28 FIELD OPERATIONS OF THE BUREAU OF SOILS, 1916. 



months of April to July, inclusive. The mean annual temperature 

 is reported as 47.5° F. The winters are long and are characterized 

 by low temperatures. There is a normal growing season of 128 

 days. 



The early agriculture of the area consisted entirely of raising 

 cattle on the open range. Farming has been carried on in a small 

 way since about 1884. The present agriculture consists of an exten- 

 sive type of dry-land farming combined with stock raising and of 

 some intensive cropping under irrigation. Only about 6 per cent of 

 the area of the county is under cultivation. 



Of the crops grown, wheat occupies the largest acreage and is the 

 most successful crop growm under dry-farming methods. It is the 

 chief cash crop. About 7,000 acres in the Lodgepole Valley is under 

 irrigation, and about 4,000 acres of this land is under cultivation, 

 chiefly to Irish potatoes, alfalfa, and sugar beets. 



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 alluvial deposits consti- 

 tute about 10 per cent of the area of the county. Loam soils pre- 

 dominate, followed by fine sandy loam and silt loam types. 



The soils of the upland plains are included principally in the 

 Sidney series. The soils occupying alluvial terraces or benches are 

 classed with the Cheyenne and Tripp series, and the recently formed 

 bottom land is classed with the Laurel series. 



The Sidney series is represented by five types and constitutes 

 about seven-eighths of the total area of the county. These types 

 have light-brown surface soils and a lighter colored subsoil. The 

 Sidney soils are mainly residual in origin. They are well drained 

 and productive under favorable conditions of rainfall. 



The Cheyenne soils are derived from alluvial-terrace material with 

 some colluvial wash. The soil is light brown, and the subsoil is 

 grayish or pale yellowish and coarse and porous. The soils are well 

 drained but droughty. These soils are of small extent in Kimball 

 County. 



The Tripp series comprises light-brown or gray surface soils and 

 a light-gray or pale-yellow subsoil. These soils occupy alluvial ter- 

 races. They are well drained and productive under irrigation. 



The soils of the Laurel series are light brown to pale yellowish, 

 with a gravelly stratum in the lower part of the subsoil. These soils 

 are comparable with the Cheyenne, but occupy a lower topographic 

 position and are not so well drained. 



Q 



