1916] SOILS FERTILIZERS. 319 



to which the index slips were received by the Central Bureau too late for 

 inclusion in the previous volumes. There are also entries dated 1913." The 

 section on the relation of climate to agriculture contains 18 references, that on 

 phenology 8. 



SOILS— FERTILIZERS. 



cJoils courses at the Iowa State College, P. E. Brown {Jour. Amer. Soc. 

 Agron., 8 (1916), No. 1, pp. 42-47).— The soils courses at the Iowa State College 

 are briefly outlined and discussed, the five distinct groups now recognized 

 being soil physics, soil fertility, soil bacteriology, soil surveying, and soil 

 management. 



Mechanical study of soil, D, J. Hissink (Indische Mercuur, 38 (1915), No. 

 47, pp. 975-977). — This is a general statement of the present status of the 

 mechanical classification of soils. 



The colloids of clay and humus soils, P. Rohland (Naturto. Ztschr. For at 

 u. Landw., 13 (1915), No. 8-9, pp. 360-367).— This is a second brief contribution 

 to the subject (E. S. R., 32, p. 318). 



Experiments on water holding in vegetation pots, P. Ehrenberg, F. Bahb, 

 and O. NoLTE (Jour. Landw., 63 (1915), No. 3, pp. 199-225) .—Pot culture experi- 

 ments with corn in sand to test the relative values of various substances for 

 Increasing the water-holding capacity of sand in pot culture experiments are 

 reported. The pots contained about 15 kg. of sand ; and emery, pulverized 

 glass, and barium sulphate were added in 1 kg. amounts ; kieselguhr, artificial 

 zeolite, and clay in amounts of i kg. ; and peat dust i kg. 



The results are taken to indicate that of the materials tested barium sulphate 

 may be used to the best advantage for increasing the water-holding power of 

 sand in sand cultures. Under certain conditions kieselguhr may be used, but 

 emery only in special cases. Powdered glass, artificial glass, clay, and peat 

 are considered unsuited for general use for this purpose. 



Miscellaneous samples, soils, L. Heimburgek (Fla. Quart. Bui. Dept. Agr., 

 26 (1916), No. 1, pp. 167-174). — This section of the report contains the results 

 of analyses of 21 samples of Florida muck, rock, and calcareous, sandy, forest, 

 and humus soils. 



Soil survey of Elkhart County, Indiana, G. B. Jones and R. S. Hesleb 

 (JJ. S. Dept. Agr., Advance Sheets Field Operations Bur. Soils, 1914, pp- 28, 

 fig. 1, map 1 ) . — This survey, made in cooperation with the Indiana Department 

 of Geology and issued May 25, 1916, deals with the soils of an area of 295,680 

 acres in northern Indiana, the topography of which is characteristic of a 

 glaciated region and varies from flat to hilly. The soils are of glacial origin 

 and are grouped as upland and sand-plains soils. Exclusive of muck, peat, and 

 meadow, eleven soil types of four series are mapped, of which the Miami loam, 

 Plainfield sandy loam, and Miami sandy loam cover 37, 27, and 12.5 per cent of 

 the area, respectively. 



Soil survey of Lafayette Parish, Louisiana, A. H. Meyer and N. M. Kirk 

 (U. S. Dept. Agr., Advance Sheets Field Operations Bur. Soils, 1915, pp. 32, 

 fig. 1, map 1). — This survey was issued May 22, 1916, and deals with the soils 

 of an area of 176,640 acres in southern Louisiana which lies mostly in the 

 coastal prairie region of the Gulf Coastal Plain province. " By far the greater 

 portion consists of the uplands, or terrace, the surface of which is, for the most 

 part, practically level." In general the drainage is fairly good. 



The soils are grouped as upland and first bottom. Excluding muck and 

 swamp, ten soil types of nine series are mapped of which the Oliver, Lintonia, 

 and Crowley silt loams cover 38.6, 25.6, and 11 per cent of the area, respectively. 



