588 



INDEX OF SUBJECT MATTER 



Time, influence on absorption by soils, 

 269. 



Time of applying fertilizers, 495. 



Tolerance of plants to soil acidity, 353. 



Tramping, influence on farm manure, 

 524. 



Transpiration, factors affecting, 188. 



Transpiration ratio, defined, 187. 

 determination of, 187. 

 of different crops, data, 189. 



Transported soil, explanation of term, 28. 



Truog test for soil acidity, 358. 



Types of farming, influence on the main- 

 tenance of fertility, 558. 



Urea, ammonification of, 414. 



decomposition of in manure, 509. 



production of from calcium cyana- 

 mid, 250. 

 Unavailable water in soil, 198. 

 Unmixed fertilizers, purchase of, 484. 



use of, 484. 

 Utilization of ammonium in salts by 

 higher plants, 450. 



of organic compounds by plants, 



Variability of farm manure, 506. 

 Value of farm manure, agricultural, 513. 



commercial, 512. 

 Vegetables, fertilizer formulae for, 491. 

 Vegetation, resistant to alkali, 340. 

 Veitch method of determining the lime 

 requirement of soils, 356. 



procedure, 356. 



value of, 357. 

 Viscosity, effect on capillarity, 170. 

 Volcanic dust, as soil, 65. 

 Volume of soil air, 257. 



calculation of, 258. 

 Volume weight, determination of, 91. 



relation to specific gravity, 94. 

 Volume weight of soils, data, 93. 



explanation of, 91. 

 Water, alkali in river water, 332. 



availability of to plants, 198. 



deposition of sediment by, 46. 



diagrams of forms in soil, 199. 



effect on rocks by freezing, 23. 



erosive effects of, 204. 



function of to plants, 184. 



in farm manure, 501. 



Water, influence on concentration of soil 

 solution, 286. 

 influence on plants, 186. 

 intake of by plants, 289. 

 loss of from soil, 202. 

 loss of from soil by percolation, 



206. 

 loss of from soil by evaporation, 



216. 

 mechanical action of, 17. 

 methods of expression in soil, 156. 

 movement in soil, 168, 175, 182. 

 movement in soil in relation to 



plants, 193. 

 production of hydration by in soil, 



27. 

 relation of to granulation, 142. 

 required to mature a crop, 193. 

 use of alkali water in irrigation, 

 333. 

 Water requirements of plants, factors 

 affecting, 188. 

 investigations of, 189. 

 nature of, 187. 

 Water slaked lime, 364. 

 Water soluble phosphoric acid, defined, 



456. 

 Weathering, character of in arid regions, 

 30. - • 



character of in humid regions, 30. 

 defined, 16. 

 losses due to, 33. 

 of granite, 33. 

 of limestone, 33. 

 of soil, practical relations of, 37. 

 relation of to alkali, 331. 

 Weeds, killing of, 219. 

 Weight of soils, data of, 93. 

 Wilting, cause of, 194. 



explanation of, 194. 

 Wilting coefficient, calculation of, 198. 

 determination of, 196. 

 effect of texture on, 196. 

 explained, 195. 

 for different soils, 197. 

 Wind in soil formation, 19. 

 Wool and hair waste, composition of, 

 446. 



Zinc-sulfide test, criticism of, 360. 



for soil acidity, 358. 

 Zeolites, not present in soil, 265. 





