LOCATION CASE               KS+OK
Established Series
Rev. CRC:JGF
05/2000

CASE SERIES


The Case series consists of very deep, well drained, moderately permeable soils formed in calcareous old alluvium of Tertiary age on uplands of the Southern High Plains Breaks (MLRA-77E). Slopes range from 1 to 15 percent. Mean annual temperature is about 58 degrees F, and mean annual precipitation is about 24 inches.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Calciustepts

TYPICAL PEDON: Case clay loam - on a cultivated 4 percent slope. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 6 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; moderate medium granular structure; hard, friable; common coarse somewhat rounded white carbonate concretions; slight effervescence; mildly alkaline; abrupt smooth boundary. (3 to 8 inches thick)

Bk1--6 to 20 inches; very pale brown (10YR 7/3) clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; hard, friable; many coarse to extremely coarse somewhat rounded calcium carbonate concretions that crumble to medium and coarse fragments, some with irregular hard centers; few soft accumulations of calcium carbonate; strong effervescence; moderately alkaline; gradual smooth boundary. (12 to 24 inches thick)

Bk2--20 to 35 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; weak coarse subangular blocky structure; very hard, friable; common medium and coarse somewhat rounded calcium carbonate concretions that crumble to medium fragments, some with irregular hard centers; common soft accumulations of calcium carbonates on faces of peds, few small accumulations of salt crystals; strong effervescence; moderately alkaline; gradual smooth boundary. (10 to 20 inches thick)

C--35 to 60 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; massive; very hard, friable; few medium somewhat rounded calcium carbonate concretions with hard centers; few soft masses of calcium carbonate; strong effervescence; moderately alkaline.

TYPE LOCATION: Pratt County, Kansas; about 5 miles south and 5 miles west of Cullison; 2150 feet north and 450 feet west of the southeast corner, sec. 31, T. 28. S, R. 15 W.

RANGE IN CHARACTERISTICS: The soil is calcareous and slightly or moderately alkaline throughout. Between the base of the A horizon and a depth of 30 inches the soil contains more than 15 percent calcium carbonate equivalent throughout a layer 6 or more inches thick.

The A horizon has hue of 5YR to 10YR, value of 4 to 7 and 3 to 6 moist, and chroma of 1 to 4. Texture is dominantly clay loam. Loam and fine sandy loam are less common. Calcium carbonate concretions range from none to common. The Bk horizon has hue of 5YR to 10YR, value of 4 through 8 and 3 through 6 moist, and chroma of 2 to 6. Texture is loam or clay loam.

The C horizon has the same color range as the Bk horizon. Texture is loam, clay loam or sandy loam. In some pedons below a depth of 18 inches, some layers are partially indurated but are not continuous.

COMPETING SERIES: These are the Shep, and Weymouth series in the same family and the Mansic, Mansker, and Ost series. Shep soils formed in calcareous alluvial-colluvial sediments of Permian age. Weymouth soils are moderately deep over weathered red clayey shales. Mansic, Mansker, and Ost soils have a mollic epipedon. In addition, Ost soils have an argillic horizon.

GEOGRAPHIC SETTING: Case soils are on convex to plane upland slopes. Slope gradients range from 1 to 15 percent. Case soils formed in calcareous old alluvium (plains sediments) containing 15 to 40 percent calcium carbonate equivalent. Mean annual precipitation ranges from 22 to 26 inches. Mean annual temperature is 57 to 59 degrees F. The Thornthwaite Annual PE Index ranges from 34 to 44.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Mansic and Ost soils and the Abbie, Farry and Fortyone soils. The Mansic and Ost soils are on slightly less sloping positions on the landscape. Farry and Fortyone soils formed in more sandy sediments that contain less carbonates and occur on similar landscapes.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is low to high.

USE AND VEGETATION: These soils are mostly cultivated. Wheat and grain sorghums are the principal crops. Native vegetation is mid and tall prairie grasses.

DISTRIBUTION AND EXTENT: Southern High Plains Breaks (MLRA-77E) of Kansas and adjacent parts of Oklahoma. Case soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Pratt County, Kansas, 1969.

REMARKS: The pedon was redescribed in August 1982 near the type location.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - light colored surface, the zone from 0 to 6 inches.

Calcic horizon - the zone from about 6 to 35 inches.

Ustic moisture regime.


National Cooperative Soil Survey
U.S.A.