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,^. 



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- 

 crease^, by irrigation, 110; effect of 

 supplementing rainfall in Wisconsin, 

 175. 



(493) 



