1020] SOILS FERTILIZERS. 209 



(14-10 in.) supposed to mark the boundary of profitable wheat production, 

 the average yield per acre outside this line being 73 bu., as compared with Hi 

 bu. inside the line. The average rainfall in the agricultural districts for the 

 five summer months ended March 31, 1850-1916, was 3.6 in. and for the fol- 

 lowing winter months, April-October, 11.9 in., while the average wheat yield 

 was 8.02 bu. 



Some notes on California rainfall, C E. Grunsky {Jour. Electricity, 44 

 (1920), Xo. 5, pp. '20Ji-20(>. ji(in. 4). — Normals and departures from normals for 

 both calendar and seasonal years (beginning July 1) and the average fre- 

 quency of dry and wet years, based on observations at San Francisco and 

 Sacramento from 1849 to 1919, inclusive, are shown in tables and diagrams, 

 and the use of normals in the study of rainfall probabilities is briefly discussed, 



SOILS— FERTILIZERS. 



Soil making, E. J. Kusskli. {Jour. Roy. Ilort. Soc, J^/f {1019), pp. 1-12). — 

 The origin, composition, and treatment of normal agricultural soils are dis- 

 cus.sed, the general conclusion being drawn that the making of soil requires 

 proper mineral matter, organic matter, and conditions suitable for the de- 

 composition of the organic matter. 



The care of the soil, H. E. P. Hodsoix {Jour. Roy. Hort. Soc, Jf'i {1919), No. 

 1, pp. 22-28). — A brief review of the mechanical, chemical, and biological prop- 

 erties of soils is given, together with information as to their proper mainte- 

 nance. 



Soil survey of Morrill County, Nebr., F. A. Hayes, H. W. Hawker, M. D. 

 Davis, and V. H. Seabury (U. S. Dept. Agr., Adv. Sheets Field Opcr. Bur. Soils, 

 1917, pp. 69, fig. 1, map 1). — This survey, made in cooperation with the Uni- 

 versity of Nebraska, deals with the soils of an area of 906,880 acres in the 

 extreme western part of Nebraska lying in the Great Plains region. By far 

 the greater part of the county is well di'ained. The topography varies from 

 flat in the alluvial lands to dissected and very steeply rolling in the rougher 

 '; uplands. 



The soils of the county are of residual eolian, alluvial, coUuvial, and mis- 

 cellaneous origin. Including dunesand, rough broken land, and riverwa.sh, 39 

 soil types of 10 series are mapped, of which dunesand, covering 25.8 per cent 

 of the area, is the mo.st extensive individual type, followed by rough broken 

 land, covering 10.7 per cent of the area, and Rosel)ud very fine sandy loam, 

 covering 10.1 per cent. 



Soil survey of Traill County, N. Dak., F. Z. Hutton and E. Nichols {TJ. S. 

 Drpt. Ayr., Adv. Shcct.'i Field Oper. Bur. Soilt, 1918, pp. .',7, pi. 1, fig. 1, map 1).— 

 This survey, made in cooperation with the North Dakota Experiment Station, 

 ilc.ils with the soils of an area of 553,600 acres in the extreme eastern part of 

 "^'Tth Dakota, which compris-es three main phy.siographic divisions, namely, 

 ial Lake Aga.ssiz, glacial river delta, and upland or rolling prairie. Tlie 

 ' — lern and soutliern parts of the county are level and in places ratlier poorly 

 'liiiined. The northwestern part is level to gently undulating, high, and well 

 ili;iiiu'(l. The southwestern corner of the county is high and well dniined, with 

 ;i rtilliiig to hilly topography. 



Tlie soils of the county. are of glacial, glacial lake, delta, and river-tlood- 

 plains origin. Twenty-three soil types of 8 series are mapped, of which the 

 Bearden very fine sandy loam, Fargo clay, Fargo silty clay, and Bearden silt 

 loam cover 22, 18.7, 13.4, and 13.2 per cent of the area, respectively. The Bearden 

 series covers nearly half the area of the county. 



II 



