492 



INDEX 



Plant, carbohydrates in, 224. 



sugar in, 224. 



woodiness in, 226. 



sugar in, 226. 



color and flavor of, 227. 



cooking value, 228. 



composition of flour, 228. 



tillage and composition, 228. 



use of rainfall in production, 231. 



producing power of rainfall, 232. 



toleration for saline water, 387. 



tolerance for alkali, 392. 



tolerance of various plants for alkali, 



394. 

 Plant-food. See also Ash constituents. 



loss by drainage, 78, 79. 



added by water, 87. 



added by river sediments, 101. 



and water used by planting, 118. 



effect on water-cost, 139. 



and alkali, 390. 



Plowing, effect on water use, 120. 

 Plow, lateral, 427. 



made first irrigation furrow, 427. 



breaking, 419. 

 Plum, protein in, 221. 



sugar in, 225. 

 Poplars, 328. 

 Potatoes, ash in, 219. 



protein in, 221. 



yield due to rainfall, 234. 



under irrigation, 298. 



duty of water, 344. 



in humid climates, 411. 



early yield, 457. 

 Powell, 457, 458, 464, 471. 

 Protein, in various plants, 220. 

 Prunes, sugar in, 225. 

 Puddling, as ditch-lining, 377. 

 Pumpkin under irrigation, 307. 



Quantity of water in one irrigation, 23. 

 Quince, 314. 



Rainfall. See also Dry-farming. 

 annual, 1. 

 variations, 2. 

 seasonal, 2. 

 conservation, 3. 

 average, 3. 



use of in crop production, 231. 

 irrigation supplementary to, 231. 

 crop-producing power, 232. 

 crop value in irrigation, 233. 

 distribution of, 235. 

 conservation of, 235. 

 types of, 235. 



Rainfall, storage in soil, 236. 



proportion conserved, 237. 

 Raspberries, 326. 



protein in, 221. 



in humid climates, 410. 

 Reclamation Act, 460. 

 Red River, 96. 

 Rees, 230, 329. 



Registers for water measurements, 441. 

 Relative humidity, effect on evapora- 

 tion, 47. 



Reservoirs, seepage from, 371. 

 Response to irrigation, 159. 

 Rhine, 84, 97. 

 Rhubarb, 310. 

 Rice, under irrigation, 262. 

 Richman, 188. 

 Ridging, tools for, 439. 

 Rio Grande River, 91, 96. 

 Ripening, delayed by over-irrigation, 



251. 



River water, salinity of, 82. 

 Riverside, Cal., 197. 

 Roeding, 290, 313. 

 Rolling, 62. 

 Roman Empire, 449. 

 Roosevelt, 462. 

 Roots, absorption of water by, 109. 



effect on water use, 122. 



development in spring, 182. 



proportion of, 160. 

 Root crops under irrigation, 297. 

 Root-hairs, 109. 



Rotation, method of distribution, 361. 

 Run-off, 40. 



how to prevent, 41. 

 Rye, under irrigation, 255. 

 Rye-grass, 278. 



Sacramento, 408. 



Salt Lake City, 78, 455, 470. 



Salt River, 96. 



Sanborn, 187, 188, 468. 



San Joaquin River, 91. 



Saskatchewan River, 84. 



Schantz, 20. 



Schlichter, 405. 



Schultze, 74. 



Season, effect of, on water use, 123. 



time to irrigate short-seaaQd crops, 

 183. 



dry, 407. 

 Second-foot, defined, 331. 



equivalents, 332. 

 Sediments, cracked, 68. 



river, composition of, 101. 



physical effect on soil, 102. 



