None
J] 03 £W O « <B C ►. S S2^ (3 3 . >.C! ■Soft!'? C3 1^ gem . w CO •=Sb2o a^feg^ tSist^ S'C.s;a a S^tSSS ■Oti5!z;(£Q S^^izitg oSo^a .& 03 bOT3 fe'C 408 APPENDIX II m* <o 05 «o t*00i-tCO 5 (NINC0C<3 •o .CO 5 wi U3 CO lO »o •toio • -^ C^ M t-J N iO CO t-.; ' C*5 ^ ^ •00 •00 ■05 CD ■ Tjl 00 • TJ4 I-t ■s 3 ■*(M(M'*'H COCD"*"0 r~(NC<lcOr-N U5Coai'-<CO 0(NIMM ^^<N05 "5 'S 0:OO0Cl^ OOOt^CO t^t^OOOOCDCO COt^'^COi-H 03i-(lOCD CO-^NW rj Si— (f-H 1— I)— ti— 41— I1-H1— ti— ti-Hi-^l— 1^ ^ 02 s t3 e b ft. C3 * >i3o6'*coeo i-jcii-loo ccJtii ;05io ;oot-;r-;opQqc<)cot-.potq !co ^ Icoc4»ri ^061-Jo o t^'^06 w .e<i c» .Meow coeo-^-i' ■* cocon cq "S -* t>; oJ cxi "*■ CO CO CO ■*■ CO ^' i-i ^ 1— tT-fl-<l— l»-t 1— ti— IfHtH »— It— (tH 05 •CD U5t~(N(NCO OOCOOU3 Tjl 3C0eOCOC0<N CTINNCO (MN<-l'-l(N(N NN'^COCO COCO ■*■>!< ■^■^COCO CO 05 ■3 r-coppT-j poqoqp p^ii-^M *« CDCOCOod-^ ».H-Ht>^CO ciT-HrHCO T)l U510C010CD OOCOt)hcO <3)t)<cO'-i O ■SiqoqcOT);t~ poqp(M_ p(NTi<oop(N ■*Ti<t~.inc<i pi-nt^p ^^cop p "wco-^N-^i^ cot^»oo t^uicDoooio osococoi-J tooii-Jci i-It^osw co 3COCOCOC0N NINCNN C^INtHi-Ii-CN t-KNNNM MCOCOCO CO(NC<lCO (N 0) APPENDIX II 409 Average Yield of Wheat Per Acre for Ten Years {1905 to 1914),* Bushels United States Russia (European) Germany Austria Hungary proper France United Kingdom 14.8 9.9 30.7 20.0 18.1 20.1 33.4. * Yearbook U. S. D. A., 1915. APPENDIX III The following maps are taken from the Yearbook of the United States Department of Agriculture for 1915 : dhUtiiit 410 APPENDIX III 411 412 APPENDIX III APPENDIX m 413 414 APPENDIX III APPENDIX III 415 416 APPENDIX III APPENDIX III 417 INDEX Ablation swamp, 30 Absolute specific gravity, 175 Absorbents, factor in conserving manure, 165 Absorption and radiation of heat, effect of, on soil temperature, 302 Acclimated seed, desirable on dry land, 255 Accumulations in pastures, aid in maintaining organic-matter con- tent, 160 Acid, chromic, method of determina- tion of organic matter, 154 phosphate, 402 Acids, decomposition of rocks by, 19 carbonic, hydrochloric, nitric, sulfuric, 20 Acre-inches, 192 Adaptation of region to dry farm- ing, factors in, 238 evaporation, 241 rainfall, 238 soils, 241 Adobe, 65 Adsorption by colloids, 132 Aeration and soil air, chapter on, 309 affecting bacteria, 320 aided by drainage, 223 or soil ventilation, 311 accomplished by atmospheric pressure, changes in, 311 diffusion, 311 removal of water, 311 temperature changes, 312 tillage, 313 wind movement, 313 Aftonian Inter-glacial Stage, 40 Agassiz, Lake, 38 extent of, 46 Agencies of weathering, chemical, 19 physical, 12 Agricultural provinces, 383 Agriculture, dry-land, chapter on, 238 permanent, 389 Air in soils, amount of, 309 convection currents of, source of loss of heat, 296 Air in soils, composition of, 310 use of, 309 Alfalfa, completely killed by heaving, 220 crop for dry land, 253 Alkali, area, absence of vegetation on, 286 black, neutralization of, 281 effect of irrigation on rise of, 281 on foliage of apricot trees, 283 on plants, 282 kinds of, 280 land, growth of barley on, partly and fully reclaimed, 288 reclaimed, wheat on, 289 lands, and their reclamation, chapter on, 278 utilization and reclamation of, by removal of alkali salts, 285 growing alkali - resistant crops, 285 neutralizing black alkali, 286 plowing deep and turning alkali under, 286 retarding evaporation, 285 limit for germination and growth, 284 origin of, 278 resistant crops, growing of, 285 rise of, prevented by cultivation, 286 drainage, 220 salts, removal of. by cropping, draining, flooding, leaching, scraping, 287 soils of humid regions, reclama- tion of, 290 spot, beginning of, 279 turning under of, 286 Alluvial soils, 38 Alluviation by glacial stream, 62 Altitude, affecting organic content of soils, 145 Ammonia, effect on floeculation, 137 Ammonification, 318 419 420 INDEX Ammonium sulfate, 399 Ampliibole, 3 Analyses, chemical, of adobe, 65 Analysis, mechanical or physical, 123 physical, systems of, 124 Andesite, 7 Animals, decomposition by, 25 Apatite, calcium phosphate, 5 Appalachian Mountain and Plateau Province, 81 Apparent specific gravity, 175 Aqueous rocks, 7 Area, and projects, irrigation, 258 internal, of soil types calculated from physical composition, 182 of soil surveyed in the United States by Bureau of Soils to 1915, 78 of spheres, columnar arrange- ment, 181 or internal surface, 181 Arid soils, 74 nitrogen in humus of, 147 subsoils, and humid, 70 Arrangement of particles. 179 columnar, area of spheres, 181 or vertical, 180 oblique, 180 Artificial mulch, defined, 233 Aspirator, King's, 128 Atkinson, A., and Kelson, J. B., stor- ing rainfall, Montana, 248 Atlantic and Gulf Coastal Plains Province, 91 Atmosphere, carbon dioxide in, 20 Atmospheric pressure, changes in, factor in aeration, 311 effect on percolation, 219 Auger, soil, 119 Available moisture, 214 increased by drainage, 223 Averitt, A. D., plant food in soil areas of Kentucky, 393 Babb, table, sediment carried by streams, 35 Bacteria, conditions for development, 319-321 a("'ration, 320 food, 319 light, 321 moisture, 319 Bacteria, conditions for develop- ment, physical composition of soil, 321 reaction, 320 temperature, 320 distriljution of, 318 number of, effect of lime upon, 321 per gram of air-dry soil, 319 Bacterial action, effect of potassium carbonate upon, 321 Barley, yield of, continuous cropped vs. after fallow, 249 Barnyard manures, 161 Barometric pressure, changes in, factor in aeration, 311 Bartlett, W. H., expansion of rocks on heating, 13 Basalt, 7 Basic slag, 402 Bates, with Lynde, osmosis in soils, 212 Beach or Marram grass, transplant- ing, 56 Beavers, J. C, manure excreted by farm animals, l(i2 value of increase for manure, heavy and light applications, 168 Bennett, H. H., Bureau of Soils, soil survey, 78-111 Biological effects of organic matter, 150 Biotite, black mica, 4 Black alkali, neutralization of, 286 Black locusts, hold sand, 59 prevent washing, 368 " Blowout," in sand dune, 59 Bog, climbing, 28 quaking, 28 Bogs, see hummocks, 30 Boiling and freezing points, colloids, effect on, 131 Bone meal, 400 Boulder, granite, 51 limestone, showing glacial scratches, 42 Boulders, from moraine, 51 Bouyoucos, G. J., effect of color on radiation, 295 on temperature of sands, 302 specific heat of soil constituents, 299 INDEX 421 Bouyoucos, G. J., time for heat to penetrate soil, 306 Briggs, L. J., ratio between viscosity and flow of water, 219 thickness of hygroscopic film, 194 Briggs, Martin, and Pearce, Bureau of Soils, sizes of particles, 124 chromic acid method of deter- mining organic matter, 154 Briggs and McLane, moisture equiv- alent centrifuge, 202 Briggs and Shantz, water require- ment of plants, Akron, Colorado, 242 wilting coefficient, 212 determination of, 197 Brown, E. E., with Sehreiner, 0., progress of humification, 146 Brown, P. E., bacteria per gram of air-dry soil, 319 Brownian movement, 130 Buckingham, little loss of water by interstitial evaporation, 232 Bureau of Soils centrifugal method of physical analysis, 127 classification of soils, chapter on, 78 grades of soil particles, 124 provinces, soil Appalachian Mountain and Plateau, 81 Atlantic and Gulf Coastal Plains, 91 Glacial and Loessial, 84 Glacial Lake and River Ter- race, 89 Limestone Valleys and Up- lands, 83 Piedmont Plateau, 79 Kiver Flood Plains, 97 regions, soil Arid Southwest, 106 Great Basin, 106 Great Plains, 100 Northwest Intermountain, 105 Pacific Coast, 107 Rocky Mountains, 104 series, soil Acadia, 92 Alamance, 79 Altamont, 107 Bureau of Soils, series, soil Amarillo, 103 Arkansas, 104 Bangor, 84 Bates, 100 Benton, 101 Berks, 81 Bibb, 97 Billings, 105 Bingham, 106 Blanco, 97 Boise, 105 Boone, 101 Brennan, 92 Brooks, 83 Caddo, 92 Cahaba, 97 Caldwell, 106 Cameron, 97 Canyon, 102 Caribou, 84 Carrington, 84 Cazenovia, 85 Cecil, 79 Chehalis, 110 Chenango, 89 Chester, 80 Cheyenne, 104 Clark, 101 Clarksville, 83 Clyde, 89 Colbert, 83 Colby, 102 Coloma, 85 Colorado, 103 Conasauga, 81 Conestoga, 83 Congaree, 97 Corning, 107 Cossaymna, 85 Coxville, 92 Crawford, 101 Crowley, 93 Dawes, 103 Decatur, 83 DeKalb, 81 Dunkirk, 90 Durham, 80 Dutchess, 85 Duval, 93 Durant, 93 Edna, 93 Elkton, 93 422 INDEX Bureau of Soils, series, soil Englewood, 101 Ephrata, 105 Eppi-g, 101 Everett, 108 Fargo, 90 Fayetteville, 82 Flushing, 85 Fox, 90 Iresno, 108 Frio, 98 Ganett, 103 Genesee, 98 Gila, 107 Glendale, 107 Gloucester, 85 Goliad, 93 Greensburg, 103 Greenville, 93 Hagerstown, 83 Halston, 98 Hanceville, 82 Hanford, 108 Hesson, 108 Holyoke, 86 Houston, 93 Huntington, 98 Imperial, 107 Indio, 107 Iredell, 80 Jordan, 100 Kalmia, 98 Kewaunee, 86 Knox, 80 Lackawanna, 86 Lake Charles, 94 Lansdale, 80 Laramie, 105 Laredo, 98 Laurel, 104 Leonardtown, 94 Lexington, 8(5 Lincoln, 104 Lintonia, 98 Ijouisa, 80 Lufkin, 94 Lynden, 109 Manchester, 90 Manor, 80 Maraeopa, 109 Marion, 86 Marshall, 86 Maverick, 94 Meigs, 82 Melbourne, 108 Bureau of Soils, series, soil Memphis, 87 Merrimae, 90 Mesa, 105 Miami, 87 Miller, 98 Mohawk, 87 Monroe, 94 Morton, 101 Myatt, 99 Nueces, 94 Ocklocknee, 99 Oktibbeha, 95 Olympic, 109 O'Neill, 102 Ontario, 87 Orangeburg, 95 Orono, 90 Osage, 99 Oswego, 101 Oxnard. 109 Penn, 80 Pierre, 101 Placentia, 109 Plainfield, 90 Plymouth, 87 Podunk, 99 Porters, 82 Portsmoutli, 95 Pratt, 103 Puget, 111 Putnam, 87 Quincy, 105 Redding, 110 Richfield, 103 Richland, 87 Rosebud, 103 Ruston, 95 Sacramento, 111 Salem, 111 San Antonio, 95 San Joaquin, 109 San Luis, 104 Sarpy, 99 Sassafras, 95 Scranton, 96 Sharkey, 99 Shelby, 88 Sidney, 101 Sioux, 91 Stockton, 110 Summit, 102 Superior, 91 Susquehanna, 96 Talladega, 82 INDEX 423 Bureau of Soils, aeries, soil Tif ton, 96 Trinity, 99 Tripp, 104 Trumbull, 88 Union, 88 Upshur, 82 Uvalde, 99 Valentine, 102 Vergennes, 91 Vernon, 102 Victoria, 96 Volusia, 88 Wabash, 99 Wade, 104 Walla Walla, 105 Waukesha, 91 Waverly, 100 Webb, 96 Westmoreland, 82 Whatcom, 110 Wheeling, 100 Williams, 88 Willows, 110 Wilson, 96 Winchester, 105 Wooster, 88 Yakima, 100 Yazoo, 100 Yolo, 110 York, 81 Yuma, 107 Zapata, 103 Calcareous rocks, chalk, marl, 8 Calcite, calcium carbonate, 5 Calcium carbonate, calcite, 5 carried by Thames River, 23 concretions, 62 cyanamid, 400 magnesium carbonate, dolo- mite, 5 sulfate, gypsum, 5 Call, L. E., methods of preparing land for wheat, 347 Campbell, H. W., pioneer in dry farming, 247 subsurface packer, 247, 337 Canals, loss of water from, 266 Capillarity, amount of water moved by, 210 Capillary lift of soil constituents, 212 pull of soils, 211 Capillary capacity or moisture-hold- ing capacity of soils, 209 rise of water in glass tubes, height of, 199 rapidity and height in dif- ferent soils, 207 water as films or waists about particles, 200 in covered and uncovered soil, 204 of soils, chapter on, 199 movement, aflected by or- ganic matter, 206-208 substances in solution, 205 temperature, 204 texture, 206 thickness of film, 203 viscosity, 204 use of, 212 Carbonated water, almost universal solvent, 20 Carbon dioxide aid in solution, 22 brought to earth in precipi- tation, 20 decomposition by, 20 in rain and snow water, 20 soil air and atmosphere, 20 Catch and cover crops, 161 aid in preventing erosion, 302 Cates, J. S., and Cox, H. R., results of corn cultivation, 28 states, 353 Caves, due to action of carbonated water, 22 Centers of accumulation, Cordil- leran, Keewatin, Labra- dorean, 45 map of, 47 Centrifugal elutriator, Yoder's, 128 method of physical analysis, Bureau of Soils, 127 Chains, for puddling mud of canals to prevent seepage, 267 aialk, 8 Characteristics of water, physical, 186 Chemical agencies of weathering, 19 changes in soil, source of heat, 294 precipitates, 8 Chernozem soils, roots and bumus in, 144 Chester, 1<\ E., effect of lime upon number of bacteria, 321 Chicago, Lake, 38 424 INDEX Chromic acid, and combustion methods, comparison, or- ganic matter, 155 method of determination of organic matter, 154 Churn elutriator, physical analysis, Hilgard, 126 Cippoletti or trapezoidal weir, 269 Classes, types and phases, in Illi- nois, 114 Clay, defined, 134 dunes, 53 effect of, on shrinkage, ISS-lS.'i loams, 115 tight, 68 Clays, 114 and clay loams, properties of coagulation or floccu- lation, 137 plasticity, 135 puddling, 136 shrinkage, 135 tenacity, 134 Clark, F. W., composition of known earth, 2 Classification of soils, by Bureau of Soils, chapter on, 78 based on color, 77 geology, 72 lithology, the parent rock, 73 moisture, 73 temperature, 73 texture, 77 vegetation, 75 need of, 72 Cleavage, vertical, characteristic of deep loess, t)3, 64 Coagulation or flocculation of clays, 137 Coal, formation of, from organic mat- ter, 146 Coffey, G. N., dark color indicating outcrop of limestone, 177 lime and magnesia in soils, 75 mineral content of soils, 74 reports clay dunes in Texas, 53 soluble salts in soils, 74 Colloids, affecting hygroscopic moist- ure, 195 dialysis and diffusion of, 131 examples of, 129 in soils, 132 organic and mineral, 132 properties of, 130 adsorption, 132 Colloids, properties of, boiling point, effect on, 131 Brownian movement, 130 dialysis, 130 diffusion, 130 electrical behavior, 131 freezing point, effect on, 131 shrinkage, 132 size of particles, 130 Colluvial soils, 30 Color of soils, 176 changed by erosion, 361 effect of deoxidation on, 21 on temperature, 303 of sands, 302 factor in classification, 77 Colorado mud-flow, 34 river, work of, 17 Grand Cafion, 17 Columbia glacier, over-riding forest, Alaska, 14 front of, 15 Columnar arrangement of particles, 180 Combustion and chromic acid methods, comparison, organic matter, 155 in oxygen determination of or- ganic matter, 154 Compacters, bar roller, 337 corrugated roller, 330 cultipacker, 336 drum roller, 335 plankers, 337 subsurface packer, 337 Compacting the soil, a part of till- age, 326 increases moisture capacity, 230 Composition of feldspars, 3 fresh manure, 163 known earth, 2 river sediments, 262 Concrete dams for filling gullies, 373 Concretions, calcium carbonate, 63 iron, 64 Conductivity of soil, effect of, on temperature, 306 material, 306 Constituents of soils, mineral, chap- ter on, 123 organic, chapter on, 142 Contour plowing, deep, aid in check- ing erosion, 364 seeding, aid in checking erosion, 365 INDEX 425 Control of moisture, chapter on, 222 Cordilleran center of accumulation, 45 Corn, acreage, 1909, 412 belt rotationa, 382 comparison, cultivated, scraped, weeds allowed to grow, 351 cultivation, 353 effect on yield of root pruning and deep and shallow cultiva- tion, 355 grown on dry land, 252 on swamp land, effect of po- tassium on, 404 method of preparing seed bed for, 348 planter, 338 production, 1909, 413 results of cultivation, 352 yields of, different methods of tillage, 354 Cotton belt, rotation for, 384 Cottrell, H. M., pounds seed per acre for different crops, 255 Cover and catch crops, 161 Cox, H. R., with Cates, J. S., re- sults corn cultivation, 28 states, 353 Cracks, in black clay loam, 136 shrinkage, effect of, on percola- tion, 219 Cropping, alternate vs. continuous, yields, 250 continuous vs. after fallow, wheat yields, Montana, 248 loss of organic matter, due to, 151 systems of, 248 Crop requirements, plant food, 390 Crops, alkali-resistant, growing of, on alkali land, 285 catch and cover, 161 deep rooting, effect of, 345 on moisture capacity, 171 for dry farming, see dry-farm- ing crops for irrigated land, see irrigated land, crops for non-tilled, factor in maintain- ing organic matter, 171 plant food in, 390 Crops, protection from erosion by catch and cover, 362 meadows and pastures, 361 rotation of, aid in maintaining organic matter, 171 ten-year average yield of, by states in United States, 407, 408 Crystalloids, dialysis and diffusion of, 131 Cultivation after irrigation, 273 and summer tillage in dry farm- ing, 246 level, 355 object of, 350 of corn on gray silt loam on tight clay, yields, 353 of corn, Illinois yields, 352 results of deep and shallow, with and without root pruning, corn, 355 ridged, 356 Cultivators, 337 blade, 339 disk, 339 shovel, 338 weeder, 340 Cumulose soils, 27 Currents of air, convection, source of loss of soil heat, 296 Cyanamid, calcium, 400 Dams, for filling gullies, concrete, 273 earth, 271, 272 Deacon, G. F., relation between ve- locity and amount of ma- terial carried by streams, 33 Debris cliff, 30 Decomposition, effect of, on loss of constituents of rock, 22 of organic matter by drainage, 225 of rocks, 11 by acids, 19 by animals, 25 by plants, 25 through solution, 22 Deep-rooting crops, effect of, 345 on water capacity of soil, 231 Deherain, effect of agration on nitri- fying bacteria, 320 loss of nitrates by leaching, 322 Denitrification, nitrates lost by, 323 426 INDEX Density, with surface tension of solutions, 20G Deoxidation, 21 Deposits, eolial, S3 glacial or ice-laid, chapter on, 41 Determination of humus, 156 Diabase, 7 Dialysis and diffusion, colloids, crys- talloids, 131 of colloids, 130 Diffusion, factor in aeration, 311 temperature for, 298 Digestibility of feeds, 162 Diorite, 7 Disintegration by plants, 19 by waves, 18 by wind, 18 of rocks, 11, 32 Distribution of alkali, vertical and horizontal, 281 of irrigation water, 268 Ditches, open drains, 226 Dobeneck, hygroscopic moisture in relation to relative humidity, 196 Dolomite, calcium magnesium car- bonate, 5 Dorsey, C. W., reclamation of alkali land by underdrainage, 289 alkali at Maryland station, 290 Drain gages, 220 Drainage, chapter on, 222 benefits of, aeration improved, 223 alkali, rise of, prevented, 226 decomposition and nitrifica- tion increased, 225 erosion decreased, 226 granulation improved, 222 heaving reduced, 225 moisture, available, in- creased, 222 stability increased, 222 temperature raised, 225 effect of, on «fermination and growth, 223 on soil temperature, 301 from 8 feet of saturated sand, 221 types of, open or ditches, 226 tile, 228 Drains, see Drainage Drills, seeders, 337 Drumlins, 44 formation of, 45 Dry-farming, crops for alfalfa, 253 barley, 251 corn, 251 emmer, 252 kafir, 252 milo maize, 252 oats, 251 potatoes, 253 rye, 251 sorghum, 252 spelt, 252 wheat, 250 deep, medium-grained soil well adapted to, 243 Dry-land agriculture, chapter on, 238 Dumont, effect alkaline carbonate on nitrate production, 321 Dunes, clay, sand, silt, 53 permanent or fixed, 55 wandering, migatory, 54 Dupr6, with Lynde, capillary pull, 211 osmosis in soils, 212 Dust and loess, physical analysis of, 64 storm, 54 volcanic, 65 Dynamiting of soils, 345 Earth, composition of, 2 dam for filling gullies, 371, 372 Earth's crust, elements of, 1 Earthworms, aid in soil formation, 315 effect of, on soil, 25 Eel-grass, 37 Elements of earth's crust, 1 plant food, 390 Electrical behavior of colloids, 133 Elutriator, method of physical analy- sis, SchSne, 124 churn, Hilgard's 126 centrifugal, Yoder's, 128 Eolial deposits, or wind-laid soils, 53 adobe, in part, 64, 65 loess, 60-64 sand, 53-64 volcanic dust, 65 Eroded hill lands, yield from, 360 soil once forested, China, 359 Erosion, chapter on, 357 cause of, rainfall, character of, 359 texture and structure of soil, 358 INDEX 427 Erosion, cause of, topography, effect of, 358 vegetative covering;, 359 checked by brush, 372 decreased by drainage, 226 by organic matter, 150 headwater, 372 in pasture, 370 kinds of, sheet, 361 gullying, 369 of streams, 16 old-field in Mississippi, 370 organic matter lost by, 151 results of, color of soil changed, 361 organic matter and nitrogen removed, 360 physical character of soil changed, 360 sheet, methods of prevention and reclamation, contour seeding, 365 crops, protection by, 361 deep contour plowing, 364 limestone, application of, 361 organic matter, in- creasing, 363 reforesting, 369 residues, 363 terracing, 365 tiling, 369 Eruptive rocks, 6 Esker, Adeline, 44 material composing it, 45 formation of, 45 Evaporation, effect of, on soil tem- perature, 300 factor in adaptability of a re- gion to dry farming, 241 from a free-water surface and rainfall, 241 large loss from, in dry farm- ing, 243 loss by, effect on transpira- tion, 191 of water, cools soil, 296 prevented by mulches, 232 rainfall and, Bothamsted, 211 rainfall and percolation, Roth- amsted, 220 retarding of, factor in cropping alkali land, 285 Everglades, Florida, 29 Exfoliated granite in California, 13 Expansion, enormous, due to hydra- tion, 2i due to oxidation, 21 of rocks, 13 Expressing moisture content, ways of, 191 Fall plowing;, 342 Fallow, continuous vs. after, wheat yields, Montana, 248 Fallowing, loss of organic matter by, 153 Farm land, value per acre, 410 property, value per acre, 411 Feeds, digestibility of, 162 Feldspars, 3 composition of, 3 Fermentation in manure, factor in loss of organic matter, 164 Fertility in Illinois soils, 394-396 Films and waists of water about particles, 200 thickness of, in soil column, 201 Fine sandy loams, 116 Fippin, E. O., with Lyon, T. L., sur- face tension and density of cer- tain solutions, 206 Fires, organic matter lost by, 152 Fischer, carbon dioxide in rain and snow water, 20 riocculation, effect of ammonia, lime, gypsum, sodium carbon- ate on, 137 or coagulation of clays, 137 Flooding orchards, basin system, 270 Florida everglades, 29 Flow of water, comparison between computed and observed, 129 Food for bacteria, 319 Forbes, R. H., value of material car- ried by Salt River, 262 Forest, being buried by sand dune, 55 resurrected, 55 Fragmental deposits, 8 Freezing and boiling points, col- loids, effect on, 131 and thawing, 14 effect on water-logged soil, 223 Furrow irrigation of potatoes, 271 Geological classification of soils, 72 Georgeson, influence of manure on soil temperature, 294 Germination and growth, effect of drainage on, 223 limit of alkali for, 284 temperature for, 296 428 INDEX Gilbert with Lawes, transpiration, 188 Glacial and loessial province, 84 drift, gravelly phase, 41 grooves, strise, 43 lake and river terrace province, 89 lakes, 50, 51 extent of, 46 or ice-laid deposits, chapter on, 41 period, 45 scratches on boulder, 42 stream, alluviation by, 62 Glaciation, extent of, in North America, map of, 46 in Europe, map of, 48 Glaciations, IlUnoisan, 47 lowan, 48 Jerseyan or Nebraskan, 46 Kansan, 46 Wisconsin, Early, 50 Late, 50 Glacier, Chenega, 41 Columbia, front, 15 over-riding forest, Alaska, 14 defined, 16 factor in weaUiering, 15 incidental features, 50 pressure of ice, 16 Graml CaSon, Colorado River, 17 Granite, 7 exfoliated, California, 13 wind-carved, 18 Granulation, effect of drainage on, 222 of organic matter on, 148 of, on percolation, 218 Grass, beach or Marram, transplant- ing, 56 bunch, holds sand, 60 Gravel and gravelly loams, 139 Gravelly loams, 116 Gravels, 116 Gravitational water, chapter on, 217 Gravity-laid soils, 30 Great Basin region, 106 Plains region, 100 Green manures, 160 Growth and germination, effect of drainage on, 223 color of soils on, 303 of plants, limit of alkali for, 284 temperature for, 297 Guide-row terrace, 365 Gulf Coastal Plains, and Atlantic, 91 Gullying, methods of prevention and filling, dams, 371 soil, 374 straw and brush, 370 vegetation, 374 Gypsum, 5 Haberlandt, time required for ger- mination at different tempera- tures, 297 Hall, A. D., rainfall and evapora- tion, Kothamsted, 211 table, rainfall, percolation, evap- oration, Kothamsted, 220 temperature of soil for growth, 298 yield of wheat with percolation large and small, 153 Hardness of minerals, 2 Hardpan, 69 effect of, in alkali lands, 290 Harrows, acme or blade, 333 disk, 334 spike-tooth, 331 spring-tooth, 332 Hay and pasture province, rotation for, 386 Heat, absorption and radiation of, effect on soil temperature, 302 and cold, factor in disintegra- tion, 12 conduction downward into soil, source of loss, 296 soil, sources of, 293 specific, affecting soil tempera- ture, 298 effect of moisture on, 300 of common substances, 299 of soil constituents, 299 of soils, 300 to penetrate soil, time for, 306 Heaving, due to lack of drainage, 225 of alfalfa, 226 "Heavy" soil, defined, 134 Hellriegel, water transpired per pound of dry matter, 188 Hematite, 5 Hilgard, E. W., changes in organic matter, 146 chum elutriator, 126 composition of salts in alkali spot, 282 of typical alkali salts, 280 effect of various substances on hygroscopic capacity, 195 INDEX 429 Hilgard, E. W., fertility in Russian soils, 392 force exerted by roots in pene- trating soil, 19 grades of soil particles, system of, 124 highest amount of alkali with plants unaffected, 284 hygroscopic capacity of soils, 194 nitrogen content of humus, 194 on use of liygroscopic moisture, 198 roots and humus in Russian soils, 144 vertical distribution of alkali, 281 Hopkins, C. G., grades of particles, system of, 124 production of sweet clover per acre, 173 Humid and arid subsoils, 70 regions, alkali of, 290 soils, 75 nitrogen in humus of, 147' Humidity, affecting hygroscopic moisture, 196 Humification, progress of, 146 Hummocks, called bogs, 30 Humus, defined, 142 determination of, 156 in Chernozem soils, 144 nitrogen content of, 147 Hydration, 21 Hydrochloric acid, decomposition by, 20 Hygroscopic capacity of soils, 194 coefficient from other constants, formula:, 197 of soils, 196 relation to wilting coefficient, 197 moisture, affected by colloids, 195 by humidity, 196 by organic matter, 196 by size of particles, 194 by temperature, 195 chapter on, 194 use of, 197 Ice-laid deposits, chapter on, 41 Igneous rocks, 6 Ignition, loss on, 154 Implements of tillage, compacters, 335 Implements of tillage, cultivators, 337 harrows, 332 listers, 332 plows, 327 seeders, 337 Insects, controlled by rotation, 377 mix soil, 315 Interglacial stages, Aftonian, 46 Peorian, 48 Sangamon, 47 Yarmouth, 46 Internal area or surface, 181 Intrusive rocks, 6 lowan glaciation, 48 important loess deposit con- nected with, 62 Irrigated land, crops for, alfalfa, 275 cereals, 273 forage crops, 275 fruits, 275 sugar beets, 275 vegetables, 275 Irrigation, chapter on, 257 by overhead spray or sprink- ling, 272 canals lined with concrete, 258 cultivation after, 273 effect of, on rise of alkali, 281 in humid climates, 275 methods of, flooding, 270 furrow, 271 sprinkling or overhead sprays, 272 sub-irrigation, 272 potatoes by furrows, 271 preparation of land for, 259 projects in United States, 257 in varied quantities, yield of dry matter, 264 sources of, diversion of streams, 258 pumping from streams or canals, 259 reservoirs, 259 subterranean supply, 259 water, character of, 261 time of, 263 Illinois soil survey, 112 Illinoisan glaciation, 47 Jardine, W. M., yield of milo maize, Texas, 253 Jerseyan or Nebraskan glaciation, 46 Johnson, S. W., carbon dioxide in fioil air,- 20 430 INDEX Karnes, formation of, 45 Kansan glaciation, 46 Karraker, substances in solution play little part in capillary move- ment, 205 Keewatin center of accumulation, 45 King, F. H., amount of soil carried, Mississippi River, 35 aspirator, 128 computed surfaces of soil par- ticles of different kinds of soil, 181 depth of mulches, 235 difference in temperature due to slope, 305 effect of drainage on tempera- ture, 224 effect of windbreak on evapora- tion, 301 manure in surface causes rise of water into upper three feet, 212 movement of moisture from wet to dry soil slow, 203, 204 rain caused rise of water from subsoil, 205 sampling tube, 119 spring discharge greater with falling barometer, 219 water evaporated with water table at varied depths below surface, 210 water used per pound of dry matter, 188 weight of particles with film of water, 33 Lahradorean center of accumula- tion, 45 Lacustrine soils, 37 Lake Agassiz, 38 beds, 37 Chicago, 38 level floor with distinct shore line, 37 filling with peat, method of, 29 Maumee, 38 terraces and beaches, 37 Lakes, ox-bow, 28 Lands, alkali, 273 value of, 290 preparation of, for irrigation, 259 surface lowered through solu- tion of limestone, 24 Lang, specific heat of soil constit- uents, 299 Lapham, J. E. and M. 206 Lyon, T. L., and Fippin, E. 0., sur- face tension and density of certain solutions, 206 Lynde and Duprd, capillary puU, 211 osmosis in soils, 212 Lysimeters or drain gages, 220 Macro-organisms, insects, 315 plants, 316 rodents, 315 worms, 315 ;nesia in prairie compared with timber soils, 75 and lime in soils, 75 Magnesium carbonate, dolomite, 5 Magnetite, 6 Maintaining and increasing organic matter in soils, chapter on, 158 Major crops, defined, 376 Mangrove marsh, Florida, 37 Mangum terrace, 366, 367 Manure, barnyard, 161 conserved by use of absorbents, 165 farmyard, influence of, on soil temperature, 294 nitrogen content of, 399 fresh, composition of, 163 green, 160 loss of, and its prevention, 163 by fermentation, 164 by leaching, 164 organic matter, in rotting of, 163 methods of applying, 168 of handling, 165 solid and liquid, value of, ex- creted by farm animals, 162 spreader in action, 167 steer, composition of, after ex- posure, 166 value of increase due to, per ton, 168 Marbut, C. F., and others, area re- sidual soils in United States, mapped, 27 Bureau of Soils, soil survey, 78 Marine soils, 36 Marl, 8 Marram, or beach grass, transplant- ing, 56 Marsh, marine, section of, 36 mangrove, Florida, 37 Marshes, early stages of formation, map, 36 defined, 27 Martin, F. O., and others, chromic acid method, 154 Material in solution in streams, 24 Maumee, Lake, 38 Maximum water capacity of soils, 209 McLane, with Briggs, moisture equivalent centrifuge, 202 Meadows, hold soil against erosion, 361 Measurement of irrigation water, 268 432 INDEX Mechanical analysis, methods of, 124-128 or physical analysis, 123 Merrill, 6. P., composition of feld- spars, 3 expansion of granite by hydra- tion, 21 glass ground by wind-borne sand, 10 table, chemical analyses of loess, 65 on lo^ of constituents of rocks, 25 physical analysis of dust, 64 Merrill, L. A., yield of wheat for different depths of plow- ing, 245 methods of seeding, 254 Metamorphic rocks, 10 Methods of soil survey, 118 Mica, black, biotite, 4 white, muscovite, 4 Micro-organisms, injurious, 317 beneficial, 317 Migratory sand dunes, 58 Miller, M. F., plant food in Mis- souri soils, 392 Mineral colloids, 132 constituents of soils, chapter on, 123 content of soils, 74 phosphorus-bearing, apatite, 5 soil constituents and their prop- erties, 129 Minerals, dissolved by carbonated water, 22 hardness of, 2 iron-bearing, hematite, magne- tite, limonite, 5, 6 soil forming, 1 specific gravity of, 175 Minor crops, 376 Mississippi River, soil material de- livered at mouth, 35 Moisture, available, 214 increased by drainage, 223 capacity of soil, methods of in- creasing, compacting soil, 230 deep rooting crops, 231 organic matter, 231 tillage, 230 control of, chapter on, 222 by tillage, chapter on, 230 content, ways of expressing, 191 Moisture content, ways of express- ing, acre-inches, 192 cubic inches, or per cent of volume, 192 per cent of weighit of soil, 191 decreasing, losses from soils, 232 effect of, on specific heat, 300 equivalent, defined, 202 determination of, from other constants, formulae for, 203 equivalents of some soil classes, 202 excess of, removed by tillage, 231 factor in amount of organic matter in soils, 143 soil classification, 73 for bacteria, 319 -holding capacity of soils, 209 hygroscopic, chapter on, 194 in soil columns, 201 retained by organic matter, 149 storing and conserving by till- age, 326 supply in soils, 189 Moraine, terminal, 43 Morrow, G. W., results of root prun- ing in shallow and deep cultiva- tion of com, 355 Moss, sphagnum, 28 Mucks, 114 specific heat of, 300 Afud flow, Colorado, 34 Miiller, Richard, solution of min- erals, 22 Mulch, defined, 233 depth of, 235 fineness of, 234 maintenance of, 236 soil effectiveness of, 235 value of, for corn, humid re- gions, 350 Mulches, permit little loss of water by interstitial evaporation, 233 Muscovite, white mica, 4 Nebraskan glaciation, or Jerseyan, 46 Nelson, J. B., with Atkinson, storing rainfall, Montana, 248 Newell, Dr. F. H., directed large irrigation projects, 258 Nitrates lost from soil by leaching, 322 by denitrification, 323 INDEX 433 Nitrate production, effect of potas- sium carbonate upon, 321 Nitric acid, amount brought to earth, Rothamsted, 20 decomposition by, 20 Nitrification, 317' increased by drainage, 225 loss of organic matter by, 152 temperature for, 2'98 Nitrogen, 393 commercial forms of, ammonium sulphate, 399 calcium cyanamid, 400 organic substances, 400 sodium nitrate, 399 content of humus, 147 fixation, 317 furnished to crops by organic matter, 151 in fertilizing materials, 405 in humus from different mate- rials, 147 lost by erosion, 360 Non-tilled crops, factor in main- taining organic matter, 171 Northwestern International Re- gion, 105 Number of particles, 178 Dats production, 1909, 414 seed bed for, 349 Objects of a. soil survey, 117 Oblique arrangement of particles, 180 Odor of soils, 177 Optimum water content, defined, 212 Organic colloids, 132 constituents of soils, chapter on, 142 matter, addition of, as sweet clover, 172 affecting capillary movement, 206-208 hygroscopic moisture, 196 and fertility, loss of, in rotting of manure, 163 and nitrogen, lost by erosion, 360 changes of, 145 comparison, chromic acid and combustion methods, 155 defined, 142 distribution of, in soil strata, 147 effect of, on percolation, 218 on shrinkage, 130, 135 in sweet clover, 173 28 Organic matter increased by plowing under legumes, 172 increases moisture - holding capacity, 231 increasing amount of, aid in checking erosion, 363 in soils, amount of, depends on altitude, 145 on latitude, 145 on limestone, 145 on moisture, 143 on vegetation, 144 kinds of, active, coal-like, inert, 142 loss on ignition compared with, 154 losses of, by cropping, 151 by erosion, 151 by fallowing, 153 by fires, 152 by l-eaching, 152 by quicklime, 152 methods of estimation of, 153 chromic acid method, 154 combustion in oxygen, 154 loss on ignition, 154 maintaining, accumulations in pastures, 160 barnyard manures, 161 catch and cover crops, 161 green manures, 160 limestone, addition of, 158 non-tilled crops, growing of, 171 organic residues, use of, 170 phosphorus, application of, 159 rotation of crops, 171 of soils, maintaining and in- creasing, chapter on, 158 turning under and incorpo- rating with soil, object of tillage, 325 residues, 170 substances lower surface ten- sion, 205 source of nitrogen, 400 Organisms, soil, chapter on, 315 beneficial, 317 injurious, as plant diseases, 317 Origin of alkali, 278 of soil material, 1 434 INDEX Osborne, grades of particles, 124 Osmosis, temperature for, 298 Osmotic pressure, sugar solution, 131 Ox-bow lakes, 28 Oxidation, 20 expansion caused by, 21 loss of organic matter by, 152 Oxygen, combustion in, determina- tion of organic matter, 154 Packing, subsurface in dry farming, 247 Pacific Coast Region, 107 Particles, colloid, size of, 130 soil, and their separation, 123 arrangement of, 179 number of, 178 shape of, 178 size of, affecting hygroscopic moisture, 194 Pastures, accumulations in, aid in maintaining organic-matter content, 160 hold soil against erosion, 361 Patten, H. E., specific heat of soils, 300 effect of moisture on specific heat, 300 Pearce, J. B.., size of particles, 124 chromic acid method, 154 Peat, filling lake, 29 method of formation, 28 Peats, 114 Peaty loams, 114 Peorian interglacial stage, 48 Percolation, affected by atmospheric pressure, 219 by granulation, 218 by organic matter, 218 by physical composition of soil, 217 by roots of plants, 219 by shrinkage cracks, 219 by viscosity of water, 219 defined, 217 evaporation, rainfall, Kotham- sted, 220 large and small, effect of, on yield of wheat, 153 loss of, by water, in dry farming, 242 source of loss pf water, 232 Pfeffer, osmotic pressure, sugar solution, 131 Phosphate, rock, and limestone, ef- fect on growth of clo- ver, 159 on wheat, 401 Phosphorus, application of, aid in producing organic matter, 159 forms of, acid phosphate, 402 basic slag, 402 bone meal, 400 compared, 402 rock phosphate, 400 in fertilizing materials, 405 Physical agencies of weathering, 12 analyses of loess and dust, 64 analysis, methods of, 124 aspirator. King's, 128 centrifugal. Bureau of Soils, 127 elutriator, Yoder's, 128 churn elutriator, Hilgard's, 126 elutriator, Schone, 124 sieve, 124 subsidence, 124 systems of, 124 changes, source of soil heat, 294 character of soil changed by ero- sion, 360 of water, 186 composition of soil in relation to bacteria, 321 affecting percolation, 217 of soils, varied, effect of, on porosity, 184 condition of soil, effect of al- kali on, 280 or mechanical analysis, 123 properties of soils, chapter on, 175 apparent specific gravity, 175 arrangement of particles, 179 color, 176 internal area or surface, 181 odor, 177 number of particles, 178 porosity, 182 real specific gravity, 175 shape of particles, 178 weight, 176 Pines growing on sand, 60 Placing of soil material, chapter on, 27 INDEX 435 Plant diseases controlled by rota- tion, 377 food, crop requirements, 390 elements of, 390 in crops, 390 in Illinois soils, surface, 394 subsoil, 396 subsurface, 395 in Missouri soils, 392 in residual soils, 392 in Russian soils, 392 locked up in mulches, 236 supply in soils, 391 Planting seed accompanied by some tillage, 326 Plants, amount of water required by, 187 disintegration by, 19 effect of alkali on, 282 on rocks, 24 remains benefit soil, 316 water requirements, 241 Plasticity of clays, 135 Plow, an early form of, 340 pan or sole, 70 theoretical action of, 327 Plowing, 340 deep, and turning under alkali, 286 contour, aid in checking ero- sion, 364 tilling, 345 depth of, 344 fall, desirable in dry farming, 246 good, essentials of, 341 sod well turned, 341 poor, crooked furrow, 342 subsoiling, 345 time of, 342 fall, 343 spring, 344 yields of wheat for different depths of, in dry farming, 245 Plows, deep tilling double disk, 331 disk, 329 general purpose, 328 lister, 332 sod, 329 stubble, 328 subsoil, 332 Plutonic rocks, 6 Pore space, amount of in soils, 180 Porosity, different grades of sand, 183 of soils, 182 Porosity of soils, of varied physical composition, 184 Potassium, 403 effect of, on com on swamp land, 404 in fertilizing materials, 405 Potatoes, on dry farm, 253 Pott, H. E., relative conductivity of soil material, 306 Prairie areas of United States, 70 soils, 76 Precipitates, chemical, 8 Precipitation, map of United States, 190 on earth's surface, 189 source of soil heat, 294 Preparation of seed bed, 345 Press drill, 337 Pressure, atmospheric, changes in, factor in aeration, 311 of waves, 18 Prestwich, lime carbonate carried by Thames River, 23 Prevention of loss of manure, 163 Properties, physical, of soils, chap- ter on, 175 Puddling of clays, 136 prevented by organic matter, 150 Pulverizing and loosening soil, an object of tillage, 325 Pumping water for irrigation, 259 Pyroxene, 3 Quaking bog, 28 Quartz, 2 Radiation, factor in loss of soil heat, 295 from sun, source of soil heat, 293 of heat, effect of, on soil tem- perature, 302 ratio, different colored soils, 295 Rainfall, affecting transpiration, 189 and evaporation from free-water surface, 241 Rothamsted, 211 and snow, precipitation on earth's surface, 189 character of, effect on erosion, 359 factor in value of region for dry farming, 238 map of United States, 190 percolation, evaporation, Roth- amsted, 220 436 INDEX Kainfall, storing of, in dry farming, 247 types of, over dry-land area of United States, 239 Beaction, alkaline, of soil desirable for bacteria, 320 Keade, rate of lowering of land sur- face by solution, 24 Real or absolute specific gravity, 175 Beclamation of alkali lands, chap- ter on, 278 Redding, R. J., depth of plowing for cotton on eroded land, 364 Reforesting stops erosion, 369 Reservoirs, storing water for irriga- tion, 259 Residual soils, 27 Residues, organic, 170 return of, aid in preventing ero- sion, 363 Resurrected forest, 55 Rhyolite, 7' River Flood Plains province, 97 sediments, composition of, 262 swamps, 28 water, suspended matter in, 262 Rock disintegration and talus slope, 32 outcrop, 116 phosphate, 400 split by tree, 19 weathering of jointed, 31 Rocks, 6 aqueous, 7 decomposition and disintegra- tion of, 11 eruptive, 6 expansion of, on heating, 13 igneous, 6 intrusive, 6 loss of constituents through de- composition, 22 metamorphic, 10 plutonic, 6 volcanic, 6 weathering of, chapter on, 11 Rocky Mountain and Plateau Re- gion, 104 Rodents, mix surface and subsoil, 315 Rogers Brothers, dissolved minerals in carbonated water, 22 Rollers, 335 to 337 Roosevelt dam, 260 Root injury, 353 pruning of corn, results, 355 Root systems, depth of, varied in ro- tations, 378 Roots and tops, legumes, compo- sition of, 398 force exerted by, 19 in Chernozem soils, 144 of plants aid percolation, 220 tree prying rock apart, 19 Rotation, chapter on, 376 advantages of, better distribu- tion of work, 377 control of insects and plant diseases, 377 of weeds, 377 compared with continuous corn, Iowa, 379 effect of, on crop yields, Illinois, Ohio, Minnesota, 379, 380 for corn and winter wheat belt, 382 cotton belt, 384 ■ spring wheat belt, 386 helps maintain good tilth, 378 organic matter, 378 produces larger yields, 378 renders toxic substances less harmful, 378 variation in depth of root systems, 378 of crops, aid in maintaining or- ganic matter, 171 place for crops in, 381 planning of, 380 Rotmistrov, weeds enemy of culture, friends of drought, 244 water not raised far by capil- larity at Odessa, 210 Run-oflF, cause of loss in dry farm- ing, 242 Russell, origin of adobe, 65 Sage brush on land well adapted to dry farming, 239 Salts, soluble, in soils, 74 Sampling of soils, 120 tube, King's, 119 Sand dune, burying forest, 55 wind ripples on, 56 dunes, migratory or wandering, 54, 58 permanent or fixed, 64, 55 held by, black locusts, 59 bunch grass, 60 partridge pea, 59 pines, 60 sensitive plant, 59 INDEX 437 Sand dunes, held bj trailing wild bean, 60 vegetation, 57 movement checked by fences, 58 porosity of difi'erent grades, 183 Sands, 116 and sandy loams, properties of, 139 radiation ratio of different colors of, 295 temperature of, effect of color on, 302 Sandstones, 8 8andy loams, 116 Sangamon interglacial stage, 47 soil, 49 Schlosing, relation, nitrates formed to oxygen, 320 Schone's elutriator method, physical analysis, 124 Schreiner, 0., and Brown, E. E., progress of humification, 146 Sedentary formations, 27 Sediment carried in suspension by rivers, 35 Sedimental soils, 33 classes of, 36 Sedimentary, fragmental, 8 Seed, acclimated, necessary in dry farming, 255 bed, preparation of, for corn, 348 for oats, 349 for wheat, 346 Seeders, 337 Seeding, different methods of, yield wheat on dry land, 254 on dry land, 254 rate per acre, Colorado, 255 Shaler, wave action. Cape Ann, Massachusetts, 18 Shales, 8 Shantz, H, L., see Briggs Shape of particles, 178 Shrinkage, affected by colloids, 132 cracks, 136 effect of, on percolation, 219 physical composition of, 135 of soils, 135 different types of soil, 133 Sieve method, physical analysis, 124 Silica, 2 Silt and silt loams, properties of, 138 dunes, 53 Silt loams, 115 Sink holes, 22 in cave region, 24 ponds, produced when outlet is clogged, 24 Size of soil particles, effect of, on capillarity, 201 Slope of land, effect of, on soil tem- peratures, 305 Snyder, loss of organic matter in forest fires, 152 nitrogen in humus from vari- ous materials, 147 Sodium nitrate, 399 Soil — soils air and aeration, chapter on, 309 carbon dioxide in, 20 composition of, 310 clluvial, 38 amount of air in, 309 of organic matter in, 142 and subsoil, chapter on, 67 are they inexhaustible? 289 arid, 74 auger, 119 Bureau of, classification, chap- ter on, 78 carried in suspension by rivers 35 capillary or moisture-holding capacity of, 209 pull of, 211 character of, factor in its adapt- ability to dry farming, 241 Chernozem, roots and humus in, 144 class, defined, 79 classes in Illinois, 112 clay loams, 115 clays, 114 gravels, 116 gravelly loams, 116 loams, 115 mucks, 114 peats, 116 peaty loams, 116 sands, 116 sandy loams, 116 fine, 116 silt loams, 115 classification of, chapter on, 72 colloids in, 132 colluvial, 30 color of, 176 effect on time of srermination, 304 438 INDEX Soils, compacted by tillage, 326 conductivity of, effect on tem- perature, 305 constituents, capillary lift of, 212 specific heat of, 299 cumulose, 27 deep, , medium-grained, well aidapted to dry farming, 243 definition of, 1 effect of alkali on physical con- dition of, 280 of color of, on growth, 303 on transpiration, 191 eolial, 53 erosion, chapter on, 358 fertility, appendix I, 389 -forming minerals, 1 glacial, 41 gravelly, not well adapted to dry farming, 240 gravity-laid, 30 gullies filled with, 374 heat, loss of, by conduction downward into soil, 29G by convection currents of air, 296 by evaporation of water, 296 by radiation, 295 sources of, 293 chemical changes, 294 physical changes, 294 precipitation, 294 radiation, direct from sun, 293 "heavy," "light," defined, 134 humid, 75 hygroscopic capacity of, 194 coefficient of, 196 Illinois, fertility in, 394 Kentucky, 393 lacustrine, 37 lime and magnesia in, 75 marine deposits, 36 material and its origin, chapter on, 1 placing of, 27 relative conductivity of, 306 methods of increasing moisture capacity of, 230 mineral constituents of, chap- ter on, 123 content of, 74 Missouri, 392 mulch, defined, 233 mulches, effectiveness of, 235 Soils, odor of, 177 organic constituents of, chap- ter on, 142 organisms, chapter on, 315 particles and their separation, 123 held together by organic mat- ter, 151 surfaces of, in different soils, 181 physical character of, changed by erosion, 360 properties of, chapter on, 175 plant food, supply in, 391 porosity of, 182-184 prairie, 75 provinces, area surveyed to 1915, 78 regions, area surveyed to 1915, 78 residual, 27 plant food in, 392 running together hinders aera- tion, 313 samplers, 1 19 sampling of, 120 Sangamon, 49 sedimental, 33 classes of, 36 series. Bureau of Soils, 79-111 shrinkage of, 133, 135 soluble salts in, 74 specific heat of, 300 strata, distribution. of organic matter in, 147 thickness of, 120 weight of, 120 stream-laid, 38 subsurface, 67 surface, 67 survey by rsureau of Soils, chap- ter on, 78 by Illinois Experiment Sta- tion, chapter on, 112 methods of, 118 objects of, 117 surveys, 116 temperature, chapter on, 293 conditions affecting, 298 absorption and radiation, 302 color, 303 conductivity, 306 drainage, 301 evaporation, 300 INDEX 439 Soils, temperature, conditions af- fecting, latitude or angle of sun's rays, 304 slope, 304 specific heat, 298 tillage, 307 water, presence of, 302 for growth, 298 for vital functions of plants, germination, 296 growth, 297, 298 nitrification, 298 osmosis and diffusion, 298 influenced by liquid water, 295 by manure, 294 raised by absorption of water vapor, 294 ten-year average, 307 texture and structure of, effect on erosion, 358 timber, 76 time for heat to penetrate, 306 top, 67 type, defined, 79 types, classes and phases in Illi- nois, 114 defined, Illinois, 112 internal area of, 182 naming of, 113 ventilation, see aeration, 311 water of, 186-222 water-laid, 33 water-logged, 313 weight of, 176 Sole, plow, 70 Solid manure, value of, excreted by farm animals, 162 Solution, decomposition by, 22 Specific heat of water, 187 gravity, apparent, 175 of soil-forming minerals, 175 real or absolute, 175 Sphagnum moss, 27, 28 Spring plowing, 344 wheat, acreage, 1909, 415 region, rotation for, 386 Stability of soil increased by drain- age, 222 Stalactites, stalagmites, in cavern, 23 Stones, 139 Stony loams, 116 Storm, dust, 54 Straw, used in filling gullies, 370 Streams, diversion of, for irriga-: tion, 258 erosion of, 16 -laid soils, 38 material carried and rolled bv, 16 ' work of, affected by velocity of current, 16 Striae, glacial, on rock surface, 43 Structure of soil, effect on erosion, 358 Sub-provinces, classes, types, sur- veys, chapter on, 112 Subsidence method, physical analy- sis, 124 Subsoil, 68 plow, 330 soil and, chapter on, 67 Subsoiling, 345 Subsoils, arid and humid compared, 70 Substances in solution, effect on vis- cosity, 205 Subsurface packing, 247 soil, 67 Sugar beets, returns from thirty inches of water, 266 Sulfuric acid, decomposition by, 20 Surface, internal, 181 soil, 67 tension, affecting capillarity, 199 and density of solutions, 206 Survey, soil, by Bureau of Soils, chapter on, 78 by Illinois Experiment Sta- tion, chapter on, 112 methods of, 118 objects of, 117 Surveys, soil, 116 in different states, 117 Swamp, ablation, 30 land, typical Eastern, 29 wet woods, 30 Swamps, defined, 27 river, 28 Sweet clover on badly eroded land, 361 plowed under, 172 quantity grown per acre, 173 Syenite, 7 Systems of physical analysis, 124 Talus, 30 slope, 32 Temperature, chapter on, 293 440 INDEX Temperature, affecting hygroscopic moisture, 195 viscosity, 204 changes, factor in aeration, 312 climate, factor in soil classifica- tion, 73 effect of, on capillary rise of water, 204 for bacterial development, 320 germination, 296 table of. 297 growth, 297 nitrification, 298 osmosis and diffusion, 208 of plowed and unplowed land, 312 sands, effect of color on, 302 soil, conditions affecting, 298 influenced by manure, 294 raised by drainage, 224 by organic matter, 150 soil, ten-year average, 307 time required for radicle to ap- pear at different, 297 Tenacity of soils, 134 Terminal moraine, formation of, 45 topography of, 134 Terrace, glacial lake and river prov- ince, 89 near Bockford, Illinois, 38 Terraced park, Mississippi, 367 Terraces in China, 364 kinds of, guide-row, 365 level beach, 366 Mangum, 366, 367 method of formation, 39 of Frazier River, 38 Texture of soil, affecting capillary movement, 206 percolation, 217 effect of, on erosiob, 358 factor in soil classification, 77 in relation to bacteria, 321 Thawing and freezing, 14 Thickness of film affecting capillary movement, 203 Thome, C. E., composition of steer manure after three months' ex- posure, 166 Thysell, J. C, summer tillage with alternate cropping vs. continuous cropping, 250 Tight clay, 68 Tile drainage, effect of, on topog- raphy of water table, 228 Tile drains, 228 Tiling, aid in ch«cking erosion, 369 Tillage, chapter on, 325 control of moisture by, 230 deep, in dry farming, 245 effect of, on soil temperature, 307 factor in aeration, 313 increases moisture capacity, 230 objects of, compacting soil, 326 killing weeds, 326 planting seed, 326 pulverizing and loosening soil, 325 storing and conserving moist- ure, 326 turning under vegetable mat- ter, 325 removal of excess of moisture by, 231 summer, in dry farming, 246 with alternate cropping, com- pared with continuous cropping yields, 250 Tilling, deep, 345 Tilth, rotation helps maintain, 378 Timber areas of United States, 76 soils, 76 Time for germination affected by color of soil, 304 at different temperatures, 297 Top soil, 67 Topography, effect of, on erosion, 358 Toxic substances less harmful in rotations, 378 Trachyte, 7 Transpiration, dependent upon evaporation, 191 soil, 191 supply of moisture, 189 from plants, large loss of wa- ter, 232 of water per pound, dry matter produced, 188 source of loss in dry farming, 244 Transported formations, 30 TuU, Jethro, "tillage is manure,'' 325 Type, soil, defined, 79 Illinois, defined, 112 Udden, J. A., estimate, dust carried in air, 53 Uloth, plants germinated on ice, 296 INDEX Ml Value of increase for manure per crop and ton, 168 organic matter to soils, 148 binds soil particles to- gether, 151 biological effects, 150 erosion, loss by, pre- vented, 150 furnishes nitrogen, 151 granulation affected, 148 moisture retained, l49 puddling prevented, 150 temperature raised, 150 Van Slyke, L. 