INDEX 



Acre-foot, 239. 



Acre- inch, 239. 



Aermetor, windmill, 313; pump, 316. 



Air, in the soil, 7, 182; humidity, 40, 44, 

 50; required by clover, 49; by corn, 

 185; interferes with percolation, 333; 

 need of in soil, 182, 370, 418; lack of 

 in puddled soil, 334: changes in tem- 

 perature and pressure influence ven- 

 tilation, 420. 



Alfalfa, roots, 233; irrigation, 237, 346, 

 348 ; utilizing waste water, 379. 



Algeria, irrigation, 85, 238 ; duty of 

 water in, 212; artesian wells, 85. 



Alkali, composition, 278; accumulation, 

 223, 266, 270, 272, 274, 284; cause of in- 

 juries, 270, 416; accumulation by in- 

 tensive farming, 274, 284; amounts in- 

 jurious, 275, 278; develops soonest in 

 clay soil, 286 ; correction by land 

 plaster, 280, 284, 287; distribution in 

 soil, 282; influenced by tillage, 284; 

 influenced by roots, 284; cause of 

 abandonment of ancient irrigation 

 systems, 289; geographical distribu- 

 tion, 272; formed by canal seepage, 

 294 ; soils which soonest develop 

 alkali, 286; cause of puddling, 335. 



Alkali lands, 269, 416; alum spots, 269; 

 soluble salts, 269, 276 ; character of 

 vegetation, 281 ; land plasters, 280, 284 ; 

 improvement by drainage, 223, 284, 

 288; ultimate remedy drainage, 288. 



Alkali salts, 266; kills barley, 276; see 

 Alkali. 



Alkali water, unsuitable for irrigation, 

 266, 284, 285; correction before use, 

 287. 



Alum spots, 269. 



Animal power for irrigation, 328. 



Ants, work in soil ventilation, 419. 



Apple, roots, 231. 



Argentina, irrigation, 87. 



Arid climate, efficiency of rainfall, 4, 

 104; accumulation of alkalies, 272. 



Armenia, irrigation, 84. 



Artesian wells, in Sahara. 85; in Ha- 

 waii, 86. 



Assyrian irrigation, 67. 



Australia, irrigation, 81. 



Austria-Hungary, irrigation, 75. 



Baker, J. O., 466. 



Barker, F. C., 236. 



Barley, water used, 21, 24, 34, 46, 235; 

 available rainfall, 124 ; yield, 129; 

 yield increased by irrigation, 110 ; 

 second crop, 130, 179; number of irri- 

 gations, 235; on alkali lands, 276. 



Barrens, 114. 



Basin irrigation, 387, 390 ; Egypt, 288. 



Bavaria, irrigation, 76. 



Bear valley dam, 302. 



Belgium, water-meadows, 362. 



Blackberry irrigation, 383. 



Black marsh soil, mulches, 201 ; alkali, 

 269, 273; vegetation, 281. 



Boussingault, 49. 



Breathing of plants, 47, 182; pores, 51. 



Bucket pump, 316, 319, 325. 



Busca canal, 210. 



Cabbage, irrigation, 387 ; yield in- 

 creased by irrigation, 110; effect of 

 supplementing rainfall in Wisconsin, 

 175. 



(493) 



