; 



578 



INDEX OF SUBJECT MATTER 



Mineral cycles in soils, importance of, 

 408. 



nature of, 407. 



organisms of, 408. 



types of, 407. 

 Minerals in earth's crust, 4. 

 Minerals of the soil, 77. 



importance of, 6. 



list of, 5. 



source of, 4. 



specific gravity of, 89. 

 Minerological analysis of soils, 76. 

 Minerological character of soils, 77. 



of soil particles, 75. 

 Minimum, element in the, 476. 



law of Mitscherlich, 477. 

 Modification of soil air, 261. 

 Moisture of soil, conservation by mulch, 

 221. 



conservation, weed control, 220. 



control, summary of, 221. 



data for sandy and clayey soils, 

 179, 200. 



determination on soil, method of, 

 161. 



effect on heat conductivity, 236. 



effect on movement of soil air, 258. 



effect on nitrification, 420. 



effect on specific heat of soils, 233. 



influence on nitrification, 420. 



influence on bacteria, 393. 

 Moisture equivalent of soils, defined, 167. 



for various soils, 168. 



method of determination, 167. 

 Molecules, absorption of by soil, 269. 

 Moraines, agricultural value, 54. 



ground, 54. 



terminal, 54. 

 Movement of soil air, factors affecting, 



258. 

 Muck, agricultural value of, 43. 



capacity for water, 164. 



character of, 43. 



chemical analysis of, 44. 



term defined, 43. 

 Mulch, artificial, 218. 



soil, use of, 218. 

 Muscovite, change of to kaolinite, 26. 



present in soils, 5, 77. 



Nitrates in alkali spots, 332. 

 Nitrates in rain water, data, 429. 



Nitrates in soils, accumulation, 419. 



accumulation as influenced by green 



manure, 544, 549. 

 accumulation, influence of grass on, 



427. 

 accumulation, influence of maize on, 



428. 

 as a source of nitrogen for higher 



plants, 415. 

 assimilation of by soil organisms, 



426, 428. 

 influence of green manures on, 543. 

 production of, 111. 

 reduction of, 424. 

 Nitrate reduction, cause of, 425. 

 control of, 426. 



influence of green manures on, 426. 

 influence of straw on, 425. 

 nature of, 425. 

 organisms of, 425. 

 Nitrification in soil, as affected by soil 



conditions, 418. 

 as influenced by carbon dioxide, 256. 

 effect of aeration on, 418. 

 effect of alkali on, 421. 

 effect of carbon dioxide on, 419. 

 effect of farm manure on, 418. 

 effect of moisture on, 420. 

 effect of soil acidity on, 421. 

 effect of temperature on, 420. 

 efficiency of, 417. 



influence of higher plants on, 422. 

 influence of lime on, 373. 

 influence of previous crops on, 423. 

 influence on carbon dioxide produc- 

 tion, 255. 

 nature of, 415. 

 organisms of, 415. 

 products of, 415. 

 reactions, 415. 



relation to ammonifi cation, 416. 

 relation of to carbon cycle, 408. 

 relation of to mineral cycle, 408. 

 relation to soil fertility, 423. 

 Nitrifying organisms, types of, 415. 

 Nitrites, production of in soils, 1 1. 

 Nitrobacter in soil, 415. 

 Nitrogen, additions to soil, by free-fixing 



organisms, 430. 

 additions to soil, in manure, 557. 

 additions to soil, in rain water, 429. 

 additions to soil, modes of, 429. 



