INDEX OF SUBJECT MATTER 



571 



Colloidal state, defined, 127. 



defined briefly, 75. 



electrical condition of, 131. 



examples of, 130. 



phases of, 129. 



practical importance of, 135. 



relation of to granulation, 142. 

 Colloids and crystalloids, 129. 

 Color of soil, compounds of, 36, 37. 



influence on absorption of insulation, 

 228. 



nature of, 36. 

 Colluvial soils, origin and nature, 45. 

 Commercial fertilizer, amounts to apply, 

 492. 



development of use, 442. 



used for their nitrogen, 444. 



used for their phosphorus, 454. 



used for their potash, 462. 



used in United States, 444. 

 Commercial value of farm manure, 512. 

 Composition of average soil, 12. 



of cow manure, 501. 



of drainage water, 304. 



of farm manure, average, 504. 



of horse manure, 501. 



of muck and peat, 44. 



of plant tissue, 100. 



of sheep manure, 501. 



of swine manure, 501. 

 Composts, use of manure in, 530. 

 Composts of sulfur, 406. 

 Conductivity of heat, measurement of, 

 235. 



formula for, 236. 

 Conductivity coefficients of various soils, 



236. 

 Conductivity of various soils, 235. 

 Conduction, loss of heat from soil by, 



240. 

 Conduction of heat in soils, factors af- 

 fecting, 235. 



nature of, 234. 

 Constituents of soil, organic and inor- 

 ganic, 2. 

 Control of alkali in soils, 343. 



of evaporation, 218. 



of soil air, 261. 



of soil temperature, 244. 

 Conservation of soil moisture, 219. 

 Conversion factors for lime, 367. 

 Convection of heat in soil, 238. 



Correction of soil acidity, bases useful 



for, 363. 

 Corrosion defined, 18. 

 Cotton and tobacco, influence of manure 



on, 535. 

 Cotton seed meal, composition of, 446. 

 Cover crops, influence on nitrates of soil, 



541. 

 Crop resistance to alkali, generalized 

 table of, 338. 

 in pounds per acre, 338. 

 Crop residues, to maintain organic mat- 

 ter, 124. 

 Crop rotation, relation of to green ma- 

 nuring, 552. 

 Crops, absorptive capacity of, 301. 

 amounts of fertilizers for, 493. 

 bacteria injurious to, 396. 

 detrimental influence of nitrogen on, 



473. 

 eftect of calcium and magnesium 



ratio on, 376. 

 effect of concentration of salts on, 



337. 

 effect of on conservation of plant 



nutriants, 308. 

 fertilizer formula for, 491. 

 for green manures, 546. 

 fungi injurious to, 396. 

 influence of green manures on, 547. 

 influence of manure on, 532. 

 influence of nitrogen on, 472. 

 influence of phosphorus on, 474. 

 influence of potassium on, 475. 

 injurious effect of soil organisms on, 



396. 

 quantities of nutrients removed by, 



303. 

 removal of nutrients by, 555. 

 removal of sulfur by, 404. 

 removal of sulfur and prohphorus 



by, 468. 

 response to lime, 372. 

 systems of fertilizing, 496. 

 Crushers, action of, 148. 

 Cultivation, implements for, 147. 



importance of, 219. 

 Cultivators, action of, 147. 

 Cumulose soils, agricultural importance, 

 43. 

 location of, 42. 

 origin, 42. 



