SOILS FERTILIZERS. 4l7 



The influence of different bases on the transformation of ammonia and 

 nitrate nitrog-en, O. Lkmmkumann, H. Fiscuku, and K. Husek (IaiikIw. IVr.s. 

 Stat., 70 {1909), No. 5-6, pp. 317-33Jt). — A series of experiments to determine 

 the effect of the addition of calcium, barium, aud magnesium carbonates, and 

 ferric hj'droxid to culture solutions on the transformation of the nitrogen of 

 ammonium suljihate and sodium nitrate into protein compounds, is reported. 



Barium carbonate increased the transformation in the case of sulphate of 

 ammonia and reduced it in the case of uiti-ate of soda. Calcium carbonate 

 slightly increased the transformation in the case of sulphate of ammonia and 

 still less in tlie case of nitrate of soda. Little or no increase in the rate of 

 transformation was observed in the case of the addition of magnesium car- 

 bonate. Ferric hydroxid in all cases reduced the rate of transformation of 

 nitrate nitrogen into protein compounds. 



In general, the sulphate of ammonia was transformed to a greater extent 

 than the nitrate of soda, and the author therefore concludes that the lower 

 efficiency of sulphate of ammonia as a fertilizer observed in many cases may 

 be due to the fact tliat it is to a larger extent used by micro-organisms in the 

 production of protein compounds. The effect of calcium carbouate in reducing 

 the efficiency of these nitrogenous fertilizers which is sometimes observed may 

 also be ascribed to the fact tliat its use favors protein formation. 



The influence of lime on the bacteria of a soil, H. Fischer {Landw. Vers. 

 Stat., 10 {1909), No. 5-6, pp. 335-3. ',2). —In the culture solution tests here re- 

 ported it was found that both ammouiacal nitrogen and nitric nitrogen were 

 converted by micro-organisms into protein compounds in considerable amounts, 

 the former more rapidly than the latter. These protein compounds are soon 

 decomposed again. The presence of calcium carbonate favored the formation 

 of protein compounds slightly in the case of sulphate of ammonia and to a less 

 extent in the case of nitric nitrogen.. The presence of barium carbonate in- 

 creased protein formation in the case of sulphate of ammonia and reduced it in 

 the case of sodium nitrate. Magnesium carbonate reduced the transformation 

 of ammouiacal nitrogen into protein substances. Ferric hydroxid reduced the 

 transformation of both ammouiacal and nitric nitrogen. 



These observations suggest an explanation of the lower fertilizing efficiency 

 in case of ammonium sulphate than in case of sodium nitrate, as well as of the 

 influence of lime in increasing these differences, caustic lime exerting an even 

 greater influence upon the activities of the mici'o-organisms of the soil than 

 calcium carbonate. 



The nitrogen economy of cultivated soils, T. Pfeiffer et al. {Mitt. Landw. 

 Inst. Brcshiu, Jf {1909), No. 5, pp. 715-851; ais. in Mitt. Deut. Landw. GeselL, 

 21, {1909), No. 17, pp. 270, 271; Chem. Ztg., 33 {1909), No. 37, Repert., p. 173).— 

 This article explains on the basis of a large amount of analytical data that very 

 delicate methods are required to distinguish small variations in the nitrogen 

 content of soils and that results obtained in pot experiments are exaggerated 

 or very different from those obtained in the field. In the former case also no 

 account is taken of drainage losses. 



Experiments are reported which show no advantage in increase of nitrogen 

 by adding 2 per cent of sugar to the soil as suggested by Koch. The effect of 

 sterilization in temporarily retarding but eventually increasing the bacterial 

 activity in the soil is discussed. 



The nitrogen economy of cultivated soils, P. Ehrenberg {Fiihling's Landio. 

 Ztg., 5H {1909), No. 7, pp. 2.'fl-2.'f6). — This is mainly a discussion of the limits 

 of error in methods of studying the nitrogen economy of soils, supplementing 

 that by Pfeiffer and others noted above. 



