INDEX 



489 



Pacific coast soils, 78. 



Palmitin, 351. 



Pancreatic juice, 394. 



Peat soils, 74. 



Pectins, 373. 



Pentosans, digestibility, 408. 



in soils, 157. 

 Pentoses, 365, 374. 

 Pepsin 393- 

 Peptones, 357. 

 Percolation, 142, 271. 

 Phytin, 377. 

 Piedmont plains, 67. 



soils, 75. 

 Pigs, digestive power, 402. 



fattening ration, 449. 



feeding young, 459. 

 Finite, 153. 

 Plants, absorption of carbon 



dioxide, 36. 



Plants and atmosphere, 6, 30. 

 Plant constituents, n. 

 Plant food, active, 180. 



definition, 17. 



factors of availability, 181. 



and crops, 276. 



and soils, 172. 



minimum requirements, 18. 



quantity needed, 20. 



washed out, 20. 

 Plant life, conditions, 5. 



essentials, 9. 



products, 4. 

 Plants, light on, 39. 

 Plant production, 3. 

 Plant stimulants 29. 

 Polariscope, 363. 

 Porphyry, 64. 

 Plant, ash essential to, 10. 



ash of (table), 23. 



assimilation of organic matter, 

 161. 

 32 



Plants, color of light on, 40. 



composition at stages of growth, 

 38o. 



conditions for life of, 5. 



constituents, 346. 



effect of temperature, ICQ. 



effect of space on development, 

 105. 



essentials for life, 9, 30. 

 Plants, harvesting, 382. 



law of minimum, 30. 



ratio essential elements, 27. 



selection, 383. 



variable conditions, 32. 



water required, 119, 124. 

 Plowing, labor of, 116. 

 Phosphates, soil, 155, 303. 

 Phosphates, availability, 308. 

 Phosphoric acid, 18. 



active, 183. 



ammonia, soluble 166. 



available, 307. 



changes in soil, 241. 



fixation, 184, 234. 



in rations, 428. 



percentages in soils, 174. 



needs of animals for, 458. 



relation of active to pot experi- 

 ments, 189. 



reverted, 306. 



water-soluble, 306. 

 Phosphoric acid essential to plants, 



13- 

 Pot expe-riments, 184, 193. 



conduct, 246. 

 Potash, active, 183. 



excess taken -up, 192. 



fixation, 185. 



loss from soils, 273. 



loss by weathering, 61. 



relation of active to pot experi- 

 ments, 191. 

 Potash salts, definition, 74. 



