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. 29S 

 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 Rockford, 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 erosion, 358 

 factor in soil classification, 77 

 in relation to bacteria, 321 

 Thawing and freezing, 14 

 Thickness of film affecting capillary 



movement, 203 



Thorne, C. E., composition of steer 

 manure after three months' ex- 

 posure, 166 



Thysell, .1. 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 checking 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 ot loss in dry farming, 



244 



Transported formations, 30 

 Tull, 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 



