SOILS FERTILIZERS. 217 



analyses of two typical virgin loam soils from the most productive grain-growing 

 region of the province are reported. The soils contain about the same amount 

 of phosphoric acid (0.04 to 0.05 per cent) found in the ordinary soils of the 

 region, but are much above the average in the amount of lime (0.1 to 0.6 per 

 cent) and potash (0.6 to 0.9 per cent). The mechanical analyses are compared 

 with such analyses <if typical wheat soils of the T'nited States as are reported by 

 Snyder. A general agreement is noted. 



The development of the modern plow in relation to the chemical and 

 bacteriolog'ical theories of soil fertility, C. Hugues {Bol. Qiiind. Soc. Agr. 

 Ital., 13 (1908), No. 4, pp. 122-126).— The history of the development of the 

 plow with special reference to its adaptation to the purpose of putting the soil 

 in the best condition for promoting beneficial chemical and bacterial activities is 

 briefly discussed. 



Natural agencies in soil improvement, E. B. Voorhees (Peiiii. Dcpt. Agr. 

 Bid. 157, pp. 63-76). — This article discusses in a general way what are termed 

 constructive and destructive natural foi'ces and explains practical systems of 

 farm management designed to improve two opposite types of soil, namely, a 

 heavy clay and a light sand, both deficient in vegetable matter and in lime, 

 though with good natural drainage. 



The productiveness of the poll: Bacteriolog'ical factors, E. Marchal (Ann. 

 Gemhloux, 18 (1908), Xo. 3, pp. 153-166). — This article supplements previous 

 articles dealing with the physical and chemical factors of soil fertility (E. S. R., 

 20, p. 16). It discusses specialization and localization of bacterial functions in 

 the soil and the intervention of micro-organisms in soil fertility, the latter 

 including an account of the efforts which have been made to control and promote 

 by artificial means the bacterial activities which increase soil fertility. 



The problem of soil bacteriology, H. Fischer (Dcut. Landw. Prcsse, 35 

 (1908). IS OS. 20, pp. 215-217; 21, pp. 231, 232),— The importance of bacterio- 

 logical activities, especially in fixing and transforming nitrogen, in the soil and 

 the methods of studying and controlling such activities are discussed, but in 

 the author's opinion more fundamental knowledge of soil bacteriological proc- 

 esses is needed before practical applications of value can be made. Of first 

 importance at present is a simple method of determining the bacteriological 

 character of soils. 



The microbiochemical processes of ammonization in cultivated soils, R. 

 Perotti (Atti R. Accud. Lincei. Rend. CI. Sci. Fis., Mat. e Nat., 5. set:, 16 (1907), 

 II, No. 10, pp. 70J,-709; CentU. Bakt. [etc.'], 2. AM., 20 (1908), No. 15-17, 

 UP. 51.'f-518), ahs. in Chem. Zenthl, 1908, I, No. 5, p. JfSl; Jour. Chcm. Soc. 

 [London], 9Jf (1908), No. 54-'i, II, p. 12Ji). — The author has shown that calcium 

 cyanamid is ordinarily converted into ammonia in the soil while its derivative, 

 dicj-andlamid, does not undergo this change under ordinary conditions. He 

 concludes that the transformation in the first case -is a biochemic pi'ocess 

 resulting from the action of organisms which by the aid of particularly favor- 

 able conditions are able to withstand the poisonous properties of the cyanamid. 

 The organisms apparently protect themselves by transforming the poisonous 

 cyanamid into ammonia. In case of the dicyandiamid, on the other hand, the 

 necessity for such transformation does not exist because in ordinary concen- 

 trations this substance is not poisonous, and certain of the organisms directly 

 assimilate it. This conclusion is borne out, in the author's opinion, by the 

 results of experiments which he reports in which an increase in concentration of 

 the dicyandiamid solution resulted in ammonization due, it is believed, to the 

 fact that in concentrated solution the dlamld became injurious to the organ- 

 isms. A bibliography of 21 references to literature on this particular phase of 

 the subject is given. 



