512 EXPERIMENT STATION RECORD. 



Petrography of some North Carolina soils and its relation to their fer- 

 tilizer requirements, J. K. Plumjieb {U. S. Dept. Agr., Jour. Agr. Restearcli. 5 

 (1915), No. 13, pp. 569-581, pi. 1). — Mineralogical analyses made at the North 

 Carolina Experiment Station of five samples of each of the soil series encoun- 

 tered in the soil survey of the State of North Carolina are reported and dis- 

 cussed. The methods of analyses used were essentially those compiled by 

 McCaughey and Fry (E. S. R., 28, p. 812). 



Wide variations in mineralogical composition were found between the soils 

 of the Appalachian Mountain, Piedmont Plateau, and Atlantic Coastal Plain 

 provinces of the State. " There is unquestionably a greater supply of minerals 

 which carry the inorganic plant-food constituents in the mountain soils than 

 are found in either the Piedmont Plateau or the Coastal Plain. Though many 

 of the former soils are derived from the same rocks as those of the Piedmont 

 pi-ovince, the forces of erosion among those of the mountains cause them to 

 contain minerals more nearly the same as the parent rocks than are found 

 elsewhere." 



It is concluded that definite information is required on the behavior of the 

 various soil-forming minerals to the forces of weathering before positive con- 

 clusions can be drawn on the availability of the plant food carried by the dif- 

 ferent minerals. The average results of seven years' fertilizer tests with cotton 

 on a typical Cecil clay loam soil, similar to those previously noted (E. S. R.. 

 31, p. 621), are also reported, which "indicate that there are some relation- 

 ships existing between the mineral component of the soil and the requirements 

 of this plant fftr the three inorganic fertilizer constituents, phosphoric acid, 

 potash, and lime." 



Geology, hydrology, and mineralogy of the Province of San Luis, E. 

 Gebth (An. Min. Agr. Argentina, Sccc. Geol., Mineral, y Mincria, 10 (1914), 

 No. 2, pp. 64, pis. 2, figs. 6). — ^Thls report deals with the geology, hydrology, 

 and mineralogy of the Province of San Luis in Argentina, and contains a 

 bibliography. The hydrological section deals with the soils and vegetation, 

 with particular reference to climatic factors affecting the water supply and to 

 certain soils containing considerable amounts of alkali. Analyses of irriga- 

 tion waters and alkali soils are included. 



Kepoii; on soils of Sierra Leone. D. W. Scotland (Ann. lipt. Agr. Dept. Sierra 

 Leone, 1914, PP- 14-25). — This report deals with the general characteristics of 

 the soils of the different districts of Sierra Leone and reports mechanical and 

 chemical analyses of seven samples of representative well-drained types. 



It is stated that the soils of Sierra Leone are of igneous origin and are about 

 80 per cent laterite. The other types occurring are sands, sandy loams, and 

 isolated pockets of clay. The results of the analyses are taken to indicate 

 that the soils are generally deficient in lime, total and available jthosjjhoric acid, 

 and reserve potash, but contain adequate supplies of nitrogen, humus, and 

 available potash. 



Studies on the agricultural value of the silts transported by the streams 

 of the Alps and Pyrenees Mountains, A. ^Mintz and E. I-AiNr^; (Coinpt. Rend. 

 Acad. Sci. [rarisi, 160 (1915), No. 16, pp. 491-495).— In further studies of these 

 silts (E. S. R., 33, pp. 718, 719) it was found that they are capable of influenc- 

 ing both the chemical and mechanical character of soils. 



With reference to the content of fertilizing constituents they are considered 

 equal to soils of average fertility, analyses showing nitrogen 0.7 to 1.2 per 

 cent, phosphoric acid 0.8 to 1.5 per cent, and potash l..^ to 2 per cent. When 

 the clay content was high the potash content was found to vary from 3 to 4 

 per cent. The silts are also rich in calcium carbonate. 



