320 EXPERIMENT STATION RECORD. [Vol.43 



same in the virgin soils befrinning with the stratum 12 to 18 in. The data would 

 seem to indicate that the water-soluble calcium and magnesium liave been 

 extracted to a depth of al)out 18 or 24 in., and that below tliat depth the calcium 

 and magnesium liave been made more soluble in water in tlie wheat soil com- 

 pared with tlie virgin soil, possibly as a result of long cultivation." 



The east German black soils (chernozem) with brief mention of east 

 German brown soils, V. Hohenstein {Internatl. Mitt. Bodenk., 9 (1919), Nos. 

 1-2, pp. 1-31; 3-4, pp. 125-178, pi. 1, figs. 5). — An extensive study of the geology 

 and physical and chemical properties of the black soils which cover an area 

 of about 2,500 sq. km, (G17,600 acres) in eastern Germany is reportetl. 



These soils are coffee-brown to black-brown in color and average from 50 

 to GO cm, in depth. For the most part the mother rock consists of pebble marl, 

 clay marl, silica, and sand, and in some localities loess, and occasionally ter- 

 tiary clay. The weathering of tlie black sorl is gradual. The soils show the 

 activities of earth worms and small burrowing animals. Where the mother 

 rock contains lime, a heavy white carbonate stratum underlies the black soil, 

 while the formation above is deficient in lime. 



As compared with the other east German soils, these soils are said to have 

 strikingly favorable chemical and physical properties, particularly with refer- 

 ence to their content of from 2 to 4 per cent of humus. Leaching is generally 

 not extensive. The black soils are, therefore, considered the best adapted for 

 wheat and sugar beets. It is the opinion that these black soils are not a 

 product of the daily climate, but the result of an extreme climate similar to that 

 of the steppes under grass and weeds. 



The soils on the edge of the east German black soil region are mostly brovm 

 soils. They are strongly leached out forest soils, with extensive layers defi- 

 cient in lime, and reddish brown subsoil having somewhat the character of pod- 

 sol formations, 



A list of 49 references to literature bearing on the subject is included. 



Studies of red soils of " djati " forests, N. BEUMfiE-NiEUWLAND {Bosch- 

 bounlc. Tijdscjir. Tcctona, 11 (1918), No. 3, pp. 187-205).— Analyses of 25 

 samples of red soils from djati forests of Java are reported and discussed, 

 together with data from other sources on the fertility of these soils. 



It is concluded, on the basis of a comparison of chemical analyses of poor 

 and rich soils, that the presence of a large amount of nutritive constituents 

 soluble in hydrochloric acid does not necessarily indicate a high state of fer- 

 tility in djati soils. The analyses indicate this with reference to total 

 fertility constituents, and in one case of apparent poverty in phosphoric acid 

 better crops were produced than in a soil rich in phosphoric acid soluble in 

 hydrochloric acid. The lowest figures for potash were associated with soils 

 of lowest productivity. It is noted also that the lime content of these soils is 

 low even in those which appear to be the most productive for djati. The phy- 

 sical properties of these soils, particularly hygroscopicity, are considered to 

 have a great influence on their fertility with reference to the availability of 

 nutritive constituents. 



The physical properties of soils, B. A, Keen {Fruit, Floircr, and Veg. 

 Trades' Jour. [London], 37 {1920), Nos. 7, p. 167; 8, pp. 195, 197; 9, p. 222; 10, 

 p. 252; 11, p. 280; 12, p. 308). — This is a series of sis lectures on the subject. 



The soil viewed as a permanent depositary of moisture, I. R. Fontana 

 (Vniv. Tiicnmdn, Ext. Agr. Bol. 19 [1918], pp. 1, 2). — This is a popular discus- 

 sion of physical and chemical factors governing the moisture content of soils. 



Effect of initial moisture content on subsequent moisture movement in 

 soil, G. Roberts {Kentucky Sta. Rpt. 1918, pt. 1, pp. 28, 29).— Experimental 



