918 EXPERIMENT STATION RECORD. 



latioii niul conservation of moisture niid for llio f(iriii:ili<in of nilnilos, and the 

 lowcrin.i,' of tlio yield is liio result. 



Productivity of the .black fallow in the steppes as dependent upon pre- 

 cipitation and the fertility of the soil, L. P. Sokalski (Zlitir. Oimitn. Aj/ron. 

 [Riis.s. .hun: I'J.rpt. L(Uidir.\. !l HHOS). Ao. J,, pp. J,.'ii)-',7.i).—lt has been well 

 establisluHl that in the steppes with their dry climate l)lack fallow cultivation 

 is tlie safest means of insuring u satisfactory crop. The favorable iuUuence 

 of the l)Iack fallow has been generally ascril)ed to the circumstance that thereby 

 moisture is best accumulated and conserved. This view the author subjects 

 to a critical study, mailing use of the data accumulated during a number of 

 years at the experiment stations of Kherson, Odessa, and the Don region. 



lie tinds that there seems to be no connection between the crops of winter 

 wheat and «Mther the annual amounts of i)recipitation or the precipitation 

 during the growing period. Tliere is, however, a direct relation between tlie 

 precii)itation dni'ing tli(> s])ring months and the crop of winter wheat. The 

 ratio expressing this relation forms the coefficient of productivity. With the 

 aid of this coefficient tlie size of the crop in a given locality can be predicted 

 in May. 



In the o])inion of the author, the accumulation of moisture, if such a condition 

 is brought about by the black fallow cultivation, does not affect the productive- 

 ness of the soil. He thinks that the favorable effect of the l)lack fallow culture 

 is due to the fact that this mode of culture increases the availability of the 

 nutritive substances of the soil. 



Brief report of the Poltava Experiment Field for 1907, S. Tret'yakov 

 and Verbetski {Zhur. Opiiit)i. Agron. [Ruf^s. Jour. Expt. Lundiv.], 9 (190S), A'o. 

 2, pp. 308-311). — Data for 12 years show that larger yields were obtained on 

 early fallow than on black fallow. 



Brief report of the Kherson Experiment Field for 1906, F. Yanovchik 

 (Zhur. Opuitn. Agron. [72».s'.s. Jour. Expt. Landiv.], 9 (WOH), No. 2, pp. SOU- 

 308). — Mean results for 15 years gave better crops of winter wheat and rye on 

 early fallow than on black fallow. Experiments on different modes of cultiva- 

 tion, fertilizing, etc., are described. 



Fertility of various horizons of the soil, V. Sazanov (Trudui Ivanov Sclxk. 

 Khoz. Opuitii. tStanizil. 1907. \o. 3, pp. 111-122; uhs. in Zhur. Opuitn. Agron. 

 [Russ. Jour. Expt. Landw.], 9 {1908), No. 2, pp. 302, 505).— Vegetation experi- 

 ments show that the fertility of the soil tested diminished from the upper to the 

 lower layers. 



Zeolites and similar compounds, their constitution and importance in 

 technology and agriculture, Iv. Gans (Jnhrh. K. Pnuss: Clro], Landcsdnst. u. 

 Bergakad. Berlin. 26 {1905), No. 2, pp. 179-211; abs. in Chem. Abs., 2 {1908). 

 No. 23, p. 3216; Jour. Soc. Chem. Indus., 28 {1909), No. 2, p. 102).— The char- 

 acter of zeolitic silicates extracted from different kinds of soils are described 

 and classified according to the substitution of their bases, as, for example, by 

 ammonia. From a study of these and other changes the conclusion is reached that 

 a fertilizer containing phosi)liates or carbonates is preferable to one containing 

 sulphates and nitrates becansi^ with the former there is no unnecessary exchange 

 of bases in the zeolitic compounds of the soil. Other results from exchange of 

 bases due to addition of various fertilizing materials are given. 



Soil moisture, A. Lehmann {Dept. Agr. Mi/xore, Ann. Rpt. Agr. Chem., 8 

 (1906-7). pp. 25-30, 57, 58). — The results of studies of the effect on soil moisture 

 of different kinds and amount of cultivation are reported, and indicate that 

 keeping the surface of the soil loose not only conserves the moisture of the soil 

 but has other beneficial effects. 



