ABSTRACTS OF REPORTS OF FOREIGN INVESTIGATIONS. 



The assimilation of free atmospheric nitrogt^n by plants in its 

 relation to species, supply of plant food, and kind of soil, B. Frank 

 {TaokIw. J((lirh., 21 (1892), pp.44). — In this paper the aulli(»r reviews 

 investigiitiuus made by himself in recent years, ou the part wliieli the 

 free nitrogen of the atmosphere plays in plant economy, as influenced 

 by species of i)laiit, by supjilyof plant food in tlie soil, and l)y the kind 

 of soil. Witli reference to the first point he cites experiments \\itli 

 cryptogamous plants [PeniciUium, pure cultures of tubercle bacteria, and 

 algie), wliieh go to show that tliese organisms are capable of growing 

 and accuinulating nitrogt'n in an atmospliere freed from ammonia com- 

 pounds and on a nitrogen-free substratum, and that alga* enrich the 

 soil in nitrogen derived from the air; and with phaMiogamous phnits 

 (oats, buck wlieat, sparry, rape, and yellow lupine *), indicating that tlies. 

 l>lants, non leguminous as well as leguminous, can derive nitrogen from 

 the atuu)si)here, provided they are lurnished with sullicient phosi)hoi it- 

 acid, ])otash, and lime, although it is not denied that non-leguminous 

 ])lauts are benelited by nitrogenous manures. ''It is reas(»nable to 

 suppose that in a soil rich in nitrogenous con'.pounds the i>lants luake 

 lessettbrt to secure nitrogen froiu the air than where this latter source is 

 the only one. It may be assuuu'd that the plant assimilates the nitro- 

 g«Mi of nitrogenous (•om[)oun(ls nnu'e leadily than the nitrogen of the 

 atmosphere.'' This leads to the question of the ett'ect of the su])ply of 

 ]»lant food on free nitrogen assimilatitm. The author studied this in 

 experiments with yellow lupine and peas grown (1) without nitroge- 

 nous manures but inoculated, and (li) with applications of calcium 

 nitrate, ammonium suli)hate and urea, respectively, both with and 

 without inoculation. He sums up the conclusions of these tests as fol- 

 lows: It is possible for yellow lupine and i>eas to «leveloi> wit1nuit the 

 aid of the symbiosis when manured with nitrates, ammonia, (U- urea; 

 but the symbiosis alone (without nitrogencms manuring) gives better 

 results with both kinds of plants than nitrogeiuuis luanures alone (with- 

 out inoculation). NVheu the above nit rogenous manures were used in con- 

 junction with the inoculation, the manures appeared to act disa<lvanta- 

 geously in the case of the lupine plants, but to be of benefit to the peas. 



*See Experiment Station Hccord, vol. ui, p. 418. 

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