346 



INDEX 



returned by, 122, 134, 289; root 

 nodules, 125; manuring of, 269. 



Coal ashes, 220. 



Color, of plants, influenced by nitro- 

 gen, 118; of soils, 47, 50; and soil 

 temperature, 314. 



Combination of elements in soils, 72. 



Commercial fertilizers, 233, 254; 

 abuse of, 245; and tillage, 244; 

 and farm manures, 254; compo- 

 sition of, 234; extent of use, 233; 

 field tests with, 248; for special 

 crops, 253; home mixing of, 243; 

 inspection of, 237; judicious use 

 of, 246; mechanical condition of, 

 238; misleading statements, 241; 

 nitrogen of, 238; phosphoric acid 

 of, 239; plant food in, 237; potash 

 of, 240; preparation of, 234; 

 valuation of, 241 ; variable com- 

 position, 234. 



Composition, of soils, 95, 97, 98; of 

 manures, 159. 



Composting manures, 178. 



Corn, fertilizers for, 254; food re- 

 quirements of, 263; and manure, 

 185; soils, 23. 



Cotton, fertilizers for, 267. 



Cottonseed meal, 151. 



Cow manure, 170. 



Crop residue, 275. 



Cultivation, after rains, 38; and bac- 

 terial action, 298; shallow surface, 

 37; and soil moisture, 313; and 

 soil temperature, 49. 



Cumulative fertility, 304. 



Cyanamid, 156. 



Davy, work of, 3. 



Deficiency, of nitrogen, 249; of 

 phosphoric acid, 250; of potash, 

 250; of two elements, 250. 



Denitrification, 141. 



De Saussure, work of, 3, 118. 



Dilute mineral acids, action of, 84. 



Diseases of soils, 301. 

 Dissolved bone, 208. 

 Distribution of soils, 62. 

 Drainage, 34, 47, 300. 

 Dried blood, 147. 



Early truck soils, 22. 

 Earthworms, 61. 

 Electricity of soil, 52. 

 Evaporation, 53; heat required for, 



46. 



Excessive use of fertilizers, 252. 

 Experimental plots, 248. 

 Experiments, 310, 325. 

 Exposure and soil temperature, 49. 



Fallow fields, 145. 



Fall plowing, 41. 



Farm manures, 158, 189; and com- 

 mercial fertilizers, 254. 



Feldspar, 64, 237. 



Fermentation of manures, 177. 



Fertility, conservation of, 285; im- 

 portance of, 305; removed in 

 crops, 254. 



Fertilizers, amount to use, 252; in- 

 fluence upon soil water, 44; on 

 barley, 253; on wheat, 253. 



Field tests with fertilizers, 248. 



Fine earth, 14. 



Fish fertilizer, 151. 



Fixation, 191; of ammonia, 194; of 

 phosphates, 192; of potash, 192; 

 due to zeolites, 191; nitrates not 

 fixed, 193; and available plant 

 food, 194. 



Flax, food requirements of, 264; soils, 

 24. 



Flesh meal, 150. 



Forest fires, 1 1 1 . 



Formation of soils, 54, 62. 



Form of soil particles, 17. 



Fruit soils, 23. 



Fruit trees, fertilizers for, 270. 



