512 EXPERIMENT STATION RECORD. [Vol.41 



well drained. With reference to origin the soils of the area are residual soils, 

 old valley-filling, and coastal plain soils, recent alluvial fan and flood-plain 

 soils, wind laid soils, -and miscellaneous material. Thirty soil types of 13 series 

 and 4 miscellaneous types are mapped, of which the Ramona loam, the Han- 

 ford fine sandy loam, and rough broken land cover 17.6, 15.9, and 10.3 per 

 cents of the area, respectively. 



" In the southeastern third of the area the water table is prevailingly high, 

 and injurious amounts of alliali have accumulated over considerable areas. 

 Alkali occurs both in continuous areas of small extent and in patches, as well 

 as in amounts too small to affect plant growth. Sodium sulphate prevails 

 over inland areas, and sodium chlorid or common salt in the marshes along 

 the coast. Black alkali has developed in some small accumulations. Con- 

 siderable areas have been drained and much of the alkali removed by leaching." 



Analyses of soils of Terrell County [Ga.], W. A. Worsham, jr. et al. (G«. 

 State CoL Agr. Bui. 112 {1919), pp. 52, figs. 2). — Chemical analyses are reported 

 of the soils of an area of 213,760 acres in southwestern Georgia, lying entirely 

 within the coastal plains soil province. They show that the principal upland 

 soils are markedly deficient in nitrogen, phosphoric acid, and potash, nitrogen 

 being the relative limiting factor. 



Preliminary report on the geology of east central Minnesota including the 

 Cuyuna iron-ore district, E. C. Hardee and A. W. Johnston {Univ. Minn., 

 Geol. Survey Bui. 15 {1918), pp. T7-f-i7S, pis. 22).— This report should be of 

 value in a study of the soils of the region. 



Rate and extent of solubility of soils under different treatments and con- 

 ditions, G. J. BouYoucos {Michigan Sta. Tech. Bui. 44 {1919), pp. 3-49, figs. 

 7). — This bulletin describes investigations begun in 1917 on the rate and extent 

 of the solubility of soils as determined by the freezing point method. Clay, 

 clay loam, silt loam, sandy loam, and sandy soils were employed, and were sub- 

 jected to different salt, fertilizer, and acid treatments accompanied by various 

 moisture contents and temperatures. Untreated samples of a number of types 

 of soil containing various amounts of organic matter and particles of different 

 degrees of fineness were also studied. The moisture contents employed in- 

 cluded an optimum and ratios of 1 of soil to 0.7 water, and of 1 of soil to 5 

 of water. Temperatures of below freezing, room temperature (about 20° C), 

 and 53° were used. The results may be summarized as follows : 



Different classes of soil, with a water content of 1 of soil to 0.7 of water and 

 kept at room temperature, when treated with N/10 salt solutions of Ca(N03)2, 

 NaNOa, KNOs, KCl, K2SO4, (NH4)=S04, MgS04, KH2PO4, CaH4(P04)2, and 

 NaC2H303 and then washed free of all soluble salts showed that the rate of 

 solubility of all the salt treatments except (NH4)2S04 was slow and gradual, 

 and that the process continued for a long time (120 days), but usually for about 

 50 days. In the case of (NH4)2S04 the initial velocity was quite rapid but soon 

 slowed down. At the end of about 60 days there was an apparent constancy 

 or equilibrium in the solubility. The extent of solubility at this point was 

 found to be very appreciable in all the salt treatments and in all the soils, 

 with few exceptions. All the soils except sand treated with NaNOs, KNO3, 

 KCl, K2SO4, (NH4)2S04, MgS04, and NaC2H302 yielded quite a large amount of 

 material to solution, the depression in many cases rising from 0.005 to about 

 0.110° C. or from 125 to 2,7.50 parts per million of .solution. The only salt 

 treatments which did not cause a large solubility product were Ca(N03)=, 

 KHjPOi, and CaH4(P04)2> the depression in some of these treatments rising 

 only from about 0.007° to 0.015° or from 175 to 375 parts per million. As a 

 general rule NaNOa and NaC^HsOj in all the soils, except sand, tended to yield 

 the greatest solubility product, CaNOs, KH2PO4, and CaH4(P04)2 the smallest, 



