INDEX OF SUBJECT MATTER 



579 



Nitrog-en, additions to soil, nature of, 429. 

 amount fixed by B. Radicicola, 437. 

 amount in ammonium sulfate, 449. 

 amount in calcium cyanamid, 452. 

 amount in calcium nitrate, 452. 

 amount in California soils, 120. 

 amount in dried blood, 445. 

 amount in Nebraska loess, 120. 

 amount in sodium nitrate, 448. 

 amount in soils, 12. 

 amount in soils of United States, 118. 

 amount in tankage, 445. 

 artificial fixation of, 450. 

 availability of in fertilizers, 454. 

 contained in rocks, 10. 

 determination of in soils, 312. 

 fixation by B. Radicicola, 433. 

 fixed in soil hy azofication, 433. 

 forms of in soil, 10. 

 from B. Radicicola;, availability of, 



437. 

 gain due to green manures, 539. 

 gain due to natural causes, 429. 

 importance in biological processes, 



409. 

 importance of in fertility evaluation, 



323. 

 importance of in soils, 409. 

 in farm manure, 501. 

 in liquid and solid manure, 603. 

 in rain water, data on, 429. 

 inert character of, 409. 

 influence on plant growth, 471. 

 losses from Bromberg lysimeters, 



306. 

 losses from Cornell soils, 307. 

 losses from decaying manure, 511. 

 losses from farm manure, 519. 

 losses from soil, 555. 

 natural addition to soil, 557. 

 of food recovered in farm manure, 



616. 

 organic forms used by plants, 411. 

 possible detrimental influences of, 



473. 

 relation of to life, 409. 

 removed by crops from Cornell soils, 



825. 

 utilization of organic forms by 



plants, 447. 

 Nitrogen cycle, addition of nitrogen to 



soil by free-fixing bacteria, 430. 



Nitrogen cycle, addition of nitrogen to 

 soil in rain water, 429. 

 ammonification, 412. 

 assimilation of nitrates by soil or- 

 ganisms, 426. 

 complexity of, 409. 

 decay and putrefaction, 410. 

 fixation of nitrogen by Azotobacter^ 



432. 

 fixation of nitrogen by B. Eadici- 



Gola, 433. 

 nitrification, 415. 

 reduction of nitrates, 424. 

 relation of to other cycles, 410. 

 Nitrogenous fertilizers, ammonium sul- 

 fate, 449. 

 calcium eyanimid, 451, 

 calcium nitrate, 452. 

 castor pomace, 446. 

 cotton seed meal, 446. 

 dried blood, 445. 

 fish scrap, 446. 

 guano, 446. 

 hoof meal, 446. 

 leather meal, 446. 

 linseed meal, 446. 

 process goods, 446. 

 relative availability, 454. 

 sodium nitrate, 448. 

 tankage, 445. 



utilized by higher plants, 411^ 447. 

 wool and hair waste, 446. 

 Nitrosomonas in soils, 415. 

 Nitrous acid, relation to mineral cycle, 



408. 

 Nodules on the roots of leguminous plants, 



nature of, 434. 

 Number of particles in soil, 96. 

 Number of soil particles, calculation of, 



96. 

 Nutrient elements used by plants, 

 amounts in soil, 12. 

 defined and explained, 8. 

 listed, 9. 

 primary, 10. 

 source of, 10. 

 Nutrients in soils, addition by leguminous 

 green manures, 557. 

 addition of in farm manure, 667- 

 difierential diffusion into plants, 



293. 

 diffusion into plants, 291. 



