was done on the same dates at all places. Harrowing after planting before the seed was up and flat cultivation for both crops was adopted, using cultivators with 2.5 to 3 inch shovels. *Manufacturer's guarantee for this guano was phosphoric acid 8 per cent, ammonia 3 per cent., and potash 2.5 per cent. To control the Colorado potato beetle hand picking was prac- ticed, beginning with the appearance of the old beetles. In this way little injury was done by them at either locality. It transpired, however, when the tubers were well set, and per- haps one-half grown, that severe "tip-burn" struck the vines at all four places, greatly interfering with and reducing the yields, except at Janesville. At all places except Janesville the vines dried completely before the crop matured. RELATION OF YIELDS TO FERTILIZATION. YIELDS OF CORN. It was the aim to have the corn cut on each soil type as soon as the ears were fully matured and the stalk at the proper stage for cutting and shocking, with the leaves and husks yet green. The weight of each row was determined as cut from the several sub-plots and the sums taken for the total mean yield under each fertilization for the respective soil types. In the next table are given the comparative green weights of corn as cut, which may be taken to represent somewhat less than the amounts of silage produced. Comparative green weights of corn. Nothing added. 5 tons manure. 10 tons manure. 15 tons manure. 300 Ibs. guano. Norfolk Sandy Soil In pounds per acre. Four poorer soils. 5080.1 8986.8 5194.9 5983.2 6311.3 8330.4 9580.6 7843.2 9248.9 8750.8 11766.7 10044.0 9297.0 10796.5 10476.1 14593.5 10299.9 10949.0 10959.4 11688.0 8887.5 8445.4 6852.4 8175.1 Selma Silt Loam Norfolk Sand Sassafras Sandy Loam Average 8090.1 Hagerstown Clay Loam Hagerstown Loam Four stronger soils. 10762.2 13307.0 24922 2 17866! 8 16714.6 13183.2 13273.1 ir>:> u. 5 22467.5 18617.1 14895.3 14576.7 26228!6 23448.2 15224.5 13510.1 27204.0 25384.0 12630.0 14627.5 24346.8 19518.9 Janesville Loam Miami Loam Average 19787.2 20330.7 17780.8 It will be seen from this table that, with each and every soil type except the Hagerstown Loam, there is a well marked ten- MANURED YJKLD AND SOLUBLE SALTS IN SOILS. dency to an increase in yield from the sub-plots to which noth- ing was added to the ones receiving 15 tons of stable manure. In the case of the Hagerstown Loam, it was found, when the field came to be studied in detail, that there were great physi- cal as well as chemical differences in the area chosen on this type, rendering it unsuited to a comparative study of this kind. There were also shown to be considerable irregularities in the soil conditions of the Sassafras Sandy Loam and in the two Goldsboro types, which could not be entirely eliminated by the repetition adopted of sub-plots, in alternate series. If these yields are expressed: percentagely on the yields of the 15-ton fertilization as a base, taking those as 100, the re- sults stand as indicated below. Percentage, relation* of yield under different fertilizations. N7othiog added. Per cent. 5 tons manure. Per cent. 10-tons manure. Per cent. 15-tons manure. Per cent. 300-lbs. guano. Per cent. Mean of 4 poorer soils Mean of 4 stronger soils Mean of 8 soils 53.98 82.19 71 89 74.47 91.59 85 32 89.65 97.34 94 50 100.00 100.00 100 00 69.21 87.46 80 83 It will be seen that in the case of the poorer soils there is a percentage difference of 46 between the yields from the 15-ton sub-plots and those to which nothing was added; but a differ- ence of only 18 on the stronger soils. The 5-ton suVplots have made a relatively greater gain than have the sub-plots to which the 300-lbs. of guano wrere added. If the differences in yield are expressed in pounds per acre, using the mean yields on the untreated soils as a basis, the re- sults will stand as next given. BULLETIN 4 E. Increase in yield due to fertilization. Nothing added. 5-tdfts manure. 10-tons manure. 15-tons manure. 300-lbs. guano. Green weight, Ibs. per acre. .. Green weight, nothing added . Difference . Mean of 4 poorer soils. 8811.8 6311.3 8750.8 6311.3 10476.1 6311.3 11688.0 6311.3 8090.1 6311.3 0000.0 2499.5 4164.8 5376.7 1778.8 Green weight, Ibs. per acre. Green weight, nothing added Difference Mean of 4 stronger soils. 16714.6 16714.6 18617.1 16714.6 19787.2 16714.6 3072.6 20330.7 16714.6 17780.8 HJ71 4. 6 1066.2 00000.0 1902.5 3616.1 These results show that, both relatively and absolutely, add- ing fertilizers to the poorer soils has had a greater effect than the same treatment with stronger soils. The guano added was the same on all soils but the presumption is that the stronger soils received a better quality of manure than the poorer soils did, from which it follows that the fertilizers have had a lower efficiency on the stronger soils. It was not practicable to determine the per cent, of water in the corn at the time it was cut, as should have been done for strict comparison of yields. It is probable that 33% per cent, of dry matter is too low, but may be taken as a safe estimate. On this basis, the mean yields of dry matter will stand as be- low. Estimated increase in yield of dry matter in corn due to fertiliza- tion. Nothing added. 5-toiis manure. 10 tons manure. 15-tons manure. 300 Ibs. guano. Dry weight, Ibs. per acre .... Dry weight, nothing added. .. Difference Mean of 4 poorer soils. 2103.8 2103.8 0000.0 2916.9 2103.8 813.1 3492.0 2103.8 1388.2 3896.0 2103.8 1792.2 2696.7 2103.8 592.9 Dry weight, Ibs. per acre . . . Dry weight, nothing added. . . Difference Mean of 4 stronger soils. 5571.5 5571.5 6205.7 5571.5 6595.7 5571.5 6776.9 5571.5 5926.9 5571.5 0000.0 634.2 1024.2 1205.4 355.4 MANURE, YIELD AND SOLUBLE SALTS IX SOILS. 7 On this basis of comparison the 15-tons of manure have about doubled the gain over the 5-tons per acre, and the 300- Ibs. of guano have only made a little more than half the gain the 5-tons of manure per acre made, as an average, on each group of soils. When the corn was husked, after drying in the shock, a com- posite sample of the ears was taken for each fertilization, at the time the corn was weighed, and the water-free shelled corn computed from the per cents, of dry matter and of shelled corn found. These results are given in the next table. Yields of water-free shelled corn, from 8 soil typw under 5 fertiliza- tions. Nothing added. Bu. 5 tons manure. Bu. 10- tons manure. Bu. 15-tons manure. Bu. 300-lbs. guano. Bu. Norfolk Sandy Soil Four poorer soils. 16.73 32.9.-) 15.80 22.02 21.875 26.68 34.31 26.68 25.39 28.265 38.55 37.32 29.70 31.82 34.348 1 51.61 39.48 £5.62 as. 40 40.028 29.62 30.94 25.59 20.16 26.578 Selma Silt Loam Norfolk Sand Sassafras Sandy Loam Average Hagerstown Clay Loam Hagerstown Loa m Four stronger soils. 35.00 49.65 70.27 50.72 51.41 42.79 49.00 73.18 64.47 57.36 54.12 49.51 77.05 66.80 61.87 58.46 46.39 68.51 73.82 61.795 47.58 51.63 72.92 56.11 57.06 Janesville Loam Miami Loam Average It is here seen that, on the four poorer soils, there is a sys- tematic difference in yield of water-free shelled corn which is closely related to the fertilizers applied to the soil. The group of four stronger soils do not show, throughout, this systematic relation. The reason for the departure, in the H|agerstown Loam, has been stated. There is this to be said regarding' the Janesville Loam; the area chosen is part of a well managed dairy farm where the fields are held well up to their maximum limits of productiveness so far as plant food is concerned. Moreover, it was observed, as the corn was coming into full tas- sel, that in the outside row of hills next to the fallow area, throughout the entire 440 feet, the corn was very materially 'E. shorter than on the balance of the field. Under ordinary con- ditions this would have been the heaviest corn. Upon making inquiry of the owner, it was learned that in the Spring of the previous year he had applied manure to a strip of land along this side of the field and it was his judgment that the shorter row of corn marked the boundary of that area. The fertiliza- tions made here were at right angles to the line referred to. It is not unreasonable, therefore, to suppose that, for this soil, the adding of 15 tons of manure per acre, toi that which had been applied the preceding year, really passed the limit of in- creasing the yield of corn for this soil under the conditions of this season, which was rather cold and abundantly wet. The mean increase in yield of shelled corn due to the appli- cation of fertilizers is expressed in the next tsable. Increase in yield of shelled corn due to fertilization. Nothing added. Bu. 5-tons manure. Bu. 10-tons manure. Bu 15- tons manure. Bu. 300-lbs. guano. Bu. Water-free shelled corn, bu. per acre . Water-free shelled corn, nothing added Difference Mean of four poorer soils. 21.88 21.88 •ix.-ll 21.88 54.35 21.88 12.47 40.03 21.88 18.15 26.58 21.88 4.70 00.00 6.39 Water-free shelled corn, bu. per acre . . Water-free shelled corn, nothing added Difference Mean of four stronger soils. 51.41 51.41 57.36 51.41 5.95 61.87 51.41 61.80 51.41 57.06 51.41 5.65 00.00 10.46 10.39 It will be seen, from the data here presented, that, on the four poorer soils, the increase in shelled corn has been nearly proportional to the amounts of manure applied to the soils, and at the mean rate cif 60.10 Ibs. of water-free kernels per ton of manure used, thus: Bu. Per ton. Increase with 15 tons manure . 18 15 1 910 Increase with 10 tons manure 12 47 1 °47 Increase with 5 tons manure 6 39 1 978 Total ... 30 tons manure 37 01 Per ton 1.234 — 6 9.101bs. MAXriCK. YlKI.ii ANJ) SOLI l:I-E SALTS IN SOILS. The increase in total dry matter was: Lbs. Per ton. Increase with 15 tons manure 1792.2 II '.1 IS 1388 2 i:;» v M.'i 1 p." i;-> :fl«)3 5 Psr ton 111% 12 The increase of yield of dry matter in the form of shelled corn is 37.01 X 36 = 2072.56 Ibs. This leaves the dry matter in the form of stalks, leaves and cobs 3993.50 - 2072.56 = 1920.94 Ibs. so that the gain here is at the rate of 64.03 Ibs. of dry matter per ton of manure applied. It thus appears that the major effect of the stable manure has been in the direction of increas- ing grain rather than stalk, leaves and cob, the ratio being 69.10 of kernel to 64.03 of stalk, leaves and cob. It is not an infrequent experience that the addition of potash to soils increases the yield of shelled corn more than it ' does stalk and foliage. It ha,s been shown, in Bulletin "C", also, that the recovered amounts of potash bore a close relation to the yields of shelled corn from these soils and the relation here pointed out is quite in accord with the view that the larger amounts of soluble potash shown to be present in the soils giv- ing the largest yields has been an influential factor in deter- mining those differences of yield. At various times during the season photographs were taken of both corn and potatoes on the same date for all of the soil types. Some of these photographs are here reproduced to ex- actly the same scale, so that they give to the eye a quantitative expression of -the differences in growth as the observer would recognize them. There have been reproduced on pages 10, 11, 12 and 13 photographs of corn taken on August 14 at the four stations which represent the appearance of the corn upon four of the soil types where 15 tons of stable manure had been ap- 10 BITLLKTIX FIG. 2. — Corn where 15 tons manure had been applied per acre to Hagerstown Clay Loam. Line stretched across target is at mean height of corn on the plot. The two small hills in squares have received no water during sea- son and have reached their development on the moisture present in the soil at planting. FIG. 3. — Corn on Hagerstown Clay Loam to which nothing was added, was planted and photograph taken on same dates as for Fig. 2. Corn MANVKK, VIl.I.D A.\!> snl.riH.K SALTS IN SOILS. 11 FiG. 4. — Corn on Norfolk Sandy Soil where 15 tons manure had been applied per acre. Corn was planted and photographed on same dates as for Fig. 2. FIG. 5. — Corn on Norfolk Sandy Soil to which nothing had been added. Corn was planted and photographed on same dates as for Fig. 2. BULLETIN "!•;.'' FIG. 6. — Corn en Miami Loam where 15 tons of manure had heen applied per acre. Corn was planted and photographed on same dates as for Fig. 2. FIG. 7. — Corn on Miami Loam to which nothing had been added. Corn planted and photographed on same dates as for Fig. 2. MANURE, HELD A.XD SOLUBLE SALTS I \ SOILS. 13 FIG. 8. — Corn on Norfolk Sand where 13 tons of manure had been applied per acre. Corn was planted and photographed on same dates as for Fig. 2. FIG. 9. — Corn on Norfolk Sand to which nothing had been added. Corn was planted and photographed on same dates as for Fig. 2. 14 lill.I.KTJX ^E." plied, and also where nothing had been applied. The photo- graphs were all taken with a target rod placed, as a scale, di- rectly in the center of the field arid in the front row of corn. With this arrangement the photographs give a quantitative ex- pression to the differences in growth of the corn. In Figs. 10 and 11, p. 15, are shown more distant views of the com on the Miami^Loam and Norfolk Sand, which show very clearly that the effects of the treatment are general lo the field and sufficiently marked to be seen distinctly, even when reduced to the small size of the Miami Loam view. In this case the camera was stationed some 60 rods distant and yet the rise and fall of the corn on the succession of plots is evident. The low corn in all cases marks the areas to which nothing was added to the soil and the places of maximum height are those where the 15 tons of manure had been applied. YIELDS OF POTATOES. The yields of potatoes, as has been stated, were much re- duced through the effect of the more or less severe "tip-burn" which developed after the tubers had been well set, and pro- gressed Avith varying degrees of rapidity at the different sta- tions. It had progressed so far and rapidly that at all stations except Janesville the foliage became much reduced by the time the tutors had attained not more than half of the normal size. The result was the yields were determined by what transfor- mation to and storage of starch could be accomplished under the imperfect condition of the foliage. Up to the middle of July a good growth of vines had been made and there was promise, at that time, of good yields everywhere, but the ''tip- burn" developed rapidly once it had started. There was, during the early stages of growth, the same marked effect of the stable manure upon the vines as was shown by the com and this can be seen in the foreground of Fig. 11, p. 15, on the Norfolk Sand. There was also, just prior to the development of "tip-burn" a well marked difference in the amount of vine produced on the different soil types and there is every reason to think that had the potatoes matured nor- mally, the yields would have reflected the capabilities of the MAMrilK, YIKI.h AM) !-ol.r I11.I-: SALTS IN SOIT.S. 15 If " if; BULLET IX k'K. different soil types quite as well as did the corn. The results which were secured from the potatoes are given! in the next table : Total yields of potatoes under five fertilizations on 8 soil types. Nothing added. 5 tons manure. 10- tons manure. 15-tons manure. 300-lbs. guano. Norfolk Sandy Soil.... Selma Silr Loam Norfolk Sand In bushels per acre. Four poorer soils. 21.50 57.50 til. in 1~>.4'2 38.10 7'i m JllMiT 101.63 70.90 78.40 132 M L01.83 95.94 67.30 71'., s<) L32.62 115.10 %!)6~ 40.80 67.20 7:1 S2 73.00 63.71 Sassafras Sandy Loam Average 53^5 82.10 Ilagerstown Clay Loam Hagerstown Loam Janesviile Loam Four stronger .^oils. 192.68 137.1*0 as. 30 188.30 168.55 167.74 159.39 2so!ao 237.29 180.91 165.95 329.90 867.80 20(5.92 17(.t.4«> 346.90 L'S<).7(> 151.78 142.24 LMM'n 211.90 Miami Loam Average.. .. 211 . 13 236.02 253.50 197.03 Notwithstanding the disturbing factor of "tip-burn," which has much reduced the yield, there is clearly shown a marked influence upon yield effected through the application of such moderate amounts of manure as have been here used. Even the 5 tons of stable manure has made a clear and even strong O increase in yield on each and all of the 8 soil types, whether naturally poor or strong. Then, too, in the cases of the Janesville Loam and the Hagerstown Loam, where there were not wholly concordant re- suite with corn, the differential effect of the varying amounts of manure are clearly defined by the yields. The soil was more uniform at Lancaster on that portion of the Ilagerstown Loam occupied by the potatoes than was that occupied by the corn, and the area at Janesville, where the potatoes were planted, had not been manured the previous year, as had been the case with that occupied by the corn, as already explained. The increase of potatoes associated with the different amounts of manure applied, and with the guano, appear in the next table. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. Increase in yield of potatoes due to manure and guano. 17 Nothing added. Bu. 5 tons manure. Bu. 10-tOU8 manure. Bu. 15-tons manure. Bu. 300-lbs guano. Bu. Mean yield per acre . Mean yield, nothing added. .. Difference From four poorer soils. 53.97 53.97 82.10 53.97 95.94 53.97 96.96 53.97 63.7.1 53. «.»7 9.74 00.00 28.13 41.97 42.99 Mean yield por acre From four stronger soils. 168.55 168.55 000.00 211.13 1(58.55 42.58 236.02 1(58.55 67.47 258.50 168.55 84.95 197. 03 168.55 28.48 Mean yield nothing added Difference The increase in yield of potatoes associated with the manure, in bushels per ton, has been : • ~ On poorer soils. On stronger soils. Total. Bu. Per ton. Bu. Total. Bu. Per ton. Bu. With 5 tons manure 28.13 41.97 42.99 113.09 3.77 5.626 4.197 2.866 42.58 67.47 84.95 195.00 6.50 8.516 6.747 5.663 With 10 tons manure With 15 tons manure Total 30 tons manure Average per ton The comparatively small effect of the manure on yields on the four poorer soils must be ascribed, in part, to the more in- tense development of "tip-burn" on these soils. Taking the amount of water in potatoes at 78.9 per cent., the mean increase of dry matter, per ton of manure, was, on the four poorer soils, 47.73 Ibs. and on the four stronger soils 82.29 Ibs. !N"o observations were made which make it possible to state the amounts of dry matter produced in the potato Tinea on the different soil types ; but on August 16 four typical hills were selected, one from each of the four sub-plots on each soil type to which 15 tons of manure had been added, and the air-dry weights of these vines was determined, from which the yields of air-dry matter in vines, computed in pounds per acre, were found to be as given in the next table. 2 18 --1 ir-dry weights of potato vines on the 15-ton sub-plots. Norfolk Sandy Soil Selma Silt Loam. Norfolk Sand. Sassafras Sandy Loam. Hagers- town Clay Loam Hac town Loam. Janes- ville Loam. Miami Loam. In pounds pe i acre. 943 1014 853 1021 1959 1931 8112 :>779 The mean height of potato vines on the different sub-plots wa> measured weekly at all stations, and in the next table there are given the values recorded on July 20. Mean height of potato vines on July JO. Nothing added. Inches. 5 tons manure. Inches. 10-tons manure. Inches. 15- tons manure. Inches. 300-lbs. guano. Inches. Norfolk Sandy Soil Four poorer soils. 19.5 23.0 16.0 18.0 20.0 21.0 21.0 23.5 23.0 23.0 24.0 84.5 28.0 26.0 84.5 L'4 5 19.0 19.0 Selma Silt Loam Norfolk Sand Sassafras Sandy Loam Hagerstown Clay Loam Hagerstown Loam Four stronger soils. 27.0 22.0 19.3 23.5 29.0 24..-) 24.3 30.0 24.0 28.3 25.7 31.0 25.0 29.7 28.0 22.0 19.8 24.5 Jauesville Loam Miami Loam At this time, it will be seen, no very marked difference [had developed between die vines at the four stations, although the influence of fertilization was making itself felt. There is, however, so much difference in the extent of branching of the vines that height alone, after branching begins, conveys no defi- nite idea of the amount of vine which has developed. At Janesville the vines came to completely cover the ground and they did to a large extent at Lancaster; but this did not occur on either of the poorer soils. MEAN INCREASES IX YIELDS ON 8 SOIL TYPES DUE TO FERTILIZATION. If the yields of both corn and potatoes from the eight soil types are brought together under the five fertilizations, the re- sults will appear as next given : MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 10 Mean increase in yields on 8 soil types due to differences in fertili- zation with stable manure. YIELDS OF CORN. YIELDS OF POTATOES. On four poorer toils. On four atrortyer toils. On four poorer soils. On four stronger soils. Total. Bu. Per ton Bu. Total. Bu. Per ton Bu. Total. Bu. Per ton Bu. Total. Bu Per ton Bu. With 5 tons manure . . With 10 tons manure.. With 15 tons manure. . Total 30 tons manure . Mean per ton 6.39 12.47 18.15 37.01 1.234 1.278 1.247 1.210 5.95 10.46 10.39 26.80 .893 1.190 1.046 .693 28.13 41.97 42.99 113.09 3.77 5.626 4.197 2.866 42.58 67.47 84.95 195.00 6.50 8.516 6.747 5.663 Mean per ton as dry matter . . 69.1041bs. ttter from 8 soils atter of 2 crops mtter of 2 cro 50.008 Ibs. 59.556 Ibs. indSsoils 62.28 ps from poorer 47. 73 Ibs. 3 Ibs. 58. 417 Ibs. 82. 29 Ibs. 65.01 Jbs. fifi 1iQ lh«. Mean per ton as dry aas Mean per ton- as dry m Mean per ton as dry n soils Mean per ton as dry matter of 2 crops from stronger soils (1) It appears from this table, as an average of all trials on 8 soils with corn and potatoes, that 1 ton of stable manure has increased the yield at the mean rate of 62.283 Ibs. of dry mat- ter in the form of grain and tubers alone. If the dry matter in stalks and vines were included, the increase would not be far from 100 Ibs. per ton. (2) The relative increase of dry matter, in the form of grain and tubers, has been in the ratio of 59.56 for corn to 65.01 Ibs. for potatoes, taking the dry matter in the potatoes at 21.1 per cent, and 60 pounds per bushel as the weight for pota- toes and 56 pounds per bushel for corn. (3) The average increase on the four1 poorer soils, as com- pared with that on the four stronger soils, has been as 58.417 to 66.149, the increase being greater on the stronger soils; but, as has been pointed out, the true relation is probably the re- verse, as it was with the corn. The "tip-burn" on the potatoes grown on the four poorer soils did have a relatively greater effect in reducing the yield there. (4) The mean increase in dry matter per ton of manure as grain and tubers alone, where 5' tons were applied, was at the 20 BULLETIN "E.'? rate of 79.311 Ibs. per ton; for 10 tons the increase was 66.740 Ibs. per ton; and for 15 tons it was at the rate of 53.636 Ibs. per ton. There has, therefore, been a relatively higher effi- ciency where the smaller amounts of manure were added. INFLUENCE OF FARM YARD MANURE ON THE WATER-SOLUBLE SALTS OF SOILS. There is given in Bulletin "C,"* p. 81, a tabular statement of the amounts of water-soluble salts recovered from 8 soil types, as an average of determinations made on 6 different dates, together with the differences between the total salts recovered from each of the fertilized sub-plots and from the sub-plots not fertilized. There is presented here a statement of the influ- ence of the stable manure upon the amounts of each ingredient recovered from the soil under field conditions. EFFECT OF 5, 10, AND 15 TONS OF MANURE UPON THE WATER- SOLUBLE SALTS OF FIELD SOILS. The observations here presented cover a study, under field conditions, from the time of applying the stable manure to the soil the last of April until near the end of June, a period of about 60 days, during which time samples were collected on six dates. The manure had been very carefully and uniformly spread over the surface of the fields and was plowed under to a depth of 6 to 8 inches. The soil samples, in all cases, were composites of four cores, one from each of the four repeated sub-plots, and extended through the entire surface foot. In the next table there are given the percentage differences in the amounts of each ingredient determined, using the amounts recovered from the umnan.ured soil as bases and call- ing these 100. Bureau of Soils. "C," Relation of Crop Yields to the Amounts of Water-solu- ble Plant Food Materials. Recovered from Soils. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 21 Percentage relations of water-soluble salts recovered from soils receiving 5, 10, and 15 tons of stable manure per acre. Nothing added. Per cent. 5 -ton s manure. Per cent. 10 tons manure. Per cent. 15- ton s manure. Per cent. 300-lb8. guano. Per cent. Yields of dry matter in grain and tubers 100 00 122 4 138 5 146 5 115 4 Amounts of K recovered 100 00 109 5 115 2 193 7 105 3 Amounts of Ta recovered 100 00 100 1 102 1 107 2 117 3 Amounts of Mg recovered 100 00 103 1 110 1 113 0 112 3 Amounts of NOg recovered 100 00 106 3 104 6 111 5 104 3 Amounts of JIPO4 recovered 100 00 105 4 114 7 107 4 98 5 Amounts of SO 4 recovered 100 00 100 8 101 5 108 4 126 9 Amounts of HCOs recovered Amounts of Cl recovered 100.00 100 00 118.3 82 1 129.8 108 0 130.4 164 0 139.1 126 8 Amounts of SiOg recovered 100 00 118 2 129 7 130 4 139 1 Amounts of total salts recovered 100.00 103.9 107.2 111.3 119.3 From this table it is very clear that the effect of the differ- ent amounts of stable manure, applied to these soils, and that of the 300-lbs. of gnano, as well, has been such, upon the recov- erable water-soluble salts, as to enable the same treatment to remove different amounts from each fertilization. As a rule, the amounts increase with the amounts of manure added, but how these amounts are related to the amounts car- ried to the soils with the manure cannot be shown, because altered plans have prevented the analyses of the manure and guano used, as had been the intention. There is a clear quan- titative relation, too, between the yields and the salts recovered, these increasing where the essential ingredients of plant food are higher. Two of these soils, the Miami Loam and the Norfolk Sand, were subjected to repeated washing with alternate drying be- tween each washing, using samples from the sub-plots to which no manure had been added and from those to which 15 tons had been applied. The results which were secured by this treatment are given in the next table. BULLETIN E. Amounts of salts recovered from manured and unmanured soils by washing 11 times in distilled water. K. Ca. Mg. N03. HP04. SO4. HCO3. 01. SiO2. 15 tons manure . . . Nothing added... Difference 15 tons manure . . . Nothing added ... Difference In parts per million of dry soil. Miami Loam. 211.12 190.84 628.00 397.50 220.18 211.12 57.24 62.42 397.40 382.00 521.00 528.50 571.00 579.00 0.00 0.00 0.00 336.80 338.60 —1.80 20.28 30.50 9.06 -5.18 15.40 — 7.50 -8.00 Norfolk Sand. 155.44 126.12 113.00 101.00 80.44 74.55 25.89 19.10 86.76 85.56 191.00 163.00 260.00 306.00 2.00 2.00 141.20 140. CO 29.32 12.00 5.89 6.79 1.20 28.00 —46.00 0.00 1.20 From this table it is seen that, so far as the three bases are concerned, materially larger amounts of each have been recov- ered from the manured soils than were recovered from those not manured, under exactly the same treatment. It must be held in mind that the bases have been demonstrated to be absorbed more by soils than the negative radicles are; and further, that the application of stable manure does bring into play the ab- sorption forces whose tendency is to liberate certain ingredients from soils while others are fixed. Notwithstanding the ten- dencies to absorption, it is shown that under the conditions of the treatment more potash, lime, magnesia and phosphoric acid have been recovered from the soils to which they were added as carried by the stable manure. Moreover, while it must be conceded that the cooking to which these soils were, in a measure, subjected, during the dry- ing, may have rendered potash, lime, magnesia and phosphoric acid soluble from the manure when it would not otherwise have been so, it is yet clear that, if rendered soluble, it was not again fixed by the soils, although in contact with them, to such an extent but that more was recovered from the manured than from the unmanured soils. The excess amount of potash dissolved from the two ma- nured soils was at the rate of 62.47 Ibs. per acre from the Miami Loam! and 105.1 Ibs. from the Norfolk Sand. If the potash is really left in a more soluble form in the Norfolk Sand MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 23 than it is in the Miami Loam, and if this more soluble potash has been an influential factor in determining the yield of corn, this relation is in harmony with what has been observed, namely, that like amounts of manure were relatively more effective on the poorer soils which have been shown to have a less strong absorptive power for the potash. INFLUENCE OF 25, 50, 100 AND 200 TONS OF MANURE PER ACRE UPON THE) WATER-SOLUBLE SALTS OF SOILS. In order to supplement the field studies regarding the influ- ence of small amounts of stable manure upon the water-soluble salts in soils, a series of experiments was started the first week in July to measure the influence of 25, 50, 100 and 200 tons of manure per acre upon the water-soluble salts which could be recovered from the 8 soil types under investigation. The farm yard manure used was cow dung, taken from the yard not more than two or three days after being dropped. It was rendered water-free by drying at 100° O. and then ground to a fine powder by running through a mill. From the water- free manure the requisite amounts were weighed out at the central laboratory, and sent in separate parcels to the field par- ties in proper amounts to be incorporated with designated amounts of soil. Like amounts of thq same manure were, therefore, used on all soils. The 20 Ibs. of soil used were composites taken with the soil tube from the surface foot of the unfertilized sub-plots of the respective soil types. Where the soils were not in their opti- mum moisture condition when collected,, they were rendered so by the addition of water. After having been thoroughly mixed, the soil was weighed out in 4-lb. lots and with these the prepared manure was thor- oughly incorporated in the following amounts. Amounts of wafer-free manure added to 4-pound lots of soil. No. 1. No. 2. No. 3. No. 4. No. :>. 0 Grams. 14. 18 Grams. 28. a") Grams. 56.7 Grams. 113.4 Grams. 24 In this condition the moist soils were transferred to 2-quart Mason fruit jars, the mouths of which were closed, with a plug of loose cotton wool, to check evaporation but permit normal aeration. The jars were then weighed and set aside. Once each week, after starting the experiment, the plugs of cotton wool were removed, the jars covered, inverted and shaken to secure a thorough exchange of air throughout the entire volume of soil. Considering the weight of the moist soil for each soil type to be 4,000,000 Ibs. per acre-foot and the manure to carry 70 per cent, of water, the amounts added, supposing them to be in- corporated with the surf ace> 6 inches of soil only, were at the rates of 25.22, 50.43, 100.87 and 201.73 tons per acre. A partial gravimetric analysis of the manure used, made by Dr. Schreiner, gave the results stated in the table. Composition of manure used. No. of sam- ple. Ash. Insolu- ble in HC1, sand, etc Solu- ble in HC1. Potash as Lime as Magnesia 1 Phosphoric as acid as K. KaO. Ca. CaO. Mg. MgO HPO4. P205. In percent, of the dry manure. 2 9 568 79")4 HI 1 3266 1 8565 5803 .9627 4 16 180 9 060 7 120 | | 2 2639 1 6744 • The Mason jars with their soil content were weighed from time to time during the interval of the experiment and enough water added to restore that lost by evaporation, and on Sep- tember 10 and 11 the samples were examined for the water- soluble salts which could be recovered from them by single washings during three minutes. The results obtained are given in the following sections. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 25 POTASH ABSORBED FROM MANURE BY 8 SOILS. Influence of different amounts of stable manure upon the water- soluble potash recovered with distilled water. NorHk Sandy Soil. Selma Silt Loam. Norf'lk Sand. Sassa- fras Sandy Loam. Hagers- town Clay Loam. Hag- erst'wn Loam. Janes- ville Loam. Miami Loam. 25.22 tons manure... Nothing added In parts per million of dry soil. 21.20 11.60 9.60 29.60 11.60 18.00 65.00 11.60 53.40 143.60 11.60 .132.00 21.20 14.12 7.08 24.40 14.12 10.28 50.80 14.12 36.68 106.00 14.12 101.88 20.00 11.92 8.08 26.00 11.92 14.08 56.80 11.92 44.88 116.20 11.92 104.28 15.60 9.56 6.04 33.40 9.56 23.84 56.00 9.56 46.44 119.20 9.56 109.64 21.20 11.48 9.72 28.40 11.48 16.92 54.10 11.48 42.62 104.00 11.48 92.52 25.60 20.30 ~5.30 39.40 20.30 19.10 42.10 20.30 21.80 108.40 20.30 88.10 19.40 19.12 18.08 16.28 1.80 22 16 16.28 ~5~88 23.60 16.28 7.32 62.60 16.28 ~~ 46.32 Difference .28 23.90 19.12 4.78 28.40 19.12 9.28 68.60 19.12 49.48 50.43 tons manure. .. N othing added Difference 100.87 tons manure.. N othing added Difference .... 201.73 tons manure.. Nothin? added Difference . The data of this table show, in a striking manner, that there is a profound difference in the capacities of these 8 soils to hold back potash from solution by the first 3-minute washing, when applied to them, in the form of fresh cow manure and left in contact, under like conditions, during 65 days, between July 1 and September 11. The differences between the soils are more clearly brought out by the diagram, Fig. 12, p. 26. The curve of 100-tons per acre shows a strong difference be- tween the Hagerstown Loam and the two Janesville soils and the other five members of the series, The application of 200- tons of manure per acre places the two Janesville soils in one group, the two Lancaster soils in another, and leaves the Nor- folk Sandy Soil alone as having the smallest capacity for hold- ing back potash. This relation was also found when! liquid manure was applied, as cited in Bulletin "D," page 114. BULLETIN K. SOF.FOLK SZLKA JJORPOLK SA3SAFF.AJ HAO?= JAJESVILLS SMDY SILT SATO SAHDY CL^ HABSRSTOWB LOAi'. LOAB LOAM LOAM FIG. 12. — Showing relative amounts of potash recovered from 8 soil types 65 days after the application of different amounts of manure. INFLUENCE OF MANURE OX WATER-SOLUBLE LIME IX 8 SOILS. In the next table there have been brought together the re- sults of the determinations for lime, made on the same soil ex- tracts as those for potash and at the same time. In these cases, as with the potash, more lime has been recov- ered from each soil after having had an application of "manure, and this is in accord with the observations made under field conditions where 5, 10 and 15 tons of manure had been ap- plied. Contrary to what was observed with the potash, more, rather than strongly less, lime has gone into solution from the Lancaster and Janesville soils. According to the view held in 1865 and earlier, the absorption of pctash by these soils has MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 27 "forced the lime into solution." It must, however, be said that the same soils which have absorbed least lime are the ones which observation has abundantly proved contain most lime in water-soluble form. Influence of different amounts of stable manure upon the quantity of water-soluble lime recovered with distilled water. Morf'lk Sandy Soil. Selma Silt Loam Norf'lk Sand. Sassa- fras Sandy Loam. Hagers- town Clay Loam. Hag- erst'wn Loam. Janes- ville Loam Miami Loam. 25.22 tons manure... Nothing added In parts per million of dry soil. 65.00 29.50 56.00 54.00 45.00 34.00 52.00 46.00 86.00 78 . 75 105.00 92.00 91.25 82.00 72.50 68.75 Difference 35.50 2.00 11.00 6.00 7.25 13.00 9.25 3.75 50.43 tons manure. .. Nothing added 45.00 29.50 59.00 54.00 51.00 34.00 57.00 46.00 102.50 78.75 112.50 92.00 107.50 82.00 90.00 68.75 Difference 15.50 5.00 17.00 11.00 23.75 20.50 25.50 21.25 100.87 tons manure.. Nothing added 56.25 29.50 70.00 54.00 65.00 34.00 76.25 46.00 130.00 78.75 125.00 92.00 125.00 82.00 112.50 68.75 Difference 26.75 16.00 31.00 30.25 51.25 33.00 43.00 43.75 201 . 73 tons manure . . Nothing added Difference 83.75 29.50 93.75 54.00 78.75 34.00 91.25 46.00 150.00 78.75 140.00 92.00 162.50 82.00 145.00 68.75 54.25 39.75 44.75 45.25 71.25 48.00 80.50 76.25 INFLUENCE OF MANURE ON THE WATER-SOLUBLE MAGNESIA IN 8 SOILS. When the results for the magnesia are brought together they stand as given in the next table. In the case of the magnesia it will be observed that the influ- ence of the manure upon the amounts dissolved has taken an intermediate position between- that exerted upon the potash and upon the lime. As was the case with the potash, less has been recovered and, therefore, more absorbed by the four stronger soils ; but the differences between the members of the two groups of soils are not nearly so strongly marked. In the case of the Janesville Loam, the manure had the effect of re- ducing the quantity of magnesia below the amount recovered from the untreated soil, unless it happened that in some way the amount determined for the unmanured soil is too high. 28 This does not appear probable, in view of the general fact that, for all soils, the manure can scarcely be said to have increased the amounts of magnesia recovered until the soils to which 100 tons per acre had been applied are reached. Influence of different amounts of stable manure upon the water- soluble magnesia recovered with distilled water. Nor- fork Sandy Soil. Selma Silt Loam. Nor- fork Sand. Sassa- fras Sandy Loam. Hagers- town Clay Loara. Hagers town Loam. Janes- ville loam. Miami Loam. 25.22 tons manure... Nothing added Difference In parts per million of dry soil. 8.78 7.61 8.78 7.40 9.64 9.78 8.68 8.56 26.71 27.17 23.14 22.82 23.46 28.06 17.64 18.40 1.17 9.65 7.61 1.38 7.40 7.40 — .14 16.30 9.78 -.12 14.89 8.56 -.46 31.71 27.17 .32 28.52 22.82 -4.60 24.82 28.06 -.76 23.46 18.40 50.43 tons manure.. . Nothing added Difference . 2.04 0.00 6.52 6.33 4.54 5.70 -3.24 5.06 100.87 tons manure.. Nothing added 36.57 7.61 31.84 7.40 33.58 9.78 27.61 8.56 57.04 27.17 41.78 22.82 £5.68 28.06 35.68 18.40 Difference 28.96 24.44 23.80 19.05 29.87 18.96 7.62 17.28 201.73 tons minure. Nothing added. . .. Difference 50.34 _I_6L 42.73 57.04 7.40 49.64 60.16 9.78 50.38 61.14 8.56 52.58 68.48 27.17 41.31 61.14 22.82 38.32 64.72 28.06 36.66 57.04 17.40 38.64 The mean differences of magnesia, as shown for the soils re- ceiving the 200 tons of manure, stand in the relations of 100 for the Southern soils to 79.31 for the Northern. INFLUENCE OF 5, 10 AND 15 TONS OF STABLE MANURE ON THE AMOUNTS OF NITRIC ACID IN SOILS. It was found in the comparative study of nitrates in field soils at various times during the season, that not infrequently less rather than more nitrates were recovered from the soils to which most manure had been applied. In the next table there are brought together the observed amounts of nitrates in the surface foot of the different soil types receiving different fer- tilizations. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 29 Amounts of nitrio acid (NOj ) in field soils receiving different amounts of manure. Noth- ing add- ed. tons ma- nure. 10- tons ma- nure. 15- tons ma- nure. 300 Ibs. guano Noth- ing add- ed. 5- tons ma- nure 10- tons ma- nure. 15- ton.s ma- nure. 300 Ibs. guano April 29 In parts ter million of dry soil. Goldsboro, North Carolina. Norfolk Sandy Soil. Selma Silt Loam. 5.26 14.52 15.80 9.32 22.70 16.52 14.02 6.37 24.22 12.52 18.16 24 22 2Y94 18.90 6.92 18.16 19.12 21.36 40.40 27.94 22.32 10.38 21.36 25.94 72.64 40.40 40.40 35.19 4.04 16.52 18.16 22.70 20.18 27.94 18.26 3.78 20.18 22.70 21.36 10.08 27.94 17.67 2.42 16.52 21.36 30.28 12.10 30.28 18.49 5.76 16.52 22.70 36.32 36.32 33.02 25.11 3.66 22.70 33.02 19.12 30.28 33.02 23.63 1.82 13.46 13.96 20.18 22.70 24.20 16. 0) May 18 May 25 June 8 June 24 Average April 29 May 18 Upper Marlboro, Maryland. Norfolk Sand. - Sassafras Sandy Loam. 3.16 8.86 8.26 16.16 19.64 12.88 11.49 4.78 8.96 10.08 19.36 20.76 9.52 12.24 4.44 11.18 11.36 17.72 26 92 lO^ 13.66 3.64 10.38 13.20 19.92 26.92 13.20 14.54 2.50 8.14 11.36 12.56 14.84 8.44 9.64 6.10 9.44 19.12 14.52 14.28 24.20 14.61 6.06 13.46 21.04 18.40 20.16 30.28 18.23 4.98 11.18 25.48 18.64 22.36 23.44 17.68 5.82 14.24 25.% 19.12 29.48 29.64 20.71 5.54 10.24 23.84 19.64 16.12 22.72 16., 35 May 25 June 1 June 24 Average April 29 May 18 May 25 June 1 Lancaster, Pennsylvania. Hagerstown Clay Loam. Hagerstown Loam. 11.54 11.72 18.16 33.02 29.06 33.02 10.08 9.96 25.06 22.70 40.40 46.00 11.00 11.00 36.32 17.30 49.10 40.40 9.08 26.90 23.44 13.20 38.60 66.00 6.80 26.90 39.90 10.18 61.60 117.20 11.54 22.70 42.80 36.32 45.40 90.80 10.08 20.76 40.40 40.40 68.50 84.40 11.00 14.52 45.40 9.44 69.80 80.80 38.49 9.08 16.90 45.40 7.14 67.30 68.60 35.73 6.80 24.22 27.94 8.08 30.50 74.20 June 8 June 24 Average April 29 May 18 22.75 25.70 27.52 29.54 43.76 41.59 44.09 28.62 Janesville, Wisconsin. Janesville Loam. Miami Loam. 36.32 45.44 61.60 74.10 45.40 88.60 58.58 28.56 55.84 64.90 98.20 55.90 iK3.SC 34.56 48.40 58.60 69.80 66.00 79.00 55.39 32.64 53.84 44.80 64.90 100.90 82.60 63.28 25.96 52.80 72.10 86.50 88.60 95.60 70.59 19.12 41.30 86.50 55.90 56.80 53.84 5.96 &5.60 61.60 58.60 38.60 64.90 44.21 11.00 43.30 67.30 18.16 42.70 55.00 "39^58 14.84 27.10 59.60 37.28 31.30 52.60 37.12 9.84 30.30 58.60 51.20 26.00 62.60 39.75 May 25 June 1 June 8 June 24 Average 65.70 52.24 From this table it will be seen that there has been no clearly and strongly marked tendency for all the manured soils to show more nitrates than the same soils otherwise treated. The mean values for all soils stand as given in the next table. 30 BULLETIN "E." Mean observed amount of nitrates in soils to which was added Nothing. Manure. Guano. Eight soil types. In parts per million of dry soil 29.21 100.00 31.30 107.50 30.38 104.00 If, however, the soils are classed, as has before been done, into the poorer and stronger groups and a comparison of the nitrification made, the results will stand as given in the next table. Relation of nitrification to fertilization. Nothing added. 5 -tons manure. 10 -tons manure. 15-tons manure. 300-lbs. guano. In parts per million of dry soil Percent age relation Four poorer soils. 15.20 100.00 16.97 111.60 19.69 129.40 23.52 154.70 15.08 99.20 In parts per million of dry soil Percentage relation Four stronger soils. 43.79 100.00 44.93 102.40 40.25 91.90 41.42 94.60 45.68 104.30 From this comparison it appears that the addition of ma- nure to the four poorer soils has augmented the development of nitrates and in amounts increasing with the manure added. The guano, however, appears to have had a, depressing effect. In the case of the four stronger soils, the two larger amounts of manure added appear to have retarded the accumulation of nitrates in the soil; while the guano may have increased the amount The two groups of soils, therefore, hold opposite re- lations as regards the influence the manure has had upon their nitrate content. Such relations as these have been many times noted by different observers and it is unfortunate that it has not yet been clearly demonstrated to what causes such rela- tions should be ascribed. It is worthy of special remark that notwithstanding the greater effect of the manure in increasing the nitric acid con- tent measured in the four poorer soils, there is, nevertheless, a greater difference as regards nitrates between these two groups MANURE, YIELD AND SOLUBLE SALTS IN SOILS. Oi of soil than the different amounts of manure have made within the poorer group. The four stronger soils stand higher above the poorer in nitrie acid than 15 tons of manure has been able to increase the nitrates in the poorer soils. INFLUENCE OF LARGE AMOUNTS OF MANURE UPON NITRIC ACID IN SOILS. In the experiments with 25, 50, 100 and 200 tons of ma- nure per acre on these same 8 soil types additional light is thrown upon the important problem of nitrification in, soils. In the next table are given the results found in that investi- gation as regards the amounts of NO3 which could be recov- ered from the 8 soils. Influence of different amounts of manure on the nitric acid content of soil. Norf'lk Sandy Soil. Salma Silt Loam. Norf'lk Sand. Sassa- fras Sandy Loam. Hagers- town CJay Loam. Hag- erst'wn Loam. Janes- ville Loam. Miami Loam. In parts per million of dry soil. Nothing added 70.00 88.60 71.40 121. CO 168.80 161.80 177.20 142.80 25.22 tons manure.. 4.32 10.68 24.24 11.72 98.20 77.20 70.00 38.24 50 . 43 tons m anure . . 2.27 2.42 3.38 3.37 95.60 35.70 4.54 5.68 100.87 tons manure.. 31.60 2.34 5.01 2.75 165.20 39.50 3.50 3.30 301 . 73. tons manure . . 5.78 2.34 4.84 4.04 3.30 3.50 3.86 3.86 Notwithstanding the fact that the five samples for each soil type were identical, that is, taken from the same bulk lot, and had been placed, during 65 days, under entirely similar condi- tions, there came to be a profound difference in the amounts of nitric acid which were recovered from them, and apparently as the result of adding the manure to the soils. A strong nitrification had occurred in each and every soil to which no manure was added ; it is therefore clear that, so far as environment was concerned, conditions were favorable for nitrification to go forward. The addition of the manure has certainly interfered with the amounts of nitrates recovered from these soils; and it is certain that denitrification (or else absorption) has taken place in all of the soils to which the largest amount of manure was 32 added, because there was present in them, when the manure was added, not less than the amounts indicated in them under "Xotliing added" on June 24, as given in the table, p. 29. How large this denitrificalioii may have been cannot be stated. It will be seen thati in the sample of the Hagerstown Clay Loam to which the next to the largest amount of manure was added, nitrification had exceeded denitrification by an amount nearly equal to the nitrification which took place in the un- manured soil. The large amounts of manure here used were chosen in or- der to cover the outside limits of both intentional and acci- dental practice, and the matter is discussed further in another part of this bulletin. INFLUENCE OF MANURE UPON THE WATER-SOLUBLE PHOSPHATES IN SOILS. The amounts of phosphates which were recovered from these 8 soils, after having been 65 days in contact with- different amounts of manure, are given in the next table. Amounts of phosphoric acid recovered from soils treated with manure. Norf'lk Sandy Soil. Selma Silt Loam Norf'lk Sand. Sassa- fras Sandy Loam. Haerers- town Clay Loam. Haer- erst'wn Loam Janes- ville Loam. Miami Loam. 25.22 tons manure... Nothing added Difference In parts per million of dry soil. 2.2 2.8 — .6 2.8 1.2 1.6 4.8 2.4 16., 6.0 10.4 6.4 7.1 3.6 6.1 3.6 17.8 -14.2 21.2 2.4 18.8 2.4 — .7 —2.5 50.43 tons manure. .. Nothing added 16.2 2.8 14.6 1.2 29.6 2.4 15.6 6.0 15.6 7.1 13.8 6.1 17.2 17.8 10.8 2.4 Difference ...... 13.4 13.4 27.2 9.6 8.5 7.7 — .6 8.4 100.87 tons manure.. Nothing added 21.8 . 2.8 36.7 1.2 59.9 2.4 35.2 6.0 23.9 7.1 19.7 6.1 31.8 17.8 36.4 2 . 4 Difference 19.0 a5.5 57.5 29.2 16.8 13.6 14.0 34.0 201. 73 tons manure.. Nothing added 90.7 2.8 115.2 1.2 149.0 86.6 6.0 61.2 7.1 52.2 6.1 89.0 17.8 126.0 - . 4 Difference 87.9 114.0 146.6 80.6 54.1 46.1 71.2 123.6 MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 33 Except in the case of the Janesville Loam, the observations show a remarkably small amount of phosphoric acid recovered from the unmanured soils, lower than is normal to the field conditions, and in view of other data in the table it appears not improbable that the determination for the Janesville Loam may be too high. It is clear that there is a general tendency for the amounts of phosphates which may be removed from the soil with water after a contact of 65 days to increase with the amounts of ma- nure added, but the data are too irregular to justify much more being said. On the whole, more has been recovered from the four poorer soils and, therefore, less has been absorbed, than from the four stronger ones, except where 25 tons of manure were added. The next table shows the relations. Mean amounts of phosphates recovered from Four poorer soils. Four stronger soils. Nothing added In parts per million. 3.1 6.6 19.0 38.4 110.4 8.2 8.7 14.4 28.0 82.1 50 tons manure 200 tons manure The amounts of phosphoric acid recovered from the soils re- ceiving the heaviest dressings are of the same order of value as that recovered from the soil from a set of greenhouse benches, where a still heavier dressing of manure had been applied, "3 barrels of soil to one barrel of manure." In this case the benches were fitted early in May and had matured a heavy X5rop of chrysanthemums when the soil was examined on No- vember 1, yielding, at that time, 105 parts per million of dry soil of HPO4. 3 34 INFLUENCE OF FARM YARD MANURE UPON THE AMOUNTS OF WATER-SOLUBLE SULPHATES IN SOIL. The next table shows the amounts of SO4 which were recov- ered from the 8 soil types after having been in contact with about 25, 50, 100 and 200 tons of manure per acre during 65 days. Amounts of sulphates, as SO4, recovered from soils treated with different amounts of manure. Nor- folk Sandy Soil. Selma Silt Loam. Nor- folk Sand. Sassa- fras Sandy Loam. Haters- town Clay Loam. Ha- pers- town Loam. Janes- ville Loam Miami Loam. 25. 22 tons manure . .. Nothing added Difference In parts per million of dry soil. 62 27 90 50 63 24 65 39 73 59 112 104 112 84 100 73 35 40 39 26 14 8 28 27 50.43 tons manure. . Nothing added Difference 88 27 61 106 27 114 50 64 150 50 65 24 41 98 24 69 39 30 112 39 88 59 29 142 59 132 104 28 164 104 126 _?L 42 152 84 112 73 39 136 73 100.87 tons manure.. Nothing added Difference 79 100 74 73 83 60 68 63 201. 73 tons manure.. Nothing added Difference.,.. 140 27 113 192 50 142 120 24 96 137 39 98 168 59 109 220 104 116 192 84 108 164 73 91 Here, as in the other cases presented, the sulphates recov- ered with distilled water increase with the amounts of manure added, the mean relations standing for the two groups of soils as next given. Mean amounts of sulphates, as SO^, recovered from Four poorer soils. Four stronger soils. Nothing added In parts per million 35.0 70.0 84.0 116.5 147.3 80.0 99.3 114.5 148.5 186.0 25 tons manure 50 tons manure „ 100 tons manure 200 tons manure MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 35 Contrary to what has occurred with the phosphates, but in line with what was true of the lime, the four poorer soils have yielded less sulphates than the stronger soils and, therefore, have absorbed more from the manure, or have rendered it less soluble. INFLUENCE OF MANURE UPON THE AMOUNTS OF WATER-SOLUBLE BICARBON- ATES, CHLORINE AND SILICA IN SOILS. There are brought together in the next table the amounts of HGO3, Cl and SiO^ v/hich were recovered from the soils to which these large amounts of fresh manure had been added. Amounts of bicarbonates, chlorides and silica recovered from soils treated with different amounts of manure. Norfolk Sandy Soil. Selma Silt Loam. Nor- folk Sand. Sassa- fras Sandy Loam. Hagers- town Clay Loam. Ha- gers- town Loam. Janes- ville Loam. Miami Loam. In parts per million of dry soil. Nothing added 25.22 tons manure. f I* r?l U 12 16 14 28 12 36 54 80 40 70 20 26 38 44 50. 43 tons manure. 8^ 22 22 44 46 104 70 46 66 100.87 tons manure. fl 1 46 32 76 80 132 126 70 66 201 . 73 tons manure . W I 84 64 146 115 225 170 110 135 Nothing added i" 2 2 4 2 2 2 2 2 25. 22 tons manure. , | 26 30 26 30 30 30 28 28 50. 43 tons manure, o •{ 52 52 54 50 52 62 52 52 100.87 tons manure. |102 98 106 100 106 108 104 102 201. 73 tons manure. L190 198 200 195 210 210 225 205 Nothing added { 6.8 9.6 9.9 11.5 24.9 26.6 36.2 37.7 25 . 22 tons manure . [ N | 8.4 11.0 8.5 10.6 26.3 31.0 41.5 28.2 50.43 tons manure. p-{ 5.9 9.3 4.7 10.1 25.6 24.6 42.0 38.2 100. 87 tuns manure, jg 1 15.2 15.3 6.6 18.0 28.8 27.5 41.9 41.9 201.73 tons manure.) I 14.4 13.7 14.1 J 27.5 34.6 35.6 54.3 38.6 From the data of this table it appears that the amounts of both chlorine and HCO3 recovered from] the soils, after having been in contact with the manure 65 days, is very nearly di- rectly proportional to the amounts of manure added; while in the case of the silica there is only a slight tendency to increase the amounts which can be recovered from the soil with water alone. Comparing the two groups of soil, as has been done with other ingredients, the mean amounts recovered are as next stated. BULLETIN E/ Mean amounts recovered OFHCO3. OF Cl. OF SiO2. 4 poorer soils. 4 stronger soils. 4 poorer soils. 4 stronger soils. 4 poorer soils. 4 stronger soils. Nothing added 25 tons manure 50 tons manure. ... . 100 tons manure 200 tons manure 25 tons manure In parts per million of dry soil. 13.0 23.5 33..-) 58.5 102.3 38.0 55.0 71.5 98.5 160.0 2.5 28.0 52.0 101.5 195.8 2.0 9.45 29.0 1 9.63 54.5 7.. 50 105.0 13.78 212.5 17.43 31. a5 31.75 32.60 35.00 40.78 Change associated with the manure. 10.5 20.5 45.5 89.3 17.0 33.5 60.5 122.0 2.-,.:, 49.5 99.0 193.3 27.0 52.5 103.0 210.5 .18 —1.95 4.33 7.98 .40 1.25 s.a> 9.43 50 tons manure 100 tons manure .... 200 tons manure From the lower section of the table it is evident that only a slight, if any, change in the relation of the HCO3 and Cl has been produced by using different amounts of manure. AMOUNTS OF SALTS RECOVERED FROM MANURED SOILS BY COX- TIXUOUS PERCOLATION". Near the close of January, 1904, 206 days after applying the manure to the soil, samples of the Janesville Loam and of the Norfolk Sand, to which manure had been applied at the rate of 200 tons per acre, were packed in the fresh, moist con- dition about Pasteur niters, inside the perforated cylinders de- scribed in Bulletin "B," p. 81.* In this condition distilled water was caused to flow slowly but continuously through lay- ers of these soils 3-16 of an inch thick, until 6000 c, c. had been collected. As these soils had never been dried, the rate of per- colation soon became very slow in the Janesville Loam and it required nearly 36 hours to get the 6 liters of water through this soil. The pressure on the Norfolk Sand was maintained low enough so that the same amount of time was required in collecting the 6000 c. c. of solution from it. *Bureau of Soils. "B," Amounts of Plant Food Readily Recoverable from Field Soils with Distilled Water. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 37 In these percolation experiments the amounts of dry soil used were, for the Janesville Loam 119.2 grams and for the Norfolk Sand 154.3 grams. In the next table there are given the amounts of the differ- ent ingredients recovered from these two soils by the percola- tion method after the manure had been 206 days in contact with them. Water-soluble salts recovered from heavily manured soils by per- colation. K. Ca. Mg. NO3. HP04. S04. acq3 Cl. Si02. Janesville Loam . . Norfolk Sand .... Difference In parts per million of dry soil. 104.62 62.24 94.56 64.19 93.12 66.60 193.86 146.89 63.26 36.88 222.33 118.26 372 22 412.34 50.30 38.90 11.40 17.69 15.38 42.38 30.37 26.52 46.97 26.38 104.07 -40.12 2.31 There is thus, at this time, not only a large amount of each ingredient recovered from the soils, except chlorine and silica, but the differences between the amounts recovered from the two soils are also large and in the usual direction, less coming away from the poorer soil. This latter relation is not what the writer had anticipated from the results which have already been given for these same soils, obtained at an earlier date, 65 days after applying the manure. It will be recalled that at that time the dried sam- ples were treated1 ini the usual manner, using 500 c. c. of water to 100 grams of soil,' with vigorous stirring during 3 minutes. Bringing the amounts recovered by the two treatments into comparison, they stand as given in the next table. BULLETIN Relative amounts of water-soluble salts recovered from heavily manured soils on different dates. K. Ca. Mg.- N08. HP04- S04. HCO3. Cl. SiO2. In parts per million of dry soil. Afler 65 days contact After 206 days cout'ct Cuange After 65 days contact After 206 dayscont'ct Change Janesville Loam. 68.60 104.62 162.50 94.. 56 64.72 93.12 3.86 193.86 +190~00 89.00 63.26 —25.74 192.00 222 33 +30. 33 110.00 372.22 +262.22 225.00 50.30 —174.70 54.30 17.69 -36.61 +36.02 -67.94 +28.40 Norfolk Sand. 116.20 78.75 62.24 64.19 — 53.9^-14.56 60.16 66.60 +6.44 4.84 146.89 +142. OH 149.00 36.88 -112.12 120.00 118. 2<3 —1.74 146.00 412.34 +266.34 200.001 14.10 38.90 15.3 —161.101 +1.28 If the observations made 206 days after applying the ma- nure were reversed and the values which are assigned to the Norfolk Sand were credited to the Janesville Loam the rela- tions would have been more nearly what it was expected would be found when they were brought into comparison, which was not done until this writing in the June following. There is nothing in the records which indicates that a transposition could have occurred and while it is not impossible that the jars containing the two solutions might have been reversed, it is not likely that this did take place. If the results are properly credited in the table, we have the Janesville Loam absorbing potash and phosphoric acid more rapidly during 65 days than the Norfolk Sand, as, indeed, from the physical standpoint, would be expected, but also, 141 days later, the reverse relation is brought out, the Janesville Loam, imparting to the same amount of distilled water and in the same time, 104.6 parts of potash and 63.3 parts of phos- phoric acid, while the Norfolk Sand gave up but 62.2 parts of potash and 36.9 of phosphoric acid. Btiit perhaps this rela- tion, after all, is demanded on account of so much larger sur- face over which the water flowed in passing through the Janes- ville Loam. So much less was the frictional surface presented by the Norfolk Sand that the 6000 c. c. of Water could have been passed through it, under the pressure maintained on the Janes- ville Loam, in 3 instead of 36 hours. Moreover, the depth of MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 39 the current, flowing over the surfaces of the grains in the coarse soil, must have been greater and this would tend to faille the concentration to be less. If it is true that the soils which absorb the largest amounts of the essential plant foods, carrying them within and about their granular units, only retain them, after such absorption has taken place, in conditions which permit these ingredients to pass again into solution when conditions- change, such a re- lation would appear to be in harmony with the observed rela- tions of yield on such soils. AMOUNTS OF WATER-SOLUBLE SALTS ADDED TO THE 8 SOIL TYPES WITH THE DIFFERENT QUANTITIES OF MANURE APPLIED. A colorimetric determination was made of the water-soluble salts which could be recovered from the manure used in the ex- periments here under consideration and the results found, after washing a quantity of the manure during three minutes in dis- tilled water, are given below : Readily water-soluble salts recovered from fresh cow durty with distilled water. K. Ca. Mg. | N03. HPO4. S04. HCO8. Cl. SiO-j. In parts per million of dry matter. 3120 1 2010 2096.4 177 .87 8208 525 747 2640 614 5 The gravimetric determinations for potash, limp, magnesia and phosphoric acid cited on p. 24 showed that there was pres- ent in the manure 2.327 times as much potash as was recov- ered in the brief treatment with distilled water; 5.244 times as much lime; 2.764 times as much magnesia; and 2.758 times as much phosphoric acid, as HPO4. In the next table there are given the amounts of readily water-soluble salts which were added to the different soil types with the manure, on the basis of the analysis of the manure, and taking into account the amount of moisture present in the soil when the manure was added. 40 Amounts of readily water-soluble salts added to the 8 soil fypes with the different amounts of manure applied. K. Ca. Mg. NO,. HPO4 SO4. HC03. Cl. 'siO2. Norfolk Sandy Soil Selma Silt Loam Norfolk Sand Sassafras Sandy Loam. Hagerstown Clay Loam Hagerstown Loam . ... Janesyille Loam Miami Loam Norfolk Sand Soil Selma Silt Loam Norfolk Sand Sassafras Sandy Loam. Hagerstown Clay Loam Hagerstown Loam Janesyille Loam . . Miami Loam Norfolk Sandy Soil Selma Silt Loam Norfolk Sand Sassafras Sandy Loam Hagerstown Clay Loam Hagerstown Loam Janesyille Loam . Miami Loam . .... Norfolk Sandy Soil Selma SiJt Loam Norfolk Sand. Sassafras Sandy Loam. Hagerstown Clay Loam Hagerstown Loam Janesyille Loam . Miami Loam in parts per million or dry soil. Soils to which 25.22 tons of manure were added per acre. 26.78 27.83 27.01 28.25 29.56 29.81 30.27 29.27 17.25 17.93 17.40 18.20 19.04 19.20 19.50 18.86 17.99 18.70 18.18 18.98 19.86 20. as M! 83 19.67 1.53 1.58 .54 .61 .68 .70 .73 .67 74.44 73.21 71.05 72.63 77.71 7S.11? 79.64 77.01 2.79 2.90 2.81 2.94 3.08 3.11 3.15 3.05 6.41 6.66 6.47 6.76 7.07 7.14 7.25 7.01 22.66 23.55 22.85 2:j,.*:> 25.01 25.22 2:,. ill 24.77 5.27 5.48 5.32 5.56 5.82 5.87 5.96 5.77 Soils to which 50.43 tons of manure were added per acre. 58.53 55.68 54.01 56.50 »!l2 59.62 60.54 58.55 34.50 .35.85 34.80 36.40 38.07 38.41 39.00 37.72 35.98 37.38 36.29 37.97 39.71 40.06 40.66 39.34 3.05 3.17 3.03 3.22 3.37 3.40 8.45 3.34 148.88 146.41 142. 09 145.26 155.48 156.84 159.27 154.02 5.58 5.80 5.63 5.89 6.16 6.21 6.30 6.10 12.82 13.33 12.93 13.53 14.15 14.27 14.49 14.02 45.31 47.09 45.70 47.60 50.01 50!« 51.23 49.54 10.55 10.96 10.64 11.13 11.64 11.74 11.92 11.53 Soils to which 100.87 tons of manure were added per acre. 107.10 111.31 108.02 113.01 118.23 119.24 121.08 117.15 69.00 71.71 69.59 72.80 76.14 76.81 78.01 75.44 71.97 74.79 73.58 75.93 79.42 80.12 81.31 78.68 6.11 e.&5 6.16 6.44 6.74 6.80 6.90 6.68 297.76 292.83 284.18 290.52 310.87 313.69 318.54 308.04 11.16 11.59 11.25 11.77 12.31 12.42 12.61 12.20 25. H4 26.65 25.96 27.06 28.30 28.55 28.90 28.03 90.63 94.19 91.40 95.20 100.02 100.98 102.45 99.08 21.10 21.92 21.28 22.26 23.24 23.48 23.85 23.06 Soils to which 201.73 tons of manure were a.dded per acre. 214.21 202.62 216.05 226.02 238.46 238.47 242.16 234.30 138.01 142.41 139.18 145.61 152.30 153.62 156.02 150.87 143.94 149.56 147.18 151.86 158.85 160.24 162.62 157.35 12.21 12.69 12.32 12.88 13.48 13.60 13.81 .3. &5 595.52 585. K) 568.36 581.05 621.94 627.38 637.08 616.09 22.31 23.19 22.50 23.54 24.62 24.84 25.22 24.39 51.29 53.30 51.73 54.12 56.59 57.10 57.98 56.07 181.26 188.37 182.81 190.40 200.05 201.78 204.90 198.15 42.20 43.85 42.55 44.51 46.56 46.97 47.70 46.12 From this table it will be seen that there was added to the different soils, in readily water-soluble form, from 26.78 to 242.16 parts per million of potash and a total, according to the gravimetric analysis, of 62.31 parts per million with the 25 tons and 563.6 parts with the 200 tons of manure per acre. Of phosphoric acid amounts were added, in water-soluble form, ranging from 71.05 to 637.08 parts per million of the dry soil; and, as a total, amounts ranging from 193.5 to 1,758 parts per million. The amounts of salts which have been added to these MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 41 soils, even with 200 tons of manure per acre, are less in propor- tion to the soil, than were used in the studies of absorption phenomena by the investigators cited in Bulletin D, pages 114 to 168. AMOUNTS OF SALTS ADDED TO THE SOILS WITH THE MANURE, WHICH WERE NOT RECOVERED BY WASHING IN DISTILLED WATER. If the amounts of water-soluble salts .recovered from the soils to which no manure had been added and those which were added with the manure are considered as the amounts which were present in the several samples at the time they were ex- amined, 65 days after they were manured, the differences be- tween these sums and the amounts which were recovered will represent the quantities which were held back by the soils. In the next table a comparison is made of the averages from the four poorer and from the four stronger soils for each of the different amounts of manure which had been added to them. Mean amounts of salts not recovered from (toil 65 days after being treated with stable manure. K. Ca. Mg. N03- HPO4. SO4- HC03. Cl. SiO2. Four stronger soils re- tained In parts per million of dry soil. Soils to which 25.22 tons of manure were added per acre. 25.46 19.76 9.14 3.98 21.29 17.83 93.39 82.28 77.85 69.39 —16.15 -32.14 -9.83 -3.92 -1.85 -2.27 5.94 '5.2, Four poorer soils re- tained , Four stronger soils re- tained Four poorer soils re- tained Soils to which 50. 43 tons of manure were added per acre. 47.79 38.38 13.85 23.27 41.26 36.28 94.93 83.84 150.40 129.76 -28.31 -43.27 -19.27 --7.35 -2.19 -3.07 10.89 12.77 Four stronger soils re- tained Soils to which 100.87 tons of manure were added per acre. 98.68 62.01 32.15 44.79 61.44 50.01 1X5.40 83.83 295.68 256.02 -56.11 -70.06 -32.05 -19.17 -2.36 -6.14 20.16 17.31 Four poorer soils re- tained Four stronger soils re- tained Soils to which 201 .73 tons of manure were added per acre. 169.25 100.53 85.50 •95.30 121.53 99.06 172.43 96.26 551.87 475.87 -81.23 -89.61 -65.08 -36.64 -9.28 —7.54 37.84 35.30 Four poorer soils re- tained... 42 From the data of this table it appears that all but three of the ingredients of the manure which were readily soluble in distilled water/ have been held back by the soils in amounts which have increased a little less than in proportion to the amounts added. The SO4, HCO3 and Cl have, without excep- tion, gone into solution in increasing quantities as the amounts of manure were increased. In other words, all of these ingre- dients that were shown to be present in the unmanured soil plus all that were added to the soils were recovered after 65 days of contact, anid in addition thereto the amounts which are given in the table, designated by minus signs. The mean amounts of the different salts actually recovered from the two groups of soils after 65 days of contact with the manure are given in the next table. Mean amounts of salts recovered from the four poorer and four stronger soils after 65 days'1 contact with, different amounts of manure. K. Ca. Mg. N03. HP04 S04. HCO3 Cl. SiO3. Recovered from 4 strong- er soils In parts per million of dry soil. Soils to which 25.22 tons of manure were added per acre. 21.07 19.52 88.69 54.50 22.74 8.97 70.91 12.74 8.70 6.55 99.25 70.00 55.00 23.50 29.00 28.00 31.70 9.63 Recovered from 4 poorer soils Recovered from 4 strong- er soils Soils to which 50.43 tons of manure were added per acre. 28.47 28.35 103.13 53.00 27.13 12.06 £5.38 2.86 14.35 19.00 114.50 84.00 71.50 33.50 54.50 52.00 32.60 7.50 Recovered from 4 poorer soils Recovered from 4 strong- er soils Soils to which 100.87 tens of manure were added per acre. 37.05 57.15 123.13 66.87 42.55 32.40 52.88 10.43 27.95 38.40 148.50 116.50 98.50 58.50 105.00 101.50 35.03 13.78 Recovered from 4 poorer soils ... .... Recovered from 4 strong- er soils Soils to which 201. 73 tons of manure were added per acre. 85.90 121.25 149.38 86.88 62.85 57.17 3.63 4.25 82.10 110.38 186.00 147.25 160.00 102.25 212.50 195.75 40.78 17.43 Recovered from 4 poorer soils . From this table it will be seen that with 25 tons of manure per acre the four stronger soils, after 65 days, gave over to the MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 43 solution more of every ingredient than the four poorer soils did. With 50 tons per acre the amounts of potash are the same in both groups and the stronger soils have yielded less phosphoric acid, but, for the other ingredients, more than the poorer soils. Where 100 tons of manure have been applied the stronger soils have yielded less of both potash and phosphoric acid but more of all other ingredients ; and practically the same can be said of the soils where 200 tons of manure per acre have been applied. If the amounts of the different ingredients which were re- covered from the soils to which no manure was added are sub- tracted from the amounts which were recovered from the soils to which the different amounts of manure were added, the dif- ference® will show the effect of the stable manure upon the salts which may be recovered from these soils with water alone, 65 days after the manure has been applied. The next table gives these results. Amounts of salts which manured soils yield to distilled water more than the same soils do unmanured. K. Ca. Mg. NO3. HP04 SO 4. HCO3 Cl. Si02. Excess : From 4 stronger soils From 4 poorer soils . . . From 4 stronger soils From 4 poorer soils. .. From 4 stronger soils . From 4 poorer soils. . . From 4 stronger soils . From 4 poorer soils. . In parts per million of dry soil. Soils to which 25. 22 tons of manure were added per acre. 4.27 7.70 8.31 13.62 -1.37 .63 —91.74 -75.01 1.60 3.45 19.25 a-j.oo 17.00 10.50 27.00 25.50 .40 .17 Soils to which 50.43 tons of manure were added per acre. 11.67 16.55 22 75 12.12 3.01 3.72 -127.27 —84.89 6.00 15.90 34.50 49.00 33.50 20.50 52.50 49.50 1.05 -1.65 Soils to which 100.87 tons of manure were added per acre. 20.25 45.85 42.75 26.00 18.43 24.06 —109.77 -77.32 19.60 ar>.so 68.50 31.50 60 .50 45.00 103.00 99.00 3.67 4.32 Soils to which 201 . 73 tons of manure were added per acre. 69.10 109.70 68.99 46.00 38.73 48.83 -159.021 73.75 -83.50107.27 106.00 112.50 122.00 89.25 210.50 193.25 9.42 7.97 From this table it appears that 25 tons of fresh cow manure applied to the four stronger soils yields in readily water-soluble form after 65 days, 4.27 parts per million of the dry soil more 44 BULLETIN "E." of potash, and 1.6 more of phosphoric acid that the unmanured soils did; while the same dressing applied to the poorer soils produced a gain of 7.7 parts of potash and 3.4 parts of phos- phoric acid. When 50 tons of manure were applied the gains were 11.67 and 6 parts for the stronger soils and 16.55 and 15.90 parts per million of potash and phosphoric acid for the poorer soils, respectively. When 100 tons of manure are ap- plied the differences then become 20.25 and 19.60 for the stronger soils and 45.85 and 35.30 for the poorer, for the pot- ash and phosphoric acid, respectively, in parts per niillion of the dry soil; while at 200 tons the gains! become enormous, reaching 69.10 and 73.75 for the stronger soils and 109.70 and 107.27 for the poorer, of potash and phosphoric acid, respec- tively, in parts per million of the dry soil. There is, therefore, abundant proof in these observations that large dressings of manure do increase in a high degree the water-soluble salts which may be recovered from a soil. INFLUENCE OF LIME AND STABLE MANURE ON WATER-SOLUBLE SALTS IN SOILS. In these experiments composite samples of the surface! foot of soil of each type were procured, and after mixing and bring- ing them to good moisture condition each sample was divided into four lots of 15 pounds each, to one of which nothing was added, to another lime at the rate of 1 ton per acre, to another 10 tons of air-dry stable manure per acre, and to the fourth 10 tons of air-dry manure and 1 ton of lime per acre. The soil? were kept at nearly constant moisture and good aeration condi- tions during a period of about fifty days, at the end of which time the soluble salts were determined, with the results given in the following table: MANUKE, YIELD AND SOLUBLE SALTS IN SOILS. 45 Changes in amounts of nitrates, expressed as .2V O3, after fifty days. Periods of Expariment. Sandhill. Selma Silt Loam. Norfolk Sand. Goldsboro Compact Satdy Loam. Norfolk . Fine Sandy Loam. Pocoson . In parts per million of dry soil. Where nothing was added to soil. 17.10 3.76 13.34 g 117.0 19.9 71.5 19.3 92.0 15.7 198.0 41.6 156.4 Present at start Amount produced — Found at close 94.3 97.1 52.2 76.3 Where lime alone was added at the rate of 1 ton per acre. 99.20 3.76 95.44 150.0 42.2 107.8 132.0 19.9 112.1 84.0 19.3 64/7 105.6 i:>.7 89.9 205.0 41.6 163.4 Present at start ... Amount produced..;. Found at close Where manure alone was added at the rate of 10 tons, air-dry, per acre. 80.00 3.76 76.24 193.0 42 2 166.0 19.9 146.1 104.0 19.3 84.7 114.4 15.7 213.0 41.6 Present at t>tart Amount produced ... Found at close 150.8 99.7 171.4 Where both lime and manure were added at rates of 1 and 10 tons per acre, respectively. 124.00 3.76 120.24 220.0 42.2 177.8 181.0 19.9 161.1 116.0 19.3 96.7 132.0 15.7 116.3 231.5 41.6 189.9 Present at start Amount produced From this table it will be seen that in the extremely sandy type of soil the addition of lime alone allowed the rate of nitri- fication to exceed that which occurred in two of the other types to which only lime was added, and also that the lime materially increased the rate of nitrification in them all. The increase during the fifty days over that present in the soil at the start, for the six types, was enough to amount to 286, 323, 336, .104, 269, and 490 pounds per acre in the surface foot, taking the mean weight of the soil at 3,000,000 pounds, and stating the amounts in the order in which the soils are named in the table. It is noteworthy, too, that the lime alone had a greater influ- ence in stimulating nitrification in the Sandhill type than did the 10 tons of stable manure alone, while in the case of the Pocoson neither the lime nor the manure alone, nor the two combined, stimulated the rate of nitrification in as marked a way when compared with the rate which was maintained in the same untreated soil, which, however, was far higher than that 46 BULLETIN in any other case. In other words, the untreated Pocoson soil was nearly in prime condition for nitrification, so that the com- bined effect of the manure and lime increased the nitrates (NO3) produced at the rate of only 101 pounds per acre in the fifty days. The changes which occurred in the amounts of sulphates (SO4) recoverable by washing three minutes in distilled water were also marked, and are given in the following table : Amounts oj sulphates, expressed as SO4, recoverable after about fifty days. Periods of Experiment Sandhill. Selma Silt Loam. Norfolk Sand. Goldsboro Compact Sandy Loam. Norfolk Fine Sandy Loam. Pocoson. Found at close In parts per milllion of dry soil. Where nothing was added to soil. 3.1 3.1 0.0 60.1 43.7 16.4 29.5 20.8 8.7 59.8 33.0 26l 53.0 16.1 36.9 28.1 _**_ 14.9 Present at start Change Found at cloce Where lime was added at the rate of 1 ton per acre. 9.2 3.1 83.2 43.7 48.4 20.8 80.9 33.0 65.3 16.1 36.2 13.2 Present at start Change 6.1 39.5 27.6 54.1 49.2 23.0 - Found at close Where manure was added at the rate of 10 tons, air-dry, per acre. 5.1 3.1 2~ 78.6 43.7 54.8 20.8 70.4 33.0 37.4 80.0 16.1 63.9 38.2 13.2 25.0 Present at start Change 34.9 34.0 Found at close Present at start Where both lime and manure were added, at the rates of 1 and 10 tons per acre, respectively. 11.4 3.1 8.3 101.7 43.7 58.0 59.0 20.8 93.6 33.0 60.6 95.2 16.1 47.2 13.2 34.0 Change 38.2 79.1 From this table it is clear that, associated with the nitrifica- tion, there has been a liberation of sulphates, apparently more from the materials of the original soils than from the materials added, and in larger amounts where the lime and manure are added together. The changes in the amounts of phosphates have all been in the opposite direction from those of either the nitrates or the sulphates, as is shown in the following table: MANURE, YIELD AND SOLUBLE SALTS IN SOILS. Changes in amounts of water-soluble phosphates, expressed HPO4, after fifty days. 47 as Periods of Experiment. Sandhill. Selma Silt Loam. Norfolk Sand. Goldsboro Compact Sandy Loam. Norfolk Fine Sandy Loam. Pocoson . Present at start In parts per million of dry soil . Where nothing was added to soil. 6.90 1.46 5.44 14.20 2.46 11.74 11.50 1.49 10.01 7.20 3.78 3.42 8.12 2.30 5~82 18.00 2.39 15.61 Found at close Change Present at start Where lime was added at the rate of one ton per acre. 6.90 1.46 14.20 3.28 11.10 2.99 7.20 3.78 8.12 2.30 18.00 3.19 Found at close Change 5.44 10.92 8.51 3.42 5.82 14.81 Present at start .. Where manure was added at the rate of 10 tons, air-dry, per acre. 6.90 2.18 4.72~ 14.20 4.92 9.28 11.50 3.74 7.76 7.20 4.54 2.66 8.12 4.22 3~90 18.00 3.99 14.01 Found at close Change Present at start Where both manure and lime were added at the rates of 1 and 10 tons per acre, respectively. 6.90 3.28 3.6JT 14.20 6.18 8.02 11.50 4.48 7.02 7.20 4.54 2.66 8.12 3.83 18.00 4.79 13.21 Found al close Change 4.29 Associated with the increased amounts of nitrates and sul- phates and of other water-soluble salts, and with the changed physical and other conditions which favor the increased rates of nitrification, there were other changes occurring which placed the phosphates in conditions preventing their recovery from the soils by single three-minute washings in distilled water in as large amounts as were recovered from the same soils imme- diately prior to their being placed in the nitrification experi- ment. The soils were under quite different physical conditions, so far as soil moisture and soil air were concerned, but how far these may have determined the changes referred to cannot yet be stated; but what seem to be comparatively slight physical differences are undoubtedly responsible directly or! indirectly for very different results in the amounts of some of the water- soluble salts recoverable from different soils. The truth of this statement will be clear from a comparison of the amounts of 48 BULLETIN nitrates recovered from the different layers of the six soils under consideration after they had stood under the mulched and unmulched conditions where all other conditions were the game so far as we know, except in so far as the condition of the two surfaces affected the soil moisture and soil air relations, and through those the differences in water-soluble salts recover- able by our method of washing. The table following shows the differences developed at different depths below the depth of the 3-inch mulch and below 3 inches in the soil not mulched : Differences in the amounts of nitrates, expressed as NO3, in six soil types at different depths below surface under 3-inch mulches and where surface was firm. Goldsboro Norfolk Depth. Sandhill. Selma Silt Loam. Norfolk Sand. Compact Sandy Fine Sandy Pccoson. Loam. Loam. T3 • •e T3 j •6 j T3 •d T3 "C • • i ® o S 05 :>ir> 5910 13880 5710 Water-soluble potash in potato plants 65 days after planting. 22730 18440 4280 20000 '•16280 3720 27440 24440 3000 33120 14800 18320 24400 18760 5640 48800 42400 6400 32000 25160 6840 30960 21200 9760 Water-soluble lime in corn plants 60 days after planting. 1200 1800 1200 2800 1060 5200 1370 5000 1925 5800 1500 5000 1750 5000 1500 5500 -600 -1600 -4140 -3630 -3875 -$300 -3250 —4000 Water-soluble lime in potato plants 65 days after planting. 5900 3200 2700 4600 4500 100 260 480 —220 3600 3950 — a50 4800 5600 —800 2900 3200 -300 6200 6400 —200 5900 5500 400 Water-soluble magnesia in corn plants 60 days after planting. 787.0 845.6 -58~6 788.0 964.8 -176.8 714.6 1801.6 —1087.0 1160.8 2489.6 -1328.8 a558.0 7027.2 -3469.2 2385.6 4148.8 -1763.2 1876.8 4563.2 -2686.4 2192.0 6848.0 -4656.0 Water-soluble magnesia in potato pJants 65 days after planting. 2977.6 1488.8 1488.8 2321.6 2208.8 112.8 744.4 1521.6 —777.2 1244.8 4278.4 -3033.6 4643.2 7204.8 -2561.6 2854.4 2913.6 -59.2 4643.2 5073.6 —430.4 3912.0 4979.2 -1067.2 Water-soluble NO3 iu corn plants 60 days after plantin g. 358.8 403.2 1321.6 830.4 632.4 2640.0 7648.0 2344.0 17104.0 12640.0 17104.0 22336.0 -5232.0 29056.0 20768.0 17344.0 20032.0 —44.4 491.2 -2007.6 1 5304.0 4464.0 8288.0 -2688.0 Water-soluble NO3 in potato plants 65 days after planting. 7264.0 6320.0 18176.0 12112.0 2153.6 1491.2 29056.0] 8304.0 24200.0 17720.0 25960.0 27920.0 33040. o! 25960.0 29040. OJ 20160.0 944.0 6064.0 —26902.4 -6812.8 6480.0 -1960.0 4000.01 5800.0 MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 51 Amounts of water soluble salts recovered from corn and potatoes growing upon manured and unmanured ground— Continued. iNorrik Stndy Soil. senna Silt Loam. Norfolk Sand. fras Sandy Loam. town Clay Loam. nag- erst' wn Loam. janos- ville Loam. Miami Loam. 15 tons manure . . . Nothing added . . . Difference — 15 tons manure . . . Nothing added . .. Difference .... 15 tons manure. .. . Nothing added.... Difference 15 tons manure — Nothing added. . . Difference 15 tons manure — Nothing added.. . Difference 15 tons manure.. . Nothing added.... Difference In parts per million of dry plant. Water-soluble phosphates, as HPO.1, in corn plants 60 days after planting. 5526.0 4720.0 806.0 4238.0 4656.0 9228.0 6120.0 3108.0 6960.0 6016.0 944.0 4900.0 7040.0 5510.0 6000.0 6552.0 6704.0 -152.0 5480.0 4208.0 1272.0 -418.0 -2140.0 -490.0 Water-soluble phosphates, as HPO-i, in patato plants 65 days after planting. 4724.0 4864.0 -140.0 4864.0 4844.0 20.0 4468.0 4252.0 216.0 4948.0 4848.0 100.0 4208.0 4228.0 -20.0 3896.0 3424.0 472. 01 4244.0 4572.0 3960.0 3932.0 284.0 640.0 Water-soluble sulphates, as SO-*, in corn plants 60 days after planting. 520.0 1220.0 1480.0 1920.0 0.0 380.0 200.0 290.0 2550.0 5200.0 2450.0 2950.0 2090.0 3100.0 1400.0 1420.0 -700.0 560.0 -380.0 -90.0 -2650.0 -500.0 -1010.0 —20.0 Water-soluble sulphates, as SO4, in potato plants 65 days after planting, 4400.0 1280.0 3200.0 3040.0 2080.0 3680.0 1700.0 1440.0 2560.0 3360.0 2800.0 4320.0 2880.0 2800.0 3120.0 2960.0 3120.0 160.0 —1600.0 260.0 -800.0 —1520.0 80.0 160.0 Water-soluble bicarbonates, as HCO3, in corn plants 60 days after, planting. 7950.0 4000.0 4100.0 4800.0 31700.0 26400.0 15500.0 24600.0 6200.0 9400.0 18200.0 12600.0 10700.0 16400.0 5700.0 14200.0 3950.0 -700.0 •5300.0 —9100.0 -3200.0 5600.0 -5700.0 -8500.0 Water-soluble bicarbonates, as HCOs, in potato plants 65 days after planting. 6000.0 5600.0 400.0 6000.0 6400.0 -400.0 15000.0 7800.0 7200.0 11400.0 11400.0 0.0 8400.0 9400.0 -1000.0 10800.0 10200.0 600.0 9800.0 9400.0 400.0 11000.0 11800.0 -800.0 52 BULLETIN Amounts of water-soluble salts recovered from corn and potatoes growing upon manured and unmanured ground— Continued. Goldsboro, North Carolina Upper Marlboro, Maryland. Lancaster, Pennsylvania. Janesville, Wisconsin. Norf'lk Sandy Soil. Selma vSilt Loam. Norfolk £imd. Sassa- fras Sandy Loam. Hagers- town Clay Loam. Hag- erst'wn Loam. Janes- ville Loam. Miami Loam. 15 tons manure — Nothing added. . . . Difference 15 tons manure .. . Nothing added. . . . Difference 15 tons manure. .. . Nothing added.... Difference 15 tons manure. • . Nothing added — Difference Water soluble chlorides, as Cl. in corn plants 60 days after planting. 3700.0 2300.0 1400.0 4400.0 3700.0 700.0 3800.0 2000.0 1800.0 8950.0 6000.0 2950.0 7900.0 8500.0 11600.0 4300.0 7300.0 11050.0 ' 7100.0 10850.0 2900.0 4400.0 3950.0 7950.0 Water-soluble chlorides, as Cl. in potato plants 65 days after planting. 15500.0 4000.0 5700.0 4600.0 3700.0 2400.0 17000.0 3200.0 5200.0 3700.0 3600.0 1400.0 6900.0 1200.0 7400.0 1600.0 5800.0 11500.0 1100.0 1300.0 13800.0 1500.0 2200.0 5700.0 In parts per million of dry plant. WTater-soluble silica, or silicates, as SiO2, in corn plants 60 days after planting. 51.2 114.8 -63.6 83.7 139.8 288.2 80.8 211.1 93.2 138.1 124.0 234.3 119.2 173.6 105.6 68.0 ia5.8 90.0 -56.1 207.4 117.9 14.1 115.1 45.8 Water-soluble silica, or silicates, as SiOo, in potato plants 65 days after planting. 180.0 118.0 118.0 118.0 62. ol 0.0 142.8 111.6 31.2 155.2 155.2 90.0 186.0 -96.0 114.8 86.8 28.0 118.0 130.4 -12.4 164.0 152.0 12.0 0.0 From this table it will be seen that, at 60 and 65 days from planting, both corn and potatoes carry in their sap notable amounts of potash. Moreover, on each and every soil type and for both crops more potash has been recovered from the soils to which the manure had been applied. From the manured ground, too, have come the largest yields and the potash recov- ered from the soil has been shown to rise and fall with the yields. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 53 INFLUENCE OF MANURE UPON THE AMOUNTS OF POTASH RECOV- ERED FROM SOILS BY PLANTS. If we combine the data in the table, making two groups, under the stronger and poorer soils, they will stand as next given : Mean amounts of potash recovered from corn and potatoes growing upon manured and unmanured ground. FOUR STRONGER SOILS. FOUR POORER SOILS. Nothing added. 15 tons manure. Nothing added. 15 tons manure. Corn In parts per million of dry plant. 19345 26880 33703 25820 20920 18490 29454 25820 Potatoes Average 23113 23113 00000 100.0 29762 23113 6649 128.8 19705 19705 00000 1 100.0 27637 19705 7932 140.3 Nothing added Difference Percentage relations It is thus shown that the crops on the manured ground have recovered 29 per cent, more potash from the four stronger soils and forty per cent, more from the four poorer soils, where the 15 tons of manure had been applied. Associated with these differences in the amounts of potash recovered by the plants there have been the following differences in yield of water-free dry matter in shelled corn and potatoes, using 21.1 per cent, as the estimated amount of dry matter in the tubers as a basis for calculating the dry matter produced in this crop : Mean amounts of dry matter produced by corn and potatoes on manured and unmanured ground. FOUR STRONGER SOILS. FOUR POORER SOILS. Nothing added. 15 tons manure. Nothing added. 15 tons manure. Corn , per acre Lb«. 2878.96 2133.84 2506. 40~ 2506.40 0000.00 100.0 Lhs 3460.52 3209.31 3334.92 2506.40 828.52 133.1 LV>s. 1225.00 683.26 954.13 954.13 000.00 100.0 Lbs. 2241.57 1227.51 734.54 954.13 780.41 181.8 Potatoes, per acre Average, per acre Nothing added Difference Percentage relation . . 54 BULLETIN E. These relations of yield appear to be not only in. accord with the amounts of potash found, but also in accord with what is demonstrated regarding the functions of potash in plant physi- ology. Loew* points out that "the paramount! importance of potassium salts for every living cell is firmly established" and holds that, in green plants, they are concerned not only in the upbuilding of carbohydrates but in that of protein bodies as well. Various observers have shown that when plants are placed under conditions where all potash salts are excluded, not only does the formation of starch stop altogether but that whatever may have been present disappears and ultimately growth stops ; but that, on the admission of potash salts into the plants again, the formation of starch is renewed and growth carried forward. With vital functions like these so intimately related to this ele- ment, it is easy to understand why deficiencies of potash in forms available to crops stand next, perhaps, to deficiencies in nitrates in determining small yields. Indeed, it has transpired in the constant cropping series begun by the writer at the Wis- consin Agricultural Experiment Station in 1896, where 700- pound lots of a strong virgin soil were placed under corn, oats, potatoes and clover, and forced to produce two to three crops annually, ihat this year (1903) when Prof. Whitson divided the series into groups to test, through the application of potash, nitrates, and phosphates, which ingredient most increased the yield (then fallen far below the first crops), the results have shown in a very striking manner that the addition of potash had far greater effect than did the addition of either of the other salts, and appear to indicate that these soils had either become absolutely deficient in potash during the constant cropping, or else that the potash still remaining was not in such form as to come into solution and enter the crops with sufficient rapidity to meet their needs. In the soil of the four plant evaporimeters t ur>on which 10 stalks of corni were matured on. each of four soil types, there was a very appreciable decrease in the amounts of potash which *United States Department of Agriculture, Bureau of Plant Industry, Bul- letin No. 45, page 28. tBureau of Soils, Relation of Differences of Yield on 8 Soil-Types to Differ- ences of Climatological Environment, p. 96, F. H. King. MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 55 could be recovered from the four soils by washing them in dis- tilled water during three minutes, as shown by determination before and after the crops had occupied the ground ; the results appear in the table which follows: Amounts of water-soluble xalts in the surface foot, under corn, at the beginning and close of the growing season. K. Ca. Mg. N03. HPO4 S04- HCO3. Cl. SiOo. In soil at start In parts per million of dry soil. Norfolk Sandy Soil. 5.61 1.84 -3.77 25.50 27.00 +1.50 10.70 8.15 ^2.55 20.46 3.13 -17.33 2.85 2.73 j9 45.50 72.50 +27.00 —17 6 +23 0 4.05 0 4.10 0 "1 +.05 In soil at close Change In soil at start Norfolk Sand. 5.20 2.38 -2.82 22.25 41.30 +19.05 11.95 9.51 16.52 6.25 -10.27 2.95 3.80 + .85 35.50 77.50 +42.00 4 +7 0 0 0 6.45 4.70 —1.75 In soil at close Change InsoU at start -2.44 Hagerstown Clay Loam. 12.10 6.68 -5.42 281.25 243.80 -37.45 28.54 32.36 50.80 26.92 14.10 12.90 -1.20 207.50 256.30 +48.80 88 124 0 0 0 15.80 15.10 In soil at close. Change -1-3.82 -23.88 +36 — .70 In soil at start In soil at close Change Average change Janesville Loam. 6.92 3.94 -2.98 -3.75 215.65 100.00 -115.65 -33.14 24.11 19.02 -5.09 —1.57 68.55 22.15 -46.40 -24.47 19.70 17.10 -2.60 -.77 150.00 46 105 .00 52 -45.00J +6 +18.20' +18 0 0 0 0 23.55 18.60 -4.95 +1.84 There is thus shown, in each of the four cases, that a reduc- tion has occurred in the amounts of potash which) could be recovered from these soils at the close of the season,, and this reduction was not confined to the surface foot, as will appear from the next table: Changes in the amounts of potash which could be recovered from the surface three feet of four soils after cropping one season. Norfolk Sandy Soil. Norfolk Sand. Hagerstown Clay Loam. Jauesville Loam. Change of potash (K) in 1st foot.. Change of potash (K) in 2d foot . . Change of potash (.K) in 3d foot.. In parts per million of dry soil. 3.77 3.23 + .07 ~6.93 26.84 2.82 .68 1.26 4.76 17.23 5.42 5.92 6.00 17.34 54.55 2.98 3.05 3.01 9.04 27.87 Change in pounds per acre 56 BULLETIN "E.: It is thus seen that a change has occurred during the matur- ing of the crop of corn upon these four soils, which has made it possible to recover by the same treatment with distilled water from 17.23 to 54.55 pounds per acre less potash in the three feet of soil occupied by the roots of the corn ; and it is clear that such a rate of decrease in the solubility of potash or in the amount of soluble potash present, could not be maintained through many seasons before the effect would be reflected in the yields of the crops, as, indeed, has been shown to have occurred in the Wisconsin series cited above: INFLUENCE OF MANURE UPON THE AMOUNTS OF LIME AND MAGNESIA RECOVERED FROM SOILS BY PLANTS. If the amounts of lime and magnesia found in the corn and potato plants are brought together from the general table and grouped under stronger and poorer soils, the results will stand as given in the next table: Mean amounts of lime and magnesia recovered from corn and potatoes growing upon manured and unmanured ground. AMOUNTS OF LIME (Ca). AMOUNTS OF MAGNESIA (Mg). U stronger soils. It poorer soils. U stronger soils. It poorer so Is. Noth- ing added. 15 tons ma- nure. Noth- ing added. 15 tons ma- nure. Noth- ing added 15 tons ma- nure. Noth- ing added 15 tons ma- nure. Corn In parts per million of dry plant. 4025 4287 4156 4156 2711 4275 3493 41.56 2831 2857 2844 2844 1623 2256 1940 2844 4028 5442 4735 4735 2610 4804 3707 47a5 1683 2483 2083 2083 1155 1693 1424 2083 Potatoes Average Nothing added Difference -^centage relations.. 0000 100.00 -663 84.05 0000 100.00 -904 68.2 0000 100.00 -1028 78.28 0000 100.00 -659 68.36 • From this table it appears that, as an average, the plants growing upon the manured ground, the ones which were mik- ing, at the time of the examination, the most vigorous growth, and the ones which produced, in the end, the largest yields had, in their plant sap or in their tissues, in a form which could MANURE, YIELD AND SOLUBLK SALTS IN SOILS. 57 be recovered by the treatment with water, relatively less of both lime and magnesia than did those growing upon the unmanured ground and which produced the smallest final yields. If reference is made to the general table it will be seen that, for the corn, there are no exceptions to this statement among the individual data ; that there is but one exception among the potatoes with magnesia ; but that there are three exceptions with lime, one of which is percentagely large. The observed relations of the three bases determined in the studies and here referred to, cannot be ascribed to a differential effect of the soils upon them, the manure holding these salts back, for it has been shown that more of all three bases existed in the manured soils in a form which could be recovered by washing in distilled water. The relations of limel and mag- nesia are, however, such as might be expected if the views of Loew* regarding the functions and movements of limei and magnesia in living tissues are correct. We refer specially to the statement, p. 56, that, "as a matter of fact, it is found that magnesia always increases where rapid development is taking place," and that "the calcium content increases with the mass of nuclear substance and chlorophyll bodies." If these state- ments are correct, and if the lime and magnesia thus accumu- lated become insoluble, or are otherwise held back from the solu- tion, then there should be observed a greater reduction of the soluble lime and magnesia in the plant sap where the most vig- orous growth is taking place. It is, of course, recognized that observations of this character are suggestive rather than demon- strative. Attention should also be called to the fact that the amounts in the table are relative to the dry matter and not absolute. *United States Department of Agriculture, Bureau of Plant Industry, Bulletin No. 45. 58 BULLETIN "E. INFLUENCE OF MANURE UPON THE AMOUNTS OF NITRIC AND PHOSPHORIC ACIDS RECOVERED FROM SOILS BY PLANTS. Determining the mean values for the nitric acid and phos- phoric acid recovered from the plants grown upon the manured and unmanured soils the values stand' as given in the next table: Mean amounts of nitric acid and of phosphoric acid recovered from corn and potatoes grown upon manured and unmanured ground. AMOUNTS OF NITETC ACID (N03). AMOUNTS OF PHOPPHOBIC ACID (HP04). It stronger soils. It poorer soils. It stronger soils'. It poorer soils. Noth- ing added. 15 tons ma- nure. Noth- ing added 15 tons ma- nure. Noth- ing added. 15 tons ma- nure. Noth- ing added. 15 tons ma- nure. Corn In parts per million of dry plant. 20152 27290 23721 18944 23710 21327 2490 7271 4881 1554 13951 7753 5611 4230 4921 5988 3886 4937 6488 4501 5495 5378 4702 5040 Potatoes Average This table shows no such sharp percentage differences as stand out clear and strong with the three bases. With the nitrates from both corn and potatoes, except on the poorer soils, tlhe relation holds which occurred with the lime and magnesia, namely, a smaller relative amount in the plants which have made the most vigorous growth ; and, with the nitric acid being transformed into organic nitrogen, this relation is what should be expected. With the phosphoric acid there is less indication of the manure having had any effect upon the percentage amounts recovered by the treatment of the plant samples with distilled water. Comparing the absolute amounts of these two ingredients, which had been recovered from the soils by the plants at the time the samples were taken and which still remained in solu- ble form in their tissues, the relations will, of course, be quite different from those shown by the table. The relative amounts of dry matter existing in the crops under comparison at the time of observation are not known, but it is likely that the MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 59 ratios which did exist at the time were, approximately, the same as would be shown by the differences in the amounts of dry matter given in the table, p. 53. If calculations are made on the basis of those values it will be found that the absolute -amounts of nitric and phosphoric acids which were recovered from tihe plants are largest from those which had grown upon the manured ground. In the case of sulphates recovered from the plants, under the two conditions, there were larger relative amounts recovered from the corn growing upon the manured land, and also from the potatoes in the case of the stronger soils. This relation was, however, reversed in the potatoes from the poorer soils. In view of the fact that the soil moisture has usually shown such large amounts of sulphates, when compared with those of other ingredients determined, it appears not a little remark- able that the plant sap should have been found to contain so little. The sulphur is, of course, appropriated as growth goes forward, and possibly the small amounts observed are due to absorption in this way. In the case of chlorine, which has invariably been found in these soils in very small amounts, the relations are the reverse so far as the plants are concerned. Not only are relatively large amounts recovered- from the plant tissues, but the differences between the amounts recovered from the plants grown upon the manured and unmanured ground are very large, and in the same direction as occurred in the case of potash. The relations are expressed in the next table: Mean amounts of chlorine recovered from corn and potatoes grown upon manured and unmanured ground. FOUR STRONGER SOILS. FOUE POORER SOILS. Nothing added. 15 tons manure. Nothing added. 15 tons manure. Corti In parts per million of dry plant. 4450 1975 ~3213 3213 0000 100.00 10350 5775 8063 3213 4850 250.95 avx) 3550 .3525 3525 0000 100.00 5213 10475 7844 £525 4319 222.52 Potatoes Nothing added Percentage relations » 00 BULLETIN It is here seen that the plants grown upon the manured ground have yielded to the treatment more than double the amounts of chlorine that were recovered from the plants which had grown upon, the unmanured ground. The observations here presented, both upon the soils and upon the plants which had grown upon the soils, make it clear that when farm yard manure is applied to fields it has the effect not only of increasing the yields but at the same time of increasing the amounts of water-soluble salts which can be re- covered from the soils themselves and from the plants which have grown upon them. LARGEST RETURNS FROM STABLE MANURE. It will be clear from the data which have been presented, relative to the yields of corn and potatoes which have been se- cured through the application of 5, 10 and 15 tons of manure per acre, to different soil types, and also from the rates of nitri- fication which were observed when larger amounts of manure had been used, that a careful observation of results and good judgment are necessary in order to secure the largest returns from manure applied to land. In general farming, there can be no question but that, it is much better to follow the practice of giving frequent and light dressings of manure to land rather than to apply large amounts at long intervals. A small increase of a few bushels of grain, potatoes or roots, or a few hundredweight increase of grass or hay per acre, steadily maintained over the whole farm year after year, will bring much larger returns than can be secured from high fertilization at long intervals, or continuonslv on small por- tions of the farm, while the balance receives little attention. One hundred tons of manure carefully applied to 10 or 15 acres well cared for will give larger returns, in general farming, than when the same amount is applied to four or five acres, as is often the case. When too much manure is applied wasteful oxidations occur which destroy the organic matter at once, returning it direct to the atmosphere; and this may happen when an unsuccessful MAM RK. YIKI.I) AND SOLUBLE SALTS IN SOILS. 61 effort lias been made to apply a moderate amount of manure, by distributing it unevenly over the surface. When manure is applied directly beneath t%he row, in the bottom of a furrow, much greater care is required not to get results which, in effect, so far as the relations of manure to soil are concerned, are not equivalent 'to 30 to 50 tons per acre. In such cases, not only may normal nitrification be interfered with, but concentration of the plant roots within a small volume of soil where the plant food has been made overabundant may result in such a defi- ciency of soil moisture that, for this reason alone, the manure becomes comparatively inefficient. BULLETIN "F." The Movement of Water-soluble Salts in Soils. In investigating the amounts of water-soluble salts in and their absorption by different soil types in reference to their bear- ing upon problems in soil management, it was necessary to take into consideration, also, the movements of these salts as deter- mined by diffusion, gravitation and capillarity. It is now well recognized that the surface cultivation of soils, such as maintains, for intertilled crops, a loose, open texture in the upper two to four inches, very materially influences the capillary movements of the* soil moisture and reduces its rate of evaporation from the surface. This being true of the soil moisture, it was to be expected that surface tillage would also exert an influence upon the movement and position of the water-soluble salts which it may* carry in solution, and observa- tions were made, both upon the capillary movement of salts through the different soil types under investigation, and regard- ing the influence of soil mulches upon the position in and movement of water-soluble salts in soils. CAPILLARY MOVEMENT OF SOLUBLE SALTS IN SOILS. CAPILLARY MOVEMENT IX SIX SOIL TYPES. In the first series of observations made only the movement of the negative radicles was determined, the work being done in 1902 before the methods for the estimation of bases had been devised. Six cylinders of galvanized iron, 5*4 inches in diam- eter and 12 inches deep, were carefully packed with the same kind of soil, which had been taken from the surface foot! in MOVEMENTS OF SALTS IN SOILS. 63 good field moisture condition. Previous to packing, the soil was screened through a sieve of one-fourth inch meshes and, in 20-pound lots, was spread over 8 square feet of surface on a mixing floor. Over this soil was sowed 2 grams of acme guano and then a second layer of soil added, sowing fertilizer again on the top, and repeating the operation until 200 Ibs. of soil had been thus treated. The whole soil was then shoveled over three times to more thoroughly incorporate the fertilizer with it. The six cylinders were then filled simultaneously, placing a cupful of soil, "struck "off," into each, in regular rotation, with gentle tamping after each addition of soil, until they were all full. At the time the soil was being placed in the cylinders a small sample from each cup was taken, with a spatula, to constitute a composite representing the condition of the soil in the several cylinders at starting. The filled cylinders, when "struck off/7 weighed : No 1 Ibs. No. 2 Ibs. No. 3 Ibs. No. 4 Ibs. No. 5 Ibs. No. 6 Ibs. 19.36 | 19.52 I 19.56 I 19.52 | 19.56 I The several cylinders were provided with reservoirs at their bases which permitted the addition of water at the bottom of the column, and its rise by capillarity through the soil. When filled, they were placed side by side, as represented in Fig. 1, p. 64, at the left, and 500 c. c. of water added ; when this had been absorbed, another 500 c. c. was added and the cylinders allowed to stand 24 hours. At this time the soil was removed from one of the cylinders in 2-inch sections and the water- soluble salts determined. The covers were removed from the remaining cylinders, 300 c. c. more of water added, and evapo- ration permitted to maintain the capillary rise of moisture through the soil during different intervals of time. Three soil types were subjected lo this treatment .and the results are given in the next tables, as mjean values, showing the change in the relative amounts of each ingredient determined in the respective depths of soil. FIG. 1. — Showing method of studying capillary movement of salts in different soil types, and the effect of mulches upon the distribution of salts in soils. Mean distribution of salts in three soil types after a capillary movement during 15 to 23 clays. Depth. NO3. Cl. SO4. HPO4. HC03 SiO3. 0 to 2 inches In parts per million of dry soil. 278.00 21.78 22.03 22.73 23.60 22.07 65.04 23.75 41.29 202.53 10.30 10.96 11.08 9.74 9.33 42.32 38.94 3.38 267.04 24.30 19. P3 15.16 9.60 8.03 57.34 53.38 ~3.96 8.94 8.87 8.93 8.92 8.68 8.19 8.76 7.02 1.74 8.24 8.42 8.72 8.62 9.27 7.53 8.47 5.59 2.88 3.91 3.95 4.41 4.52 4.92 5.09 4.47 2.40 2.07 2 to 4 inches 4 to 6 inches 6 to 8 inches 8 to 10 inches 10 to 12 inches Average at close Present at start Difference This table contains only the data obtained from that cylinder in each series which was subjected to the longest capillary movement. Each of the other cylinders was also examined in such a succession as to show the capillary movements of salts which had taken place at the end of intervals of different dura- tion. MOVEMENTS OF SALTS IN SOILS. 65 In this table it will be observed that each and every ingredi- ent has been recovered from the soil in larger amounts than were recovered from the soil at the start and tjhe mean differ- ences are recorded in the last line of the table, where, it will be seen, that the excess amounts recovered range from 1.74 parts of HPO4 per million of dry soil in a column one foot in depth to 41.29 parts per million of nitric acid (NO3). A portion of this increase is due to sails, which were carried in 1300 c. c. of tap water, added to each cylinder to secure capillary movement and whose composition is given below. The water added was about one-fifth the dry weight of the soil. Amounts of salts in water added to the soil. NO3. HPO4. S04. HCO3. Cl. SiO3. In water . . In parts per million. .38 .07 1.53 .31 5.28 1.06 2.32 .46 3.92 .78 9.79 1.96 Added to soil In the surface two inches of soil there has been an extremely large accumulation of nitrates, sulphates and chlorides ; so, too, has there been an increase of the other three ingredients deter- mined and, in every probability, considerable amounts of one or more of the bases which are essential plant foods. So large was this capillary concentration of the most soluble salts that only 30.8 per cent, of the total nitrates, in the foot of soil, remained below the surface two inches; only 20.6 per cent, of the chlorides and only 25.3 per cent, of the sulphates; and yet, to be serviceable to a crop, it should all remain below the sur- face 2 inches. The amount of water which passed by capillarity through the bottom layer of these 12 inches of soil was about 4. 37 inches inj depth. It must be said that the data given in the table, p. 64, do not represent the maximum concentration which occurred in the surface 2 inches. It was the cylinders examined on the fourth or fifth dates which showed the largest accumulation of salts in the surface two inches. Later, the capillary rise had become so slow, on account of the drying out of the soils, that the back- ward diffusion of the very soluble sa^ts, in several cases, espe- 5 66 cially of the chlorides, became more rapid than the forward movement due to capillarity, and the result was the salts dimin- ished at the top after a certain relation of concentration to the rate of capillary movement had become established. The mean rates of accumulation of the most soluble salts — chlorides, nitrates and sulphates — as shown by the examina- tions made on successive dates, are given in the next table, where the mean intervals of time during which capillary move- ment acted in effecting this distribution, are also given. In the same table are given the corresponding data for the phos- phates, by way of contrast. Mean distribution of water-soluble salts, as affected by capillarity r at the close of different intervals. Mean time. 0-2 inches . 2-4 inches. 4—6 inches. 6-8 inches. 8—10 inches 10—12 inches , 1 day... In parts per million of dry soil. Nitrates (NO3). 46.43 46.93 127.93 24.27 157.33 17.09 163.73 17.74 181.57 16.94 278.00 21.78 29.48 17.05 11.74 13.79 16.97 22.03 13.12 11.21 8.59 11.48 16.68 22.73 6.68 6.69 7.06 9.80 15.01 23.60 2.59- 2.61 3.46 7.19 15.40 22.07 4.3 days 7.3 days 10.3 days 15 days 19 days 1 day... Chlorides (CD. 90.55 190.50 196.07 207.76 210.91 202.53 79.48 18.53 11.76 7.99 8.89 10.30 46.10 ."> . 55 9.08 6.74 7.16 10.96 16.88 5.66 7.12 7.35 10.10 11.08 11.83 5.48 7.67 6.90 8.36 9.74 8.04 5.31 6.05 7.62 8.92 9.33 4 3 days 7 3 days 10.3 days 15 days 19 days 1 day Sulphates (SOi). 104.34 185.38 188.63 231.44 257.13 267.04 121.15 72.92 60.60 46.54 33. 56 24.30 96.81 47.65 38.43 30.96 24.93 19.93 47.90 26.22 20.56 17.35 17.37 15.16 29.28 9.78 10.31 10.55 12.99 9.60 19.84 8.75 7.96 9.30 12.12 8.03 4.3 days 7.3 days 10.3 days 15 days .... 19 days 1 day Phosphates (HPO4). 8.66 8.58 8.88 8.56 10.44 8.94 8.49 8.18 7.85 8.33 9.44 8.87 8.75 8.81 7.92 8.28 9.22 8.93 10.10 8.13 9.12 9.54 9.76 8.92 8.37 9.52 10.88 10.89 10.44 8.68 9.22 10.52 10.54 10.84 11.07 8.19 4.3 days.. . 7.3 days 10.3 days 15 days 19 days . . MOYKMK.Vrs OK SALTS I \ SOILS. 67 From ihis table it will lie s«>n tlut, as an average, the salts of the three soils increased in the surface layer up to the end of 19 days. This, however, was not true of two of the soils making up the average. In the bottom, layer the nitrates in- creased, period by period, after the first day; and the same relation was true of the 8 to 10 inches. These increases are probably due to nitrification which was progressing in the soils. >^vrr. Till m M Star t FIG. 2. — Showing the mean distribution of sulphates in three soil types result- ing from capillary movement. In the case of the chlorides there was an increase in the sur- face layer until the end of 15 days, when these fell off, but increased in each and every layer below the surface during the 68 BULLETIN F.x last four days, showing a downward diffusion which exceeded the capillary rise. The changes in sulphates, from period to period, are shown graphically in Fig. 2, p. 67, for the several depths. In this case the surface layer gained in SO4 until the end while the bottom layer had least in it at this time, indicating that the diffusion rate was too slow to counteract the capillary rise. In the case of the phosphates, the absorption was evidently so strong from the first that the amounts left in recoverable form were too small to bring out clearly the movements within so short a series of observations. In the next table the percent- age amounts of phosphates found are given, using that recov- ered from the soil at the start as the basis of comparison. Amounts of phosphates recovered in different layers, expressed in per cents. 0-2 inches. 2-4 inches. 4-6 inches. OS inches. 8-10 inches. 10-12 inches. In soil at start In per cent, of amount at start 100.0 123.3 122.2 126.5 121.9 148.7 127.4 100.0 120.9 116.5 111.8 118.7 134.5 126.3 100.0 124.6 125.5 112.8 117.9 131.3 127.2 100.0 144.9 116.6 129.9 ia5.9 139.0 127.1 100.0 123.5 1.35.6 155.0 155.1 148.7 123.6 100.0 131.3 149.8 150.1 154.4 157.7 116.7 After 1 day After 4 3 days After 7.3days After 10. 3days After 15 days After 19 days The amount of phosphoric acid added to the soil with the water was only 4.4 per cent, of the amount present at the start, but the smallest amount recovered was 116.7 per cent, of that found in the soil at the start, while the largest amounts found range near 150 per cent. These differences are larger than the error of the method and indicate that more phosphoric acid has come into recoverable condition with water alone, during this capillary treatment, than existed in the soils before being so treated. It has been -demonstrated, through both field and laboratory studies, that one effect of capillary movement is to concentrate nitrates to such an extent that larger amounts of them may be recovered from a soil than it is possible to recover where capillary concentration has not taken place. That this may also be true for other salts isl to be expected unless it b© in those cases where large absorption takes place, as so often happens with potash and phosphoric acid. MOVEMENTS OF SALTS IN SOILS. 69 CAPILLARY CONCENTRATION OF SALTS UNDER FIELD CONDITIONS. Field studies relating to this subject were made by the writer and Mr. J. O. Belz during the season of 1901*, which demon- strated that, under the conditions of furrow irrigation, on both a medium clay loam and on a light, sandy soil very notable movements of nitrates occur through downward, lateral and up- ward capillarity ; and it appears from those studies that the in- fluence of the lateral capillary sweeping of salts was great enough to be reflected in the yield of potatoes across a distance of more than 6 feet or in the third row away from the last irrigated fur- row. As an illustration of the magnitude and rapidity of the movement of nitrates in field soils, resulting from capillary action, after irrigation by the furrow method, and to show what must often take place after heavy rains where ridge and furrow cultivation is practiced, as is so generally done in many parts of the South, the following observations are cited : IN A COARSE SANDY SOIL. A field of potatoes, on coarse sandy land, at Stevens Point, Wis., with rows 3 feet apart and hilled, was examined for nitrates under and between the rows just before it was to be irrigated. The same rows were again examined for nitrates at different intervals after the water had been applied. Four series of observations were made upon this sandy soil and the results are given in the next table : Concentration of nitrates by lateral capillary movement in xandy soil. UNDER POTATO Rows. BETWEEN POTATO Rows. 1st ft. 2nd ft. 3rd ft. 4th ft. 1st ft. 2nd ft. 3rd ft. 4th ft. Before irrigation 1 hour after irrigation . Change In parts per million of dry soil. 9.37 12.67 7.17 21.55 3.55 7.78 2.40 12.12 27.58 5.57 6.84 8.51 4.23 12.52 3.81 11.54 3.30 14.38 4.23 25.18 1 -6.55 1.67 8.29 7.73 * United States Department of Agriculture, Office of Experiment Stations, Bulletin. No. 119, p. 345. 70 BULLETIN F.' From this table it is clear that, during the short interval of about one hour during which the water was running between the rows and another hour after the water was turned off, a very marked change had occurred in the distribution of nitrates in the soil. As soon as the water was led into the furrows per- colation began and in front of the advancing water, as well as laterally from it under the rows from both sides, capillary ac- tion shoved the water, already in the soil, together with the ni- trates which it carried, downward and sidewise, causing a con- centration at the places where the capillary water accumulated. IN MEDIUM CLAY LOAM. In the next table are cited similar observations made at Mad- ison, Wis., also in a potato field, but on a medium clay loam richer in nitrates. Concentration of nitrates by lateral capillary movement in a me- dium clay loam rich in nitrates. UNDER POTATO Rows. BETWEEN POTATO Rows. 1st ft. 2nd ft. 3rd ft. 4th ft. 1st ft. 2nd ft. 3rd ft. 4th ft. Before irrigation ....... 4 hours after irrigation In parts per million of dry soil. 248.26 294.80 21.75 41.71 19.96 21.75 14.90 -6.85 21.75 114.84 6.29 11.53 5.24 6.29 10.03 5.80 23.04 51.09 29.68 34.45 35.33 .88 34.45 40.80 26.60 18.90 9,73 8.52 -1.21 9.73 7.93 -1.80 9.73 7.20 46.54 248.26 303.92 55.66 248.26 349.26 17.24 5.80 4.77 -21.41* 51.09 31.02 -7.70 26.60 26.80 Before irrigation 26 hours after irrigation Change .. 3.74 6.29 10.74 —1.03 5.80 5.42 -20.07 51.09 33.42 6.35 34.45 32.64 .20 26.60 21.06 Before irrigation 50 hours after irrigation Change . . 101.00 93.09 4.45 -.38 17.67 -1.81 -5.54 -2.53 In all of these series, the determinations were made upon composite samples of 4 cores, each taken within 10 to 12 inches of the place where the ones of the preceding series were taken. In the first group of the table the interval of time between the taking of the two sets of samples is too short to admit of either nitrification or denit'rification having occurred to such an extent MOVEMENTS OF SALTS IN SOILS. 71 as to cause the differences observed. Time enough did, how- ever, intervene between the start and the last series to permit considerable changes of a biological character to take place ; but the associated changes which were observed to have occurred, in the water content of the soils, were usually in the direction which would explain the observed changes in the amounts of nitrates had they resulted from translocation by capillarity. IN NORFOLK SANDY SOIL. A field on the Norfolk Sandy Soil had been planted to peas the latter part of January, 1902, in rows 3.5 feet apart, under which had been applied 500 Ibs. of guano together with stable manure at the rate of 50 bushels per acre, both drilled in the furrows before planting. The fertilizer applied carried the manufacturer's guarantee to contain 5 per cent, potash, 5 per cent, ammonia, and 8 per cent, of phosphoric acid. In 1901 this field had been given an application of guano, drilled under cotton rows, at the rate of 1,000 Ibs. per acre. On May 5, just as the .peas1 were approaching the stage of maturity for picking, samples of soil were taken, in one-foot sec- tions, to a depth of four feet, both under and between the rows; the cores of the respective composites being taken in pairs im- mediately adjacent, one under and the other between the rows. Two sets of these samples were taken at this time, one where the peas were large and vigorous and the other where they were smaller. In the next table are given the results found. BULLETIN "F. Water-soluble salts under and between fertilized rows of peas. Rows. UNDER GOOD PEAS. UNDEE POOR PEAS. 1st ft. 2nd ft. 3rd ft. 4th ft. 1st ft. 2nd ft 3rd ft. 4th ft. Under In parts per million of dry soil. Amounts of nitrates (NOa). 8.16 3.86 4.30 4.70 2.42 2.28 4.68 2.54 2.14 4.34 5.51 —1.20 4.76 3.33 1.43 3.28 2.24 1.04 3.25 3.05 .20 3.81 3.51 .30 Between Difference Under . .... Amounts of phosphates (HPO.i). 11.34 9.35 7.91 6.62 5.37 4.66 5.30 4.54 8.01 5.83 5.16 5.23 3.88 3.88 3.83 2.99 Between Difference Under 1.99 1.29 .71 .76 2.18 — .07 0.00 .84 Amounts of sulphates (804). 48.88 32.85 31.42 22.87 34.58 30.66 34.13 33.91 3.08 2.05 11.44 20.01 37.23 33.91 14.93 12.64 Between Difference 16.03 8.55 3.92 2° 1.03 -8.57 3.32 2.29 Under Amounts of bicarbonates (HCO3). 12.68 12.92 13.17 13.69 10.39 13.62 13.55 12.97 12.97 13.17 10.09 17.40 10.39 13.69 16.79 Between 16.00 Difference —3.32 — .25 3.30 .07 00.00 3.08 7.01 -3.10 Under Amounts of chlorides (Cl). 18.41 11.25 7.16 22.55 15.32 7.23 11.92 8.08 3.84 19.78 15.74 -T5T| 18.87 15.09 3.78 19.13 15.64 3.49 16.18 12.09 4.09 11.93 11.73 .20 Between Difference Under Amounts of silicates (SiOa). 1.36 .35 3.13 2.48 5.16 5.29 4.39 4.74 2.09 2.09 3.19 4.35 5.62 6.35 5.53 5.43 Between Difference 1.01 ! .65 -.13 -.35 0.00 -1.16 -.73 .10 On this field, as is the practice generally for intertilled crops here, ridge and furrow cultivation was practiced. The data of the table show that there is an unequal distribution of readily water-soluble salts in this field, which extends even into the 4th foot. On account of the method of applying the fertilizers under the row it is to be expected, even so long after the treat- ment as was the case here, that a difference would obtain in the direction observed, so far as the first foot and, perhaps, MOVKMKNTS ( ) I-' SAI.TS IX SOILS. 73 oven the second foot is concerned. So, too, if it had transpired that a heavy rain fell, before the rows had been ridged, and es- pecially while they were depressed after applying the fertilizer, the more soluble salts and those less strongly absorbed by the soil might have been carried by percolation into the third and fourth feet, so as to have developed differences at these levels. It appears highly probable, however, that differences due only to such a cause would have been obliterated by lateral diffusion before the date of collecting the samples. The more probable explanation of the observed differences is that they had been developed, partly as stated, but also as the result of heavier percolation between the rows after rainfalls and the capillary sweeping which followed. The rainfall rec- ords show that on April 29, 30 and May 2, rain fell to the ex- tent of .35, .20 and .16 inches, respectively, the latter occurring only 3 days prior to taking the samples. With the ridged con- dition of the surface and the generally level nature of the field, a rapid fall of rain does have the effect of sometimes throwing into the furrows the equivalent of 2 or 3 times the amounts of water indicated by the rainfall observed, and in this way may have established such conditions as are associated with furrow irrigation, whose effects upon the movement of nitrates have been cited. The table shows that, except in the case of the silica, and perhaps the bicarbonates, the distribution of salts is such as would be expected from furrow irrigation, and it appears more probable that the differences are due to such an effect rather than that the salts have either percolated or diffused directly downward from the furrow where the fertilizers were applied. ON GOLDSBORO COMPACT SANDY LOAM AND SELMA SILT LOAM. In two other cases similar comparisons were made on sam- ples taken under and between rows of peas, one on the Grolds- boro Compact Sandy Loam and the other upon the Selma Silt Loam. Both crops were planted the last of January, the 24th and 25th. Under the pea rows, on the former soil, were ap- plied 400 Ibs. of guano arid 25 bushels of cotton seed per acre; 74 under the latter 400 Ibs. of guano per acre. To the latter there was also applied 625 bushels per acre of a compost made from one part of yard manure and one of soil, spread broad- cast and plowed in. The following table gives a portion of the data determined May 2nd and 3rd. Water-soluble salts under and between rows of peas. On Goldsboro Compact Sandy Loam. On Selma Silt Loam. 1st ft. 2nd ft 3d ft. 4th ft. 1st ft. 2nd ft. 3d ft. 4th ft. Under rows In parts per million of dry soil. Amounts of nitrates (NO8). 7.60 8.80 7.82 4.60 8.22 4.92 11.60 17.50 34.00 25.70 21.60 22.80 21.50 21.50 15.50 14.90 Between rows 1 20 3.22 3.32 5 90 8.30 1 °3 00.00 .60 Amounts of phosphates (HPO4). 10.63 8.01 4.60 3.80 .80 6.29 6.29 0.00 6.38 7.07 8.54 7.38 7.28 6.65 .63 6.47 6.06 .41 5.98 5.06 .92 Between rows 2.62 -.69 1.16 Under rows Amounts of sulphates (SO4). 24.97 2.05 22.92 31.34 17.19 14.15 31.07 2S.11 2.30 3.37 3.33 .04 50.36 23.11 27.25 31.92 19.94 11.98 9.56 11.00 -1.44 8.43 5.94 2.49 Between rows Difference In these cases the differences are not as strongly marked throughout the four feet as they were. in the former series, but there can be little doubt but that either the fertilizer has ad- vanced downward directly beneath the rows or else there has been lateral capillary sweeping of salts which has caused the concentration under the rows. CAPILLARY MOVEMENT OF SALTS IN EIGHT SOIL TYPES. METHOD OF TREATMENT. In these studies a pair of the 2-foot cylinders represented in Fig. 1, p. 64, were filled, at each station, with the soil of the surface foot of each type, in a nearly air-dry condition. The MOVEMENTS OF SALTS IN SOILS. 75 soil used was collected from the immediate surface of the un- fertilized sub-plots and packed in the cylinders in the normal crumb-structure condition. To study the effect of the different soils upon the capillary movement of salts a bulk lot of solution was prepared at the central laboratory and shipped in glass-stoppered bottles to the stations. This solution as used was found, by the colorimetric methods, to contain the different ingredients in amounts as stated in the following table: Composition of solution used in capillary movement of salts in soils. K. Ca. Mg. NO8. HPO4. SO4. HC03- CL Si02. In parts per, million of solution. 119.54 ) 30.00 I 41.80 | 55.65 | 49.95 | 162.66 J 143.50 | 24.17 [ 9.95 The solution was added to the reservoirs of the two cylinders of both pairs at the same time, as rapidly as capillarity would permit, until the soils became wet on the surface, the covers being kept on to prevent evaporation. At about this time the soil was removed from one of the cylinders in one- or two-inch layers, as indicated in the tables beyond, weighed and dried and the per cent, of moisture determined. The other cylinder of soil had its cover removed and was set out in a free circu- lation of air, to strengthen the loss of water by evaporation and distilled water was kept supplied until about as much had been added to the soil as it had taken of the salt solution. There are thus two series of soil samples: (1) one through which a salt solution had risen by capillarity until the soilwas wet on the surface, and, (2) another in which distilled water was per- mitted to follow, also by capillarity, the salt solution until enough more had entered the soil to have about displaced the salt solution. Through a misunderstanding, these conditions were not fully realized in all cases, as will appear in the next section. AMOUNT OF CAPILLARY MOVEMENT. The amount of capillary movement which took place in each cylinder will be indicated by the amounts of solution and of distilled water which were added in each case, and these are given in the next table. Amounts of solution and of distilled water added ti each soil. Nor. folk Sandy Soil. Selma Silt Loam. Nor- folk Sand. Sassa- fras Saudy Loam. Hag- erst'wn Clay Loam. Hag- erst'wn Loam. Janes- ville Loam. Miami Loam. c. c. c. c. c. c. c. c. c. c. c. c. c. c. c. c. No. 1. Solution added . . . 2330 2260 2309 2270 2300 2400 2445 2165 No. 2. Solution added . . . 2366 2248 2097 2127 2400 2400 2481 2262 No. 2. Disti'ed w'ter add 652 518 750 J 1039 2350 2400 2505 2227 The amount of solution which passed into the soil of each cylinder is thus something more than two liters. In the Janes- ville and Lancaster soils to which distilled water was added Jhere was applied as much more; but the other four soils re- ceived less. It must be understood, in considering! the results obtained, that the conditions of the experiment were such that the lower section of each soil column had practically been washed with a salt solution, while the upper section in each case had had a salt solution added to it by capillarity, the solution rising into it from the layers below. In addition to this, the bottom layer of the second cylinder of each pair, had been washed with a certain amount of distilled water passing upward through it DURATION OF CAPILLARY MOVEMENT. The Norfolk Sandy Soil and Selma Silt Loam, which re- ceived only the salt solution, were under the conditions of cap- illary movement during 20 days; while the cylinders1 receiving the distilled water were under these conditions 51 days. The Norfolk Sand and Sassafras Sandy Loam were under the conditions of capillary movement during 19 days, where no distilled water was added, and during 50 days where it was MOVEMENTS OF SALTS IN SOILS. 77 added, the soil being removed 7 days after the last distilled water had been introduced. In the case of the Lancaster soils the salt solution was added to all cylinders between July 12 and 19, and the soils were re- moved from the ones to which no distilled water had been given, on the 29th, making a capillary period of 17 days. Dis- tilled water was introduced between July '28 and August 24 and the soil was removed on August 31, making a capillary period of 50 days for the second pair of cylinders. At Janesville the solutions were added to the soils between July 11 and 15, and the distilled water between July 27 and August 29. The cylinders receiving the solution had the soil removed on July 29, making the period of capillary movement 18 days. The soil was removed from the distilled water pair on September 1, making this period 52 days. WATER-SOLUBLE SALTS RECOVERED AFTER CAPILLARY MOVEMENT. At the close of the period of capillary movement, in each case, the soil was removed in consecutive layers, the first four, one inch each, and the balance, two inches deep. At Upper Marlboro the soil was not sufficiently firmed to prevent settling when the water was added, with the result that the columns were shortened by shrinkage the amounts indicated in the tables which follow, where the amounts of salts found at the several depths in the different soils and under the different conditions are given. Distribution of water-soluble salts resulting from capillarity. Depth. Inches. K. Ca. Mg. N03. HP04. S04. HCO3. Cl. Si02. 0— 1 In parts per million of dry soil. Norfolk Sandy Soil. After a period of 20 days. 100.00 21.68 18.50 17.12 17.76 13.20 12.84 12.04 12.52 1312.5 187.5 103.1 62.5 40.0 40.0 37.5 41.3 35.0 37.5 42.5 48.8 13.5 4.5 110.0 269.12 25.93 15.22 13.98 13.17 11.41 10.07 9.26 9.01 9.26 11.04 9.01 8.40 9.01 16.79 1004.80 181.20 100.80 53.40 16.52 10.68 7.72 10.08 8.26 10.38 7.26 10.68 5.68 5.50 103.80 2.6 3.0 3.3 3.9 4.1 4.3 4.2 4.8 5.3 5.4 4.5 3.9 5.4 7.7 3.8 200.0 97.5 95.0 95.0 92.5 95.0 90.0 92.5 .:> 90.0 95.0 92.5 4.0 9.0 55.0 —30 -10 10 135 5 0 0 0 0 0 0 0 0 0 0 0 0 0 2.9 3.3 3.6 4.1 4.5 4.2 ") 1' 5 . 5 5.4 4.9 5.7 4.6 4.9 7.1 4.4 1—2 2— 3 3- 4 -6 2 6 4 4 2 4 6 6 8 14 4 4- 6 6— 8 8-10 10-12 12—14 14-16... 12.20 9.56 10.84 13.00 43.36 17.12 16-18 18—20 .... 20-22 22-24 In soil at start 0— 1 After a period of 51 days. 152.40 13.92 12 68 1150.0 75.5 28.8 28.5 29.0 29.0 29.0 29.5 30.5 30.5 30.0 29.0 23.0 16.0 110.0 273.92 11.61 11.04 11.04 10.37 10.37 10.07 11.04 11.41 10.87 10.37 10.07 9.93 10.37 16.79 1620.00 33.76 16.16 19.12 21.36 17.28 18.16 °2 72 24^20 19.64 10.38 5.04 3.49 3.95 103.80 3.3 4.7 4.2 3.9 3.9 4.9 4.3 4.0 4.7 4.5 4.1 4.4 4.8 6.2 3.8 437.5 160.0 120.0 115.0 115.0 112.5 90.0 92.5 92.5 100.0 95.0 80.0 37.5 21.0 55.0 —4 4 2 0 4 8 8 2 8 0 4 21 23 4 170 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4.9 5.3 4.9 5.0 4.8 5.2 5.1 5.1 5.3 5.2 4.9 5.6 5.3 6.0 4.4 1— 2... 2— 3 3— 4 15.48 13.00 15.00 13.36 13.72 13.72 14.36 12.52 13.72 22.16 30.96 17.12 4— 6 .. 6- 8... 8-10 10-12 12—14 14-16 16-18 . 18-20 20-22 22-24 In soil at start 0- 1.. 1- 2 .. Selma Silt Loam. After a period of 20 days. 65.00 31.52 24.40 20.32 15.48 12.36 12.84 10.88 8.42 2125.0 487.5 450.0 437.5 400.0 262.5 120.0 90.0 75.0 273.92 41.78 27.61 23.46 21.39 15.92 12.03 11.61 11.41 11.41 11.80 11.22 8.78 8.56 15.56 3632.0 1068.0 908.0 726.0 466.0 196.4 86.5 58.6 47.8 37.1 34.6 10.38 3.03 3.63 201.60 3.3 4.5 5.0 5.2 5.5 6.0 6.5 7.1 7.3 7.1 7.2 7.6 7.5 10.0 4.9 375.0 210.0 160.0 150.0 170.0 180.0 190.0 175.0 130.0 130.0 160.0 175.0 180.0 115.0 95.00 -18 —16 -12 —14 C 0 4 2 2 10 10 10 16 40 -8 145 45 25 20 10 0 0 0 0 0 0 0 0 0 5 4.1 4.6 4.8 4.9 5.0 5.4 5.8 6.5 7.0 7.1 7.2 6.6 6.8 9.0 5.2 2- 3 3-4... 4- 6 .. 6- 8 8-10 . . 10-12 .... 12-14 . . 14-16 .. 8.28 6.86 6.36 46.48 46.00 16.84 75.0 75.0 90.0 85.0 23.0 450.0 16-18 18-20.... 20-22 22-24 In soil at start 0- 1 After a period of 51 days. 130.00 18.08 17.12 13.92 11.08 10.60 8 56 4500.0 312.5 250.0 206.3 156.3 112.5 100.0 92.5 90.0 90.0 92.5 87.5 70.0 23.0 450.0 342.40 26.34 19.02 17.57 13.70 12.94 11.80 10.70 9.78 11.04 9.51 9.51 8.40 10.70 15.56 2968.0 346.0 279.2 201.6 201.6 53.4 41.3 31.6 94 9 26 .'92 20.16 8.26 5.68 5.68 201.60 3.0 3.7 4.2 4.9 5.1 5.7 6.2 6.6 7.2 7.9 8.0 7.0 8.0 8.8 4.9 337.5 122.5 105.0 115.0 130.0 122.5 105.0 102.5 95.0 95.0 97.5 90.0 40.0 14.0 95.00 -5 -6 -8 -4 — 2 2 -2 _2 2 2 0 20 26 -8 295 15 0 0 0 0 0 0 0 0 0 5 0 0 5 4.0 5.4 5.6 5.8 6.2 7.0 7.5 7.7 8.2 8.2 8.3 7.7 8.3 9.0 5.2 1- 2 .. 2- 3... 3- 4 4- 6... 6-8... 8-10 .. . 10-12 7.18 7.74 8.28 7.88 8.28 21.68 28.24 16.84 12-14 14 16 16-18 18-20 . . 20 22 22-24 In soil at start MOVEMENTS OF SALTS IN SOILS. 79 Distribution of water- soluble salts resulting from capillarity. Depth . Inches. K. Ca. Mg. N03. HPO4. S04. HC03. Cl. SiO,. 0- 1 In parts per million of dry soil. Norjolk Sand. After a period of 19 days. 31.52 15.48 15.24 14.36 13.00 11.48 8.72 8.56 10.00 10.60 10.60 14.56 22 72 38^24 15.48 300.0 45.0 42.0 38.5 34.0 32.5 29.0 26.0 21.0 21.0 19.0 18.0 17.0 14.0 15.0 63.42 18.01 15.92 15.56 13.70 12.45 11.61 10.37 10.37 12.68 11.61 11.61 12.03 12.03 11.80 1068.0 145.2 145.2 117.2 100.8 69.12 51.92 43.36 38.24 31.60 29.04 9.82 2.59 2.75 46.60 4.8 4.4 4.3 4.3 4.1 4.5 4.3 4.3 4.9 4.5 4.4 5.1 5.1 4.8 3.7 34 34 30 30 30 33 36 36 44 86 82 80 80 74 40 12 28 28 32 32 32 36 38 40 38 42 42 52 82 24 45 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4.7 5.3 :,.r, 4.9 5.1 ."> . 5 5.6 5.5 5.1 5.3 5.3 5.5 5.5 5.3 4.7 1- 9 2- 3 3-4 4- 6 6- 8 8-10 10-12 12 14 14-16 16-18 . . . 18-20 20-22 22-"->4 In soil at start 0- 1 After a period of 50 days. 36.80 17.12 12.20 320.0 72.0 52.0 46.0 30.0 29.0 25.0 22.0 21.0 20.0 20.0 17.0 13.0 15.0 59.02 21.14 13.17 11.61 10.54 10.37 10.07 9.51 9.26 10.07 10.54 10.37 10.07 11.80 982.0 316.0 103.8 72.6 50.4 44.0 44.0 36.32 24.20 15.80 3.13 2.02 1.82 46.60 4.02 4.3 3.96 3.91 4.5 3.9 4.2 4.2 4.1 3.96 3.8 4.2 3.9 3.7 50 28 27 27 28 30 30 32 41 74 80 64 60 40 8 18 22 22 26 26 26 26 26 26 30 48 30 24 55 0 0 0 0 0 0 0 0 0 0 0 0 0 4.3 4.7 4.8 5.1 4.5 4.1 5.0 4.7 5.1 4.8 4.5 4.9 4.9 4.7 1-2 2- 3 3- 5 10.60 10.00 9.38 6.86 6.96 7.50 9.56 11.08 19.52 28.72 15.48 5-7 7- 9 9-11. 11-13 13-15 15-17 17-19 19-21 21-23 In soil at start 0- 1... Sassafras Sandy Loam. After a period of 19 days. 45.44 21.68 18.76 13.36 10.40 9.56 9.20 7.06 6.42 6.34 10.00 14.36 30.46 9.38 380 140 98 80 64 54 46 38 36 36 30 26 19 36 58.04 21.70 20.14 16.79 13.98 12.68 12.68 12.03 11.61 11.61 11.04 10.87 11.04 11.41 1252.0 395.0 324.5 245.5 133.5 84.44 70.88 51.92 50.40 39.28 22.72 9.08 2.02 90.80 5.5 6.0 5.3 5.6 5.7 6.0 5.5 6.2 6.0 5.6 5.5 6.0 5.2 5.1 26 26 26 27 36 48 50 54 68 86 89 144 128 25 16 18 18 30 32 32 34 34 34 34 38 42 90 26 265 85 65 10 0 0 0 0 0 0 0 0 0 10 5.6 5.7 5.8 5.8 5.7 5.8 6.1 5.7 5.9 5.8 5.8 5.8 6.1 5.8 1- 2 2- 3 3- 5 5- 7.. .. 7- 9... 9-11 11-13 . . 13-15 15-17 17-19 19-21 21-23 In soil at start 0- 1... After a period of 50 days. 61.00 22.96 10.84 9 56 700 187.5 108 64 52 39 36 33 31 29 28 26 17.25 36 244.56 24.45 14.89 12.03 11.04 10.07 9.65 9.78 10.70 11.04 10.54 10.37 10.70 11.41 3028.0 413.0 207.6 139.6 88.6 75.7 58.1 51.9 44.0 40.32 25.04 2.93 2.93 90.80 4.5 4.4 4.5 4.6 4.4 5.0 4.8 5.1 4.9 5.0 4.7 4.7 5.4 5.1 23 24 29 31 32 35 38 45 60 66 88 77 50 25 6 8 12 18 20 18 18 20 24 24 26 38 120 26 530 60 20 0 0 0 0 0 0 0 0 0 0 10 4.3 4.9 5.0 4.8 5.1 4.9 5.1 5.0 5.3 4.7 4.7 4.9 5.3 5.8 1- 2 2-3... 3- 5... 5- 7 8.56 7.18 5.88 5.48 5.44 4.64 6.10 17.44 25.68 9.38 7- 9. . 9-11 11-13 13-15 15-17 17-19 . 19-21... 21-23 In soil at start 80 Distribution of water-soluble stilts due to capillarity. Depth. Inches . K. Ca. Mg. NO3. HP04. SO4. HCO3. Cl. SiO3. 0- 1 In parts per million of dry soil. Hagerstown Clay Loam. After a period of 17 days. 28.72 27.84 22.16 20.80 18.76 16.56 15.24 15.00 18.40 18.76 19.52 20.80 21.68 51.36 13.20 560 360 262.5 237.5 209.4 187.5 140.0 108.0 108.0 108.0 100.0 100.0 100.0 79.0 116.0 155.60 103.72 74.44 67.28 56.12 53.48 41.78 41.78 45.64 47.54 55.22 48.24 35.68 29.02 33.64 1730.0 1100.0 908.0 605.0 519.0 323.2 165.2 145.2 100.8 90.8 72.6 79.0 86.5 82.6 234.4 9.3 10.1 10.4 10.0 10 2 11.2 10.6 10.3 10.5 10.7 12.9 11.3 9.9 10.7 9.9 168 200 216 216 224 224 224 228 248 272 312 270 170 165 75 78 95 100 100 100 120 130 130 145 145 155 155 145 140 135 85 40 35 20 20 10 0 0 0 0 0 0 0 0 0 9.4 10.7 10.4 10.5 10.6 11.1 10.2 10.8 10.5 11.0 11.7 10.7 10.3 10.5 14.9 1- 2 2-3 3-4 4- 6 6- 8 8-10 10-12 . . . 12-14 14-16 16-18 18-20 20-22 22-24 . In soil at start 0- 1 After a period of 50 days. 32.56 24.40 21.20 20.00 19.52 19.12 19.12 18.76 17.76 17.44 22.16 22.72 25.16 43.36 13.20 1500 170 150 150 142.5 140 132 120 112 110 110 90 76 62 116 503.40 55.22 48.90 48.24 45.04 43.40 38.90 35.68 35.68 34.94 33.64 32.92 25.93 23.77 33.64 3928.0 302.8 165.2 151.4 158.0 106.8 110.0 63.2 67.3 41.3 9.56 3.25 11.72 8.08 234.4 10.6 13.0 13.5 13.6 13.3 13.9 13.9 13.6 13.2 13.0 12.9 12.7 12.8 11.4 9.9 430 320 260 250 230 230 200 160 155 150 150 142.5 125 112.5 75 90 143 160 160 155 165 160 160 165 170 185 185 195 170 135 240 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11.7 12.7 12.9 12.5 12.3 12.8 12.9 13.0 12.9 13.6 12.5 12.1 12.5 11.5 14.9 1- 2 2-3 3- 4 4-6 6-8 8-10 . 10-12 12-14 14-16 16-18 18-20 20-22 22-24 In soil at start 0- 1 . Hagerstown Loam. After a period of 17 days. 88.80 77.40 72.80 58.60 50.00 45.20 42.80 41.40 38.10 37.50 42.10 680 520 350 310 260 128 125 120 107.5 100 100 95 82.5 75 72.5 236.08 232.16 106.96 93.84 51.86 46.28 43.90 54.34 32.92 28.52 36.42 34.94 35.68 25.68 31.71 2424 1864 1346 966 550 245.5 158.0 108.0 125.2 95.6 95.6 95.6 90.8 93.2 316.0 7.2 6.9 5.8 5.9 5.6 7.5 8.0 8.7 7.0 5.8 6.8 7.0 7.2 7.1 6.7 160 128 104 120 120 180 208 310 240 220 220 205 200 200 112 42 44 53 50 61 64 62 73 66 66 68 70 66 66 52 74 74 35 20 16 0 0 0 0 0 0 0 0 0 0 7.4 7.4 6.5 6.5 6.4 7.4 8.5 8.9 7.3 6.5 7.2 7.3 7.6 7.7 7.5 1- 2 2-3 3- 4 4- 6 6- 8 8-10 10-12 12-14 14-16 16-18 18-20 46.00 52.00 54.20 45.20 20-22 22-24 In soil at start 0- 1 .. After a period of 50 days. 125.80 106.00 75.00 66.80 58.80 56.80 55.40 55.40 55.40 55.40 55.40 56.80 95.60 113.60 45.20 1350 375 163.5 160 114.5 108 93.8 90 90 85 80.75 79 75 73 72.5 489.00 92.56 44.44 38.90 36.92 34.24 31.12 31.12 30.57 32.92 32.92 38.04 41.98 47.54 31.71 6628 1252 227 175 133 80.64 55.84 50.08 9.56 9.82 8.64 11.36 10.68 19.64 316.00 7.0 8.9 8.9 8.6 '8.8 8.6 9.3 9.2 9.4 9.6 8.2 8.0 7.9 8.3 6.7 232 224 218.4 216 192 188 208.8 211 203.5 202 200 200 190 178 112 46 68 90 106 112 114 133 135 140 145 140 140 150 140 52 185 37.5 0 0 0 0 0 0 0 0 0 0 0 0 0 7.6 8.2 8.2 8.3 8.0 8.6 8.8 9.0 8.8 8.7 8.4 8.3 8.0 8.1 7.5 1- 2 2- 3 3- 4 4- 6 6- 8 8-10... 10-12 12-14 . .. 14-16 16-18 18-20 20-22 22-24 In soil at start MOVEMENTS OF SALTS IN SOILS. 81 Distribution of water -soluble salts due to capillarity. Depth. Inches. K. Ca. Mg. N03. HPO4. S04. HCO3. Cl. SiO». 0- 1... [n parts per million of dry soil. Janesville Loam. After a period of 18 days. 19.12 11.76 8.42 7.28 6.68 6.34 4.64 3.26 3.71 5.14 5.30 5.54 7.18 18.76 8.88 640 250 150 145 126 .84 58 54 51 51 50 48 44 40 76 190.16 64.72 52.68 98,90 42.80 26.74 25.17 25.60 24.45 24.45 26.34 24.4:> 20.75 18.51 32.36 2344.00 646.40 675.20 539.20 363.20 177.20 110.00 80.80 64.90 58.60 50.08 50.08 50.08 50.08 196.40 14.54 14.32 16.14 15.98 15.76 16.87 16.44 16.17 17.40 18.40 17.60 18.02 17.70 18.60 11.30 88 96 96 96 104 112 122 124 136 160 176 160 152 136 146 8 22 22 24 28 28 30 36 44 44 46 46 52 66 26 25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 13.8 14.1 14.9 13.2 14.4 14.8 14.9 19.7 15.1 15.6 13.7 14.2 14.3 14.8 14.9 1- 2 2- 3 3- 4 4- 6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 In soil at start 0- 1 After a period of 52 days. 34.88 11.48 11.20 9.64 8.14 7.50 6.86 6.10 5.88 7.88 8.72 9.56 11.08 23.84 8.88 925 145 110 52 50 50 45 44 40 37.5 34 34 33 33 76 441.76 38.90 26.34 24.93 25.60 25.60 27.61 25.60 23.77 22.09 21.39 19.02 19.02 17.57 32.36 4910.00 240.00 53.40 8.16 5.16 3.82 5.19 3.63 3.13 2.84 3.95 3.49 3.49 3.95 196.40 15.4 17.6 15.6 18.4 15.0 16.5 16.6 15.0 16.6 15.3 15.6 16.2 15.8 14.8 11.3 370 162.5 155 150 150 150 148 148 132 102 100 83 16 9 146 8 16 26 26 30 32 44 44 52 56 58 66 68 82 26 85 0 0 0 0 0 0 0 0 0 0 0 0 0 0 17.1 20.2 18.8 20.0 18.8 19.4 19.3 18.7 19.1 17.8 17.2 17.8 16.5 15.4 14.9 2- 3 . 3- 4 4- 6 6- 8 ... 8-10 10-12 .. . 12-14 14-16 16-18 18-20 20-22 . . 22-24 In soil at start 0- 1 Miami Loam. After a period of 18 days. 48.80 20.80 16.00 14.80 13.36 7.74 7.18 6.34 10.84 11.36 11.36 11.62 12.58 20.32 15.76 1000 237.5 170 165 145 128 112. 92.5 85 85 77.5 71.25 64.0 54 100 297.76 60.16 48.90 46.28 38.04 29.51 24.82 26.34 23.14 25.17 23.77 22.52 21.14 20.89 30.08 3370.0 638.0 534.0 454.0 302.5 132.0 100.8 79.0 56.8 51.9 49.1 42.2 40.3 42.7 103.8 12.2 13.9 14.2 13.0 12.8 13.4 13.6 13.4 11.9 12.6 12.1 12.2 11.8 11.5 9.8 76 76 80 80 84 92 92 100 112 140 164 112 104 92 108 14 22 26 30 30 30 42 42 42 44 44 44 46 68 38 25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15.8 16.5 16.0 15.6 15.0 16.5 16.6 16.4 16.0 14.7 14.9 15.2 15.1 14.9 15.9 1- 2 2-3 3-4 4- 6 6- 8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 In soil at start 0- 1. .. After a period of 52 days. 85.60 20.32 11.36 5.74 6.02 6.42 6.68 6.86 8.72 8.88 11.62 12.58 12.58 30.96 15.76 1300 78 60 58 58 54 54 52 52 49 46 46 40 38 100 409.60 30.57 24.45 23.46 21.40 21.40 21.14 20.75 21.39 20.14 18.51 19.56 18.51 18.51 30.08 5192.00 121.00 5.86 3.95 4.54 4.13 3.79 3.79 3.95 3.95 3.25 3.25 2.93 3.79 103.80 11.4 13.0 12.5 13.5 12.5 14.0 13.3 13.7 12.7 12.3 12.2 12.4 12.7 12.0 9.8 210 165 165 155 150 147.5 125 110 88 76 68 56 35 10 108 20 42 46 48 58 62 75 76 84 96 108 106 100 102 38 95 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16.2 18.5 18.3 18.6 18.7 20.6 19.3 18.5 17.7 17.3 16.7 16.6 17.4 17.2 15.9 1- 2 2-3... 3- 4... 4- 6 6- 8 8-10 10-12 12-14 14-16 16-18 .... 18-20 20-22 22-24 i In soil at start 82 BULLETIN F. MOVEMENT OF POTASH BY CAPILLARITY. Two features regarding the capillary movement of potash through the eight soils under investigation, are brought out in a striking1 manner by the data of the several tables of the pre- ceding pages ; these are the large amounts of potash "which, in every instance, have been left in recoverable form in the soil at the lower ends and in even larger amounts at the upper ends of the soil columns. If the mean amounts of potash recovered from the different sections! of the soil columns of the eight types are obtained for both capillary periods, they will appear as expressed in the table next given. Mean amounts of potash recovered from different sections of soil columns after capillary movement has taken place. Depth. Inches. After 20 days. After 50 days. 0- 1 .. In parts per million of dry soil. 53.43 28.52 24.54 20.83 18.18 15.31 14.19 13.07 13.54 13.78 14.41 16.26 25.77 39.35 22 23 19^62 82.38 29.29 21.45 18.97 16.89 16.50 15.35 15.06 15.27 15.78 16.94 20.08 30.34 41.27 25.40 19.62 1- 2 2-3 3- 4 4- 6 6- 8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 Average ... From soil at start From this table it is seen that the general tendency has been for the potash to concentrate at the bottom of the columns where the solution entered, while higher up in the soil capillarity had the effect of forcing the potash upward until it was arrested in the surface inch. The general character of this resulting distribution is more clearly brought out in the diagram, Fig. 3, p. 83, where the imean ampunts found in the several layers after 20 and 50 days of capillary movement had taken place are plotted to the same scale. From these curves it will be seen that the amounts' of water-soluble potash recovered from MOVEMENTS OF SALTS IN SOILS. 83 the bottom layer was greater than at any other level except that of the surface inch, .and also that at the end of 50 days more potash was recovered than was recovered at the end of 20 days. Between the 18 to 20 inch level and the 3 to 4 inch level less potash could be recovered from the soil than before the cap- illary movement had taken place, indicating that these layers had been washed and the potash moved on into the layers above. 0-1 /-Z 1-3 unt in- St6f FIG. 3. — Showing distribution of water-soluble potash after capillary movement. Solid line indicates results after fifty days ; broken line after 20 days. Val- ues are means for 8 soil types. The mean amount of potash recovered from the surface inch at the close of the 50 days was 82.38 parts per million of dry soil. Taking the mean weight of a cubic foot of soil at 73.36 Ibs., as given in Bulletin "C", "Relation of Crop Yields to the Amounts of Water-Soluble Plant Food Materials Recov- ered from Soils," p. 51, this accummulation of potash is equiva- lent to about 22 Ibs. per acre in the surface inch of soil. 84 The absolute amounts of potash recovered from the 24 inches of these eight soil types before and after capillary movement had taken place are given in the next table, expressed in pounds per acre. Amounts of potash recovered from 24 inches of soil after capillary movement. Before treatment. After 20 days. Before treatment. After 50 days. Norfolk Sandy Soil In pounds per 2 acre-feet. From four poorer soils. 151.55 . 134.00 118.28 66.38 117.55 172.66 160.46 116.10 97.80 136.76 155.43 134.00 116.94 65.15 200.13 139.43 100.87 80.61 Selma Silt Loam Norfolk Sand. Sassafras Sandy Loam 117.88 130.26 Hagerstown Clay Loam Hagerstown Loam From four stronger soils. 92.55 325.76 61.97 126.14 151.61 155.71 359.59 52.38 109.46 169.29 92.81 325.01 62.30 125.75 151.47 161.22 512.71 76.40 118.05 ~217\10 From this presentation of the data, it is to be observed that in but one soil, the Janesville Loam, has the absorption of the potash added to the soils been so great by them that less was recovered after 20 or after 50 days of capillary movement than was present in them, in water-soluble form, before the solution was added. In three out of four of the poorer soils, more potash was recovered after 20 days of capillary movement than after 50 days; while with the four stronger soils the reverse was the case. These relations are not unlike the case cited in Bulletin "E," "Influence of Farm Yard Manure Upon Yield and Upon the Water-Soluble Salts of Soils," p. 37, where sam- ples of the Janesville Loam and of the Norfolk Sand were each washed by percolating 6,000 c. c. of water through them! and the Janesville Loam yielded 104.62 parts per million where the Norfolk Sand yielded but 62.24, both soils having been pre- viously treated alike with an application of manure at the rate of 200 tons per acre. It must be admitted, however, that, so MOVEMENTS ( ) K SALTS IX SOILS. 85 far as the evidence shows, these relations between the two groups of soils may be the result of coincidences, for in the eight soil types we have three where less salts are recovered after the longer capillary washing and five where the amounts are more, the cases, therefore, being nearly equally divided and one of the poorer soils standing in line with the stronger soils. That capillary sweeping does have the effect of permitting more nitrates to be recovered from soils than can be secured by ordinary washing has been proven and will be referred to after discussing the! effects of the capillary movement upon the other ingredients determined. MOVEMENT OF LIME BY CAPILLARITY. The observations of Way, Frankland and Voelcker, which have been cited in Bulletin "B," Bureau of Soils, "Amounts of Plant Food Readily Recoverable from Field Soils with Dis- tilled Water,'7 p. 16, show that lime passes from soils into drain- age waters more abundantly than any other base, and from this relation it would be expected to be moved rapidly by capillarity also. If reference is made to the tables it will be seen that this has been the case with each and every soil type. In the next table there are brought into comparison the amounts of potash and lime recovered from the surface layer and from the bottom layer of each soil type after 50 days of capillary movement. Relative amounts of potash and of lime moved by capillarity which remain water-soluble. Nor- foJk Sandy Soil. Selma Silt Loam. Nor- folk Sand. Sassa- fras Sandv Loam. Hagers- town Clay Loam. Haters- town Loam. Janes- vine Loam. Miami Loam. Potash K In parts per million of dry soil. Amounts accumulated in surface layer. 152.40 1150.00 130.00 36.80 4500.00 320.00 61.00 700.00 32.56 1500.00 125.80 1350.00 34.88 925.00 85.00 1300.00 Lime Ca . . . . Potash K... Amounts remaining in bottom layer. 30.96 16.00 28.24 23.00 28.72 13.00 25.68 17.25 43.36 62.00 113.60 73.00 23.84 33.00 30.90 38.06 Lime Ca . . . 80 From this table it will be seen that there is a remarkable dif- ference- between the amounts of lime and of potash recovered from the surface soil, the mean amounts! for the 8 soil types being 1468 for lime and 82.38 for potash or as 18 to 1 ; while in the bottom layer the mean amounts recovered wrere 34.41 of lime to 40.67 of potash, the relations being reversed. In the language of the earlier chemists, the potash has forced the lime into solution at the bottom and maintained it there at the top. There has been enough potash added to these soils to repre- sent, for the entire weight, in the neighborhood of an average of 26 parts per million, and of lime 7 parts; there was present in them,, before this addition, enough more to make a mean to- tal of 43.73 of potash and 128 of lime. But at the end of 50 days of capillary movement and after rendering the soils water- free at 110° G., there was recovered from the top layers of soil a mean of 82.38 parts per million instead of 43.73 parts and from the bottom layer 40.67 parts per million, only 3 parts less; while in the case: of lime the surface layer yielded an average of 1468 parts per million instead of 128 parts, and the bottom layer 34.41 parts. The! capillary movement had re- duced the lime which could be recovered from the bottom layer to about one-fourth and had increased that at the top 12-fold; while with the potash the decrease had been only about 6 to 7 per cent, at the bottom and the increase at the top less than 2-fold. There is thus shown a strong difference between the movement of the potash and of the lime, through these soils under the influence of capillarity. MOVEMENT OF MAGNESIA BY CAPILLARITY. The movements of magnesia have been, in general, more nearly analogous to those of the lime than to those of the potash, but there has been no such larg'e accumulations in the surface inch. The relative concentrations are shown in the next table. MOVKMK.XTS OK SALTS I .\ SOILS. 87 Relative concentrations of magnesia in the surface inch of 8 soil types. Before treat- ment. After 20 days. After 50 days. At top At bottom. At top. At bottom. Norfolk Sandy Soil . . In parts per million of dry soil. Four poorer soils. 16.79 15.56 11.80 11.41 269.12 273.92 63.42 58.04 166.13 9.01 8.56 12.03 11.04 10.16 273.92 342.40 59.02 244.56 229.98 10.37 10.70 10.07 10.70 10.46 Selma Silt Loam .. Norfolk Sand Sassafras Sandy Loam.. . Average 13.89 Hagerstown Clay Loam Hagerstown Loam : Four str nger soils. 33.64 31.71 32.36 30.08 81,. 95 155.60 236.08 190.16 297.76 219.90 29.02 35.68 18.51 20.89 26.03 503.40 489.00 441.76 409.60 460.94 23.77 47.54 17.57 18.51 26.85 "IsTeeT Miami Loam Average General average 22.92 193.02 18.10 345.46 From the data of the table it is seen that the movement of magnesia into the surface inch has been enough to increase that which may be recovered by water alone to 345.46 parts per million, as an average of the 8 soil types after 50 days of cap- illary action. There was magnesia enough added to these soils with the solution to represent about 9 parts per million, which, added to 22.92, gives 31.92 as the amount which should be re- covered from the bottom layer if no change had taken place as the result of the treatment. The mean amount which was re- covered from the bottom layer was 18.66 parts per million, only a little more than one-half the amount called for with no change. The top layer of soil had increased its content of re- coverable magnesia, after 50 days, about 18-fold, which is rela- tively more than had occurred with the lime, that increase being 12-fold. The differences between the magnitudes of the movements of magnesia in the two groups of soils appear to be about such as would be expected from the differences in the amounts of the water-soluble magnesia which has been recovered from the untreated soils of the two groups. 88 The absolute amounts of magnesia which were recovered from the 24 inches of these soils are given in the next table. Amount of magnesia recovered from 24 inches of soil after capil- lary movement. Before treatment. After 20 days . Before treatment. After 50 days. Norfolk Sandy Loam In pounds per 2 acre-feet. From four poorer soils. 148.63 123.82 90.17 80.75 110.84 192.44 205.15 107.16 105.60 152.59 152.43 123.82 89.14 79.24 111.16 201.74 206.13 89.63 128.15 158.91 Selma Silt Loam NorfolkSand Sassafras Sandy Loam Average Hagerstown Clay Loam From four stronger soils. 235.87 22S.54 225.85 240.76 232.76 387.19 443.56 259.01 327.19 354.25 236.54 228.01 227.03 240.00 232.90 427.r,5 438.62 314.15 312.95 373.34 Hagerstown Loam Janesville Loam Miami Loam Average In these cases the 50 days of capillary movement have re- sulted in a larger accumulation of magnesia in form to be re- covered with the distilled water, as was the case with the pot- ash ; the differences, however, are very small and in the case of the Hagerstown Loam and of the Miami Loam the relation is reversed. MOVEMENT OF PHOSPHATES BY CAPILLARITY. The tendency of nitrates to change one way or the other is so great, on account of biological influences, that the capillary movement of them cannot well be indicated by such a series of observations, except in a most general way. It will be seen from the tables of details that there had been a heavy accumu- lation of the nitrates in the surface layer and a large reduction of them in the lower portions of the columns, which was un- doubtedly due, to a great extent, to capillary movement. In the case of the phosphates, notwithstanding the addition of them to the soil with the solution, the absorption was so strong as to reduce the amounts which could be recovered to so MOYKMENTS OF SALTS IN SOILS. 89 narrow a margin that the movements can be measured by the methods only with great difficulty. There are given in the next table the mean amount of phos- phates recovered from the) eight soil types after the capillary periods of 20 and 50 days. Mean amounts of phosphoric acid (HPO4) recovered from different sections of soil columns after capillary movement has taken place. Depth in inches. After 20 days. After 50 days. 0_ i In parts per million of dry soil. 7.18 7.90 8.06 7.99 7.97 8.72 8.64 8.87 8.79 8.89 8.88 8.89 8.73 9.74 8.52 6.90 7.41 8.76 8.43 8.93 8.44 9.07 9.08 8.93 9.11 8.95 8.69 8.71 8.92 9.57 8.79 6.90 1-2 2- 3 3-4 . 4-6 6-8 . . : . 8 10 10-12 I9 -14 14-16 16-18 18-20 . 20 22 92-^4 Average From soil at start From these data, there appear to be real differences between the amounts of phosphoric acid recovered at the close of the two capillary periods, but they are very small. Larger mean values are, also, found for the phosphoric acid after than be- fore the treatment, as indeed must be expected unless complete absorption or precipitation occurs. The probable relation of these two sets of data may be more clearly seen from the graphic representation, Fig. 4-, p. 90. From this it will be seen that both curves, where they represent the conditions in the lower portions of the soil columns, show a tendency to develop the same features possessed by the potash curves in Fig. 3, p. 83. This is especially marked in the 50 day curve and the differences shown may be interpreted as in- dicating that, after a sufficient amount of movement, the form of the potash curve would be reproduced. In other words, there is a strong absorption of the phosphoric acid as it enters, the soil but slowly it is moved forward by the water, thus re- ducing the amounts between and increasing that above, which 90 BULLETIN may be recovered by washing with water. These observations appear to be quite in harmony with observations on drainage waters, which show that only small amounts of phosphoric acid, relatively, escape from the soil with the water. FIG. 4. — Showing distribution of water-soluble phosphates after capillary move- ment. Solid line indicates results after 50 days ; broken line, results after 20 days. Values are means for 8 soil types. MOVEMENTS OF SULPHATES BY CAPILLARITY. The general tables show that, in the capillary movement of the sulphates upward through the soils, they advanced much as the lime and magnesia did, concentrating at the surface, but not as. intensely as did either the chlorine or nitric acid. The Norfolk Sandy Soil increased its content of SO4 in the surface inch nearlv 4-fold in the first 20 davs and nearly 8-fold in 50 MOVEMENTS OF SALTS IN SOILS. 91 days; but l.el< \v the surface inch it bmi acquired a ncjirl-- uni- form distribution to the two lower layers, which showed so little as to appear like incorrect determinations or else large absorp- tions. The strength of the solution added was such that 20 per cent, of it in the soil would carry to the soil about 32 parts per million of its dry weight. The soil itself gave over to dis- tilled water, before treatment, 55 parts per million, which added to 32 parts gives 87 parts, and this is below the amount found in nearly all except the upper and lower layers. In the column to which distilled water was added the SO4 in the bottom lay- ers also fell but not so low as the results found in the 20 day cylinder. In the Selma Silt Loam, too, above the 22-24 inch layer, nearly constant amounts were recovered from the successive lay- ers up to the 1-2 inch level, but these amounts exceed the sum of that recovered from the untreated soil and that which would be carried to the soil with the solution used, this ranging, ac- cording to the per cent, of water in the soil, from 130 to 150 parts per million of the dry soil. Indeed the solution, on its way upward through the soil, dissolved other sulphates present and to such an extent as that the amount found, at the end of 20 days of capillary movement, was equivalent to 1,362 Ibs. per acre for the 24 inches of soil under treatment. If refer- ence is made to the data of the 50 day cylinder, it will be seen that a change must have occurred before its close, whereby the sulphates which were at first liberated became again absorbed or were precipitated, from which it appears that soil solutions may undergo frequent and often radical changes as they reverse their direction of movement with, changes of the water-content in the soil, and it may be reasonably expected that such changes influence the growth of crops, sometimes favorably and some- times adversely. In Fig. 5, p. 1)2, the changes, in, the distribution of sulphates, which occurred in the Miami Loam, are graphically repre- sented, and from this it appears that, during the advance of the solution through the Miami Loam, it had the effect of leaving less SO4, in form to be recovered, at the end of 20 days than there was present in the soil to begin with in all layers, except 92 the 12—14 to 18—20 inches. Moreover, as time progressed and the distilled water followed the solution, forcing it upward through the soil, the sulphates were carried forward until, in the surface inch, they had increased almost as much above the normal as, at the bottom, they had fallen below it. Observa- '00 SO /-I 2*3 \ H-t /:*- \ LA \ FIG. 5. — Showing distribution of water-soluble sulphates after capillary move- ment. Solid line indicates results after 50 days ; broken line, results after 20 days. Values are means for 8 soil types. tions.like these emphasize with much force that the soluble salt content of soils is liable to suffer profound changes with the change in the character of the soil moisture and with its amount which must result from heavy rains and very drying weather, especially if at all protected, as is not infrequently the case. MOVK.MKNTS ()I SALTS IN SOILS. 93 MOVEMENT <>I CHLORIDES BY CAPILLARITY. Xo salt in the series investigated moves with such apparent freedom and abandons the soil so completely as do the chlorides, or, at least, as does the chlorine. The most striking feature in the tables of data presented in this series of observations is the completeness with which the chlorine has disappeared from all but the surface inch of soil, in four of the types under treatment, even at the end of 20 days. This statement applies with entire fullness to the two Janes- ville soils and to the Norfolk Sandy Soil and the Xorfolk Sand. With the Selma Silti Loam, the Sassafras Sandy Loam and the two Hagerstown Loams, the chlorine was not completely forced into the upper layer, but well up toward it. Another point, to which special attention should be directed, is the fact that the absolute amount of chlorine recovered at the end of 50 days is greater than that which is recovered at the end of 20 days. This is doubtless partly due to the fact that the zeros in the table must be understood to mean amounts too small to measure by the method rather than no chlorine present, and the more complete capillary sweeping results in concentrat- ing the chlorine until the quantities become large enough to be determined. There is stall another feature of these chlorine data which calls for an explanation and this is the reduction of the chlorine in the solution added to the soil, which contained 25 to 30 parts per million, to so small an amount as to fall below the limits of the method. It must be understood that: the Hagerstown Loam, for example, carried in the lower two inches of soil, 30 per cent, of its dry weight of the solution, which contained not less than 24 parts per million when it entered the soil. This is enough to represent 7.2 parts per million of the dry soil could it. all be recovered by the method of washing used. Moreover, it is true, in most cases, that the absolute amounts of chlorine recovered from the soils are nearly equal to, or even greater, than the amounts called for by the known amounts added to the soils with the solution plus the measured amounts in the soils before the solution was added. 7 94 It docs not appear that the apparent absence of the chlorine can be explained by a failure of the method. A more probable hypothesis is that the absorption of the chlorine by the soil took place to the extent of trio amount present in the solution used. If these soils contained 3, 5 or 7 parts per million more chlor- ine than could be recovered by the method of washing used, it is quite probable thai; when a solution, carrying these amounts of chlorine, is allowed to sweep the soil by capillary action, it may be able to displace a portion of that already present, and to such an extent that that which the solution carries would be absorbed sufficiently during the 20 days so that the amounts which could then be recovered by washing are too small to be measured by the methods used. This view finds support in the retention of nitrates by soils in forms still recoverable by suitable treatment. RECOVERY OF ABSORBED NITRIC ACID. During the investigations relative to the movements of ni- trates in soils under furrow irrigation, reported in Bulletin No. 119, Office of Experiment Stations, a series of observations was made which demonstrated that nitrates absorbed by soils may be displaced by capillary sweeping with distilled water. When an effort was made to account for the increase of ni- trates under the rows, referred to in the observations previously cited, p. 69, it was found that there was not enough nitric acid in the water added by irrigation plus that which appeared to have been lost from the soil beneath the furrows to account for the gain which had occurred beneath the rows. Moreover, the very short intervals of time during which the observed gains had taken place, togelher with the great depth below the sur- face where the increases were observed, appeared, at that time, to preclude the possibility that such additions to the soil could be made through nitrification; and it appeared that in some manner the capillary sweeping had the effect of washing the soil grains more thoroughly than was done by the method used in the laboratory and that, on this account, there resulted a con- MOVKM KNTS OF SALTS IN SoII.S. 95 contratioii suck that larger absolute amounts of nitric acid were recovered. To test this hypothesis, two soils were procured ; one a loamy sand and the other a sandy soil, each containing at the time a low per cent, of moisture. Bulk lots of both soils were screened and thoroughly mixed, so that 'closely duplicate samples could be obtained. Three sets of an apparatus represented in Fig. 6, p. 95, were filled with the two kinds of soil. Each piece of apparatus consisted of glass tubes, 2 inches long and seven- eighths inch inside diameter, held together with rubber tubing and closed at the lower end with a piece of muslin. CAPIUARY CHICS CU1IDER --- UPPER SECTIOF --- --RUBBER BA*D ', - - LOWER SECTIOH . FIG. 6. — Showing apparatus used in demonstrating the possibility of recovering larger amounts of nitrates from soils by capillary sweeping than by agi- tation or by percolation. When the cylinders were filled with these respective soils they were placed in nitrate-free water until, at the end of 15 minutes, the soils became moist at the surface and capillarity sat- urated. At this stage the two sections of the tubes were sepa- rated and the amounts of nitrates in each determined at once, obtaining the results which are given in the table which fol- lows: 96 BULLETIN F. Concentration of nitrates by capillary sweeping. Coarse Sandy Soil. Loamy Sand. Upper section. Check. Lower section. Check. Upper section. Check. Lower section. Check. No. 1.. . No. 2 . No. 3.... Av In parts per million of dry soil. 120.435 122.873 107.380 46.462 48.400 50.400 1.487 1.751 1.509 48.224 44.963 47.722 324.398 341.187 347.070 164.062 176.364 143.757 161.394 4.799 5.645 4.796 154.132 176.765 160.951 116.896 48.421 1.602 46.970 337.552 5.080 163.949 From this table it is seen that there had been a very strong concentration of nitrates in the upper half of the soil column and if the amounts recovered from the upper and lower sections of the capillary cylinders are combined and compared with the amounts recovered from the two sections of the check cylinders, the results will appear as given in the next table : Differences in amounts of nitrates recovered by capillary concen- tration and by ordinary washing. From Coarse Sandy Soil. From Loamy Sand. Capillary tubes. Check tubes. Capillary tubes Check tubes. Upper section In parts per million of dry soil 116.896 1.602 48.421 46.970 337.552 •5.080 171.316 162.672 161.394 163.949 59.249 47.695 47.695 47.695 00.000 162.672 162.672 Difference ... 11.554 8.644 000.000 It thus appears that, under the influence of capillary sweep- ing, it was possible to recover 24.22 per cent, more nitrates in one series and 5.31 per cent, more in the other series. In another soil, a medium clay loam, under a bluegrass sod, which had been reduced so low in its nitric acid content by the action of the roots that only small amounts could be recovered by washing the soil in the ordinary way, capillary sweeping, by the method described, enabled solutions to be obtained which yielded an increase of 17.57 per cent, in nitrates over the ordi- nary method of washing, and of 23.83 per cent, in total salts as indicated by the electrical method. MOVEMENTS OF SALTS IN SOILS. 97 RETENTION OF NITRATES BY CLEAN SAND. In February, 1902, a sample of "Sea Island sand" in the collection of this Bureau, was rendered nitric-acid-free by re- peatedly washing the dry sand in disulphonic acid and then treated with a solution of potassium nitrate. A quantity of this sand — 50 grams — was washed during 3 minutes without dry- ing, 10 consecutive times in 100 c. c. of distilled water, and the amounts of NO3 determined in each case. After the last wash- ing the sample was dried and the sand itself treated directly with disulphonic acid and an examination made for nitric acid. The results obtained are given in the next table : Amounts of nitric acid recovered by repeated washing and then treating the washed sand with disulphonic acid. Recovered with 1st washing of three minntes 3.12100 mg. Recovered with 2nd washing of three minutes 32840 mg. Recovered with 3rd washing of three minutes 04515 mg. Recovered with 4th washing of three minutes 01736 mg. Recovered with 5th washing of three minutes 01380 mg. Recovered with 6th washing of three minutes 01280 mg. Recovered with 7th washing of three minutes 01109 mg. Recovered with 8th washing of three minutes 01100 mg. Recovered with 9th washing of three' minutes 01100 mg. Recovered with 10th washing of three minutes 01101 mg. Recovered with disulphonic acid after drying 76290 mg. Total recovered 4.34551 mg. Amount present 4 . 12500 nag. Thepe and the previous observations point strongly to the retention of nitric acid in some manner by soils, and indicate that the close and slowly moving layers of water which move over the surfaces of soil grains and granules by capillarity are able to wash them more thoroughly than is practicable by simple agitation in water or by the percolation of water through them. The larger amount of nitric acid, recovered by the repeated washing, may be due simply to the failure of agreement between duplicate determinations on samples taken from the same bulk lot ; it may be in part due to the very slight color which the disulphonic acid imparts to distilled water after neutralization with ammonia, this becoming additive in such a series. Or, again, there are forms of organic matter in soils which develop, in connection with disulphonic acid, a color resembling the- yel- low of the standard color solution ; these, if present in this sand, 7 98 may also have had an additive effect The sand, however, had been repeatedly treated with disulphonic acid for the purpose of removing this source of error as well as to get rid of all ni- trates which might be present. THE INFLUENCE OF EARTH MULCHES UPON THE MOVEMENT AND DISTRIBUTION OF WATER-SOLUBLE SALTS IN SOILS. In our earlier investigations relating to the influence of deep and shallow cultivation upon the yields of crops, and in regard to the influence of mulches generally, conducted at the Wiscon- sin Agricultural Experiment Station, relations were observed which made it appear that mulches influence yields in other ways than by merely controlling the movement and amount of soil moisture. »• CONDITIONS OF THE EXPERIMENT. Using a set of 24 cylinders, represented in Fig. 1, p. 64, the effect of 3-inch earth mulches upon the movement and distribu- tion of water-soluble salts in six soil types was studied during a period of 70 days. Four cylinders were charged, by careful and unifornn tamping, with each type of soil, in the manner al- ready described, and a composite sample of each taken to give the soluble salt condition of the soils when the observations were begun. After all of the cylinders had been charged and put in place, 3 inches of the soil were removed from two of each set. of four cylinders and so much of it returned in a loose condition as was required to fill them again level full. The soils used were, in all cases, taken from the surface foot of the respective types and were placed in the cylinders after a thorough mixing of the bulk samples, in their normal moisture and textual field conditions. Water was then added to the reservoirs with the covers in place, until each had become cap- illiarily saturated, when all were exposed to surface evapora- tion under a canvas shade, which excluded the rain. MOVEMENTS OF SALTS IN SOILS. 99 After a period of TO days' duration, the soils were removed from the cylinders in sections and the water-soluble salts de- it- r mined for the different levels. The total amounts of water added to these different soils, un- der the two conditions, are given in the next table : Amounts of water added by capillarity. Sandhill. Selroa Silt Loam. Norfolk Sandy ;Soil. Goldsboro Compact Sandy Soil. Norfolk Fine Sandy Loam. Pocoson. In c. c. . . . To the mulched cylinders. 1044.5 2.98 2084.5 5.96 2036.5 5.82 1955.5 5.44 2794.5 7.98 2425.5 6.93 In inches In c. c. To the unmulched cylinders. 1869.5 5.34 3227.5 9 22 3504.5 10.01 3797.5 10.85 4974 14.21 3512.5 10.04 In inches The water used was drawn from the hydrant of the field labo- ratory and its composition is given in, Bulletin "B," " Amounts of Plant Food Readily Recoverable from Field Soils with Dis- tilled Water/' p. 94, No. 13 of the table. The amounts of salts conveyed to these soils in the! water added and the amounts which were present in. the soil when the cylinders were filled are given in the next table: 100 Total water-soluble salts in upper 18 inches of soil at commence- ment of trials and the amounts added with the ivater, expressed in pounds multiplied by 1.000,000. NO3. UC03. Cl. S04. HPO4. SiO3. Mulched. Un- mulched. Mulched. Un- m niched. Mulched. Un- mulched.' Mulched. Un- mulched. Mulched. Un- mulched. Mulched. Un- mulched. Soil at start .... In water added. Soil at start In water added. Soil at start In water added. Soil at start In water added. Soil at start.... In water added. Soil at start... In water added . Sandhill. 22.6 .5 23.4 .9 61.2 4.3 63.4 7.6 59.9 10.7 62.2 19.0 0.0 9.7 0.0 17.2 43.1 3.1 44.7 5.5 7.0 22 7 7.2 40.1 Selma Silt Loam. 385.3 1.1 416.5 1.6 306.5 9.3 331.3 13.7 326.5 23.4 a~>2.9 34.3 1056.9 | 21.2 1142.2 31.0 143.8 i 6.8 •J 10.0 50.4 49.9 54.5 72.5 Norfolk Sandy Soil. 1372.5 1.0 1442.2 1.6 166.4 8.5 174.9 13.8 399.8 21.4 420.1 34.7 1131.9 19.3 1189.4 31.4 138.9 6.2 146.0 10.1 f 74.2 45.1 78.0 73.2 Goldsboro Compact Sandy Loam. 248.2 1.0 263.3 1.9 65. OJ 69.0 8.0 15.8 379.7 20.1 402.7 39.6 1072.0 18.2 1137.0 35.9 159.9 5.9 169.5 11.5 21.0 42.5 22.3 83.7 Norfolk Fine Sandy Loam. 1821.3 1.4 1944.4 2.4 ! 78.5 j 11.7 i 83.8 20.2 1262.1 29.3 1347.4 50.6 618.1 26.5 659.9 45.8 174.3 8.5 186.1 14.8 14.2 15.1 61.9106.9 Pocoson. 695.0 713.31 236.7 1.21 i.7l| 9.9 242.9 14.7 153.8 24.8 157. 9J 50.7 42.61149.6 36.911 22.ol 33.4)| 7.2 153.5 10.7 42.4 52 . l 43.6 77.9 DISTRIBUTION OF SALTS IX MULCHED AND UXMLTLCHED SOILS AFTER A CAPILLARY MOVEMENT OF 70 DAYS. In removing the soil from these cylinders at the close of the trials the upper 3 inches were taken out in 1-inch layers, but the balance, down to and including 18 inches, in 3-inch layers. The lower 6 inches of soil in the cylinders were not examined. In the table which follows are given the amounts of the dif- ferent water-soluble salts recovered from the cylinders carry- ing the different soil types under the mulched and unmulched conditions. These observations were made during the season of 1902, before the methods for the determination of bases had been devised, and hence only the movement of the negative radicles was observed : MOVKMKNTS < > I-' SALTS IN SOILS. 101 Amounts and distribution of water-soluble sattv in G ceil types 70 da,i/s of capillary movement under mulched' and unmulched surfaces. Depth. Inches. NO 8. HCO3. Cl. S04. HP04. 8i03. 1 J3 B & •1 P1 1 o o 13 4 S TJ • X) J> "3 •d • *! 'O ® £ "3 a .i s| Q I 3 s A, a 1 jj °3 H i £\ 0- 1 1- 2 2-3 In parts per million of dry soil. Goldsboro Compact Sandy Loam. 232.8 47.8 47.8 46.8 a5.8 30.6 27.2 7.0 395.0 10.0 8.1 8.2 7.0 5.7 4.8 2.8 10.94 24.74 11.81 12.14 13.76 14.48 16.37 15.50 13.55 10.30 11.13 8.43 17.60 17.38 28.00 22.66 182.80 20.20 17.78 9.15 10.94 8.41 12.97 9.02 280.49 7.18 4.85 7.37 6.60 8.48 8.52 8.76 111.0 40.0 r>0.4 50.6 51.3 45.6 34.1 34.7 825.0 42.7 41.6 26.6 26.6 17.1 11.6 5.3 9.35 6.70 6.98 6.38 6.42 5.66 5.82 T>.20 11.40 9.20 9.32 8.65 7.86 8.09 7.40 8.43 2.07 2.88 2.99 3.07 3.09 3.51 3.21 4.58 3.67 3.71 2.99 3.40 3.43 3.49 4.37 4.47 3- 6 6-9 9-12 12-15 15-18 0- 1... 1- 2 2- 3 3-6... Norfolk Fine Sandy Loam. 768.0 51.8 38.6 25.0 25.3 16.1 16.2 7 8 1120.0 15.5 12.8 12.3 11. 0| 9.9 H ;>.7| 16.34| 13.91 19.39 13.73 15.30 15.30 17.901 14.101 18.101 15.20 13.95 16.88 26.80 28.88 31.501 30.181 503.80 1 16.31 8.08 1 9.15 I 13.46 9.38 9.78 ! 11.89 977.20 6.38 8.08 7.37 5.89 17.17 6.13 5.41 371.26 63.20 56.14 45. OC 34.20 32.40 15.45 4.3c 301.0 24.9 19.2 18.9 12.5 10.4 7.1 4.9 9.821 11.70 7.47 9.97 7.77 8.54 1.9t\ 7.86 8.09| 8.09i 8.20 8.20 8.54 7.60 8.7'J. 7.80 1.69 3.59 3.72 4.02 3.89 4.37 4.52 5.06 6.79 4.46 3.72 4.17 5.45 5.56 5.72 5.87 6- 9 9-12... 12-15 15-18 0- 1 .. Pocoson. 1004.0 93.6 88.8 91.2 78.1 52.0 26.5 13.7 845.0 31.2 31.7 33.2 26.4 27.2 19.6 10.7 10.57 12.14 10.86 10.42 11.48 9.31 25.38 24.30 12.36 21.40 17.38 16.15 28.791 25.50 23.60 24.301 244.08 56.30 48.80 24.15 17.73 16.23 11.05 9.42 261.62 6.66 5.89 10.30 9.64 10.82 10.98 14.12 125.00 24.74 18.24 | 18.74 15.66 13.44 13.64 11.49 243.00 13.49 12.54 11.65 11.88 11.00 11.16 8.93 16.2 13.6 11.3 10.8 12.8 15.6 22 0 21.7 16.1 1 17.6 17.8 18.0 21.1 24.3 21.1 19.9 1 4.5 6.9 7.0 10.5 12.3 14.2 16.2 14.4 7.1 7.7 7.0 7.2 11.8 12.1 11.0 11.3 1-2... 2-3 3- 6 6- 9 9-12 12-15 15-18 0- 1... Sandhill. 2.58 3.58 2.11 4.00 6.24 3.76 3.91 1.92 20.401 3.85 4.41 4.6ll 4.54 4.74 2.59 2.29 10.36 9.80 8.16 6.56 8.02 8.35 10.71 12.42 10.15 12.87 8.37 11.74 9.25 8.13 9.06 9.95 9.91 9.97 8.75 12.19 12.43 11.22 11.55 12.48 16.19f 9.72 11.96 10.60 13.81] 12.60 14.02 10.701 4.32 4.83 3.96 4.11 3.16 2.19 2.41 1.83 7.99 5.07 4.05 4.11 4.16 3.20 2.38 1.81 6.81 6.12 7.02 5.13 | 5.98 6.21 7.70 I 7.80 7.80JI .66 7.19 .66 7.91 .68 7.28|| .71 7.3711 .72 6.06 .75 6.74 1.67 7.7211 1.66 1.36 1.04 .69 .71 .72 .73 .81 1.24 1- 2 2- 3 3- 6 6- 9 9-12 12-15 15-18 0- 1 1- 2 2- 3 3- 6... Selma Silt Loam. 1140.0 138.0 97.2 98.0 52.4 52.9 32.5 20.4 1076.3 99 2 28.5 26.8 28.1 24.6 20.1 15.2 7.82 17.40 12.31 9.81 21.42 21.02 36.48 39.40 10.43 26.42 11.58 14.68 32.211 29.20 54.01 47.18) 317.56 27.86 18.50 14.02 14.22 15.32 21.19 12.33 74.00| 9.15 10.091 13.64] 9.64 12.44 9.15 9.28 1554.0 110.0 182.0 85.6 82.0 59.8 • 33.5 25.1 1100. 0|| 16.7 50.6 14.8 39.9 11.3 34.7|| 11.8 26.7 12.0 21.7 13.0 19.7 17.6 13.8!J 19.0 17.9 (I 1.8 13.6 4.1 11.3 1 5.9 12.3 | 6.9 12.6 || 9.1 15.4 10.1 16.6 10.2 17.8 II 12.7 6.0 7.3 8.2 6.8 9.4 9.1 10.9 9.5 6- 9 9-12... 12-15 15-18. 0- 1 1- 2.. .. Norfolk Sandy Soil. 652.0 131.0 50.8 52.8 46.8 13.9 16.9 3.1 694.01 11.2 9.4 9.l| 11.5 9.3 7.3 7.8. 20.49 12.39 14.04 9.74 16.78 17.60 26.82 46.04 7.26 15.38 14.23 4.09 26.12 25.27 40.48 52.971 169.47 13.64 7.77 9.70 6.46 9.83 9.25 10.52 160.331 6.21 7.87 9.45J 7.98( 6.55 9.15 12.97 488.0 131.6 45.2 47.0 42.7 33.3 17.1 3.6 520.0 17.8 17.1 13.9 11.9 11.0 4.5 2.4 10.36 9.47 8.93 9.28 10.93 11.85 12.13 13.52 14.0 [1 1.00 12.0 2.10 11.4 2.51 10.6 J| 2.61 10.7 If 3.01 12.6 3.05 13.6 3.11 12.5 1 3.69 1.07 2.15 2.45 2.20 4.81 4.91 3.82 4.01 2- 3 3- 6 6- 9... 9-12... 12-15 15-18 102 . It will be seeii, from this table that there came to be, at the eiKl'O^fp^daysj a marked inequality in the distribution of the water^olubie salts which could be recovered by washing in dis- tilled water. Instead of the perfect uniformity which existed at the time the cylinders were charged with the soil, the 70 days of capillary movement has resulted in very large concentra- tions, especially of the nitrates, chlorides and sulphates, at and near the surface. The nitrates, for example, range from; 20.4 parts per million at 15 to 18 inches below the surface to 1140 parts per million in the surface inch of the mulched surface; and from 15.2 parts at the bottom to 1076.3 parts at the top, where the soil was firm. It will be seen that the water-soluble salts in the upper layer of the loose soil of the mulcheed cylinders are often greater than* in the corresponding layer of the unmulched or firm surface. This difference results partly from the fact that the weight of soil in the loose condition is less than where the soil was firm, and hence the same amount of salts brought into the surface inch represents ,a larger number of parts per million of the soil. Because the data of the last table, p. 101, are not fully comparable, on account of the differences stated, there have been brought together in the next table the absolute amounts of the several water-soluble salts which were recovered from, the respective levels. These amounts are obtained by multiplying the observed dry weights of soil recovered from each layer by the parts per million taken from the last table. As the weight of the soil was obtained in pounds the results are in pounds, but on account of multiplying by parts per million they are one million times too large, and are stated in this way to avoid long decimals. In studying the data of this table it will be needful to bear in mind that because there are approximately 3 times the amount of soil in the 3-inch layers that there are in the l-inch layers, the amounts in the 3-inch layers appear to be relatively higher than is the case. To avoid this confusion the totals for the three 1-inch layers are also given in the table. The data of lines 0-3, 3-6, etc., to 15-18, show the distribution of the sev- eral salts in the respective levels in a strictly comparable man- MOVEMENTS OF SALTS IN SOILS. 103 ner, and they express the true relation between the quantities of water-soluble salts which were recovered after 70 days of cap- illary sweeping. Absolute amounts of water-soluble salts recovered from mulched and unmulched soils. Depth. Inches. N03. HCO8. Cl. S04. HPO4. Si08. 1 • 3 a 4 1 'O ® >1 H 1 0 3 * 5J | a J 3 4 S i 1 "1 0-1 In pounds multiplied by 1,000,000. Sandhill. 2.1 3.6 1.8 22.3 4.1 5.0 8.3 9.8 7.1 11.1 13.7 9.5 7.9 10.0 7.6 17.7 10.4 13. 6j 3.5 4.8 3.5 8.8 5.4 4.6 5.5 6.1 6.1 8.5 7.7 9.0 .5 . 7 .6 1.5 1.1 .8 1- 2 2- 3 0- 3 7.5 14.4 21.2 13.2 14.7 6.8 31.5 16.7 16.4 16.8 9.4 8.2 25.2 23.7 27.4 29.3 40.3 44.1 34.3 42.6 33.5 28.9 32.9 35.4 25.5 44.0 42.5 39.4 43.4 44.3 41.7 38.5 50.0 44.7 50.9 38.1 11.8 14.8 10.8 7.7 9.1 6.5 18.8 14.9 15.1 11.4 8.6 6.4 17.7 18.5 20.5 21.8 29.0 27.7 25.2 26.4 26.7 21.5 24.5 27.5 1.8 2.6 2.5 2.6 6.3 5.9 3.4 2.6 2.6 2.6 2.9 4.4 3- 6 6-9 9-12 12-15 .. 15-18 Sum . . . 0- 1 .. 77.8 98.9 190.0 207.6 239.1 263.9 60.7 75.2 135.2 151.8 21.7 18.5 Selma Silt Loam. 826.5 89.7 76.8 993.0 277.3 168.2 161.4 KM). 4 64.5 1764.8 1270.0 31.5 29.9 1331.4 85.0 88.0, 73. ll 60.7, 50.6 1688.8 5.7 11.3 9.7 26.7 27.8 68.8 64.1 112.7 124.9 425.0 12.3 28.5 12.2 230.2 31.1 14.6 87.3 9.9 10.6 401.7 71.5 64.8 1298.0 54.7 41.9 !12.1 9.6 8.9 21.1 14.7 11.9 1.3 2.7 4.6 7.1 7.9 8.6 1- 2 2- 3 .. 0- 3... 53.0 46.5 100.8 86.7 163.1 157.1 607.2 275.9 39.7 45.7 46.7 65.5 39.1 512.6 107.8 43.2 30.2 37.0 27.6 30.9 276/7 538.0 242.3 263.2 182.4 103.5 79.6 1409.0 1394.6 110.0 83.7 64.4 59.6 46.1 1758.4 30.6 33.4 38.5 39.7 54.4 60.2 256.8 47.7 39.0 39.4 45.7 50.1 59.3 281.2 8.6 19.5 29.1 30.7 31.6 40.4 159.9 23.6 21.4 29.4 27.1 33.0 31.5 166.0 3- 6 6- 9 9-12 12-15 15-18 Sum. .. 0- 1 1- 2 Norfolk Sandy Soil. 599.8 110.0 50.8 957.7 14.3 11.5 18.9 10.4 14.0 10.0 19.7 17.4 155.9 11.5 7.8 221.3 8.0 9.6 449.0 110.5 45.2 717.6 22.8 20.9 9.5 8.0 8.9 19.3 15.4 13.9 4.6 3.8 4.3 .9 1.8 2.5 2- 3 0- 3 .. 760.6 194.3 168.5 50.6 60.0 10.6 983.5 31.8 43.1 33.9 26.0 26.5 43.3 35.8 60.4 64.1 95.2 158.4 47.1 14.2 98.0 92.5 144.5 179.0 175.1 35.7 26.4 35.8 32.8 36.2 238.9 32.9 29.9 24.0 32.7 43.8 604.7 173.0 153.7 121.2 60.7 12.3 761.3 48.4 44.6 40.4 16.0 8.0 26. 34. 39. 43. 43. 46.5 48.6 36.9 40.1 46.1 48.6 42.3 12.7 16.5 18.9 20.8 20.8 22.4 5.2 9.6 10.8 11.1 11.0 12.7 60.4 3- 6 6-9 9-12 12-15 15-18 Sum... 1244.6 1144.8 457.2 575.3 342.0 402.2 1125.6 918.7 232.7 262.6 112.1 104 BULLETIN Absolute amounts of water-soluble salts recovered from mulched and unmulched soils — Continued. Depth. Inches. NO3. HC08. Cl. S04. HP04. SiO3. 'B o ja ."8 || 1 • 1 A .1 i A ' 2 I ,1 1 | 3 pps 3 s a 1 s S ' | s & ^3 3 a ' a 0- 1 1- 2 In pounds multiplied by 1,000,000. Groldsboro Compact Sandy Loam. 253.8 44.5 51.2 604.4 13.0 9.8 627.21 31.3 26.6 99 •} 19^8 11.3 738.7 11.9 23.0 12.6 20.7 13.4 13.5 47.6 32.1 66.9 69.0 116.2 92.7 424.5 199.3 18.8 19.0 237.1 36.2 42.3 32.4 48.8 37.4 434.2 429.2 9.3 5.9 444.4 28.1 25.1 33.7 .35.4 35.8 602.4 121.0 37.2 53.9 1262.3 55.5 50.3 1368.1 101.4 101.1 67.9 47.9 21.8 1708.2 10.2 6.2 7.5 23.9 25.3 24.9 21.8 21.9 21.6 139.3 17.4 12.0 11.3 40.7 33.0 29.9 32.1 30.7 34.5 200. 8J 1 2.3 2.7 3.2 5.6 4.8 3.6 14.1 13.0 13.0 13.9 18.1 18.3 90.3 2- 3 0- 3 3-6 349.4 185.3 138.6 117.8 102.3 29.1 47.6 48.1 53.3 55.8 61.6 64.3 330.5 212.1 200.4 198.5 175.6 128.3 144.0 1058.9 8.1 12.2 12.0 13.5 12.1 19.0 76.9 6- 9 9-19 12-15 15-18 Sum . . . 0- 1 .. 922.4 Norfolk Fine Sandy Loam. 668.2 36.8 36.7 741.6 86.0 89.8 56.5 56.4 27.1 1057.4 1624.0 18.0 14.4 1656.4 41.9 39.2 35.3 27.5 20.2 1820.5 14.2 14.0 14.5 42.5 61.6 64.3 49.0 93.3 109.0 419.6 20.2 15.9 17.6 53.7 48.1 54.1 59.9 100.2 107.7 423.8 438.3 11.6 457.6 31.5 47.8 32.9 34.0 41.1 644.9 141.7 7.4 9.3 158.4 25.1 21.0 61.0 21.3 19.3 306.0 323.0 44.9 53.3 421.2 154.8 121.4 113.7 50.3 15.0 876.4 436.5 28.9. 22. ll 487.4 64.3 44.6 36.91 24.7 17.5 675.5 8.5 5.3 7.4 21.2 27.5 28.7 28.8 29.7 30.4 17.0 11.6 9.8 38.4 26.8 28.8 29.1 26.4 27.9 1.5 2.6 3.5 7.6 13.8 13.8 15.3 15.7 17.5 9.9 5.2 4.3 19.3 14.2 19.4 19.7 19.9 21.0 113.5 1- 2 2- 3 0- 3 3-6 6- 9 9-12 12 15.... 15-18 ... Sum . . . 0- 1 1- 2 2- 3 0- 3.. . 3- 6... 6- 9... 166.3 177.3 83.8 Pocoson . 652.6 75.8 79.0 963.3 30.3 30.4 6.9 9.8 9.7 14.1 20.8 16.7 ! 158.7 ! 45.6 ! 43.4 298.3 6.5 5.7 81.3 20.0 16.2 117.5 57.3 50.1 42.5 43.8 38.0 349.3 277.0 13.1 12.0 10.5 11.0 10.1 18.4 17.1 17.1 2.9 5.6 6.3 8.1 7.4 6.7 807.5 279.1 249.9 164.3 85.1 45.4 1631.2 1024.0 100.3 82.1 88.1 61.7 34.0 1390.3 26.4 31.9 36.7 29.4 81.5 80.4 286.3 51.5 48.8 89.5 82.6 74.3 77.3 424.1 247.7 73.9 56.7 51.3 35.5 31.2 496.3 310.4 31.1 30.0 35.1 34.6 44.9 486.0 302.2 35.2 37.0 35.6 35.2 28. 4j 473.5 31. P 33.1 41.0 49.3 70. ( 71.8 297.4 52.5 54. 4j 65.6! 78.61 66.5 63.3 380.9 14.8 32.0 39.4 44.8 52.0 47.8 230.8 22.2 21.6 36.7 39.1 34.7 35.9 190.2 9-12 12 15... 15-18 Sum. .. MOVEMENTS OF SALTS IN SOILS. 105 INFLUENCE OF CAPILLARY MOVEMENT IN SOILS UNDER NAKED FALLOW TREATMENT UPON THE AMOUNTS OF WATER-SOLUBLE SALTS IN SOILS. One of the purposes of this investigation was to ascertain if the amount of water-soluble salts of soils change under naked fallow treatment, and if so, in what manner; and the data of the tables on pp. 100, 103 arid 104, m,ay be used to sliow if a measurable change has occurred during the 70 days of treatment to which the six soils have been subjected. The addition of river water to maintain capillary movement did not do violence to normal field conditions, for it was itself a ground water closely similar to that normal to the several soil types under observa- tion. The abnormal conditions are the large and rapid move- ment of the water ; its somewhat higher temperature ; and per- haps a slightly different aeration than would be normal to fields. If the total water-soluble salts observed in these soils at the time they were placed under treatment are increased by the amounts of salts carried to them in the water, the results may be compared with the amounts found at the close of the capillary period to show whether measurable changes have occurred. Such a comparison is made in the following table: 10G Changes in the amounts of water-soluble salts in the surface 18 inches of soil in cylinders, associated with naked fallow and cap- illary movement. NO3. HC03. Cl. SO,. HPO4. Mulched. 1 03. Mulched. Un- mulched. Mulched. Un- mulched. Mulched. Un- mulched. Mulched. Un- mulched. Mulched. Un- mulched . Un- mulched. | Close Start Change . Close . In pounds multiplied by 1,000,000. Sandhill. . 77.8 23.1 98.9 24.3 190.0 65.5 207.6 71.0 239.1 70.6 263.9 81.2 60.7 9.7 :.-,.. 17.2 1 135.2 46.2 151.8 50.2 101.6 1 21.7 29.7 18.5 47.3 54.7 74.6 124.5 1'36.6 168.5 182.7 51.0 58.0 89.0 —8.0 —28.8 Salem Silt Loam. 1764.8 386.4 1378.4 1688.9 418.1 1270.8 425.0 315.8 607.2 345.0 262.2 1 M2.7 349.9 276.7 387.2 -110.5 1408.9 1078.1 330.8 1758.4 1173.2 2.56.9 150.6 1 281.2 165.4 159.9 100.3 166.0 127.0 39.0 Start Change.. Close Start .. .. 109.2 162.8 585.2 106.3 115.8 59.6 Norfolk Sandy Soil. 1244.7 1373.5 -128.8 1 1143.8 1443.8 -299.0 457.2 174.9 282.3 575.3 188.7 386.6 342.0 421.2 402.1 454.8 1125.6 1151.2 918.6 1220.8 232.7 145.1 87.6 262.6 156.1 106.5 1 112.1 119.3 —7.2 60.4 151.2 —90.8 Change. . Close -79.2 -52.7 —25.6 -302.2 Goldsboro Compact Sandy Loam. 922.5 249.2 738.6 265.2 ;340.7 424.5 73.0 84.8 429.2 399.8 602.5 442.3 1058.9 1090.2 1708.2 1172.9 139.4 165.8 200.9 181.0 76.9 63.5 90.4 106.0 Start .... Change. . Close Start Change.. Close Start Change.. 673.3 473.4 267.7 339.7 29'. 4 160.2 —31.3 5&5.3 —26.4 19.9 13.4 -15.6 Norfolk Fine Sandy Loam. 1057.41820.5 1822.71946.8 419.7 90.2 423.7 104.0 644.9 1291.4 306.1 1398.0 876.4 644.6 675.4 705.7 166.3 182.8 177.4 200.9 83.8 76.1 113.5 122.0 -765.3 -126.3 329.5 319.7 -646.5 1091.9 231.8 -30.3 —16.5 -23.5 7.7 —8.5 Pocoson. 1091.3J1390.2l 696.2 715.0 395. ll 675.2] 286.3 246.6 39.7 424.0 275.6 148.4 422.4 178.6 243.8 486.1 194.8 291.3 349.2 473.6 73.2 76.0 276.0! 397.6) 297.4 156.8 140.6 380.9 164.2 216.7 230.8 94.8 136.0 180.2 121.5 58.7 From this table it will be seen .that, in the majority of cases, there has been an increase in the water-soluble salts during the 70 days of capillary movement. In the Sandhill type, except in the case of silica, there has been an increase of 1 to 2-fold. In the Selma Silt Loam there was a loss of chlorine in one case, MOVKMKXTS OF SALTS i.\ SOILS. 107 but otherwise there was a large percentage of gain, the phos- phates increasing 60 to 70 per cent. In the Norfolk Sand and in the Norfolk Fine Sandy Loam there were considerable losses in many cases. It is true of these soils that they are the ones v/hich had been most heavily fertilized the season the trials were made, and an absorption was, perhaps, to; be expected. There is no case where. the HC03 has not increased and only three cases of a reduction of the phosphates. The mean changes for the six soil types are given in the next table : Mean change in water-soluble salts in six soil types after 70 days of naked fallow and capillary movement. NO3. HCO3. Cl. S04. HPO4. Sio8. Close In pounds multiplied by 1,000,000. 1086.7 780.4 306.3 39.2 489.4 168.1 32ll~ 191.1 410.6 472.5 -61.9 13.1 874.1 701.1 173.0 24.6 223.6 147.1 76^5~ 52.0 109.5 96.5 13.0 13.5 Start Change Per cent., change These general averages point with some assurance to a ten- dency of naked fallows to increase the water-soluble salt con- tent of the soil, especially if it was low to begin with, and the observed relations are in accord with, the usual immediate in- creased productive power of naked-fallow fields, if it is true that an increase in the amounts of readily water-soluble salts in soils favor an increase of yield. INFLUENCE OF 3-INCH EARTH MULCHES ON THE DISTRIBUTION OF NITRATES, SULPHATES AND CHLORIDES, IN SOILS. If the mean amounts of nitrates, sulphates and chlorides, which were recovered from the respective levels in the six soil types under the loose and firm surfaces are brought together, they stand as given in the next table: 108 Mean distribution of nitrates, sulphates and chlorides, in six soil types under mulched and unmulched surfaces. Depth.| Inches. NO3. Cl. SO4. Mulched. Un- mulched. Mulched. Un- mulched. Mulched Un- mulched. 0- 1 .. In pounds multiplied by 1,000,000. 500.5 60.1 49.4 610.0 172.7 139.4 94.0 69.8 30.6 1116.5 100.00 907.0 18.5 16.8 942.4 51.2 49.2 45.0 34.2 25.1 198.4 21.4 16.7 236. ~ 43.5 43.6 39.8 43.3 38.2 199.3 8.6 9.1 216.9 33.2 31.0 39.3 33.8 86.5 229.9 48.2 39.5 317.5 140.4 133.0 107.2 66.0 49.2 666.7 30.1 25.3 722.1 62.4 54.4 42.8 32.0 21.4 1-2 2- 3 0- 3 . 3- 6 6-9 9-12 12-15 15-18 Total Percentage . . 1147.1 102.74 444.9 100.00 389.7 85.59 813.3 100.00 935.1 115.08 From this table it is seen that the more rapid capillary movement upward under the unmulehed surfaces had so counter- acted diffusion downward as to leave all of these salts much more concentrated under the unmulched surfaces. Comparing the data in the table it will be seen that the 3 to 0 inch level con- tains more than 3 times as much nitrates and more than twice as much sulphates under the mulched surfaces, and similar re- lations hold down to and including the 12- to 15-inch level. In the case of chlorine, whose rate of diffusion is higher, there is less difference, but the tendency here is clearly marked. It has been shown in preceding pages that the three important bases, are rapidly carried upward also by capillarity, and it is to be expected that had these been determined in this series, some- what similar relations would have been found. INFLUENCE OF 3-INCH EARTH MULCHES ON THE DISTRIBUTION OF PHOSPHATES, SILICA AND BICARBONATES. In the next table there are brought together the mean values showing the relative distribution of phosphates, silica and bicar- bonates under the two conditions of surface. MOVEMENTS OF SALTS IN SOILS. 109 Mean distribution of phosphate*, silica, and bicarbonate* in six soi I types under mulched and unmulched surfaces. Depth. Inches. HC03. HP04. Si08. Mulched. Un- mulched . Mulched. Un- mulched. Mulched. Un- mulched . 0- 1 In pounds multiplied by 1,000,000. 11.0 13.1 11.3 14.7 18.7 14.5 9.4 7.7 8.2 17.0 13.1 12.2 2.2 3.0 3.8 5.5 4.7 4.4 1- 2 2- 3 0- 3 35.3 38.2 51.8 48.6 80.8 96.9 47.7 38.7 73.8 69.9 105.4 108. 2 25.3 28.7 32.2 34.1 41.5 43.0 42.2 36.1 38.4 42.2 41.1 42.:, 8.9 16.1 19.3 21.3 23.1 25.5 14.6 13.7 18.7 18.9 19.9 20.5 3- 6 6- 9 9-12 12-15 . .. 15-18 Total 351.6 100.00 443.7 126.19 204.8 100.0 242.5 118.63 114.2 100.00 106.3 93.08 Percentage In the case of the phosphates, silica and bicarbonates, the dis- tribution, shown by the data of the table, is, in some respects, the reverse of what occurred with the nitrates, chlorides and sulphates ; with these, the amounts decrease with 2'reat rapidity through the first three inches and continue to decrease, only less rapidly to the bottom ; with the phosphates and the other two radicles, there is but a small decrease, if any, through the first three inches, but a well marked tendency for the amounts to increase with the depth. This general difference, in the be- havior of the two groups of salts, is clearly shown in the! dia- gram, Fig. 7, p. 110, where the mean combined amounts of XO3, SO4 and Cl, have been plotted as a single curve, on one-third the scale used for plotting the other three ingredients. From this figure it will be seen how strong is the tendency for the members of the nitrate group to concentrate at the surface, while the others, and in a less marked degree, show the reverse order of distribution. It should be observed, that in each case, more salts were re- covered at the top from the soil which had sustained the greatest evaporation. Moreover, there were more phosphates and silica in the surface inch than there were in the second and third inch, which shows that this reversal of the order in the distribution of no the two groups of salts is not due entirely to an effect the more soluble salts may have had upon the solubilities of the other three. FIG. 7. — Showing the effect of capillarity on the mean distribution of water- soluble salts in 6 soil types under an earth mulch of 3 inches. The NO3, SO4 and Cl curve is plotted on one-third the scale of the other three. BEARING OF CAPILLARY MOVEMENT OF SALTS UPON SOIL MANAGEMENT. CULTIVATION TO MAKE WATER-SOLUBLE PLANT FOOD MATERIALS- MORE AVAILABLE. It is evident, from the tendencies of good earth mulches to restrain the rise of water-soluble salts to the immediate surface of the field, which has been demonstrated by the series of experi- ments of the preceding section, that in so far as the presence- of 'MOVEMENTS OF SALTS IN SOILS. Ill water-soluble salts in the zone of greatest, root activity may in- fluence yield, good surface cultivation must be beneficial in holding the nitric acid, lime, magnesia and potash well down within the zone of 3 to 15 inches, where the roots of crops are usually most abundant, and for this reason, where the salts may be expected to be most immediately available. The table on p. 108 shows that, for an average of 6 soil types, the amounts of nitric acid (NO3) in the layer of soil 3 to 6 inches below the surface, had come to be in the ratio of 172.7 under the good 3-inch mulch, to 51.2, where no mulch was maintained ; and this difference, so far as can be seen, was due wholly to the effect of the mulch. In the 6 to 9 inches the mean ratio was 139.4 to 49, or nearly three times as much ni- trates had accumulated under the mulch; and even at 12 to 15 inches below the surface the ratio had come to be 69.8 tot 34.2, or twice as much nitric acid existed there; and this is one of the most essential plant food materials, for it is the immediate source of all the nitrogen of cultivated crops, at least so far as is as yet demonstrated. In Figures 8 and 9, p. 112, there are two illustrations of a form of surface cultivation very generally practiced in the South, but which, for all except very unusual soils in very wet seasons, or for certain special cro^s, is far from the best. In both of the fields there shown a small plow had been run close to the row, first throwing the dirt away from the plants, leaving a firm, moist furrow bottom exposed to the dry- ing action of the hot sun and winds and, at the same time, the loose earth turned away left in a condition to dry out com- pletely. After a day or two the dried and loose earth was again turned back against the row with the plow and another furrow bottom left exposed to the drying action which brings the nitrates, lime and other soluble salts to the immediate sur- face where they are useless to the crop and where the first heavy rain is liable to carry much of them away in the surface drain- age. The curled condition of the leaves of the corn, as shown in the engraving, Fig. 8, is the direct effect of this faulty cul- tivation rather than the result of a necessary deficiency of soil moisture at the time. 112 FIG. 8. — Showing ridge and furrow cultivation of corn and wilting which is chiefly the result of the cultivation. FIG. 9. — Showing recently plowed field of cabbage, leaving surface in condition, for rapid evaporation. MOVEMENTS OF SALTS IN SOILS. 113 LOSS OF PLANT FOOD IN SURFACE DRAINAGE. When the methods of cultivation are such asi to intensify the concentration of water-soluble salts at the immediate surface, and where the texture of the soil, the character of the rainfall and the topography are such as to cause frequent surface drain- :itiv, there must be, of necessity, heavy losses of soil fertility as the result of such conditions. It was showni, from the data of the table, p. 64, that through capillary concentration during 15 to 20 days, 60 per cent, of all nitrates contained in the surface foot may be brought into the surface 2 inches, and much the larger share of this 60 per cent, is carried to or very near the immediate surface. At the end of less than 5 days the surface 2 inches of soil contained 127.93 parts per million of dry soil, while the 10 to 12 inch level contained but 2.61 parts. Rapid movements like these under consideration are liable to occur whenever very drying weather follows a rainfall which leaves the surface 12 inches of soil nearly saturated with water, and with it there must be a concentration of nitric acid and lime at the immediate surface, with other salts also. Where the granular structure of the soil is feeble, as it is so often in the South, heavy rains, and even very moderate ones, so puddle the immediate surface that the water does not enter the soil readily but quickly flows to the lowest places, carrying with it the soluble salts which have been concentrated at the surface and, if the fields are furrowed, as is shown in the two engravings, much of the rainfall is liable to pass away in sur- face drainage and with it whatever of salts have been dissolved. Deeper plowing, which incorporates more of organic matter, and flat cultivation are two essential conditions which will very materially lessen these bad effects. 8 BULLETIN D. Absorption of Water-soluble Salts by Different Soil Types. Between the time of the earlier studies of Thompson and Way, beginning about 1845 and extending on into the later 60?s, a large amount of work was done, by various1 observers, on the absorptive power of soils over substances carried in solu- tion when brought in contact with them and allowed to remain there during different intervals of time under different condi- tions. The work done along these lines was very carefully and thor- oughly reviewed by Johnson* in 1873, who then pointed out its practical bearings in a very helpful and masterful way. In lines of investigation of the character of those which have been presented in Bulletins B and C this matter of the absorp- tive power of soils could not be left out. of consideration and references have been made to it in speaking of the development of the methods for determining small quantities of various salts in soil solutions. ON THE EXTENT OF THE POWER OF SOILS TO ABSORB AMMONIA. OBSERVATIONS OF WAY.f After making a number of qualitative experiments Way un- dertakes more exact quantitative studies, and first in regard to the absorption of ammonia, in which he uses different soils and *How Crops Feed. Edition 1902, pp. 333-361. t Journal Royal Agricultural Society of England, Volume II, 1850, pp. 313-379. AIISOUI'TION OF SALTS liV SOILS. 115 solutions of both ammonia and ammonium chloride, each hav- ing a strength of a little above .3 per cent, of ammonia. The following are his results put in tabular form: Amounts of ammonia absorbed by soils. Reference . Kind of Soil. Ratio of Soil to Solution. Time of Digestion. Absorption in Parts. Per 100. Per Million. Exp. 63, p. 341 . Exp. 64, p 342. Exp. 65, p. 342. Exp. 66, p. 343. Exp. 66, p. 343. Exp. 67, p. 344. Exp. 69, p. 346. Exp. 70, p. 347 . Exp. 79, p. 354. Exp. 80, p. 354. Exp. 80, p. 355. Loamy soil 'Ammonia solution .3173 per cent, ammonia. 760 to 1787 456 to 4082 , 2 hours. 2 hours. 2 hours . 2 hours. 16-18 hrs. .3083 .3921 .3504 .3438 .2652 3083 3921 .3504 3438 2652 Light soil Loam soil Loam soil Loam soil Black soil .. Ammonium chloride sol' ion .3060prct. ammonia. 594 to 3988 400 to 4000 450 to 4000 2200 to 4000 2200 to 4000 2200 to 4000 2 hours . 2 hours. 2 hours . 2 hours . 2 hours. 24 hours. .3478 .2847 .2820 .2010 .1248 .0818 3478 2847 2820 2010 1248 818 Pipe clay.. Pipe clay and chalk . Pipe clay digested in HC1+ chalk Pipe clay dig'ed in HC1 Clay subsoil It will be observed that very large amounts of ammonia are absorbed from the) two kinds of solutions by the soils used. From the standpoint of field problems and conditions Way's so- lutions were far too strong to* give the precise knowledge which is needed to satisfactorily illuminate the absorption phenomena for the very dilute solutions which nearly always occur, under field conditions, in cultivated soils. OBSERVATIONS OF VOELCKER. Voelcker, following Way, did a large amount of work bear- ing upon the absorption and retention power of soils for not only ammonia but for other substances as well. To obtain the results here cited he used five soils: 1. A calcareous clay. 2. A fertile loam, containing a little lime, mixed in equal proportions with its clay subsoil. *Journal Royal Agricultural Society, Volume XXI, 1860, p. 105. 116 BULLETIX 3. The surface and subsoil of a heavy clay field containing little sand. 4. A sterile, sandy soil, containing much organic matter and scarcely any lime. 5. Pasture land, being a vegetable mould containing abund- ance of organic matter and a fair proportion of sand and clay. The ammonia solution used by him contained .332 grains per 1000 of NH3, or at the rate of 332 parts per million of solution. His results follow : Amounts of ammonia absorbed 6.y five soils. Kind of soil. Ratio of soil to water. Time of digestion In parts per million of dry soil. Percentage relations. 1. Calcareous soil 30 to 140 3 day« 889 100 00 2. Fertile loam and subsoil 3. Heavy clay soil. 4. Steiile sand v soil 35 to 140 35 to 140 35 to 140 3 days. 3 days. 3 days 804 754 868 91.16 85.49 98 41 5. Pasture land 35 to 140 3 days 576 65 30 When he used a still stronger solution, on the same samples of soil, containing 673 parts of NH3 per million of solution, he obtained the results given in the next table. The digestion was allowed to continue 3 days and 14,000 grains of the stronger solution were used in each case. Amounts of ammonia absorbed by second treatment. Kind of soil. In parts per million of dry soil. Percentage relations. 1 Calcareous soil 1519.3 98.89 2 Fertile loam and subsoil 1536 3 100.00 1124 0 79 67 4 Sterile sandv soil 1522.0 99.07 5 Pasture land 1521.7 99.05 In a third series Yoelcker used 4 solutions of different strength on the same soil, which was a! moderately stiff cal- careous clay. In each case 7,000 grains of solution were agi- tated with 14 lb. of soil, -and after four days the solutions were examined. ABSORPTION OF SALTS BY SOILS. 117: Amounts of ammonia absorbed by the same soil from solutions of different strength. Strength of solution. Ammonia ab- sorbed by the soil. 1 .. In parts per million. 634 304 176 88 1320 640 260 100 2 ,., 3 4 Regarding these experiments Voelcker slates that, while the two stronger solutions gave up to their soils about half of their ammonia, the third solution only gave up one-third, and the fourth but one-fourth. Relatively larger absorptions, therefore, took place from the stronger solutions. THE POWER OF SOILS TO RETAIN AMMONIA. Another series of observations was made by Voelcker to meas- ure the power of a given soil to hold back the absorbed ammonia against washing with water. He used a soil which had absorbed at the rate of 4.655 grains of ammonia for each 1750 grains of soil, or 2660 parts per million. This sample was washed 7 consecutive times, using each time 7,000 grains of distilled water. His results appear below : A mounts of ammonia recovered from one-fourth Ib. of soil by 7 con- secutive washings with 7000 grains of water. AMMONIA. Grains. Parts per mil- lion of soil. .236 .642 .610 .622 .120 .193 .228 134.9 366.0 348.5 355.4 68.6 110.3 130.3 Fifth 7000 grains of water removed 2.651 4.655 2.004 1514.0 2660.0 1146.0 Total absorbed Total retained 118 Only a little more than one-half of the absorbed ammonia had ttms heen recovered. In still another series of observations Yoelcker used ammo- nium chloride, as Way had done, and upon the same series of soils which he used in the cases first cited. His solution con- tained 360 parts per million of ^H3, and 3500 grains of soil were used to 14000 grains of solution, the determinations being made after 3 days. In another series, but on the same soils, he used n solution of ammonium sulphate which contained 288 parts per million of ammonia. The ratio of soil to solution was 3500 to 14000. The following are the results: Amounts of ammonia absorbed by five soils J'rom solution* of am- monium chloride and ammonium sulphate. From NH4 Cl. From (NH4)2 SO4. 1. Calcareous soil absorbed in parts per million NHa. 680 NHs. 608 2. Fertile loam and subsoil absorbed in parts per million 3. Heavy clay soil absorbed in parts per million ... 760 800 640 576 4. Sterile sandy soil absorbed in parts per million 5. Pasture land absorbed in parts per million 160 640 256 448 The sandy soil has, in each case, absorbed least ammonia, but otherwise the results do not show much tendency to a marked difference in absorptive effect ; but the question naturally arises whether, in experiments conducted under these conditions, a ni- trification of the ammonia salts may not have occurred, and more with one soil than with another. OBSERVATIONS OF O. KUKLENBERG.* This investigator, in his absorptive studies, used a soil from the Ida-Marienhutte Experiment Station, which, when di- gested in water and in hot hydrochloric acid, gave the following results : *Hoffman's Jahresbericht der Agrikultuv-Chemie. 1SG5, p. 15. ABSORPTION OF SALTS BY SOILS. 119 Materials recovered from noil used in ammonia absorption experiments. Soluble in 2.:> times its weight of cold water. Soluble in three times its weight of HC1,1 .17sp. gr. Residue insoluble in HC1. 0116 "> 1380 Lime 0065 2436 .3959 0022 2846 2023 Iron oxide. 004T) 1.5912 .4398 0022 1 8480 5 3483 Potash . .0012 .1950 •1 Hr.'j Soda 0027 0612 .9588 003") 0413 Phosphoric acid 0006 0863 0055 0059 Silicic acid 0122 0930 78.5175 0082 87 9650 Water driven off at 150° C 5.2840 2412 Total 0609 100 0783 87 8650 The soil also contained .0059% ammonia, .0105% nitric acid and .0673% total nitrogen. Four strengths of solution were used in the ratio of 1, 2, 4 and 10, and 100 grams of soil were digested 3 days in 250 c. c. of solution. The results appear in the next table. Amounts of ammonia absorbed by a soil from different strengths of ammonia salts. Solutions Used. Ammonia, NH3, in Solution. Ammonia absorbed. Before absorption. After absorption . In parts per million. ( 160 83.2 229 I 340 197.6 375 Chloride of ammonia .4 680" 448.0 612 (NHUC1) 1700 1392.4 811 3400 2953.2 1174 r 160 83.2 229 \ 340 199.2 371 Nitrate of ammonia .J, 680 446.4 616 (NH4NO5) 1 1700 1370.0 871 I 3400 2914.8 1280 ( 160 60.0 290 \ 340 184.8 409 Sulphate of ammonia .\ 680 419.2 688 (NHdO $0*0 1700 1255.2 1173 3400 2869.2 1400 \ 160 71.2 260 \ 340 184.4 410 Carbonate of ammonia 680 398.0 744 (2NH4O, 3CO3) ' \ 1700 1232.8 1233 I 3400 2734.8 1755 f 160 HB.2 307 1 340 137.2 535 Phosphate of ammonia (NH4O, 2HO, PO5) •\ 680 1700 331.6 941.6 919 2000 I 3400 2151.6 3294 120 These observations show a large absorption of ammonia in whatever form it enters the solution, but it must also be said that even the weakest solution, 160 parts per million, is con- centrated, when compared with normal soil solutions. The strongest solutions used contained 3400 parts per million. The largest absorption shown by the table is 3294 parts per million of the soil, while the smallest is 229 parts. Kullenberg tried recovering the ammonia again, by percolat- ing distilled water through the soil placed in a funnel. He digested during 24 hours 100 grams of this soil with 250 c. c. of an ammonium phosphate solution, which contained .7260 grams of phosphoric acid and .2911 grams of ammonia; then added enough water to obtain a filtrate of '250 c. c., repeating the addition of water, with the results as given in the next table. Amounts of phosphoric acid and ammonia washed away from soil with distilled water. PHO8PHOEIC ACID. AMMONIA. Grams. Parts per million. Grams. Parts per million. 1st 2ari 3rd 4th 5th 250 c. c... .0927 .0255 .0140 .0095 .0076 .1493 927 255 140 95 76 1493 .0187 .0054 .0045 .0026 .0009 .0321 187 54 45 26 9 321 250 c c 250 c. c 250 c c ... 250 c c Total . . . Enough has been cited to show the tendency to absorption from a solution of ammonia. by soils when the solutions are strong. ABSORPTION OF POTASH BY SOILS. OBSERVATIONS OF VOELCKER.* There have been brought together here in tabular form, with additional data, the results of a considerable number of the absorption experiments of Yoelcker, without commenting on his mode of procedure more than is indicated by the table, as it was 'Journal Royal Agricultural Society, Volume XXI, 1860, p. 105. ABSORPTION OF SALTS BY SOILS. 121 similar to that adopted by him in his work regarding the absorp- tion of ammonia, already cited. Amounts of potash absorbed by different soils. Type of Soil. Ratio of soil to water. Time of contact with solution. Days. Absorbed by soil. K2O. Retained by solution . K20. K2O given to soil by solution left, when retaining 20 per ct. 10 per ct. 1 Calcareous soil In parts per million. First Series. 1 to 8 1 to 8 1 to 8 1 to8 1 to8 1 to8 4 4 4 4 4 4 6400.0 6510.0 5690.0 6570.0 7260.0 6160.0 413.0 399.0 501.0 390.0 305.5 443.3 82.60 79.80 100.20 78.00 61.10 88.70 41.30 39.90 50.10 39.00 30.50 44.30 2 Stiff clay 3 'Fertile sandy loam 4 Pasture land 5 Marly soil . t 6 Sterile sand 1 Soil No. 7 .. Sacond Series. 1 to 2 1 to 2 1 1 5917.9 5435.5 1221.6 1575.0 204.30 315.00 122.20 157.50 2 SoiJ No 12 1 Soil No. 7 . Third Series. 1 to 2 1 to2 1 to 8 1 to 8 1 4 4 4714.8 4808.8 3671.0 1189.0 1684.8 1619.4 706.5 1016.7 337.00 323.90 141.30 203.30 168.40 161.90 70.70 101.70 2 Soil No. 12 3 Marly soil 4 Sterile sandy soil 1 Calcareous soil Fourth Series. 1 to 8 1 to 8 1 to8 1 to 8 1 to 2 1 to 2 1 to 8 1 to8 1 to 4 4 4 4 4 1 1 4 4 3 3578.0 3970.0 2626.0 3758.0 5066.0 6903.0 1465.0 3373.0 3776.0 744.8 695.8 863.8 722.3 1641.0 722.6 944.6 756.2 755.0 149.00 139.20 172.80 144.50 328.20 144.50 198.90 151.20 155.00 74.50 69.60 68.40 72.20 164.10 72.30 99.50 75.60 75.50 2 Clay soil 3 Fertile lieht sandy loam... 4 Pasture land 5 Soil No. 7... 6 Soil No. 12 . . 7 Sterile sandy soil 8 Marly soil 1 Clay marl For this absorption work Voelcker's solutions were all strong, rangingj with two exceptions, from, 1213 to 6617 parts per mil- lion of K2O. The Nos. 3 and 4 of the third series contained only 215.7 parts per million, which is still higher than occurs in natural soils, judged from amounts recovered by single wash- ings of short duration. In the last two columns of the table have been set the amounts of K2O in parts per million of dry soil which 20 per cent, and 10 per cent, of soil moisture would carry if it had the residual strength of the several solutions ; or the strength after they had 122 come in contact with the soil and had been weakened by what- ever absorption took place. The amounts of potash used in these solutions were so large that it can hardly be expected to show well any differential ef- fect of the different soils in removing the potash from solu- tion; moreover, the number of observations is too limited, but the results are suggestive of differential effects. There are four soils, in the table, which were used in each of these series, and the amounts of potash absorbed in these trials are grouped in the table below : Amounts of potash absorbed by four soils. No. 7. No. 12. Marly soil. Sterile sand. 1 .. In parts per million of dry soil. 5917.9 4714.8 5066.0 5232.9 91.55 5435 . 5 4808.0 6903.0 5715.8 100.00 7260 3671 3373 4768 83.42 6160.0 1016.7 1465.0 2... 3..... Average 2880.6 50.39 Percentage amounts. There is thus shown a difference in the absorptive effect of these four soils ranging from 8 to 50 per cent. OBSERVATIONS OF WAY.* In the six trials made by Way, which are here cited, he used three strengths of solution, two prepared from potassium nitrate and the third from caustic potash. Their strengths were: 1st solution 8255 parts per million of potash. 2od solution 10029 parts per million of potash. 3rd solution 10023 parts per million of potash. When 2000 grains of white pottery clay were digested with 4000 grains of the first solution, for several hours at ordinary temperature, it was found that 100 grains of the clay had ab- sorbed .4366 grains of potash, or at the rate of 4366 parts per million of the clay. When the second solution was used, in the same ratio as in the preceding case, the absorption amounted to 4980 parts per million, after a contact with the clay during 24 hours. "Journal Royal Agricultural Society, Volume II, 1850, p. 356. ABSORPTION <>!• SALTS BY SO U.S. 123 In the next four1 trials the third solution was used and the ;in miii its of potash absorbed were: Exp. 83 Potash absorbed = 10500 parts per million of clay. Exp. 84 Potash absorbed = 11716 parts per million of clav. Exp. 8T> Potash absorbed — 121.">4 parts per million of clay. Exp. 86 Potash absorbed = 20870 parts per million of clay. In experiment 83 the digestion covered 12 hours with the solution cold, in the ratio of 2000 of soil to 4000 of solution. In experiment 84 the mixture was boiled one-half hour. In experiment 85 the clay was first treated with hot hydro- chloric acid and afterwards as in experiment 84. In experiment 86 a yellow clay from Cromwell was used, first treated with hydrochloric acid, boiling one hour, and sub- sequently digested, at high temperature, 24 hours ; then washed with distilled water and dried before using. The ratio of clay to solution was 500 to 2000 in this case. To obtain the results here cited Dr. Peters prepared a quanr tity of a rather clayey soil derived from the disintegration of a claystone porphyry, the analysis of wThich is given in Bulletin "B,"p. 7. Solutions containing different potash salts in different amounts were prepared and 100 grams of the air-dry soil were digested in 250 c. c. of these solutions during 24 hours; the soils being introduced into a stoppered flask and the mixtures, at first, subjected to vigorous shaking. Portions of the liquid above the soil were drawn off with a pipette for analysis. There is given in the next table two sets of absorption re- sults, one with the solution cold and in contact with the soil 24 hours, the other, where the soil was boiled in the solution one-fourth hour and then allowed to stand 24 hours. *Die landwirthschaftlichen Versuchs-stationen, Volume 2, p. 113. 124 Amounts of potash absorbed from different solutions. Solution contained AMOUNTS ABSOKBED Percentage relation. from solu- tion cold K2O. from solu- tion boiled KaO. Potassium chloride In parts per million of dry soil. 2355.5 4711.0 9422.0 2355.5 2355.5 2855.5 2355.5 1990 3124 4503 2089 3154 4018 4895 2018 3617 4567 2368 4018 4438 5798 34.80 PotEssium chloride Potassium chloride Potassium sulphate 40.48 69.30 76.54 100.00 Potassium carbonate Potassium hydrate Potassium phosphate These results appear to establish, clearly, that all salts of potash are not absorbed in like amounts from solutions contain- ing1 the same amounts of K20; the smallest absorption occurring with the chloride and the largest with the phosphates. Heating to boiling for one-fourth hour has increased the ab- sorption very materially while we have found that heating soils to dryness increases the amounts of most salts which may be re- covered from them with distilled water, as pointed out in Bul- letin B, p. 64. In another series of experiments where Dr. Peters varied the time of digestion from % hour to 14 days, using the same KC1 solution:, there was no certain increase beyond 8 hours, and the difference between 14 hour and 14 days is only 2037 — 1417 =620. Peters miade another series of observations in which he treated four different soils with the same solution of potassium chlor- ide containing 2355.5 parts per million of K2O, using 250 c. c. of the solution to 100 of soil. These were the mean results of his determinations : Amounts of potash absorbed by four soils from a solution of KCl. NAME OF SOIL. TEXTURE. K20 in parts per million of dry soil. Percent- age differ- ences. Coarse sand. Per cent. Fine sand. Per cent. Fine clay. Per cent . Calcareous soil 25.50 39.68 23.14 51.62 33.10 28.04 43.70 33.15 41.40 32.28 33.16 15.23 3238 1928 1841 1495 100.00 59.54 56.86 46.17 Colditz loam soil Folgengutes soil . .. .. Calcareous sandy soil ABSORPTION OF SALTS BY SOILS. 125 RECOVERY OF ABSORBED POTASH. Dr. Peters made a series of observations to measure the amounts of absorbed potash he could recover again from the soil after absorption had taken place, using distilled water. Work- ing with some of the same soil, he digested 100 grams 24 hours with 250 c. c. of a potassium chloride solution containing 2.3555 grams per liter of K2O. At the end of this time he drew off 125 c. c. of the solution, replacing as much more distilled water, repeating the operation at the end of succeeding 24 hours, until he had obtained the 10th extraction. From his analyses and computations he determines that the following amounts of pot- ash, which had been observed, were redissolved by the action of the cold water. Amounts of absorbed potash redissolved by water in successive treatments 2nd. 3rd. 4th. 5th. 6th. 7th. 8th. 9th. 10th. Total. In parts per million of dry soil. First series. 48.0 75.0 70.0 76.0 78.0 105.0 83.0 87.0 102. 704.0 Second series. 75.0 96.0 82.0 69.0 75.0 82.0 112.0 201.0 83.0 875.0 In the first series the original absorbed amount of K2O was 1937 and in the second 2114 parts per million of the soil; there were, therefore, still left in the soil First series 1937-704.0=1233 parts per million of K8O. Second series 2114—875.0=1239 parts per million of K2O. The strengths of the solutions used in these various experi- ments are so great that it is, perhaps, impossible to foresee what would result with solutions whose strength is more nearly what occurs in average field soils. Starting again with 1000 grams of soil placed in a large flask, he added 1000 c. c, of >a potassium chloride solution con- taining 28.8066 grams of K2O. The soil absorbed, according 126 to analysis, 2.7504 grams, equal to 2750.4 parts per million of the K2O, this having occurred at the end of two days. At this time 250 c. c, of solution were removed and 2250 c. c. of water put in its place, when it was vigorously shaken and allowed to stand two more days. At the end of this time 1500 c, c. of solu- tion were removed and as much more water added, the operation being repeated 8 times, making determinations on each portion of solution removed. The results stand as given in the next table: Amounts of potash redissolved after absorption by a soil. No. of Ex- tract. Retained in former Solution in soil . Amounts found. Amounts. Ab- sorbed. Redis- solved . CaO. MgO. K2O. Na3O. CaO. MgO. K2O. Na3O. K8O. K2O. In parts per million. 2... . 3... . 4... . 109.0 .V)..-) 27.0 11.2 4.7 2.2 19542.2 9852.2 4966.1 18.1 9.7 4.7 110.9 53.9 26.9 9.3 4.3 19704.4 9932.1 5041 7 19.3 9.3 4 9 2588.2 2508.3 2439 7 162.2 79.9 75 6 5... . 13.5 2520.9 2 1 13 4 9590 1 9 1 °363 5 69 2 6... 6 7 1295 1 10 1 1364 5 2994 j 69 4 7... 5.1 682.3 769 5 viQS 9 87 2 8 384.8 459 6 9J39 I 74 8 9... 229 8 994 9 9QQ7 o 65 1 10 147 5 9Q9 4 9Q19 J 54 9 Total 216.8 18.1 39620.9 34.6 215.2 13.6 40359.2 34.9 20602.9 738.3 It is seen from the last column of this table that, from! the standpoint of the amounts of potash usually found in soil mois- ture, a large amount was still recovered by the 10th digestion, equal to nearly 55 parts per million of dry soil, which is more than double that usually recovereed by single short period wash- ings. Moreover, after the send, until the 10th, the amounts of potash redissolved each time by the water were about the same, or about 77 parts per million of soil as an average. In addition to the experiments cited, relative to the recovery of potash from soils, after absorption, Peters compared the ef- fects of carbonic acid and weak solutions of acetic and hydro- chloric acid. The results of these observations are brought to- gether in the next table. AHSOHI'Tlo.N OF SAI.TS i;v SOILS. Amounts of potash absorbed by soils recovered with dilute acid solutions. Soil used. CaO. MgO. K8O. NajO. SOj. P.OB. In parts per million of dry soil. Dissolved with water holding carbonic acid. 1490' 1490 828 828 918 904 60 60 24 36 80 64 84 92 378 554 488 548 46 18 32 8 20 20 Soil \\ ith 1226 p.p.m. absorbed Soil with V'-'G p p m absorbed Ordinary untreated soil Dissolved with dilute acetic acid. 3290 3290 3010(?) 2625 2860 2842 2212 72 60 75 64 32 32 60 355 355 915 1085 1010 1010 1291 260 280 160 180 115 190 83 Soil with 1535 p.p.m. absorbed Soil with 1535 p p.m. a ^sorbec' Soil with 1226 p.p m. absorbed Ord inary untreated soil Dissolved with dilute hydrochloric acid. 3584 3472 2676 2620 2820 2820 2072 128 180 106 110 80 96 96 636 636 2216 2060 1852 1960 2628 520 500 328 404 348 ase 244 240 240 172 240 172 172 1024 1024 832 832 1088 1028 Ordinary untreated soil Soil with 1535 p.p m. absorbed Soil with 1535 p.p m. absorbed Soil with 1226 p p.m. absorbed Soil with 1226 p.p.m. absorbed Soil with 2039.6 o.n m. absorbed . To obtain the results with carbonic acid, soil was used which had previously been treated with a potassium chloride solution and had then been washed with water equal to 4.5 to 5 times the volume of the chloride solution. After this treatment the two samples, under experiment, still retained 1535 and 1226 parts per million of absorbed K2O. The soils were then di- gested with 5 times their weights of distilled water, previously saturated with carbonic acid, in closed flasks during 8- days, the water being recharged with carbonic acid 4 times in that interval. It would have been extremely helpful, in considering these results, if there had been introduced into the series sam]>l3 01 After 8 days 100.00 77 12 65 24 62 59 68 89 After 96 or 17 days 100 00 94 19 89 85 To 74 73 42 From this presentation of the data, it is seen that the fixing of soluble phosphates by the calcareous soil, during the first day, exceeds that of the other four soils by as much as 33.18 to 46.99 per cent; at the end of 8 days its effect is in excess from 22.88 to 3 7. 41 per cent. ; while, at the close of the last period, it is still in excess by as much as 5.81 to 26.58 per cent, It is to be noted that, even at the end of 26 days, not all of the phosphate had been absorbed, although the quantity for the cal- cerous soil, found in the solution, is recorded as a "trace." The unfortunate aspect of these observations, as indeed of all which have been cited, is the very large amounts of phosphates used in proportion to the soil. ABSORPTION BY SOILS OF SULPHURIC AND CITRIC ACIDS, AND CHLORINE. It seems to have been quite the universal opinion of the earlier investigators along these lines that little or none of the negative radicles are absorbed by soils, with the exception of phosphoric and silicic acids. It is true, however, that sonue in- dications of absorption of sulphuric acid and of chlorine have been observed, but the tendency was to attribute them either to errors of observation or else to the formation of ammonium chloride or sulphate, in which cases (Voelcker's instances) they were regarded as being lost on heating after evaporation. In our own experience, however, as will be given later, there appears little question but that nitric acid and sulphuric acid, ABSORPTION OF SALTS BY SOILS. 130 and possibly even chlorine to a small extent, and under some conditions, are removed from solution or retained by soil sur- faces. COMPARATIVE STUDY OF THE ABSORPTIVE POWER OF EIGHT SOIL TYPES. From the observations which have been cited, relative to tlio absorptive power of soils for different water-soluble salts, and in regard to the recovery of them after absorption has taken place, it is abundantly clear that here is an extremely important sub- ject which has, as yet, received far too little attention, either as to its nature, origin, extent or relation to differences in soil fer- tility. The results which have been cited show unmistakably, not only that the absorptive power of soils for plant food ingredi- ents is large, but they indicate that wide differences in this power may exist between different soils. Moreover, the results which have been presented, in Bulletins "B" and "C," regarding the differences in the amounts of water-soluble salts which may be recovered, by water alone, during very brief periods of conr tact, and the relation of these amlounits to yields, make it ex- tremely pertinent to inquire whether or not differences in the immediate productive capacities of soils may not be indicated by, if not' in part due, to differences in the amounts of plant food materials which have, from time to time, been absorbed from so- lutions coming in contact with them. Not only this, but it is equally important to ascertain whether or not good, as contrasted with poor, soil management does not bring about, through one and another means, a gradual upbuilding of the absorbed essen- tial ingredients of plant food. In other words, if the farmer does not, in fact, by good handling and good feeding, cause the skel- eton of the soil to become clothed, through this absorption pro- cess, with materials which make it better capable of nourishing crops. In view of the fact that the water-soluble salts in 8 soils were being critically studied in relation to the yields of crops from them, it seemed especially important to compare their absorptive powers for water-soluble salts also, and a preliminary study was made. 140 METHODS OF OBSERVATION. The aim in this preliminary work, has been, first of all, to secure a body of observations upon mixed or complex solutions, such as the dissolved portions of stable manure, fertilizers and soil solutions are. Since it is true that' soils are all of the time, so long as they are moist and exposed to climatic conditions, being treated with a mixed solution moving either capillary or by gravitation, it appeared best to make the first observations with solutions of a similar nature and not so concentrated, as most of the solutions employed in the cases which have been cited. In all cases the volume of the solution used has been equal to .five times the water-free weight of the samples treated and gen- erally 600 c. c. of solution and 120 grams of soil have been taken. Most of the observations have been made with short periods of contact of the solution with the soil, this being made sometimes by shaking in bottles and sometimes by percolation, using the arrangement described in Bulletin "B," p. 81. The soils have been examined for the amounts of water-solu- ble salts which could be recovered from them by washing three minutes in distilled water, and the amounts so recovered have been added to the amounts which were added with the solution to the duplicate samples of soil treated, and the absorption has been taken as the difference between the amounts remaining in the solution and those originally present, plus those shown to be present in the soil before treatment. Only colorimetric methods have been used in determining the changes which occurred in the solution. ABSORPTION OF SALTS BY JANESVILLE LOAM. The first series of observations was made on the surface four feet of the Janesville Loam, one sample from each of the five fertilizations, thus giving five determinations for the same soil type at each depth. The full set of data are given in this case, so as to indicate the character of fluctuations which occurred in the results obtained. ABSOIM'TION OF SAI.TS |!\' SOILS. 141 The solution used was prepared gravimetrically from stock chemicals to contain approximately the following amounts : Approximate composition of solution used. K. Ca. Mg. NO8. HP04. S04. Cl In parts per million of .solution. L':> | 2.') I 10 40 20 40 30 This solution was analyzed in duplicate with these obtained from the soils and the average of the two. analyses taken to rep- resent the composition of the solution. Since the amount of solution applied to the soil was five times the weight of the soil, the total salts added to the soil in this way, in case they were all absorbed, would be, when expressed in parts per million of the soil, five times that found in the solution. The treatment of the samples consisted in weighing into stop- pered bottles 120 grams of the dry soils and 4 grams of carbon black, to decolorize the solutions. To each sample was then added 600 c. c, of solution and vigorously shaken during 3 min- utes; and then allowed to stand 24 hours, but shaken, during 3 minutes, 10 times during that interval. The results which were obtained are given in the table which follows, together with the amounts obtained from duplicate samples, using distilled water instead of the solution. 142 Amounts of water-soluble salts recovered from Janesville Loam by washing in a salt solution and in distilled water. K. Ca. Mg. NO3. HPO4 SO 4 HC03 Cl. SiOo. Nothing added ... 5 tons manure added. 10 tons manure added . 15 tons manure added. 300 Ibs. guano added. .. Average In parts per million of dry soil. Recovered with salt solution. 1ft. 40.70 62.90 48.00 54.40 50.60 195.00 165.00 165.00 157. -V) 155.00 51.20 49.64 49. 64 50.34 48.90 145.20 140.00 145.20 132.00 181.60 11.80 18.40 13.00 18.20 16.80 264.00 260.00 256.00 268.00 252.00 22 24 52 18 20 140 146 150 150 152 70.60 66.00 69.80 60.10 67.20 51.32 167.50 49.94 148.80 15.64 260.00 23.2 147.6 66.74 Nothing added 5 tons manure added . 10 tons manure added . 15 tons manure addnd. 300 Ibs. guano added... Average 2ft 53.00 44.40 50.00 56.20 34.80 47.68 1165.00 162.50 155.00 150.00 145.00 155. 5€ 52.68 51. W 54.74 48.90 49.64 51.56 168.80 161.60 168.80 161.60 158.00 163.76 17.40 15.60 15.00 11.60 19.40 15.76 236.00 256.00 244.00 256.00 264.00 251.20 • -4 -2 —4 —4 -2.4 150 148 150 150 152 150 74.10 78.00 78.80 79.50 74.50 76.98 Nothing added 5 tons manure added. 10 tons manure added. 15 tons manure added . 300 Ibs. guano added . . . Average 3ft. 58.10 55.40 42.80 53.00 55 . 40 52.94 145.00 147.50 132.50 127.50 135.00 137.50 49.64 50.34 50.34 49.54 51.20 50.21 196.40 11.00 172.80 5.00 191.20 9.00 172.80 7.60 196.40 15.60 185.92 9.64 252. 00 ' 2 236.00 —2 220.00 —4 248.00 -4 244.00 6 240.001 -0.4 152 152 150 148 152 150.8 99.30 90.80 90.40 94.30 87.70 92.50 Nothing added 5 tons manure added . 10 tons manure added. Average 4ft. 37.50 37.30 39.00 37.93 21.20 21.04 21.12 125.00 142.50 150.00 139.07 20. 50 22.00 21.25 50.34 55.22 52.68 52.75 9.51 9.78 9.645 181.60 177.20 186.40 181.73 28.00 27.44 28.72 11.20 11.20 14.80 12.40 23.86 23.94 23.90 224.00 208.00 216.00 216.00 41.60 40.00 40.80 -8 i_ —2.67 —1.6 —1.6 ~.6 150 150 150 150 29.2 30.0 29.6 100.90 99.70 99.30 99.97 0.00 0.00 0.00 Known solution Known solution Average Nothing added . 5 tous manure added. 10 tons manure added. 15 tons manure added. 300 Ibs. guano added. .. Average R3covered with distilled water. 1ft. 11.76 20.00 18.08 17 . 12 19.12 77.: 50 78.75 78.75 75.00 61.25 24.45 25.93 23.4(5 21.95 25.60 88.60 90.80 79.00 82.60 95.60 24.60 16.20 20.20 19.40 19.20 116.00 126.00 98.00 112.00 128.00 20 16 10 18 14 4 9 9 9 .50.13 54.79 40.82 42.06 48.42 17.22 74.25 24.28 87.32 19.92 116.00 15.6 2.4 47.24 Nothing added 5 tons manure added. 10 tons manure added . 15 tons manure added. 300 Ibs guano added... Average 2ft. 18.40 12.28 13.32 15.12 14.84 55.00 45.00 48.00 51.00 45.00 18.02 16.64 15.56 17.47 15.16 39.28 40.96 33.44 31.92 32.64 16.40 15.60 14.60 24.20 22.00 136.00 122.00 122.00 108.00 118.00 o 9 9 24 10 7.2 0 I 0 0 0 59.29 ^9.82 49.04 47.80 48.58 14.79 48.80 16.57 33.65 18.56 121.20 50.91 Nothing added .... 5 tons manure added . 10 tons manure adder! . 15 tons manure added. 300 Ibs. guano added... Average 3ft. 28.56 20.00 19.52 17.76 18.08 41.00 19.45 37.50 15.16 35.50' 16.40 85.00 15.04 33.00 15.16 36.32 41.52 a5.84 26.96 36.32 27.60 16.80 20.00 23.40 21.60 136.00 118.00 112.00 110.00 104.00 —8 10 8 * 6 0 0 0 0 0 67.67' 56.18 59.60 59.13 57.27 20.78( 36.40 16.44 35.39 21.88 116.00 3.6 0 59.97 Nothing added 5 tons manure added . 10 tons manure added. Average. .. 4ft. 17.24 21.20 18.56 19.00 24.00 30.00 29.50 27.83 16.82 16.18 17.12 56 -.36 55.84 55.84 56.21 13.80 16.20 26.40 18.80 89.00 75.00 91.00 10 10 12 0 0 0 0 66.58 64.72 67.05 66.12 16.71 85.10 10.67 ABSORPTION OF SALTS BY SOILS. 143 From the data in the table, it will be seen what variations have occured in the individual determinations of samples of the same soil type, taken from different portions of the same field, and from different depths, both when washed in the salt solution and when washed in the distilled water. The duplicate deter- minations made on the salt solution will show what should be allowed for the methods themselves, when working with such concentrations as these have been. For purposes of comparing the absorptive effects of these soils it will be proper to use the averages of the five determinations for each depth, and this has been done in the next table: Amounts of salts absorbed in 24 hours by 120 grams of Janesville Loam from 600 c. c. of a salt solution. K. Ca. Mg. NO,. BPO4 S04. HCO3 Cl. Si02. In soil at start Added with solution Total present Amount recovered In parts per million of dry soil. Surface foot. 17.22 105.60 122.82 51.32" 71.50 74.25 24.28 106.25 48.23 180.50 72.51 167.50 49.94 13.00 22.57 I 87.32 143.60 230.92 148.80 82.12 19.92 119.50 139.42 15.64 123.78 116.00 204.00 320.00 260.00 60.00 15.60 -8.00 7.60 23.20 --15.60 2.40 148.00 150.40 147.60 2.80 47.24 0.00 47.24 66.74 -19.50 Change in soil In soil at start Added with solution Total present . ... Second foot 14.79 105.60 120.39 47.68 72.71 48.80 16.57 106.25 48.23 155.05 64.80 155.50 51.56 -.45 13.24 £5.651 18.56 143.60 119.50 179.25 138.06 163.76 15.76 15.49 122.30 121.20 7.20 204.00 -8.00 325.20, —.80 251.20, -2.40 74.00 1.60 0.00 50.91 148.00 0.00 148.00 50.91 150.00 76.98 —2.00-26.07 Amount recovered Change in soil In soil at start Third foot. 20. 7s' 36.40 105.60 106.25 126.38 142. 65 52.94 137.50 73.44 5.15 16.44 48.23 64.67 50.21 14.46 a->.39 143.60 178.99 185.92 -6.93 21.88 119.50 141.38 9.64 131.74 116.00 204.00 320.00 240.00 80.00 3.60 -8.00 -4.40 -0.40 -4.00 0.00 59.97 148.00 0.00 148.00 59.97 150.80 92.50 -2.80 32. .Vi Added with solution Total present Amount recovered In soil at start Added with solution Total present . . Fourth foot. 19.00 27.83 105.60 106.25 124.60' 134.08 87.93 139.07 86.67| -4.99 16.71 48.23 64.94 52.75 12.19 56.21 143.60 199.81 181.73 18.08 18.80 119.50 138.30 12.40 125.90 85.10 1204.00 289.10 216.00 73.10 10.67 -8.00 2.6: -2.6' -5.S 0.00 148.00 148.00 150.00 -2.00 66.12 0.00 66.12 99.97 -33.85 Amount recovered Change in soil From this table of averages it will be observed the data show less phosphoric acid has been recovered from each of the four depths than was recovered from the soil when washed 144 in :> 99.80 51.40 220.00 5 00 52.00 -19.00 154.00 4.00 36.40 -33.90 Amount recovered Change in sand In second trial. 108.40 3.34 -3.461 120.00 -12.00 -9.00 50.34 3.63 5.34 87.50 117.60 11.73 33.60 3.861 42.50 224.00 -9.00 -7.00 8.00 158.00 20.50 25.00 0.00-18.00 3.00) 2.00) 25.95 Average .From the data of this table it is clear that this washed sand has effected but a very small absorption of salts from the solution used when compared with the absorption by the Hagerstown Loam, and they serve to emphasize the point already made, that very strong differences may exist in the absorptive power of dif- ferent soils and that, until the reverse is proven by careful ob- servation to be true, we must expert to find that soils having a high absorbing power are capable, under favorable conditions, of giving larger yields than those having small absorbing power, and there can be no question regarding the desirability of carry- ing out suitable researches to establish what relation there may ABSORPTION OF SALTS BY SOILS. 151 be between yields and the absorptive power of soils for salts car- ried in solutions which are brought in contact with them. The results of these observations on the sand are in several ways quite in accord with those obtained from the ILagerstown -Loam. To illustrate, during the shorter digestion, more lime went into solution during the 24 hours than during the 72 hours, as was the case with the ITagerstown Loam. More SO4 went into solution from the sand during the shorter period and less was fixed by the soil referred to. In the case of the potash, too, both in the surface foot and in the fourth foot of the Hagerstown Loam, there was a smaller absorption associated with the longer period, and there are indications that this was also true of the sand. We have no reason to think that these relations may have resulted from some systematic error affecting all the observa- tions, but it is, perhaps, not impossible that such may have been the case. The observations here cited are in some ways quite in accord with some of the observations and remarks of Voelcker,* made in connection with his study of the absorptive power of different soils on liquid maniures, and there have been presented in the next table two sets of his determinations made upon two quite different soils, with a view to ascertaining their relative absorp- tive powers. The two cases chosen are the soil of a, permanent pasture and a poor, sandy soil from the neighborhood of Cirencester, con- taining : Sandy soil. Permanent pasture. 11.70 per cent. Clay .. 4 ~tl per cent. 48. 39 per cent. Lime 25 per cent. 1.54 per cent. Sand 89.82 per cent. S5.95 per cent. "Journal Royal Agricultural Society, Volume XX, 1859, pp. 141-148. 152 BULLETIN The final results of Voelcker's determinations are given in the next table. Composition of liquid manure before and after filtration through two soils. One Imperial Gallon Contains Before filtra- tion. Grains. AFTER FILTRATION. CHANGE. Permanent pasture. Grains. Sandy soil. Grains. Permanent pasture. Grains. Sandy soil. Grains. Water and volatile ammonia com- pounds containing Am'nid as carbonate and muriate Organic matters 69888.14 (35.58) 20.59 ( 1 . 41) ) (91.27) 2.31 69856.85 (20.83) 31.14 «2.20i (112.01) 3.06 2.97 69892.41 (33.151 25.00 11.40 (82.53- 5.10 'i'39' 8.03 .74 12.01 0.00 39.25 1.92 3.67 7.90 -31.29 —14.75 +10.55 + -71 +20.74 + -72 + 2.97 " "+13*. 73" 0.00 —11.73 + 2.14 - 1.12 — 3.09 — 1.21 +18.33 +42.70 - 2.43 + 4.47 - .09 - 8.74 + 2.76 +Y.39" - 3.35 - 2.13 — 4.91 — 2.74 - 1.10 — 2.91 — .27 + 2.10 Containing nitrogen Inorganic matters consisting of. Soluble silica Insoluble siliceous matter Oxide of iron Lime 11.48 25.21 2.87 5.19 4.88 39.23 1.74 2.73 24.13 Magnesia Potash 16.92 2.47 40.35 4.83 3.94 5.80 Chloride of potassium Chloride of sodium Phosphoric acid Sulphuric acid . . . Carbonic acid and loss The amount of soil used in these cases was 20,000 grains. The 70,000 grains of solution contained 09 parts per million of phosphoric acid and from this solution the pasture land increased its phosphoric acid content 154.5 parts per million and the sandy soil 145.5 parts. From a solution containing 241. T parts per million of potash the pasture land absorbed 586.5 parts per mil- lion of itself and the sandy soil 245.5 parts per million. It will be further observed that the manure solution reduced the amount of lime carried by the pasture land, taking into itself 13. 73 grains, whereas the sandy soil exerted an opposite effect, withdrawing 3.35 grains. The two soils differ, therefore,, in their effects upon this solution by the sum of these amounts, or 17.08 grains; one of them yielding from itself 686.5 and the other taking to itself 167.5 parts per million of its dry weight. One of these soils showing that it possessed so much lime, in sol- uble form, that it could, under the conditions imposed, give up about a ton per acre-foot; while the other was in so different a condition that it must draw from the same solution and fix about its grains, more than 500 Ibs. of lime per acre-foot With differ- ences like these between the effects of two soils upon one and the ABSORPTION OF SALTS BY SOILS. 153 same solution, and with the- admitted dependence of crops upon soluble matter in soils, it is, perhaps, not strange that Voelcker should describe his least absorptive samjple as token .from a "very infertile soil.'7 ABSORPTION OF SALTS BY EIGHT SOIL TYPES FROM A DILUTE MANURE SOLUTION. After having washed the samples of 8 soil types eleven times in distilled water, as described in Bulletin "B," p. 81, the same samples were washed with a prepared manure solution to which a quantity of potassium nitrate was added in order to have (1) a considerable amount of potash in the solution, and (2) to study the effect of these soils upon nitric acid in the presence of other ingredients of such a solution. The potassium nitrate was not added until everything was ready to make the washing, this pre- caution being taken to avoid denitrification. The manure solution was prepared by choosing such an amount as would be equivalent to a dressing of 15 tons of stable manure per acre, allowing the surface foot of soil to weigh 3,000,000 Ibs. ; the manure to be incorporated with one-half the surface foot of soil ; and the manure to contain 70 per cent, of moisture. The amount of water-free manure used was 14.396 grams, the solution being prepared in the manner of plant solu- tions, making it up first in 3 liters which, after straining, were diluted to 12 liters. The solution was prepared on October 7 and used the next day, when it was analyzed after adding the potassium nitrate, giving, by the colorimetric method, the amount stated in the table. Amounts of ivater-soluble salts in a manure solution to which po- tassium nitrate was added. K. Ca. Mg. NO3. HPO4. SO4- HC08 Cl. SiO,. Of solution Of dry manure. . In parts per million . 59.79 49839. 2.48 2067.2 2.383 96.08 1986.4 180089. 1 ft.OW 3.75 3125.9 1 3.2 2667.4 3.2 2667.4 1.04 866.9 154 Five times the weight of the drv soil of this solution was used on each sample and it was caused to percolate through the sam- ple three times in quick succession, the whole time required be- ing from 30 to 45 minutes. The interval of contact is, therefore, short, but the whole solution was forced to come three times in contact with the soil by causing it to percolate under pressure through a layer about three-sixteenths of an inch thick. As these soils had not ceased to yield salts to distilled water, at the time they were used for this experiment, although they had been 11 times washed, there has been made, from the amounts of salts recovered by the last washing, an estimate of what would probably have been recovered by another similar cashing; and these amounts have been introduced into the tables which follow and used in computing the effect of the soils upon this solution. Ihe results found are given in the next table. ABSORPTION OF SALTS BY SOILS. 155 Amounts of salts absorbed by 8 soil types from a dilute manure solution to which potassium nitrate is added. K I Ca. M*. N0». HP04 S04. HCO» Cl. SiO,. In soil at start Added with solution . . . Total present In parts per million of dry soil. Norfolk Sandy Soil. 7.52 298.95 306.47 278.40 28.07 2.50 12.40 14.90 37.00 -22.10 5.00 11.91 16.91 11.80 5.11 3.16 480.40 483.56 415.20 68.36 2.50 29.55 32. 05 11.80 20.25 4.50 18.75 23.25 12.00 11.25 8.00 16.00 24.00 10.00 14.00 0.00 16.00 16.00 18.00 -2.00 11.50 5.20 16.70 11.80 4.90 Amount recovered In soil at start Added with solution Total present Selma Silt Loam. 12.50 298.95 311.45 247.20 64.25 1.50 12.40 13.90 44.00 -30.10 4.95 11.91 16.86 11.04 5.82 3.03 480.40 483.43 415.20 68.23 8.50 29.55 38.05 13.20 24.85 9.50 18.75 28.25 15.50 12.75 8.00 16.00 24.00 8.00 16.00 0.00 16.00 16.00 16.00 0.00 14.50 5.20 19.70 15.00 J 70 Amount recovered Change in soil In soil at start Norfolk Sand. 5.85 298.95 304.80 232.00 72.80 2.75 4.&5 12.40 11.91 15.15 16.26 39.00 17.12 —23.851 —.86 >> 40 480 ! 40 482.82 427.20 55.62 6.50 29.55 36.05 11.90 24.15 7.50 18.75 26.25 12.50 13.75 8.00 16.00 24.00 10.00 14.00 0.00 16.00 16.00 16.00 0.00 12.00 5.20 17.20 11.70 5.50 Added with solution Total present Amount recovered Change in soil In soil at start Sassafras Sandy Loam. 11.50 298.95 310.45 184.00 126.45 4.50 12.40 16.90 46.00 -29.10 6.79 11.91 18.70 15.92 2.78 2.90 480.40 483.30 392.80 90.50 4.50 29.55 34.05 10.60 23.45 6.50 18.75 25.25 13.00 12. 25 12.00 16.00 28.00 14.00 14.00 0.00 16.00 16.00 14.00 2.00 15.40 5.20 20.60 15.00 5.60 Added with solution Total present Amount recoverd Change in soil In soil at start ... Hagerstown Ciay Loam. 17.50 298.95 316.45 160.00 156.45 10.50 5.50 12.40 11.91 22.901 17.41 58.75 28.06 -35. 85 -10.65 5.19 480.40 485.59 398.40 87.19 7.50 29.55 37.05 18.30 18.75 4.50 18.75 23.25 15.00 8.25 30.00 16.00 46.00 32.00 14.00 0.00 26.50 16.00 5.20 16.001 31.70 16.00! 24.10 0.00' 7.60 Added with solution Total present Amouut lecovered Change In soil at start Hagerstown Loam. 11.50 298.95 310.45 157.60 152.85 24.00 15.50 12.40 11.91 36.40 27.41 60.00 37.20 -23.601 -9.79 4.04 480.40 484.44 372.80 111.64 7.50 29.55 37.05 18.10 18.95 3.50 39.00 18.75 16.00 22.25 55.00 18. OO1 36.00 4.25 19.00 0.00 16.00 16.00 14.00 2.00 26.40 5.20 31.60 21.83 9.80 Added with solution Total present Amount recovered Change In soil at start Janesville Loam. 17.44 293.95 316.39 95.60 220.79 12.50 12.40 24.90 65.00 -40.10 6.50 11.91 18.41 26.74 -8.33 4.54 480.40 484.94 382.40 102.57 28.50 29.55 58.05 34.60 23.45 2.50 18.75 21.25 22.50 -1.25 45.00 16.00 61.00 34.00 27.00 0.00 16.00 16.00 16.00 0.00 35.50 5.20 40.70 ::vsn 1.90 Added with solution Total present Amount recovered Change in soil In soil at start Miami Loam. 13.50 10.50 298.95 12.40 312.45 22.90 122.00 62.50 190. 45 1-39. 60 7.50 11.91 19.41 26.74 -7.33 3.82 480.40 484.22 403.20 81.02 18.50 89.55 48.05 22.30 26.78 1.00 18.75 19.75 17.00 2.75 24.00 16.00 40.00 16.00 24.00 0.00 16.00 16.00 16.00 0.00 36.50 5.20 41.70 38.60 3.10 Added with solution Total present Amount recovered Change 156 If the computed amounts of change which occurred in these soils, as the result of contact with the solution, are brought to- gether they appear as shown in the next table. Amounts of change in the salt content of 8 soil types resulting from contact with a manure solution containing potassium nitrate. Nor- folk Saudy Soil. Selma Silt Loan Nor- folk Sand. Sassa- fras Saudy Loam. Ha- gers- town Clay Loam. Ha- gers- town- Loam. Janes- ville Loam. Miami Loam. Changes in K In parts per million of dry soil. 28.07 —22.10 5.11 68.36 20.25 11.25 14.00 —2.00 4.90 64.25 -30.10 5.82 68.23 24.85 12.75 16.00 0.00 4.70 72.80 —23.85 -.86 55.62 24 . 15 13.75 14.00 0.00 5.50 126.45 -29.10 2.78 90.50 23.45 12.25 14.00 2.00 5.60 156.45 -35.85 -10.65 87.19 18.75 8.25 14.00 0.00 7.60 152.85 -23.60 -9.79 111.64 18.95 4.25 19.00 2.00 9.80 220.79 -40.10 -8.33 102.57 23.45 -1.2.-. 27.00 0.00 1.90 190.45 -39.60 -7.33 81.02 25 . 75 2.75 24.00 0.00 3.10 Changes in Ca Changes in M g Changes in NOg .... . Changes in HKh Changes in SO, Changes in HCOa Changes in Cl Changes in SiOa Total absorbed... 151.94 24.10 196.60 30.10 185.82 24.71 277.03 29.10 292.24 46.50 318.49 33.39 375.71 51.94 327.07 47.99 Total dissolved From this assembling of the data it is seen that all soils have absorbed large amounts of potash f rom| the solution used, but the .Norfolk Sandy Soil least and less than one-eighth that absorbed by the Janesville Loam, which produced the heaviest yields. While potash has been absorbed by all soils, in every case has lime gone into solution, and in larger quantities from the four soils which have given the largest amounts of lime from treat- ments with distilled water. So, too, have the four soils, yielding largest amounts of magnesia, under repeated washing, given this base over to the solution ; but in three other cases magnesia was absorbed. Very large amounts of nitric acid have failed to appear in the solution after contact with the soils and it has clearly been held back or transformed. Denitrification, in the biological sense, win- not have taken place to this extent, (1) because the soils them- selves have been repeatedly dried at 120° O, and came to this experiment warm from the dry oven; (2) because sufficient time did not intervene for so much de-nitrification to have oc- curred as the result of vital activity. We were not able, with our reduced force at this time, to make tests for either ammonia or nitrous acid. The solution was analyzed in duplicate and there ABSORPTION OF SALTS BY SOILS. 157 is no reason to question the original ainiount present in the solu- tion. Moreover, the amount of potassium nitrate added was made an indefinite amount more than one gram by adding enough to quickly tip a Springer Torsion balance against a gram weight. More potash, in every case but one, has been absorbed than is required to represent the chemical equivalent of the nitric acid disappearing from the solution. The retention of phosphoric acid has not been very different with the different soils, but this, too, was the case in the in- stances cited from Voelcker. The solution contained phosphoric acid enough to represent 29.55 parts per million of the dry soil. In no case has this amount been absorbed ; and the amounts left in the solution ranged between 10 and 22 parts per million of the soil, as may be seen from the general table, p. 155. Comparatively large amounts of SO4 were also fixed by the four poorer soils, the Janesville Loam being the only one which corresponds with the observations of earlier investigators. Chlorine is the only negative radicle, existing in the solution used, which does not appear to have been fixed by the soils. COMPARISON OF YIELDS WITH THE AMOUNTS OF ABSORBED AND DISSOLVED SALTS. In the last two lines of the last table there are given the foot- ings of the absorbed and dissolved salts for each soil type. In the next table these amounts are brought into comparison with the yields from the same soil types. Comparison of yields with the amounts of snlts absorbed by 8 soil types from AI.ls i;v SOILS. L6Q same amount of chlorine in both cases and absorbing most nitric nc id where it was combined with lime. Lime was thrown into solution by the soils under good and poor corn, where it went in as chloride but was absorbed as the nitrate ; while the "no corn" soil showed the reverse relation. Magnesia was absorbed in largest amount by the soil under good corn and in least amount by that under poor corn. Nitric acid was; thrown into solution by the poor soil in both cases, but in largest amount when it went in with the lime. It was absorbed in much the largest amount from the potash salt by the good corn soil but in least amount as the lime nitrate. The good corn soil has absorbed more phosphoric acid than the poor corn soil in both cases and more than the "no corn" soil in one case. Another set of these same! soils were treated with the same solution in the same manner, except that they were left in con- tact over night or during about 18 hours, instead of 20 minutes, as in the preceding case. The results of these determinations are given in the next table. Salts absorbed from a solution during 18 hours by black marsh soil in three productive conditions. K. Ca. Mg. NO8. HPO4 S04. HCO3 Cl. SiO2. (1) Under poor corn .... (2) Under good corn — (3) Under no corn (1) Under gcod corn (2) Under poor corn .... (3) Under no corn In parts per million of dry soil. Absorbed from solution "A" by the soil. -62.62 22.56 190.64 41.00 -85.00 -165.00 8.52 70.00 18.84 172.80 292.80 187.32 197.60 187.20 174.40 -288.0 —200.0 -98.0 -234.0 20.0 —414.0 —18.0 —12.0 —16.0 24.9 82.7 45.4 Absorbed from solution "B" by the soil. 104.58 88.16 119.84 30.0 9.36 -66.0 58.08 -66.0I —.12 198.00 268.40 249.00 182.40-272.0-294.0 -32.0 160.80-254.0-116.0 -44.0 214. 401- 152. Oj- 510.01 -36.0 13.7 74.6 1 9.1 166 If comparison is made of the changes which have occurred during the1 20 minute 'and the 18 hour intervals, it will be seen that the same marked differences are shown. UNDER POOR CORN UNDER GOOD CORN UNDER No CORN. Solution A. Solution B. Solution A. Solution B. Solution A. Solution B. During 20 minutes During 18 hours In parts per million of dry soil. Changes in potash. 83.68 -62.62 —146.30 84.12 104.56 20.44 83.36 22.56 85.36 88.16 2.80 107.84 190.67 82.83 80.84 119.84 Difference -60.80 39.00 During 20 minutes Changes in lime. -59.0 41.0 100.0 70.0 30.0 —40.0 -25.0 —85.0 -60.0 19.0 -66.0 -85.0 10.0 —165.0 V175.0 -16.0 —66.0 -50.0 During 18 hours Difference During 20 minutes Changes in magnesia. 14.32 8.52 —5.80 14.96 9.36 —5.60 60.08 70.00 9.92 54.88 58.08 3.20 31.32 18.84 -12.48 37.64 12 -37.76 During 18 hours Difference From this grouping of the data it is seen that the tendency has been for the absorption of potash to increase with the longer interval of contact, and for the lime and magnesia to be absorbed less, or else more to go into solution. Under the influence of the "A" solution, however, the fixation of potash has been less, or more has gone into solution with two of the soil conditions, namely, under the poor and good com ; at the samei time, the soil under the poor corn has fixed lime instead of throwing it into solution. ABSORPTION OF SALTS BY SOILS. 167 If we compare the changes in nitric and phosphoric acid, and silica, they appear as below: UNDER POOR CORN UNDBR GOOD CORN UNDBR No CORN. Solution A. Solution B. Solution A. Solution B. Solution A. Solution B. During 20 minutes In parts per million of dry soil. Changes in nitric acid. -8.0 172.8 180.8 -51.6 198.0 249.6 115.2 292.8 177.6 33.2 268.4 2X5.2 29.40 187.32 157. 92~ 48.2 249.0 200.8 Daring 18 hours Difference During 20 minutes Changes in phosphoric acid. 167.2 197.6 30.4 120.8 182.4 61.6 200.0 187.2 -12.8 127.2 160.8 33.6 106.4 174.4 68.0 134.4 214.4 80.0 Difference During 20 minutes Changes in silica. -56.6 24.9 38.9 13.7 —19.0 82.7 87.6 54.0 74.6 45.4 32.3 9.1 Difference 81.5 -25.2 101.7 —13.0 II —8.6 -23.2 Here it is seen that everywhere more nitric acid has been fixed during the longer interval or else — and which is probably the case — more denitrification has occurred. More phosphoric acid has also been 'fixed, except from the "A" solution, by the soil under "good corn." In the case of silica it has been less extensively fixed during the longer period, except in those two cases where, during the 20-minute period, it was forced into solution and where less potash was fixed, or the potash had been actually forced into solution at the end of the 18 hour period. Comparing the changes which occurred during the two periods in the case of the remaining three negative radicles SO4, HCO3 and Cl, we have the results shown in the next table. "168 UNDER POOR CORN UNDER GOOD CORN UNDER No CORN. Solution A. Solution B. Solution A. Solution B. Solution A. Solution B. In parts per million of dry soil . Changes in SO4. -168 —288 -132 —272 —100 -200 Q* -254 —18 -98 28 -152 During 18 hours Difference —120 -140 -100 -160 -80 -180 During 20 minutes Changes in HCO3. 64 -234 -298~ 54 — 2il4 —348 160 20 —140 84 -116 -200 162 —414 -566 114 —510 -624 During 18 hours Difference During 20 minutes Changes in chlorine. —10 -18 -8 -6 -32 -8 1 — —16 -44 -12 -16 -4 -12 -36 During 18 hours Difference -26 -4 -28 24 In these three cases the negative radicles have gone into solu- lution in increasing amounts in all cases with the longer contact of the solutions with the soil. It is also to be observed that the changes have been, throughout, greatest with the "B" solution where the nitric acid went in, in combination with lime, as was the case also with nitric and phosphoric acids, only these de- creased rather than increased in the solution. Attention should be called herfc, as was done in a previous section,-p. 54, to a well marked indication of chlorine, previously absorbed by the soil and not readily recovered by single wash- ings in distilled water, being forced into solution under the con- ditions to which the soils were here subjected. Indications of absorbed chlorine have also been pointed out in Bulletin "B," in connection with observations made in the preliminary study and development of the methods. An alternate hypothesis, in con- nection with this series of data, would be that the decomposition of organic matter attendant upon the denitrincation which oc- curred in these cases, may have liberated both combined chlorine and perhaps SO4, from difficultly soluble compounds, thereby in- creasing the amounts in the solutions after contact with the soils. teprinted from SCIENCE, N. &, Vol. XX., No. 614, P"(je* 605-GOS, November 4, Wto SOIL MANAGEMENT.* ?he three papers here printed have been ed departmental publication by the Chief e Bureau of Soils." glancing at this note on the title page lis pamphlet of 168 pages, the reader is rally struck with the query, why the U. Department of Agriculture should decline .iblish the results of the work of such a as King, working under its auspices. the salt indeed lost its savor? Both rican and European scientists have been stomed for many years to regard with dence and respect the work and publica- i of the man upon whom, by common con- the mantle of Wollny has fallen since the tature death of the soil physicist of Ger- v. It is certainly worth the while of j worker in agricultural science to see and e for himself whether a star has been sed or blotted out from the scientific iment, and if so, from what cause, e are, at the outset, somewhat reassured D the totality of the conjectured eclipse, nding that the three rejected bulletins are a portion of a series of six forming the rt of King, as head of the Division of Management, for the years 1902 and 1903. ie three out of the six have been accepted he department for publication, it is evi- L that King's right hand has not wholly lost sunning during these two years. What, , is the matter with Bulletins D, E and F, presented to us by the author at his per- il expense and risk, and as he expressly 33, in their original form ? : Investigations in Soil Management,' being e of six papers on the influence of soil man- aent upon the water-soluble salts in soils, the yield crops, by F. H. King, Madison, conain. Published by the author, with per- lion of the Secretary of Agriculture. As it happens, the rest of the series, letins B, C and G, have not yet reached ] cation by the bureau of soils. We must, 1 fore, rely upon the intrinsic evidence tained in the three now before us, to sett reason for their rejection. In his preface the author reticently that the ( adequate discussion was wit in order to avoid, as far as possible, anta* ing the published views of the Bureau Soils) ; and hence the three papers are lished without general comments. It the conclusions deducible from the facts ( then, that we must look for the substarj these papers, and for the possible can their falling under condemnation. Bulletin E, the first in the pamphle the most important of the three, treats < results obtained in the fertilization with manure, in different multiple proportioi eight different types of soils. The e ments were conducted on eight two-acre located respectively near Goldsboro, I Upper Marlboro, Md., Lancaster, Pa., Janesville, Wis., and representing two g of four each, ' strongly contrasted in native productive capacities, in order strongly marked differences might be with.' The dressings of barnyard m used were at the rate of five, ten and i tons per acre. The crops grown potatoes and corn, with a series of unma check-plots between, in each case. The crops from each series of plots weighed, mostly both in the green and i dry condition ; and concurrently, the kin< amounts of soluble salts extractable by from the soils of each of the plots befoi at different intervals after the applicati the manure, were determined according SCIENCE. ate methods used in the investigations of ous soil extracts.* Moreover, the amounts .e several substances contained in the soil .cts, present in the sap of the plants them- s, were likewise determined, in order to tain the relations between the soil solu- and the substances taken up by the crops, is not easy for the outsider to detect any- f reprehensible in this well-considered of operations. It seems to be admirably jived for the determination of the relation le soil solutions to plant nutrition and production under normal, practical condi- . The details given regarding the actual ing out of the experiments are equally ceptionable, except as concerns some ;s in respect to which, apparently, there interference of some sort with the plan; in the matter of making chemical anal- of the stable manure used at the several ities. But however regrettable, this and other omissions, apparently imposed by •ior authority, do not vitiate, to any ma- l extent, the conclusions arrived at by e plan and methods of experimentation f thus unexceptionable so far as any one ining the record given can judge, the only ion remaining is 'whether the conclusions sed from the experimental results are fled, and whether these are in conflict with ical or scientific experience, or with corn- sense. Of these conclusions it will be to give the chief ones in the words of the >r. ter giving, on page 5, a table showing the mtage relations of crop yield under dif- t fertilizations, he says : ' It will be seen in the case of the poorer soils there is a ntage difference of 46 between the yields e fifteen-ton subplots and those to which ng has been added; but a difference of eighteen on the stronger soils/ Recal- ing these results on the next page so as to their relations more clearly, he adds: se results show that both relatively and utely, adding fertilizers to the poorer soils lad a greater effect than the same treat- iulletin No. 22. Bureau of Soils. ment with stronger soils.' Farther on, giving a table of the several yields of V free shelled corn, he says : " It is here seen on the four poorer soils, there is a systei difference in the yield of water-free si corn, closely related to the fertilizers ap to the soil. The group of four stronger do not show, throughout, this systematic tion." Photographic views of the corn o: growing plots show these differences clear the growth of the plants. The only criticism that could be, per made of the work leading to these conclu from an outside point of view, is that are so clearly and thoroughly in accord all former experience, both practical am peri mental, that they are largely foresee: Then follows the record and discussic corresponding experiments with pot* which yield practically the same results conclusions. Then are given the results of analysi leachings of the same soils upon which crops had been grown. The results are sented in a table, from which " it is very that the effect of different amounts of s manure applied to these soils * * * has such upon the recovery of the water-so salts as to enable the same treatment t move different amounts from different fe zations. * * * There is a clear quantit relation, too, between the yields and the recovered, these (the former) incres where the essential ingredients of plant are higher." King also details the experiments i with small (four-pound) samples of soils n with much larger amounts of the same ma: the leachings of which after 65 days, i in general, results corresponding to thosi tained from the field tests ; and he discuss detail the apparent effects upon the solubi of the several ingredients of plant food, the influence upon the formation and redu< of nitrates; showing that there is no d ratio between the amount of manure a and the nitrates found in the different ! He determines and discusses, likewise, th lation of the salts added to the soils in SClL'\rr. tiure to those recovered by leachiug, all ched for by full analytical data, "mally, King shows the effects upon the tits of different doses of manure, with re- ct to the water-soluble salts recoverable tn the plants themselves. In both cases influence of manuring is mainly seen to a direct one, as has, in fact, already been wn by Godlewski. " It is thus shown that crops on the manured ground have recov- 1 29 per cent, more potash from the four >nger soils, and 40 per cent, more from the rer soils, where the fifteen tons of manure been applied." Lime and magnesia, on the trary, were diminished where the potash increased. 7hat may be considered the final sum- ig-up of this bulletin is given by King in following paragraph on page 60, the last one: he observations here presented, both upon the 5 and upon the plants which had grown upon a make it clear that when farmyard manure pplied to fields it has the effect not only of easing the yields, but at the same time of easing the amounts of water-soluble salts 2h can be recovered from the soils themselves from the plants which have grown upon them. have thought it necessary to present to readers of SCIENCE somewhat in detail the tents of this bulletin E, in order to show it kind of work it is to which the bureau of 3 refuses its imprimatur. To the unofficial id — the 'besclirankte Unterthanenverstand ; appears as an admirable piece of work, in ue but little touched by agricultural inves- itors thus far, and manifestly likely to lead mportant new lights, as well as to definite ntitative corroboration of old ones. As to letins D and F, respectively, on ' The Ab- )tion of Water-soluble Salts by Different I Types ' and on ' The Movement of Water- ible Salts in Soils/ they are in a measure iplementary to bulletin E, affording most sresting side-lights upon the general subject the latter; they are altogether of similar h. scientific grade. They also figure among * rejected papers/ 'he clew to that rejection evidently lies in 'the published views of the Bun-au «>i which King for the time being does i sire to antagonize by discussion, as sit the preface. What those views are specified; but it is easy to see that the of King's work are wholly incompatibl the remarkable utterances of 'Bullet now well known to all interested in a tural science. Essentially, that bulleti mulgates the doctrine that while fertiliz* sometimes, and even frequently/ seem crease production, yet since, according given therein, the aqueous soil solul always of the same composition in al it follows that all soils contain sufficient able plant food to maintain product indefinitely; and that the moisture su] the one controlling condition, climat mitting. Such being the official, orthodox doct: becomes clear why especially bulleti: showing pointedly the very reverse official doctrine to be true, could not : the official approval and imprimatur. that a man of King's standing and repi could not, under such circumstances, do wise than tender his resignation, to tak( after his report had been completed an mitted, is obvious. This having been do Bureau of Soils is now rid of a contum insubordinate person, who refuses to sul to his chiefs scientific dicta as set fc Bulletin 22; which, it is well known, h received the assent of a single scieni weight, and has been controverted and diated both in America and Europe by £ have taken any notice of it. But worse than the ill-founded hyp< of the head of one of the most importa reaus of the Department of Agric which, moreover, receives and spends one largest appropriations in the budget o department, is the return to medievalist] cated in the case before us. It is not on of a deliberate attempt to suppress the but it indicates on the part of the n responsible head of that bureau a mon child-like confidence in the permanent E of the obscurantist regime such as is pn SCIENCE. lefended by Pobyedonostseff. Yet it is any length of time. King has uttered ful that even the latter, or the puissant ' e pur si muove ' by the publication of hi of the Russian Empire himself, would jected papers; it now behooves the sciei •take to pass the censor's black brush over men of the country to voice their empl tive scientific papers like these of King, protest against the dictation of official 0] is impossible to conceive that in the dox science of any kind, from headquarte: ieth century, and especially in a country Washington. E. W. HILGAI ing to be progressive par excellence, such BERKELEY, CALIF., ime should be allowed to continue for September 29, 1904. RETURN CIRCULATION DEPARTMENT TO— ^ 202 Main Library LOAN PERIOD 1 HOME USE 2 o 4 5 6 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS Renewals and Recharges may be made 4 days prior to the due date. Books may be Renewed by calling 642-3405. DUE AS STAMPED BELOW SEP 011987 Qv-V ^ AUTO. DISC. OCT 1 3 1937 UNIVERSITY OF CALIFORNIA, BERKELEY FORM NO. DD6, BERKELEY, CA 94720