580 



INDEX OF SUBJECT MATTER 



Nutrients in soils, direct influence of 



plants on solubility of, 295. 

 how lost from the soil, 289. 

 influence of lime on solubility of, 



373. 

 lost by drainage and cropping, 307. 

 lost by leaching, Cornell data, 210. 

 lost by plant influence, 303. 

 lost during manurial production, 



cows, 516. 

 lost during manurial production, 



heifers, 516. 

 lost during manurial production, 



sheep, 516. 

 lost during manurial production, 



steers, 516. 

 lost from Cornell soil, 554. 

 lost from soil, relative losses, 308. 

 lost in handling and storage of ma- 

 nure, 517. 

 natural additions of to soil, 556. 

 quantities removed by crops, data of, 



303. 

 recovery of in farm manure, 516. 

 solubility as influenced by carbon 



dioxide, 255. 

 Nutrient losses from and addition to soil 



under various types of farming, 



558. 



Ocean, soils found in, 50. 



Ohio results with raw rock phosphate, 



462. 

 Optimum soil moisture, influence of 

 structure on, 201. 

 for plant growth, 200. 

 Organic carbon, determination of, 311. 



use of by higher plants, 402. 

 Organic compounds of soil, character of, 

 105. 

 classification of, 107. 

 nitrogenous, 106. 

 relation to plants, 108. 

 Organic decay, effect on soil tempera- 

 ture, 239. 

 Organic decomposition, simple products 



of, 110. 

 Organic matter, amount in Nebraska 

 loess, 120. 

 amount in soil of United States, 117. 

 decay of, 103. 

 compounds isolated from, 108. 



Organic matter, defined, 99. 



determination of in soils, 112. 



effect of on soil acidity, 353. 



effect on capillary capacity of soil, 



164. 

 effect on carbon dioxide of soil air, 



253. 

 effect on specific heat, 233. 

 influence in soil, 8. 

 influence of soil conditions on decay 



of, 124. 

 influence on availability of rock 



phosphate, 460. 

 influence on the soil, 121. 

 in Minnesota soils, 119. 

 maintenance of in soil, 122. 

 Organic matter of soil, effect on heat 

 conductivity, 236. 

 general nature, 7. 

 influence on bacteria, 394. 

 portion alive, 100. 

 sources of, 7, 99. 

 Organic nitrogenous compounds, utiliza- 

 tion by higher plants, 411, 446. 

 Organic nitrogenous fertilizers of secon- 

 dary importance, 445. 

 Organic toxins, elimination of, 109. 



of soil, 108. 

 Organisms, benefits of in soil, 397. 



pounds of in soil, 384. 

 Orthoclase, change of to koalinite, 26. 



importance in soil, 6. 

 Osmosis, defined, 289. 



how demonstrated, 290. 

 pressure developed by, 290. 

 Osmosis of water into plants, 290. 

 Osmotic pressure, nature of, 290. 

 Oswald method of converting ammonia 



into nitric acid, 453. 

 Outlets for tile drains, construction of, 



214. 

 Oxidation, effect of on composition of soil 

 air, 254. 

 importance of in soil formation, 24. 

 of sulfur in soil, 403. 

 Oxidases, production of by plant roots, 



297. 

 Oxygen, importance in soil air, 256. 



Packers, action of, 148. 

 Partial analysis of soils, 315. 



digestion with dilute acids, 317. 



