None
In England the areas of soil are determined, first, by means of their texture ; secondly, by means of their con- THE SOIL SURVEY 739 tent of humus and lime carbonate, with which color and drainage are associated; and thirdly, by means of the geological formation and mode of origin. Fairly com- plete mechanical and chemical analyses of representative samples of the important types are included, and the rela- tion of the soils to crops and farm practice is discussed at some length. The grouping of the types into series, groups, provinces, and the like, is not so distinct as in the American surveys. That the fundamental importance of the larger factors in classification are recognized is shown in the discussion of the relation of precipitation and temperature to the properties and agricultural uses of the soil, in which the controlling influence of these over large areas is pointed out. 635. Uses of the soil survey. — The soil survey is useful in many ways, but it is not a final investigation. It is to be regarded rather as a means of determining the status of the soil and related conditions in the field. These may throw light on many farm practices and lead to their improvement. More frequently the soil survey points to lines of further investigation that should be carried out. The uses of the soil survey may be conveniently divided into two groups — its use to the individual, and its use to the state. For the individual, the soil survey (1) points out the character and location of the several types of soil on his farm which may be correlated with particular crops and farm practices ; (2) shows him the relationship of soils over wide areas, which may form a basis for the adoption of new crops or new methods of soil manage- ment; (3) provides a reliable central source of informa- tion concerning soil conditions ; (4) standardizes methods of description and representation of soils ; (5) reveals in 740 SOILS: PROPERTIES AND MANAGEMENT many cases important problems of soil improvement that need attention; (6) affords a guide in the exchange of real estate and in the selection of land for particular pur- poses. For the state the soil survey (1) shows its soil resources; (2) by the collection of this data at a central point, affords the basis for the correlation of all other types of information, the character of which is affected by the soil relations; (3) shows in main cases the occur- rence and importance of large questions of soil improve- ment, and may point out the need for further investiga- tions; (4) gives a basis on which much of the results of experiments, investigations, and observations on soil im- provements, crop growth, and in many cases farm man- agement, should be applied ; (5) is a means of commu- nication and mutual understanding between the state institutions concerned with agricultural information and the individual farmer; ((>) by affording a basis of facts, promotes sound commercial, social, and governmental development. The soil survey is essentially an inventory of the re- sources in land and closely allied interests. It helps the farmer to understand the situation of his farm and its relations to other farms. It helps the state to get ac- quainted with its domain, and promotes a better sense of mutual understanding and helpfulness. The soil survey in some form is an essential step in sound community building, for the success of most interests — commercial, social, and institutional — rests ultimately, to a large extent, on the character and value of the soil AUTHORS' INDEX Adams, G. E., Salt as fertilizer, 544. Age ton, C. U.*, Lime and magnesium, 538. Aikman, C. M., Composition of manure, 595. Production of manure, 597. Alway, F. G.f Composition of humus, 148. Ames, J. W., Lime in soil, 378. Soil investigation, 69, 70. Ammon, C, Hygroscopicity, 203. Appiani, G., Silt cylinder, 91. Ashley, H. E., Colloidal clay, 161. Estimation of colloids, 167. Plasticity, 172. Atkinson, A., Storage of moisture in soil, 715. Atterberg, A., Classification of soil par- ticles, 96. Cohesion test, 176. Measurement of cohesion, 181. Mechanische Bodenanalyse, 84. Plasticity, 171. Silt cylinder, 91. Baker, M. N., Sewage irrigation, 711. Bancroft, W. D., Colloidal chemistry, 153. Barakov, F., Carbon dioxide in soil, 409. Baumann, A., Composition of humus, 133. Beal, W. H., Absorptive capacity of litter, 603. Handling manure, 602. Bennett, H. H., Classification of soils in U. S., 724. Bertrand, G.,. Manganese, 531. Biltz, W., Soil solution, 345. Bizzell, J. A., Composition of drainage water, 372. Legume cultures, 545. Blanck, E., Law of minimum, 554. Bolly, H. L., Disease-producing organ- ism, 426. Boullanger, E., Sulfur, 524. Boussingault, J. B., Snow and tempera- ture, 306. Bouyoucos, G. J., Bibliography of soil heat, 289. Manure and soil temperature, 316. Radiation, 302, 304. Soil temperature, 301. Specific heat of soil, 295. Texture and conductivity, 309, 312. Bowie, A., Practical irrigation, 682. Breazeale, J. F., Acid toxicity, 379. Estimation of organic matter, 143. Brenchley, W. E., Soil solution and plant growth, 347. Briggs, L. J., Analysis of soil, 143. Capillary movement, 225. Classification of particles, 96. Hygroscopic and capillary water, 208. Hygroscopic moisture, 206. Mechanical soil analysis, 84. Moisture equivalent, 220. Soil solution in situ, 343. Water requirements of plants, 245, 712. Wilting point, 258. Britton, W. E., Availability of ferti- lizers, 510. Bronet, G., Penetration of fertilizers, 354. Brown, B. E., Carbonized materials, 141, 144. Fertilizers and acidity, 381. Brown, C. F., Alkali land reclamation, 399. Brown, C. W., Bacteria in soil, 439. Brown, P. E., Bacteria in soil, 432. Bryan, H., Soil analysis, 93. Buckingham, E., Capillary movement, 232. Capillary water, 217. Diffusion of gases in soil, 483. Movement of water vapor in soil, 241. Natural mulching, 277. 741 742 AUTHORS INDEX Buckman, H. O., Formation of residual clay, 25. Moisture control, 379. Storage of soil moisture, 71"). Buddin, \Y\, Partial sterilization of soil, 471. Burmester, H., Temperature of soil, 821. Burr, W. W., Storage of soil moist ure, 715. Caldwell, J. S., Wilting point, 258. Cameron, F. K., Estimation of organic matter, 141*. Litmus paper test, 386. Physical condition of soil, 181. Soil solution, 346. Solubility of phosphate.-. Test for cohesion, 176. Campbell, B. W„ Dry-farming. 71 J. Carpenter, L. C, Measurement of \v;it«T, 707. Cates, J. S., Mulch and moisture, 280. Cato, M. P., Land drainage, 629. Chamberlin, T. C, Drift less area, 67. Chamberlain, C. W., Molecular attrae- tion, 206. Chester, F. D., Bacteria in soil, 432. Chilcott, E. C, Dry-farming, 712. Christie, G. I., Soil survey of Iowa, 718. Clark, F. W., Data of geochemistry, 5, 24, 72. Composition of loess, 59. Coffey, C. N., Reconnoissance survey of Ohio, 737. Classification of soils, 718. Conn, H. J., Bacteria in soil, 431. Coppenrath, E., Catalytic agents, 529. Coville, F. W., Acid-tolerating plants, 384. Coville, J. V., Acids in plants, 379. Cox, H. R., Mulch and moisture, 280. Craig, C. E., Weeds and crop growth, 281. Crosby, W. O., Colors of soils, 76. Cushman, A. S., Air elutriator, 86. Colloids, 161. Plasticity, 172. Czapek, J., Solvent action of roots, 406. Czermak, W., Hygroscopic coefficient, 190. Darwin, C, Earthworms, 19, 422. Daubree, A., Solubility of orthoclase, 24. Davis, N. B., Plasticity, 172. Davis, R. O. E., Electrical bridge, 728. Salts and capillarity, 229. Deherain, P. P., Lime and photj D.nuloii, A , Sulphur, '■: Penetration <>f fertilizer Digby, K . Miuenil manure, 490. Diller, Q. S., Composition ..f li: soil, 66. Residual alt Dobeneck, A I ration, 897. lfygroseopicitv Dorsch, F., Availability of fertilize I).... (' \\ ".. Alkali lan<l reelamat in ., 399. Composition of alkali, 898. Duchaoek, !■'.. Paotoria io nfl, Fermentation and phosphates, 520. Dugardin, M . Bntftti i >upre. M A., Capillary innveii,. Dyer, B , Citric acid method soil an- alysis. 886. Plant food in Broadbalk Bold, .'W7 Ebermayer, E , Temperature of soil, 322. Ehrenbers, P., Effect of Hoi! ■ntionptioi, I7(i Estimation of colloids, 168. l'.ichhoni, EL, Absorption by chabazite, 356. Elliott, C. G., I^nd drainage, 6:27, 839. 659. Siae of tile. 681. Ernest, A., Carbon dioxide production, 139, 408. Etcheverry, B. A., Linings for canals, Failyer, G. H., Absorption by soils, 351. Composition of soil, 70. Minerals in soil separates, 101. Faure, L., Land drainage, 627. Feilitzen, H. von, Sulfur, 525. Fippin, E. O., Causes for granulation, 188. Classification of soils, 718. Fletcher, C. C, Soil analysis, 93. Flugel, M., Law of minimum, 554. Forbes, R. H., Irrigation, 686. Fortier, S., Application of irrigation water, 695. Mulches under irrigation, 705. Orchard irrigation, 682. Small water supply, 682. Frank, B., Effect of heat on soluble matter, 466. Fraps, J. S., Availability of phosphates, 338. Fertilizers, 546. AUTHORS' INDEX 743 Frear, W., Losses of manure, 605. Fred, E. B., Effect of soil antiseptics, 468. French, H. F., Drainage, 629. Freundlich, H., Kapillar chemie, 153. Friedlander, K., Soil antiseptics, 470. Gaither, E. W., Lime in soil, 378. Soil investigation, 69, 70. Gallagher, F. E., Absorption of gases, 367. Cohesion tests, 176. Physical condition of soil, 181. Temperature and hygroscopicity, 208. Gardner, F. D., Fertilizers and acidity, 381. Gedroiz, K. K., Phosphate fertilizer, 519. Geikie, A., Geology, text of, 40. Georgeson, C. C., Manure and soil tem- perature, 316. Gerlach, U., Composition of drainage water, 350. Drainage water, 370. __Gieseker, L. F., Storage of soil moisture, 715. -—Gilbert, J. H., Composition of drainago water, 240. Gile, P. P., Lime and magnesium, 538. Nitrogen in plant nutrition, 491. Girard, A., Soil antiseptics, 465. Goddard, L. H., Cost of drainage, 655. Goessman, C. A., Poultry manure, 589. Golding, J., Partial sterilization, 474. Grandeau, L., Estimation of humus, 144. Greig-Smith, R., Effect of partial ster- ilization, 472. Haberlandt, H., Cohesion test, 175. Heat and germination, 290. Hall, A. D., Accumulation of soil nitro- gen, 463. Classification of soil particles, 96. Classification of soils, 718. Composition of crops, 418. Composition of drainage water, 369. Composition of manure gases, 594. Crop adaptation and texture, 105. Denitrification, 457. Fermentation of manure, 591. Losses of manures, 600. Losses of nitrates, 454. Losses of nitrogen, 500. Lysimeter records, 266. Manures, 579. Mechanical analysis, 103. Hall, A. D., Nitrification, 453. Nitrogen fertilizers, 547. Residual effect of manures, 614. Soil separates, 102. Soil solution and plant growth, 347. The Soil, 11. Halligan, J. E., Composition of rotted manure, 596. Fertilizers, 546. Hart, R. A., Alkali land reclamation, 399. Handling manure, 602. Sulfur as a fertilizer, 526. Hartwell, B. L., Acidity test, 387. Fermentation and phosphates, 520. Hasenbaumer, J., Catalytic agents, 529. Colloidal chemistry, 153. Hassler, C, Colloid chemistry, 153. Headden, W. P., Nitrates in alkali soil, 292. Heinrich, R., Hygroscopic coefficient, 257. Heinze, B., Soil antiseptics, 470. Hellriegel, H., "Water requirement of plants, 246, 249, 250. Henneberg, W., Absorbed bases, 354. Absorption, 353. Henry, W. A., Production of manure, 588. Hess, E. H., Lime, 541. Hess, R. H., Social aspect of irrigation, 691. Hilgard, E. W., 79, 82. Absorption and temperature, 367. Alkali land reclamation, 399. Churn elutriator, 88. Composition of alkali, 393. Dilution of plant food in soil, 332. Estimation of humus, 144, 147. Retentive power of soil for water, 221. Roots and humus, 127. Soil analysis, 96. Soil and climate, 62, 72. Soils of arid and humid regions, 71. Temperature and hygroscopicity, 208. Vegetation and soil classification, 720. Hills, J. L., Commercial fertilizers, 562. Hiltner, L., Effect of soil antiseptics, 469. Hoffman, C, Fermentation and phos- phates, 520. Hopkins, C. G., Library system of soil naming, 726. Manure and the rotation, 616. Nitrogen storage by legumes, 621. Soil survey of Illinois, 719. u AUTHORS INDBX Hoiiston, H. A., Estimation of huniun, 142. Hunt, T. F., Manure and the rotation, 616. Nitrogen fertilizer . Hutchinson, H. B., Nitrogen assimila- tion, 495. Organic matter in soil, 188* Partial sterilization of soil, 470. Jenkins, E. H., Availability of fertilizers, 510. Commercial fertilizers, 564. Jodidi, EL I-., Nitrogen compounds. 138. Johnson, B. W., Availability of fert P 610. y Composition of soil air, 477. Johnston, J., Early drainage in America, 630. Jones, C. H., Commercial fertilizer, .">f._\ Kellerman, K. F., lime, 887. Nitro-cultures, 462. Litmus test, 386. Kellev, W. P., Ammonia as plant food, 488. Magnesium and nitrate*, 888, Kcllner, ( ).. Ammonia as plant-food, 495. Kelly, M. P., Manganese, 530. Kerr, W. C, Composition of mar! Kiesselbach, T. A., Water requirement of corn, 248. ~~f]&\n%, F. H., Absorption and produc- tivity, 368. Aspirator, 124. Capillary and ground water, 21 I. Capillary movement, 225. Drainage and soil temperature, 314. Drainage and free water, I'M. Effect of barometric pressure, 234. Effective diameter of soil particles, 123. Effective surface of soil particles, 125. Irrigation, 682. Land drainage, 627. Movement of ground water, 235. Pore space in soil, 116, 117. Slope and soil temperature, 319. Spring plowing, 284. Surface tension and temperature, 227. Temperature and hygroscopicity, 208. Water requirement of plants, 247. Wind breaks and moisture, 285. Kinnison, C. S., Plasticity, 171. Kinsl< \ Klippart, .1. EL, I. arid dr Knisety, \ I Koch, A., Theory as to - Konig, .) Colloid rliemi-r , . . 1 "> i. !..-fT, If. P., Roots and humus, 127. Krdfw I ria in soil, 1 Fermentation and phosphates, 520. KQmmel. \ K . BoU and n< surveys, 719. Lang, C, Radiation l.apham, J. E., Classification of soils of 1'.. l.apham. M If . 01— Ifteathffl of soils of United State-. Capillary moven Lawes, J. B , Composition of drainage Nitrogen in plant nutrition, 491. Leather, •' W., Waier reciuirements of plant- LeClerc, J. A., Acid toxicity, 379. Liebenberg, R- von, Specific heat of soils, 294. l.iebig. J. J. von. Composition of plants, 491. Law of minimum, 858* Solvent action of root - Lint, H. C, Sulfur and soil aotd I.ipman, C. B., Bacteria in arid soils, 73. Lipman, J. G., Availability of fertilizers, 510. Fermentation of manure, 591. Green manures 818. Loew, ()., Lime and magnesia, 538. I.ohnis, F., Bacteria in soil, 438. Loughridge, R. H., Crop tolerance to alkali, 395. Distribution of irrigation water in soil, 704. Hygroscopic water, 204. Soil separates, 102. Lynde, C. J., Capillary movement, 231. Lyon, T. L., Composition of drainage water, 372. Legume cultures, 545. Lysimeter tanks, 241. McBride, F. W., Estimation of humus, 142, 144. McCall, A. G., Solution of soil in situ, 344. authors' index 745 McCaughey, W. J., Color of soil, 77. Soil-forming minerals, 100. MacDonald, W., Dry-farming, 712. McLane, J. W., Moisture equivalent, 220. Soil solution in situ, 343. McLaughlin, W. W., Capillary move- ment, 224. Movement of irrigation water, 704. Marbut, C. F., Classification of soils of United States, 718, 724. Soils of United States, 34. Marchal, E., Ammonification, 447. Mares, M. N., Sulfur, 525. -Mayer, A., Optimum moisture, 263. Mayo, U. S., Bacteria in soil, 432. Maze, P., Law of minimum, 554. Mead, E., Extent of irrigation, 685. Irrigation institutions, 682. Legal status of irrigation, 691. Lining for canals, 694. Preparation for irrigation, 682. Mellen, C. R., Drainage of Johnston farm, 630. Merrill, G. P., Color of soil, 77. Residual clay, granite, 27. Pock weathering, 13, 26, 62. Weathering of gneiss, 66. Zeolitis, 357. Merrill, L. A., Irrigation of crops, 682. Merzbacher, G., Origin of loess, 60. Miles, M., Drainage in Europe, 629. Miller, N. H. J., Nitrogen assimilation, 495. Organic matter in soil, 136. Miner, H. L., Commercial fertilizers, 562. Mitscherlich, A. E., Estimation of colloids, 168. ir.vgroscopicity, 208. Law of Minimum, 553. Water and plant growth, 253. Molisch, H., Enzymes of roots, 407. Montemartini, L., Catalysis, 530. Montgomery, E. G., Water require- ments, 245, 248, 249. Water requirement of corn, 251. Mooers, G. A., Soil survey of Tennessee, 719. Mulder, T. J., Organic matter of soil, 131. Miiller, R., Solubility of minerals, 24. Newell, F. H., Irrigation, 682. Niklas, H., Colloid chemistry, 153. Norton, J. H., Composition of surface water, 373. Noyes, A. A., Properties of colloids, 153. Oberlin, C, Soil antiseptics, 465. Olin, W. H., American irrigation, 682. Osborne, T. B., Beaker method of mechanical analysis, 96. Classification of soil particles, 90. Paddock, W., Irrigation of fruit, 682. Pagnoul, M., Effects of carbon bisul- fide, 466. Parks, J., Drainage and soil tempera- ture, 314. Patten, A. J., Bacteria in soil, 439. Patten, H. E., Absorption of gases, 367. Absorption by soils, 351. Heat of condensation, 209. Heat transfer, 309, 313. Specific heat of soil, 295. Temperature and hygroscopicity, 208. Patterson, H. J., Lime, 541. Peake, W. A., Estimation of organic matter, 143. Pember, F.- R., Fermentation and phos- phates, 520. Penny, C. L., Clover as green manure, 621. Green manures, 619. Penrose, R. A. F., Composition of resid- ual soil, 33. Peters, E., Absorbed bases, 354. Absorption of potassium, 350. Peterson, W. H., Sulphur as fertilizer, 526. Petit, A., Temperature of soil, 300. Pettit, J. H., Soil survey of Illinois, 719. Pfaundler, L., Specific heat of soil, 294. Pfeiffer, T., Effect of soil antiseptics, 470. Law of minimum, 554. Carbon dioxide as soil solvent, 409. Pick, H., Estimation of colloids, 168. Pickel, G. M., Composition of muck. 37. Piper, C. V., Green manures, 619. Pitra, J., Bacteria in soil, 437. Fermentation and phosphates, 520. Plummer, J. K., Acid materials, 376. Potts, E., Texture and conductivity, 309. Pranke, E. J., Cyanamid, 503. Prianischnikov, D., Availability of phos- phorus, 518, 521, 535. Puchner, H., Cohesion test, 176. Composition of soil separates, 102. Measurement of cohesion, 178. Pugh, E., Nitrogen in plant nutrition. 491. 746 AUTHORS' INDEX Rafter, G. W., Sewage irrigation, 711. Ramann, E., Carbon dioxide in soil air, 480. Colloid chemistry, 153. Reed, H. S., Oxidation by roots, 407. Toxic material in soils, 136. Reid, F. R., Catalysis, 529. Rice, T. D., Reconnoissance, 737. Richthofen, F., Character of loess, 59. Roberts, I. P., Losses of manun Production of manure, 587. Robinson, F. R., Lime, 537. Robinson, F. W., Root nodules and nitrogen storage, 621. Robinson, T. R., Litmus test, 386. Robinson, W. O., Color of soils, 77. Manganese, 531. Rodewald, H., Estimation of colloids, 168. Rostworowski, S., Absorption by per- mutite, 867. Russell, E. J., Plant food elements, 3. Classification of particles, 96. Classification of soils, 718. Crop adaptation and texture, 105. Mechanical soil analysis, 103. Nitrogen fertilizers, 547. Partial sterilization of soils, 470. Sewage sick soils, 474. Russell, I. C, Subaenal deposits, 62. Sachs, J., Solvent action of roots, 406. Sackett, W. CJ., Ainmonification, 146 Availability of fertilizers, 511. Salisbury, R. D., Driftless area, 07. Glacial geology, 47. Sanborn, J. W., Roots of crops, 81. Sargent, C. L., Acidity tests, 387. Saussure, T. de, Composition of plants, 490. Schantz, H. L., Water requirements, 245, 712. Wilting point, 258. Schlicter, C. S., Effective diameter of particles, 123. Schone, E., Elutriator, 87. Schreiner, O., Absorption by soil, 351. Carbonized material in soil, 141, 144. Composition of humus, 134, 136. Organic substances in soil, 132. Oxidation by roots, 407. Schubler, G., Cohesion test, 175. Schucht, F., Mechanische Bodenunter- suchung, 84. Schulze, B., Temperature of soil, 321. Schulze, F., Water extract of soil, 341. Schutt, M A., Losses of manure, 583 599,600. Seelhorst, C. von, Water requir. 261,. Sheppard, J. H., Roots of crops, 82. Sherman, ('. W , Boil survey of Indiana, 719. mine, 497. Organic sol D soil, 132. Shutt. F. T., Nitrogen storage by !<•-:- nines, 621. Simniermacher, W , Lime :in<l phos- phates, 536. Skinner, J. J., Creatinine Organic matter in soil, 136. Smith, C. I)., Root nodules and nitrogen, storage, 621. Smith, H. E., Bacteria in frozen soil, 433. Snyder, H., Ash of humus. 1 l :» Complete solution of soil, 330. Composition of humu.s, 149. Production of humus, I HI Sj)illinau. \V J., «ree:> manures, 619. Stevenson. W. II.. Soil survey of Iowa, 718. Stewart, -I. B.. Moisture control, 285. Capillary movement, 225. Btohman, P., Absorption, 353, 354. Stoklasa, J., Bacteria in soil, 437, 439. Carbon dioxide production, 139. Carbon dioxide production in soil, 408. Carbon dioxide in soil air, 479, 482. Fermentation and phosphates, 520. Stonr, F. H., Farm manure, 578. Green manure, 619. Humus and capillarity, 219. Poultry manure, 588. Stormer, K., Effect of soil antiseptics, MM. Stover, A. P., Carey Act, 688. St rem me. II . Estimation of colloids, 167. Sullivan, M. X., Catalysis, 529. Manganese, 531. Swezey, G. D., Temperature of soil, 321, 485. Teel, R. P., Losses of irrigation water. 694. Ten Eyck, A. M., Roots of plants, 81. Thaer, W., Properties of colloids, 153. Thome, C. E., Application of manure 607. Cement versus dirt floors, 604. Effect of food on manure, 582. AUTHORS INDEX 747 Thome, C. E., Farm manure, 581 Losses of manure, 599. Manure and the rotation, 616. Production of manure, 587. Reinforcing manure, value, 610. Value of manure, 590, 601. Trowbridge, A. C, Classification of sedi- ments, 31. Truog, E. A.. Sulfide test for soil acidity, 387. Tularkov, N., Classification of soils, 718. Tull, Jethro, Effects of tillage. 490. Ulrich, R., Specific heat of soil, 295. Underwood, T. M., Soil solution and plant growth, 347. Vail, C. E., Composition of humus, 148. Van Bemmelen, J. M , Adsorption, 359. Colloids, 161. Colloidal humus, 365. Colloidal material, 346. Color of soil, 77 Composition of humus, 133. Estimation of colloids, 167. Soil solution, 345. Van Slyke, L. L., A general fertilizer, 571. Composition of manure, 584. Fertilizers, 546. Fertilizer mixtures, 565. Production of manure, 587. Van Suchtelen, F. H. H., Soil solution in situ, 344. Veitch, F. P., Complete solution of soil, 330. Composition of soil, 66. Test for acidity, 390. Voelcker, J. A., Composition of rotted manure, 596. Manure, 579. Soil acidity, 383. Von Engeln, O. D., Glaciation and agri- culture, 70, 71. Voorhees, E. B., Availability of fer- tilizers, 510. Poultry manure, 588. Waggaman, W. H., Absorption by soil, 351. Wagner, F., Conductivity in soil, 310. Manure and soil temperature, 316. Texture and conductivity, 309. Wagner, H., Law of minimum, 553. Wagner, P., Availability of fertilizers, 510. Wahnschaffe, F., Silt cylinder, 92. Warington, R., Causes of granulation, •186. Colloids, 161. Composition of crops, 418. Composition of drainage water, 240. Denitrification, 456. Estimation of organic matter, 143. Evaporation losses, 271. Lime and granulation, 194. Nitrification, 453. Snow and soil temperature, 306. Warren, G. M., Marsh land drainage, 627 Waters, H. J., Lime, 541. Watson, G. C, Production of manure, 587. Way, J. T., Absorption by soil, 355. Colloids, 161. Weir, W. W., Soil acidity, 383. Test for carbonates, 388. Welitschkowsky, D. von, Temperature and movement of water, 234. Wheeler, H. J., Acid-tolerating plants, 38. Acidity tests, 387. Forms of lime, 542. Plants injured by acidity, 385. Salt as a fertilizer, 544. Wheeler, W. P., Poultry manure, 582. Whipper, O. B., Irrigation of fruit, 682. Whitbeck, R. H., Glaciated and residual soils, 70. Whitney, M., Apparent specific gravity, 114. Soil classes, 104. Soil solution, 346. Specific gravity of soil, 113. Whitson, A. R., Soil acidity, 383. Test for carbonates, 388. Wickson, J. A., Irrigation of fruit, 682. Widtsoe, J. A., Amount of water to apply, 710. Capillary movement, 224. Dry-farming, 712. Dry matter and water, 254. Irrigation water and yield, 708. Movements of irrigation water, 704. Principles of irrigation, 682. Storage of water in soil, 709. Water requirement of plants, 248, 251. Wiegner, G., Absorption by permutite; 357. Wiley, H. W., Complete solution of soil, 328. 748 AUTHORS' index Wiley, H. W., Estimation of organic matter, 143, 144. Mechanical soil analysis, 84, 92. Soil analysis, 338. Willcox, O. W., Soil survey of Iowa, 718. Williams, H. F., Soil-forming minerals, 100. Williams, M. B., Irrigation in humid regions, 690. Wilson, H. M., Irrigation engineering, 692. Wing, H. H., Losses of manure, 599. Production of manure, 587. Winton, A. L., Commercial fertilizers, 564; Wolff, E., Composition of manure, 595. Wollny, E., Capillary movement, 226, 228, 230. Wollny, E., Capillarity and temperature, 214 Color and temperature, 302. Composition of soil air, 139. Effect of earthworms, 422. Gravitational movement of water, 234. Optimum moisture, 262. Roots and humus, 127. Slope and temperature, 319. Water requirements of plants, 246. Water and soil temperature, 315'. Woodward, S. M., Land drainage by pumping, 627. Yoder, P. A., Centrifugal elutriator, 89. Zsigmondy, R., Colloid chemistry, 153. INDEX Absolute specific gravity of minerals, 112. of soil, 113. of soil particles, 113. Absorption by the soil, 349. causes, 355. formation of insoluble substances, 358. influence of chabazite, 356. influence of colloids, 165, 359, 360. influence of organic matter, 150, 365. influence of silicates, 363. influence of zeolites, 355. influence on soil analysis, 340. insolubility of absorbed substances, 354, 358. of ammonia, 366. of carbon dioxide, 366. of gases, 366. of heat, 300. of nitrogen and oxygen, 367. of phosphoric acid, 357. relation to temperature, 367. relation to drainage, 368. relation to productiveness, 368. selective, 362. time necessary, 353. Absorptive power of different plants, 414. Absorbed bases, solubility of, 354. Abundance of common minerals, 11. of plant-food elements, 5. Acetic acid secreted by roots, 408. Acid, a flocculating agent, 159. in plant juices, 336. rocks, 7. soils, 375. soils caused by ammonium sulfate, 499. test for carbonates, 388. Acidity and climate, 382. and colloids, 165. and forests, 380. and sulfur, 382. and plants indicating, 382. Acidity, effect on phosphate fertilizer, 519. relation to bacteria, 436. relation to fertilizers, 381. quantitative determinations, 389. tests for, 386. Acid phosphate, 514. for reinforcing manure, 610. Acids formed from fermenting manure, 593. in plant juices, 379. secreted by plant roots, 408. Acme harrow, 677. Adobe, awlian soil, 47, 59. described, 61. wind origin, 16. ^Eolian soils, deposition of, 58. adobe, 61. composition of, 60, 62. distribution, 61. loess, 59. sand dunes, 63. Aeration and denitrification, 456. and toxic materials, 133. effect of drainage on, 631. effect on nitrification, 452. influence on decay, 129. promoted by soil organisms, 422.. Aerobic bacteria, 433. bacteria and decay, 444. fermentation of manure, 592. Agencies of rock decay, 14. Agricere in soil, 275, 472. Air of the soil, 475. analyses, 478, 139. carbon dioxide, 139, 478. composition of, 477. control of, 486. effect of organic matter on, 139, 476. effect of soil moisture on, 476. effect of texture, 475. effect of tillage, 487. function of, 480. movement of, 483. volume, 475. 749 750 INDEX Air-slaked lime, 539. Alga?, aid to nitrogen fixation, 464. Alinit, nitro-culture, 463. Alkali in soils, 392. accumulation of, 397. and irrigation, 397. and the mulch, 282. block alkali, 392. composition, 393. correction, 399. control, 402. effect on plants, 394. effect of method of irrigation, 706. formation of, 724. outfit for testing, 728. salts in soil, 391. Alkali land, drainage of, 659. Alkali lands, management of, 399. Alkali lands of foreign countries, 398. Alkali spots, 402. Alluvial soils, described, 39. distribution of, 41. humus and nitrogen in, 148. Alternaria, disease organism, 426. Alternate cropping, 714. Aluminum, 6. Aluminum phosphate, 337. Aluminum in soil separates, 102. Amendments of the soil, 534. calcium sulfate, 542. calcium carbonate, 540. caustic lime, 539. common salt, 543. effect on nitrification, 536. effect on tilth and bacteria, 534. effect on toxic materials, 537. liberation of plant-food, 535. lime and granulation, 193. muck, 545. Amid nitrogen, plant-food, 497. Ammonia, absorption of, 353, 366. as plant-food, 494. from plant decay, 139. salts and acidity, 381. test for acidity, 387. Ammonification in soil, 446. Ammonification, effect of partial ster- ilization, 470. Ammonium sulfate, as fertilizer, 499. Amount of water to use in irrigation, 710. Anaerobic bacteria, 433. Anaerobic bacteria and putrefaction, 444. Anaerobic fermentation of manure, 593. Analysis, mechanical, of soil, 97, 104, 107. Analysis, mineralogical, 100. of adobe. I of air, 139. 478. of alkali, 393. of arid and humid soils, 72, 147. of coastal plain soils, 70, 66. of crops, 419. of cumulose soil, 37. of cyanamid, 503. of drainage water, 351, 371, 374, 500 of gases from manure, 594. of glacial soils, 68, 70. of granite and residual soil, 27. of humus, 149. of humus ash, 145. <>f limestone and residual clay, 27, 33, 68. of litter, 580. of loess, 60. of manure, 581, 582, 583, 584, 588. 595. of marl, 38. of residual soils, 66, 68, 70. of soils, humus, 147, 148. of soil, organic matter, 146. of soil separates, 101, 102. of water extract, 348. Animals, capacity to produce manure, 587. effect on granulation, 192. effect on composition of manure, 581, 582, 584. soil-forming agent, 18. Antiseptics, treatment of soil with, 465. Apatite, mineral, 9. as a fertilizer, 512. Apophyllite, solubility, 339. Apparent specific gravity, 113. Application of water, time, 709. Arginine, plant-food, 497. Arid and humid soils, 71. composition of, 72. properties of, 72, 82. soil particles, composition of, 100, 101. Arrangement of soil particles, 108. Artificial mulch, 273. Ash composition of humus, 145. Ash constituents of plants, 416. Aspergillus niger in soil, 427. Atmospheric pressure affects soil air, 484. Attraction of soil particles, 206. Auger, for soil examination, 727, 732. Augite, 9. Availability of organic fertilizer, 510. INDEX 751 Availability of plant-food and bacteria, 428. Availability of soil water, diagram, 262. Azotobacter bacteria, 464. Bacillus, denitrificans, alpha and beta, 456. mesentericus, reducing organism, 455. mycoides, reducing organism, 455. pestifer, reducing organism, 455. radicicola, 459, 545. rndiobacter, 464. ramosus, reducing organism, 455. subtilis, reducing organism, 455. vulgatus, reducing organism, 455. Back furrow, 671. Bacteria and ammonification, 446. and plant decay, 129. and root nodules, 458. carbon dioxide production, 408. conditions for growth, 433. distribution, 429. functions, 436. in frozen soil, 431. influence of sulfur on, 525. influence on organic matter, 435. inoculation with, 460. nitrate reduction, 455. number in soil, 430. nitrogen supply, 428. non-symbiotic, 460. solvent action of, 439. Bacteria in soil, 427, 428. Bacterial action, effect on phosphates, 520. Bacteroids, 460. Bacterium ellenbachensis, 463. Balanced fertilizer, 551. Barnyards, covered for manure, 605. Barometric pressure and drainage, 234. Basalt, 8. Bases absorbed, solubility of, 354. Bases, absorbed by colloids, 165. Bases and toxicity, 379. Bases in plant ash, 378. Bases, removed in drainage, 378. Basic rocks, 7. - Basic slag phosphate, 513. Basic soil, effect on phosphates, 519. Bacillus amylobacter, 440. Bedding, absorptive capacity, 603. Biotite, 9. Biotite, solubility, 330. Black alkali, 392. Blood, dried, as fertilizer, 507. Bones as fertilizer, 511. Bone phosphate, 511. Bone tankage, 512. Brands of fertilizer, 555. Broadcasting fertilizer, 570. Bromberg, composition of drainage water, 370. Bureau of soils, classification of alkali, 396. Calcium, 4, 6. Calcium carbonate, 7, 10. Calcium carbonate in soil, 333. Calcium combinations, 539. Calcium compounds, root action on, 406. Calcium cyanamid, 502. Calcium hydrate in fertilizer, 566. Calcium in soil separates, 101. Calcium loss in drainage, 372. Calcium nitrate, 505. Calcium phosphate, effect of bacteria on, 439. Calcium salts, as amendments, effects, 534. Calcium sulfate to reinforce manure, 609. Calculation of air space of soils, 238, 477. of apparent specific gravity, 113. of free water, 238. of number of soil particles, 118. of pore space, 116. of surface of soil particles, 120. of wilting point, 260. Canals for drainage, construction, 635. Canals for irrigation, 693. Capillarity and texture, 214. Capillarity carries nitrates to surface, 454. Capillary movement, 221. and alkali formation, 298. in wet and dry soil, 225. influenced by thickness of film, 223. influenced by surface tension, 227. influenced by texture, 229. influenced by structure, 232. intercepted by green manure, 624. Capillary water, 201, 210. Capillary water, amount, 213. and organic matter, 218. and structure, 217. and surface tension, 213. and texture, 214. estimation of, 219. factors affecting amount, 213. form of surface, 212. relation to plant, 261. Capillarity and ground water, 214. 752 INDEX Carbohydrates and nitrogen fixation, 464. Carbohydrates as source of energy, 466. Carbohydrates in soil, 127. Carbon, 4, 6. Carbon dioxide, absorption of, 366. as an influence on climate, 4'.». and root action, 406, 408. end product of decay, 138. functions in soil, 481. in soil air, 21, 139, 410, 478. in atmosphere, 139. product of decay, 130. production by bacteria, 408. use in soil analysis, 339. Carbon disulfide as soil antiseptic, 465. Carbon disulfide from plant decay, 140. Carbonate of lime, 640. Carbonates of lime, effect on nitrates, 536. Carbonates, acid test for, 388. Carbonates in earth's crust, 11. Carbonates, effect on soil, 482. Carbonation as weathering agent, 19. Carbonized material in soil, 140, 144. Carriers, in fertilisers, 555. Catalytic action of soil, 528. Catalytic fertilizer, 528. Catch crops, and nitrate conservation, 455. Caustic lime, 539. Cement pit storage of manure, 604. Centrifugal soil analysis, 93. Cephalothecium, disease organism in soil, 426. Cereals, absorptive power, 414. Chabazite, 356. Checking of losses by evaporation, 272. of losses by leaching, 267. Chemical agents of rock decay, 14. Chemical analysis of soil, 327. complete, 328. extraction with acids, 329. extraction with water, 340. Chemical changes due to heat, 291. Chemical composition of soils. See Analysis. Chili saltpeter, 498. Chloride of potash, 523. Chlorine, 6. Chlorine as fertilizer, 544. Chlorite, 9. Chloroform as soil antiseptic, 473. Cistern storage of manure, 605. Citric acid method, 336. Class, the soil, defined, 103. Class, the soil, in classification, 722. Classification of rocks, 6. Classification of soil material, geological, 31. Classification of soil particles, 95. Classification of soil, factors used, 720. Classification of soil, outline of, 721. Clostridium paatorianum, 463. Clay, character of separate, 98. Clay, colloidal, 161. Climate and acidity, 382. Climate and efficiency of fertilizer, 568. Climate, influence on soil, 65. Climate as factor in soil classification, 724. Clouds, effect on radiation, 306. Clod crushers, 678. Coefficient of cohesion, 175. Coefficients of drainage, 651, 652. Coefficients of expansion of rocks, 17. Coefficient of friction, 229. Coefficient of hygroscopicity, 208. Coefficient of plasticity, 171. Coefficient of wilting, 257, 258. Cohesion defined, 173. Cohesion, determination, 174. Cohesion, control, 183, 197. Cohesion, factors affecting, 178. Cold and heat as weathering agents, 16. Collectotrichum, disease organism in soil, 426. Colloids in the soil, 153. Colloids, absorption by, 359. and acids, 165. chemistry, 153. effect of roots on, 411. estimation of, 166. factors affecting, 165. organic, 140. preparation of, 163. Colloidal humus, 133. materials, 346. matter, relation to phosphates, 517. phases, 158. state, 154. Colluvial soils described, 38. Color of soil, 73. Color of soils, due to weathering, 20. due to humus, 75. due to iron, 75. agricultural significance, 78. and temperature, 301. Color of arid and humid soils, 72. of glacial soil, 53. of marine soil, 44. of residual soil, 33. INDEX 753 Colters, types, 672. Commercial value of fertilizer, 560. Complete solution of soil, 328. Composition, of arid and humid soils 72. of animal manures, 584. of alkali, 391. of cumulose soil, 37. of crops, 419. of drainage water, 369. of gases from manure, 594. of glacial soil, 52. of glacial and residual clay, 68, 69. of humus, 131, 140. of horse and cow manure, 581. of loess, 60. of marl, 38. of manure litter, 580. of plants, 127, 418. of residual and marine soil, 66. of rotted manure, 596. of residual soil, 33. of soil in general, 2. of soil-forming minerals, 9. of soil due to weathering, 29. of soil separates, 101. of subsoil, 332. of soil air, 139, 477. of surface water, 373. of yard manure, 578. Composting manure, 613. Concentration and growth, 417. Concrete tile, 641. Condensation, heat of, 209. Conduction of heat in soil, 307. Conservation of moisture in irrigation, 710. Convection in soil, 307. Coprolites as fertilizer, 512. Cornell tanks, composition of drainage water, 372. Cornell University, bacteria in soil, 429. effect of magnesium, 539. nitrates in soil, 451. production of manure, 587. soil inoculation, 462. Cottonseed meal, as fertilizer, 507. Cover crops and green manure, 620. Covered barnyards for manure, 605. Cow manure, composition, 584. Creatinine, plant-food, 497. Cropping, alternate in dry-farming, 714. Cropping, effect in soil ventilation, 488. Crops, composition of, 419. drought-resistant, 715. effect of alkali on, 394. So Crops, efficiency of fertilizer, 568. feeding power, 415. for green manure, 622. suited to basic soils, 385. suited to acid soil, 384. Crumb structure, 109. Crushers and packers as soil pulverizer, 678. Cultivators, types, 673. Cultures, mixed nitrogen-fixing, 464. Cultures of nitrogen-fixing bacteria, 458, 461. Cumulose soils, 35. Cyanamid, nitrogen fertilizer, 502. Cyanamid in fertilizer mixtures, 566. Cytase, enzyme, 440. Dam, canvas, 701. Damping-off fungi in soil, 425. Dead furrow, objectionable, 671. "Dead" furrows, for drainage, 635. Decay of green manure in soil, 622. of organic matter in soil, 128. organic, and soil temperature, 315. and putrefaction, 443. of rocks, law of, 24. Decomposition of organic matter, 440. Decomposition of rock, 14. Deep-tilling plow, 667. Deflocculation of sodium nitrate, 499. Delta defined, 41. Denitrification, 456. Denudation, rate of, in U. S., 14. Denudation by Mississippi River, 15. Deoxidation as weathering agent, 20. Department of Agriculture, U. S. Nitro- culture, 462. Depth of moisture storage in soil, 710. for plowing, 669. of soil in relation to humus, 148. of soil mulch, 278. of tile drains, 646. Detention of plant-food in soil, 332. Dewey system of classification, 726. Diabase, 6. Diffusion of gases in soil, 483. Dihydroxystearic acid, 376. Diorite, 6. Disease of plants and moisture, 253. Diseases of plants, effect of lime, 536. Disease organisms in soil 426. Disease resistance, effect of phosphorus, 550. effect of nitrogen, 549. Disintegration of rock, 14. Disk harrow, single and double, 676. 754 INDEX Disk plow, 666. Disking to hold moisture, 714. Ditching machines, 649. Dolomite, 6, 9. Drag as soil pulverizer, 680. Drain till, quality, 640. Drainage and absorption, 368. Drainage and denitrification, 456. coefficient, 651. effects on soil, 630. effect on soil ventilation, 477, 488. ' effect on soil bacteria, 484. extent of need, 628. efficiency of fertilizer, 568. formation of humus, 152. history of development of irrigated and alkali land, 659. of land, indications of need, 627. methods, 634. muck and peat soil, 658. promoted by soil organisms, 422. reclamation of alkali land, 400. relation to green manure practice, 624. relation to colloids, 166. run-off checked, 269. systems, arrangement, 643. toxic materials eliminated, 137. use of explosives, 661. tile drains, 639. vertical, 660. Drainage water at Bromberg, 370. Drainage water, composition, 369, 351. Drainage water, relation of phosphates and carbon dioxide, 482. Drains, protection of joints, 642. Dried blood, 507. Drift defined, 52. Drought-resistant crops, 715. Dry-farming practices, 713. principles, 712. drought-resistant crops, 715. soils best suited for, 716. extent, 717. Drying and wetting, effect on granula- tion, 187. Dust mulch, 272. Dust mulch under irrigation, 705, 710. Duty of water in irrigation, 708. Dynamite, drainage by means of, 661. Earthworms, action on soil, 19. Earthworms and productiveness, 422. Effective diameter of soil particles, 122. Effective surface of soil, 125. Effects of organic matter on soil, 150. Electrical production of nitrogen f.r tUtor, Elements of plant-food, 3. Enzymotic action of bacteria, 129. Enzymes, effect on plant-food, 438. Enzymes in roots, 407 Epidote, 9. Kn.sion, agencies causing, 14. ctTcct of dramas in ditches, limits of Krade, 636. ice as agen< in irrigation canals, 694. rateot. in U.B., 14. wind action, l~>. Eskers, 50. Evaporation and alkali, 282. and temperature. 314. and wind movement, 285. at Kotham.-ted. 871. from plants, 27<>. prevented by, 272. rainfall lost by, 271. •i from animals, 577. Exhaustion of soil, 410. Expansion of minerals by heat, 16. Explosives, drainage by means of, 661. Factors for plant growth, 3. Factory-mixed fertilizer, 563. Fall plowing, relation to dry-farming, 713. Fall and spring plowing, 283. Farm manures, 577. Farm manure, waste, 597. Fats in soil. 127. Fats, effect on capillarity, 211. Feeding power of plants, 414. Feldspar, as potash fertilizer, 524. Feldspar in soil separates, 101. Fermentation, effect on phosphates, 520. Fermentation of manure, 591. Ferrie phosphate availability, 337. Fertilizers, 489. Fertilizers and acidity, 381. amounts to use, 572. application of, 570. brands, 555. catalytic, 530. commercial value, 560. commercial, extent of use, 492. effect on toxic material, 137. factors in efficiency, 568. for special crops, 571. grades of, 562. home mixing, 563. incompatible material, 565. INDEX 755 Fertilizers, inspection, 556. mixed, 561. nitrogen, 493. penetration into soil, 354. practice, 546. potash, 522. systems of, 573. sulfur, 524. • trade value, 559. Fertilizing crops, 571. Filler in fertilizer, 556. Filler in fertilizer, muck, 545. Film water, 206, 210. Fineness in phosphates, 513. Finger lakes, 50. Fire-fanging, manure, 596. First bottom land, 42. Fish as fertilizer, 508. Floats to reinforce manure, 610. Flocculation, 159. Flooding, as means of soil infection, 425. Flooding, irrigation by, 699. Flume, for measurement of water, 707. Flushing, correction for alkali, 401. Food of animal, effect on manure, 582. Food elements, sources, 4. Food material in crops, 418. Food of plants, absorption of, 404. Forces of weathering, 14. Formic acid secreted by roots, 408. Forests and acidity, 380. Forest trees, mycorrhize of, 428. Free water in soil, 236. Free water, bad effects, 262. Freezing, effect on granulation, 189. relation to soil colloids, 166. Fresh versus leached manure, 601. Friction and available water, 256. Friction coefficient, 229. Frost as soil pulverizer, 680. Frost as weathering agent, 17. Frozen soil, bacteria in, 431. Fruiting effect of nitrogen, 548. Fruits, feeding power, 416. Functions of fertilizers, elements, 547, 549, 551. of soil to plant, 1. of water to plant, 243. Fungi and fire-fanging of manure, 596. Fungi in soil, 423. Furrow, back, productive, 671. correct position, 668. dead, objectionable, 671. depth and width, 669. use in irrigation, 702. Fusarium as a disease organism, 426. Gabbro, 6. Gases, from manure, 594. Gel colloids, 159. Geological classification of soil material, 31. Germination, effect of heat on, 290. Glacial drift, 47. Glacial ice, as erosive agent, 16. Glacial lakes, 55. Glacial soil, composition, 52. Glacial soil, humus in, 54. Glacial soils, 47. Glauconite, solubility, 339. Gneiss, 6. Grade of drains, 645. Grain, effect of phosphorus, 550 effect of potassium, 551. effect of nitrogen, 548. Granite, 6, 8. weathering of, 27. Granular soil, 111. Granulation, 185. Granulation, cause of, 187. defined, 170. effect of plow, 195. effect on cohesion, 179. Granulation of soil and optimum mois- ture, 263. effect of drainage, 630. modified by tillage, 663. Granulabacter, group of bacteria, 464. Granules in soil, 109. Grass crops, feeding power, 415. Gravel, 99. Gravitational water, 201, 233. Gravitational water, injurious to crops, 261. calculation of, 237. control of, drainage, 627. movement, factors affecting, 233, 235. movement of, 233. study of, 238. Green manure, 151. Green manure, and acidity, 379. conditions for plowing under, 624. constituents added, 621. crops, 622. decay in soil, 622. denitrification, 547. effects, 619. lime relations, 625. relation to the rotation, 625. Ground limestone, 540. Ground water and capillarity, 214. Group, the, in soil classification, 723. 756 INDEX Growing season, effect of drainage, 631. Growth, effects of nitrogen, 547. Guano, as fertilizer, 507. Guarantee, fertilizer, 558. Gypsum, 9, 542. Gypsum, correction for alkali, 400. Gypsum, lime fertilizer, 539. Gypsum, solvent action of roots on, 406. Gypsum to reinforce manure, 609. Handling manure, 602. Hardpan, alkali, effect on drainage, 659. Harrow as cultivator, 676. Heat, absorption of, 300. and cold, mechanical action, 16. chemical and physical changes due to, 291. condensation, 209. convection in soil, 307. functions of, in soil, 289. effect on soil, 466. unit defined, 314. sources in soil, 292. specific heat of soil, 294. Head of water, defined, 706. Head of water for irrigation, 702. Heaving of soil indicates wetness, 628, 632. Heiden's formula for manure production, 588. Helminthosporium, disease organism, 426. Hematite, 9. Hematite, hydration of, 21. Herring-bone system of drainage, 645. High-grade fertilizer, 562. Hillside plow, 670. Histidine, plant-food, 497. Home-mixing fertilizer, 563. Home-mixing fertilizer, method, 567. Hoof meal as fertilizer, 507. Hornblende, 9. Hornblende in soil separates, 101. Horse manure, composition, 584. Humid and arid soils, 71. Humid climates, irrigation in, 689. soils, composition of, 72. soils, organic matter of, 146, 147. Humidity, effect on hygroscopicity, 207. Humus, absorption by, 365. Humus ash composition, 145. and conductivity, 310. and capillarity, 219. and efficiency of fertilizer, 569. and roots of plants, 127. Humus and run-off, 269. and specific heat, 297. as plant-food, 495. composition of, 131. content of soils, 147. effect of drainage on formation, 632. effect on hygroscopicity, 204. effect on granulation, 190. effect on cohesion, 170. • effects on soil, 150. i>tim:ition of, 142, 144. in glacial soil, 54. nature of, in soil, 130. specific gravity of, 113. Humus, defined, 130. Hydration as weathering agent, 20. Hydrochloric acid used in soil survey, 728. Hydrochloric acid solution of soil, 329. Hydrochloric acid test for carbonates, 388. Hydrogen, 4, 6. Hydrogen, from plant decay, 140. Hygroscopic coefficient, 257. Hygroscopic moisture, 201, 202. Hygroscopic moisture and plasticity, 171. relation to colloids, 168. relation to plants, 256. Hygroscopicity, determination of, 208. Ice, as erosive agent, 16. Ice-formed soils, 52. Ice sheet, 47. Igneous soil-forming rocks, 6. Implements, tillage, 664. Infection by soil fungi, 425. Inoculation of soil for legumes, 460. Inorganic colloids, 158, 162. Insects in soil, 423. Inspection of fertilizers, 556. Interception losses in forests, 287. Iodine in ash of sea weed, 404. Iron, 4, 6. Iron a catalytic fertilizer, 529. Iron as a soil color, 75. Iron phosphate available, 337. Iron in soil separates, 102. Irrigation, amount of water applied, 708. amount of water to apply, 710. and alkali, 397. application of water and yield, 208. canals, 693. canals, linings, 694. conditions that warrant, 683. development in the United States, 686 / INDEX 757 Irrigation, erosion in canals, 694. flooding, 699. furrow, 702. history, 685. in humid regions, 689. legal, economic and social effects, 691. land, drainage of, 659. land, extent of, 685. methods of water supply, 688. methods of applying water, 695. movement of water, 704. preparation of land, 695. relation to rainfall, 682. setting of fruit, 709. sewage, 711. sources of water, 693. sub, 696. theory and practice, 682.. units of water measurement, 706. Jointer, 672. Joints, protection in tile drains, 642. Kainit, potassium salt, 522. Kainit to reinforce manure, 609. Kames, 50. Kaolin, specific heat, 299. Kaolinite, 9. Lacustrine soils, 56. Lagoons, 40. Land drainage, indications of need, 627. Land plaster, 542. Land plaster to reinforce manure, 609. Leaching of manure, 599. Leather meal as fertilizer, 507. Legumes and symbiosis, 458. Legumes, feeding power, 415. Legume manure, nitrogen added by, 621. Leguminous green manures, 623. Lento-capillarity, 257. Lento-capillarity, defined, 224. Leucite, solubility, 339. Level tillage, 286. Lime as amendment, effects, 534. Lime carbonate, 333. Lime, a catalytic fertilizer, 528. effect on bacteria, 432, 436. effect on nitrates, 536. effect on toxic substances, 536. effect on efficiency of fertilizer, 569. effect on sanitation of soil, 138. effect on granulation, 193. fertilizer mixtures of, 566. Lime, flocculating agent, 160. forms of, 539. formation of humus, 152. green manure and, 625. loss in drainage, 372. manure and, 612. nitrogen fixations, 464. relation to available phosphorus, 517. relation to soil colloids, 166. relation to soil diseases, 426. run-off relationships, 269. soil separate content, 101. soil and subsoil content, 378. Lime-magnesia ratio, 538. Lime phosphate, effect of bacteria on, 439. Limestone, 6, 8. Limestone for soil, 539. Limestone, residual soil from, 33. Limestone soil, not rich in lime, 28. Limestone, weathering of, 27. Limewater test for acidity, 390. Limonite, 9. Linseed meal as fertilizer, 507. Liquid manure compared with solid, 585. Lister, seeder cultivator, 678. Listing, effect on soil ventilation, 487. Lysimeter described, 239. Litmus test for acidity, 386. Litter, absorptive capacity, 603. Litter in manure, 578, 580. Loam, defined, 104. Loess, ^Eolian soil, 58. description and composition, 59. wind origin, 15. soil distribution of, 51. Loss of manure in handling, 583, 600. Low-grade fertilizer, 562. Machinery, tillage, 664. Macroorganisms in soil, 421. Macrosporium, disease organism in soil, 426. Magnesium, 4, 6 Magnesium carbonate, and nitrates, 536. catalytic fertilizer, 530. in soil separates, 102. Manure, 489. Manure, amount produced by animals, 587. commercial value, 589. composition, causes of variation, 580. composition of gases from, 594. composition of rotted, 596. composting, 613. 758 INDEX Manure, covered yards and pits, 605. damnification of, 457. destruction of organic matter in feed, 597. effect of food of animal, 582. effect of handling on composition, 583, 600. effects on the soil, 613. effect on soil ventilation, 488. farm, 597. farm corrects alkali, 403. fermentation, 501. frequent small applications, 607. fresh versus leached, 601. fire-fanging, 596. functions, 489. green, 619. green and lime, 625. Heidens formula for production, 588. lime and, 612. muck and, 613. needs and plant food deficiency, 334. organic and nitrification, 450. plowing under, 608. reinforcement, 609. residual effects, 614. rotation relation, 615. small versus large applications, 608. spreader, 608. storage in open piles, 606. yard composition, 578. Marble, 6, 43. Marine soil compositions, 66. Marl, 539. Marl, composition, 38. found under muck, 37. Marsh mud composition, 37. Maturity, effect of nitrogen, 548. Maturity, effect of phosphorus, 550. Maximum water content, 262. Measurement of water in irrigation, 706. Meat, as fertilizer, 507. Mechanical analysis, 84. Mechanical analysis of samples, 728. Meeker harrow, 677. Metamorphic soil-forming rocks, 6. Methane in soil air, 140. Mica in soil separates, 101. Microcline, solubility, 338. Microorganisms, 424. Microorganisms, effect of sulfur, 525. Mineral acid, method of analysis, 338. colloids, 162. definition of, 7. matter, decomposition by bacteria, 437. Mineral acid, nutrients of feed in ma- nure, 597. phosphates as fertilizer, .*il2. Mim r:ii>, sbeorbsd by plants, 416. law of decay, 24. relative abundance, 11. rock-forming, 8. soil-forming, 8. Mineralogical character of soil separates, 99. Miner*! inch of water, defined, 7<>d. Minimum, law of, .V.I Mississippi River, denudation by, 15. Mixed fertilizers, ffl. Mollification of structure, 187. Module, for measuring water, 709. Moisture of the soil, 198. conductivity relations, :<1<>. capacity of soil, effect of drainage, 681. capillary form, 210. conservation in irrigation, 710. content, effect on soil air, 476. control of, 264. effect on bacteria, 434. effect on cohesion, 179. effect of movement on soil air, 484. equivalents of soil, 220. forms of, 200. gravitational, 233. hygroscopic, 202. maximum content, 221. methods of stating relation to colloids, 165. relation to decay, 129. relation to plowing, 196. used by plant, 261. uses to plant, 243. Moldboard plows, 667. Moldboard, shapes for best result, 196. Molds in soil, ammonify proteins, 427. Mole drainage, 638. Moraine, terminal, 50. Movement, of soil air, 483. heat, 307. heat factors affecting, 308, 310. moisture, capillary, 221. moisture, factors affecting capillarity, 223. moisture, gravitational, 233. moisture, thermal, 241. water, affected by friction, 223. water, affected by texture, 229. water, affected by structure, 232. Muck, defined, 36. INDEX 759 Muck, as fertilizer, 545. and manure, 613. and moisture control, 272. nitrogen compounds in, 133. specific growth of, 113. Mulch and the control of alkali, 402. Mulch, depth of, 278. depth in irrigation farming, 705, 715. dry-farming, use in, 714. effectiveness in arid regions, 277. effect other than on moisture, 280. factors of effectiveness, 275. formation of, 276. functions of, 274. kinds of, 273. management of, 278. of soil, 233. r6sum6 of control, 278. usefulness of, 282. water saved by, 279. Mulching grain crops, 282. Muriatic acid used in soil survey, 728. Muscovite, 9. Muscovite, solubility, 339. Mycorrhiza, relation to fertility, 423. Mycotrophic plants, 423. Natural mulch, 273. Negative acidity, 376. Nematodes in soil, 424. Nephelite, solubility, 339. Nitrate assimilation by bacteria, 456. Nitrate of calcium, fertilizer, 505. Nitrate of soda, as plant food, 498. Nitrate, reduction of, 455. Nitrates, conserved by green manure, 620. constituent of alkali, 392. effect of lime on, 536. in soil, effect of absorption on, 341. loss from soil, 454. product of decay processes, 130. returned to surface, 454. Nitric acid method of analysis, 338. Nitric acid solution of soil, 329. Nitrification in soil, 447. effect of aeration, 452. effect of antiseptics, 465. effect of carbon bisulfide, 466. effect of depth, 453. effect of organic matter, 449. effect of sod, 452. temperature for, 435. Nitrobacter in soil, 448. Nitrogen, 4, 12. absorption of, 367. Nitrogen, added to soil by legumes, 621. available from atmosphere, 501. chemical estimation, 329. cycle, 443. effects on plant growth, 547. effect on toxic material, 137. fertilizers, 493. fertilizer from the air, 501. fertilizers, organic, 507. fixation, 457. fixation and mycorrhiza, 428. fixation by molds, 427. fixation, non-symbiotic, 463. fixing organisms, 463. forms in soil, 493. forms used by plants, 448, 494. found in animal manures, 597. in humus, 147. loss in drainage, 372. loss from Rothamsted soil, 500. necessary to plants, early studies, 491. supply and bacteria, 428. utilized by bacteria, 459. "Nitrogen" culture, 461. Nitrosococcus in soil, 448. Nitrosomonas in soil, 448. Nodules on plant roots, 458. Number of soil particles, 118. Nutrient salts, absorption of, by plants, 404. absorption by soils, 349. selective absorption, 362. Odometer used in soil survey, 727. Oils, effect on capillarity, 214. Oils in soil, 128. Oily material, and capillary movement, 226, 228. Oily materials in soil, 275. Olivine, 9. Open ditches, construction, 635. Open-ditch drainage, objections, 634. Optimum water content, 262. Orchards, manure in, 617. Organic colloids, 157, 161. Organic fertilizer availability, 510. Organic constituents of soils, 2, 12, 128, 131. Organic decay and soil temperature, 315. Organic matter, 12. absorption by, 365. and capillary water, 218. catalytic action, 529. composition in soil, 135. effect on granulation, 190. 760 INDEX Organic matter, effect on nitrification, 449. effect on phosphates, 520. effects on soil, 150. effect on soil bacteria, 435. efficiency of fertilizer, 569. estimation of, 141. losses in digesting food, 597. maintenance in soil, 151. relation to air in soil, 476. soil content, 126. soils of U. S. content, 146. source of carbon dioxide, 479. specific heat relations, 297. Organic nitrogen, plant food, 497. Organisms in soil, 421. effect of heat on, 289. effect of drainage on, 632. 