1918.] SOILS PERTILIZEBS. 719 



is situated in the northeastern part of the State, lying in three gladations and 

 comprising an area of 513 sq. miles. A small portion of the northwest corner of 

 the county is in the lowan glaciation, but the material deposited by that glaciation 

 has been almost entirely covered by a late Wisconsin gravel outwash. The 

 east and northeast parts of the county lie in the late Wisconsin glaciation, 

 while the western and southern parts of the county are in the early Wisconsin 

 glaciation. The Illinoisan glaciation preceded all the glaciations named, cov- 

 ering the area with a layer of drift 20 to 60 ft. deep. The topography of the 

 county is undulating to slightly rolling in the intermorainal tracts, while the 

 morainic areas are composed of a series of irregular ridges containing many 

 kettle holes now mostly filled with partially decayed vegetation. Natural 

 drainage is said to be frequently imperfect, and, although no large lakes exist 

 in the county, many swamps occur that need artificial drainaga 



The soils of the county include (1) upland prairie soils, (2) upland timber 

 soils, (3) terrace soils, and (4) late swamp and bottom land soils, covering, 

 respectively, 46.37, 29.4S, 4.73, and 18.8 per cent of the area. Chemical analyses 

 of the various soil types are reported. 



The fertility needs and methods of management of the soils are fully dis- 

 cussed. 



Soil survey of Kimball County, Nebr., A. H. Meyer, J. O. Veatch, B. W. 

 Tillman, F. A. Hayes, H. C. Mobtlock, and C. E. Collett {U. S. Dept. Agr., 

 Adv. Sheets FMd Oper. Bur. Soils, 1916, pp. 28, fig. 1, map-1). — This survey, 

 made in cooperation with the Nebraska Soil Survey, deals with the soils of an 

 area of 613,120 acres in the extreme western part of the State and lying within 

 the Great Plains province. The county is a high, nearly level to moderately 

 rolling, practically treeless plain with an elevation of from 4,800 to 5,300 ft 

 above sea level. Drainage is generally good. 



" The soils of the county are prevailingly light brown in color at the surface 

 with grayish, highly calcareous subsoils having a loose, friable structure. Over 

 the greater part of the county the soils are residual in origin, the material 

 being derived entirely from a single geologic formation. The soils derived from 

 allu%aal deposits constitute about 10 per cent of the area of the county." 

 Twelve soil types of 5 series are mapped, in addition to rough broken land. 

 Sidney loam, Sidney gravelly sandy loam, and Sidney silt loam predominate, 

 occupying 40.3, 28.9, and 12.8 per cent of the total area, respectively. 



The experimental detennination of a dynamic soil moisture minimum, 

 H. E. Pulling {Johns Hopkins Univ. Circ, n. ser.. No. S {1917), pp. 186-188). — 

 It is stated that a method has been devised by the use of which soil samples 

 may be obtained with so small a water content that during 24 hours only 

 about 0.001 gm. is moved through a space having a cross section of 30 sq. mm. 

 The graphs obtained by plotting the data are discussed with their bearings. 



Moisture equilibrium in pots of soil equipped with auto-irrigators, F. S. 

 Holmes {Johns Hopkins Univ. Circ, n. ser.. No. 3 {1917), pp. 208-210). — The 

 author has employed the auto-irrigator devised by Livingston, studying the 

 details of adjustment required by this device for different soils and different 

 moisture contents. Three soils were used, medium fine white sand, light clay 

 loam, and a mixture of volumetrically equal parts of the two, each being 

 tested, with auto-irrigators having 1, 3, and 5 porous cups, respectively. 



Approximate equilibrium of the soil moisture content was reached in 75 

 days for the loam, 80 for the mixture, and 90 for the sand. The number of 

 porous clay cups appeared to influence the period required to attain equilibrium in 

 case of the sand but not in case of the loam or the loam-sand mixture. The 

 larger the number of cups, the sooner equilibrium was reached. With a pres- 

 sure of 5.5 cm, of a column of mercury, the soil moisture content at equilijjrium 



