LOCATION REDSTOE SD+NEEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Calciustolls
TYPICAL PEDON: Redstoe loam - in native grass on a 3 percent, west-facing, slightly convex slope. When described the soil was dry to 32 inches and moist from 32 to 44 inches. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; very dark grayish brown (10YR 3/2) loam, black (10YR 2/1) crushing to very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable; strong effervescence; 32 percent calcium carbonate equivalent; slightly alkaline; clear wavy boundary.
Ak--4 to 9 inches; grayish brown (10YR 5/2) loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable; few fine accumulations of carbonate; strong effervescence; 43 percent calcium carbonate equivalent; slightly alkaline; clear wavy boundary. (Combined A horizon ranges from 7 to 10 inches thick.)
Bk1--9 to 15 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to weak medium subangular blocky; slightly hard, very friable; few dark brown (10YR 3/3) organic stains on the vertical faces of the peds in the upper 2 or 3 inches; few fragments of soft siltstone; few fine accumulations of carbonate; strong effervescence; 52 percent calcium carbonate equivalent; slightly alkaline; clear wavy boundary.
Bk2--15 to 23 inches; very pale brown (10YR 7/4) silt loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, very friable; few fragments of soft siltstone; few fine accumulations of carbonate; violent effervescence; 70 percent calcium carbonate equivalent; slightly alkaline; gradual wavy boundary. (Combined Bk horizons is 0 to 24 thick.)
By1--23 to 28 inches; very pale brown (10YR 7/4) and light yellowish brown (10YR 6/4) silt loam, yellowish brown (10YR 5/4) and dark yellowish brown (10YR 4/4) moist; weak coarse and medium subangular blocky structure; slightly hard, very friable; 6 percent by volume fragments of soft siltstone; few fine threads and common medium nests of gypsum; strong effervescence; 31 percent calcium carbonate equivalent; slightly alkaline; gradual wavy boundary.
By2--28 to 32 inches; very pale brown (10YR 7/4) silt loam, yellowish brown (10YR 5/4) moist; thick platy structure; slightly hard, very friable; 12 percent by volume fragments of soft siltstone; many threads and nests of gypsum, strong effervescence; 70 percent calcium carbonate equivalent; slightly alkaline; gradual smooth boundary. (Combined By horizons is 0 to 15 inches thick.)
Cr--32 to 44 inches; very pale brown (10YR 8/4) siltstone, brownish yellow (10YR 6/6) moist; many nests and seams of gypsum between rock fracture planes; 68 percent calcium carbonate equivalent; strong effervescence; neutral.
TYPE LOCATION: Davison County, South Dakota; about 5 miles south of Bett; 2155 feet south and 285 feet east of the northwest corner of sec. 22, T. 102 N., R. 61 W.
RANGE IN CHARACTERISTICS: The depth to siltstone typically is 24 to 32 inches, but ranges from 20 to 40 inches. The thickness of the mollic epipedon ranges from 7 to 12 inches. In some native grass areas, pedons are leached of carbonate to a depth of 6 inches. The control section typically is silt loam or silty clay loam estimated to average between 18 and 35 percent clay. Some pedons have up to 15 percent by volume fragments of soft siltstone in the lower part of the subsoil.
The A horizon has hue of 10YR, value of 3 to 5 and 2 or 3 moist, and chroma of 1 to 3. It is loam or silt loam, and ranges from neutral to moderately alkaline.
The Bk and By horizons have hue of 10YR or 2.5Y, value of 4 to 8 and 3 to 6 moist, and chroma of 2 to 4. They are loam, silt loam, or silty clay loam and slightly alkaline or moderately alkaline. The calcium carbonate equivalent ranges from an estimated 30 to 70 percent. Accumulations of carbonate and gypsum typically range from few to many and fine to coarse. Some pedons have AC or C horizons.
The Cr horizon is bedded siltstone in hue of 10YR, 2.5Y, or 5Y; value of 6 to 8 and 4 to 7 moist; and chroma of 3 to 6. Seams of gypsum are between fracture planes of the bedrock in most pedons and ranges up to 1/2 inch or more in thickness. The bedded siltstone is rippable. It is neutral to moderately alkaline.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: The Redstoe soils are on nearly level to steep uplands. Slopes are plane to convex. Slope gradients range from 0 to 25 percent. They formed in residuum derived from soft chalky siltstone of the Niobrara formation. In some areas a thin mantle of glacial till is in the surface 10 inches. The mean annual temperature ranges from 45 to 52 degrees F, and mean annual precipitation range from 17 to 26 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Betts, Clarno, Delmont, Ethan, Firesteel, Gavins, and Hand soils. Betts, Ethan, and Gavins soils are on crests and upper side slopes of the ridges and knolls. Betts and Ethan soils formed in loamy glacial till. Gavins soils do not have a mollic epipedon. Clarno, Delmont, and Hand soils are on similar landscapes. Clarno soils formed in glacial till, Delmont soils are shallow to sand and gravel and Hand soils formed in stratified loamy glacial meltwater deposits. Firesteel soils have a wetter moisture control section and are in swales and low areas.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is low or medium on lower slopes and high on the steeper areas. Permeability is moderate.
USE AND VEGETATION: Most areas are in native vegetation and used for grazing and hay. Native vegetation is mainly little bluestem, big bluestem, sideoats grama, needleandthread, western wheatgrass, and blue grama. Small areas are cultivated. Corn, oats, alfalfa, and grain sorghum are the main crops.
DISTRIBUTION AND EXTENT: South-central South Dakota and northeastern Nebraska. Is is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Davison County, South Dakota, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 9 inches (A and Ak horizons); calcic horizon - the zone from about 4 to 23 inches (Ak, Bk1 and Bk2 horizons).