LOCATION GRIGSTON KS+NEEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Fluventic Haplustolls
TYPICAL PEDON: Grigston silt loam - in a cultivated field. (Colors are for dry soil unless otherwise stated.)
A1--0 to 16 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; slightly hard, friable; many fine pores; few worm casts; neutral; gradual smooth boundary. (8 to 20 inches thick)
B2--16 to 24 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; slightly hard, friable; many fine open pores; few worm casts; mildly alkaline; gradual smooth boundary. (6 to 24 inches thick)
Clca--24 to 48 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weakly stratified with darker colors; massive; hard, friable; many fine pores; few threads and films of segregated lime; strong effervescence; moderately alkaline; diffuse smooth boundary. (20 to 30 inches thick)
C2--48 to 60 inches; pale brown (10YR 6/3) silty clay loam, brown (10YR 4/3) moist; massive; very hard, firm; stratified with few thin lenses of darker colored silty clay loam; strong effervescence; moderately alkaline.
TYPE LOCATION: Lane County, Kansas; about 13 miles south and 7 1/2 miles east of Dighton, Kansas; 2,250 feet east and 400 feet south of the northwest corner of sec. 29, T. 20 S., R. 27 W.
RANGE IN CHARACTERISTICS: The thickness of the solum ranges from 15 to 40 inches. Depth to free carbonates ranges from 15 to 48 inches. The mollic epipedon is 10 to 20 inches thick. The control section contains less than 15 percent fine sand or coarser material. Stratification, evidenced by minor variations in color value and in clay content, is between depths of 15 to 40 inches.
The A horizon has hue of 10YR, value of 4 or 5 and 2 or 3 moist, and chroma of 1 or 2. It commonly is silt loam but range includes silty clay loam. It is neutral or mildly alkaline.
The B2 horizon has hue of 10YR, value of 5 or 6 and 3 or 4 moist, and chroma of 2 or 3. It is silt loam or silty clay loam. It is mildly or moderately alkaline.
The C horizon has hues of 7.5YR, 10YR, or 2.5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It commonly is silt loam or silty clay loam, but some pedons contain strata of loam or fine sandy loam. This horizon mildly alkaline or moderately alkaline. Horizons containing sand or clay, or both, and faint mottling are below 40 inches in some pedons.
COMPETING SERIES: These are the Bridgeport series in the same family and the Detroit, Hobbs, Hord, Humbarger, McCook, Muir, Roxbury, and Tobin series. Bridgeport and Roxbury soils contain free carbonates at depths less than l5 inches. Detroit soils have a thicker mollic epipedon and the argillic horizon contains more than 35 percent clay. Hobbs soils lack a mollic epipedon and are thinly stratified. Hord, Humbarger, and Tobin soils have a mollic epipedon more than 20 inches thick. McCook soils are coarse-silty. Muir soils have a thicker mollic epipedon and more acid upper horizons.
GEOGRAPHIC SETTING: Grigston soils are on flood plains and low stream terraces. The slope gradient ranges from 0 to 2 percent. The soils formed in calcareous silty alluvium. The mean annual temperature ranges from 50 to 57 degrees F, and the mean annual precipitation ranges from 17 to 28 inches. Thornthwaite annual PE index ranges from 30 to 52.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Roxbury, Hord, and Detroit soils on similar topography, and the Humbarger and McCook soils on lower areas. The competing Bridgeport soils are associated on adjacent fans on flood plains in some areas.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to slow. Permeability is moderate. Ground water table is below 6 feet except during periods of high stream flow.
USE AND VEGETATION: Mostly cropped to wheat, sorghums, and alfalfa. Native vegetation is tall and mid prairie grasses with few to many deciduous trees.
DISTRIBUTION AND EXTENT: Western and central Kansas and southern Nebraska. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Lane County, Kansas, 1970.