SOIL PHYSICS, CHEMISTRY AND MICROIilOI.OC.Y l2-[{) 



The workers succeeded in obtaining considerable quantities of organic 

 phosphoric acid. In one case it represented 17.67 % of the total phosphoric 

 acid content of the soil, and in another, 10 %. There is reason to believe 

 that higher percentages would be obtained in proportion as the method 

 applied to this investigation is improved. 



By these means, in the "podzol" and " tchernoziom " the presence 

 of a considerable proportion of phosphoric acid in the form of an organic 

 combination which appears to be one of the nucleinic acids was definitivel}' 

 established. The ascertainment of this fact does not yet furnish the required 

 answer to the question of the dynamics of phosphoric acid in the soil. 

 Nevertheless, in view of the fact that J. J. Stozkij succeeded in proving 

 that with 3 % hydrochloric acid not only mineral but also organic phosphor- 

 ic acid is extracted from the soil, and that probably a substantial propor- 

 tion of this mineral phosphoric acid in the hydrochloric solution is not of 

 mineral but of organic origin, and that it becomes mineral in the process 

 of evaporation of this solution, then the importance, not merely theoreti- 

 cal but also practical, of investigations of this kind will become clearl}' evid- 

 ent. Bearing this in mind, and also the fact that the best results on "tcher- 

 noziom " are obtained by means of phosphate manure in spite of the 

 richness of that soil in phosphoric acid, the writer suggests the possibil- 

 ity of overcoming the condition of inertia of the large stores of phosphoric 

 acid contained in the soil by a knowledge of the djaiamics to which its pre- 

 sence therein is subject. 



Finall)', it may be presumed that the organic combinations of phos- 

 phorus differ according to the soils, and it is highlj' desirable that investi- 

 gators should in a greater degree devote their attention to this point. 



960 - Method of Sterilisation and Chloroforming of the Soil in the Study of the Proper- 

 ties of "Tchernoziom". — Skalskij S. in H),>icHO-pilcchaii fe.lhciiO-.ro.iUKc- 

 nmcHHau Fasema {The Agricultural Gazette of Southern Russia), Year XVIIl, 

 N°s I ; 2; 5; 7 and 9; pp. 7-8; 6-7 ; 5-7 ; 9-10. Kharkov, January -February -March 1916. 

 On the basis of his experiments carried out in the laboratory of bacte- 

 riological chemistry of the agricultural experiment Station of Ploty (Russia) 

 the writer proves that under the influence of fertilisation and chloroforming 

 the fertihty of the tchernoziom increases. He ascertains the degree of sucli 

 increase, and, to the extent permitted by the results obtained, explains the 

 modifications which take place in the sterilised and chloroformed tcherno- 

 ziom and which produce the increase in its fertilit}-. The experiments were 

 conducted in the following way : 



vSmall Wagxer vessels to the number of two for each experiment were 

 filled with tchernoziom, under different conditions of cultivation : i) an 

 April fallow (that is, fallow ploughed in April) ; 2) a soil cleared several 

 years since ; and 3) a 3 year-old lucerne soil. From each of these soils 

 two layers were taken, namely the arable (from o to 17.7 cm. deep) and the 

 layer immediately below (from 17.7 to 35.5 cm. depth). With the samples 

 of soil mentioned 6 set of vessels were filled. The vessels of the first se- 

 ries, wliich were to serve as controls, were filled with the normal soil, that 

 is to saj- neither sterilised nor chloroformed ; those of the second series, by 



