LOCATION CARTER SDEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Vertic Paleustolls
TYPICAL PEDON: Carter silty clay loam - on a plane south-facing slope of less than 1 percent in native grass. When described the soil was moist between 8 and 34 inches. (Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; weak medium and fine subangular blocky structure parting to weak thin platy; slightly hard, very friable, slightly sticky; neutral; abrupt smooth boundary.
A2--6 to 8 inches; gray (10YR 5/1) silty clay loam, very dark gray (10YR 3/1) moist; weak thin and medium platy structure parting to moderate medium granular; slightly hard, very friable; slightly sticky; neutral; abrupt smooth boundary. (Combined A horizons 6 to 12 inches thick)
Bt1--8 to 11 inches; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; moderate medium columnar structure; extremely hard, extremely firm, very sticky and very plastic; tongues of dark gray (10YR 4/1) soil material; slightly alkaline; abrupt wavy boundary.
Bt2--11 to 13 inches; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure parting to moderate medium blocky; extremely hard, extremely firm, very sticky and very plastic; shiny surfaces on faces of peds; tongues of dark gray (10YR 4/1) soil material; slight effervescence; moderately alkaline; clear wavy boundary.
Bt3--13 to 22 inches; grayish brown (10YR 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak medium blocky structure; extremely hard, extremely firm, very sticky and very plastic; shiny surfaces on faces of peds; slight effervescence; moderately alkaline; gradual wavy boundary. (Combined Bt horizons 8 to 20 inches thick)
Bk--22 to 34 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak medium blocky structure; extremely hard, extremely firm, very sticky and very plastic; few fine accumulations of carbonate; strong effervescence; moderately alkaline; clear wavy boundary. (8 to 25 inches thick)
C--34 to 60 inches; light brownish gray (2.5Y 6/2) silty clay, grayish brown (2.5Y 5/2) moist; massive; very hard, firm, sticky and plastic; common fine nests of salt; strong effervescence; slightly alkaline.
TYPE LOCATION: Tripp County, South Dakota; about 7 miles north of Carter; 1230 feet west and 585 feet south of the northeast corner, sec. 17, T. 100 N., R. 79 W.
RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 10 to 23 inches. The thickness of the mollic epipedon ranges from 10 to 20 inches and extends into or through the Bt horizon. Exchangeable sodium percentage in the Bt and C horizons ranges from 5 to 15 percent.
The A horizon has hue of 10YR, value of 4 or 5 and 2 or 3 moist, and chroma of 1 or 2. It typically is silty clay loam or silt loam, but some pedons are clay loam. It ranges from medium acid to neutral.
Some pedons have a weakly expressed E horizon.
The Bt horizon has hue of 10YR or 2.5Y, value of 4 or 5 and 2 to 4 moist, and chroma of 1 or 2. It is clay averaging between 60 and 70 percent clay. It ranges from neutral to moderately alkaline.
The Bk horizon has hue of 2.5Y or 10YR, value of 5 or 6 and 3 or 5 moist, and chroma of 2 or 3. It is clay or silty clay. It has few to common accumulation of carbonate and is slightly or moderately alkaline. Some pedons have a Bkz or BC horizon.
The C horizon has 5Y or 2.5Y hue, value of 4 to 6 and 3 to 5 moist, and chroma of 1 to 4. It is clay or silty clay. It has few to many accumulations of carbonate and salt crystals. It is slightly or moderately alkaline.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Carter soils are nearly level in slightly concave swales of the uplands and on long plane slopes. Slope gradients range from 0 to 6 percent. These soils formed in clayey material weathered from shale. Mean annual temperature ranges from 46 to 50 degrees F, and mean annual precipitation ranges from 16 to 23 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boro, Boyd, Erd, Hurley, Lakoma, Millboro, Opal, Promise and Witten soils. Boro and Lakoma soils do not have a mollic epipedon. Boro, Boyd, Lakoma, Millboro, Opal, and Promise soils are on nearby uplands. Erd soils are more poorly drained and do not have an abrupt textural change between the A and B horizons. Hurley soils have a natric horizon. Millboro, Promise, and Witten soils do not have an abrupt textural change between the A and B horizons. In addition, Millboro and Witten soils have a fine textured argillic horizon and Promise soils do not have an argillic horizon. Erd, Hurley, and Witten soils are on similar nearby landscapes. Boyd, Lakoma, and Opal soils have bedrock between depths of 20 and 40 inches.
DRAINAGE AND PERMEABILITY: Well drained and moderately well drained. Surface runoff is negligible to very high depending on slope. Permeability is very slow.
USE AND VEGETATION: About equally divided between cropland and rangeland. Native vegetation is mainly western wheatgrass, green needlegrass, blue grama, buffalograss, needleandthread, sedges, and forbs.
DISTRIBUTION AND EXTENT: South-central South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Tripp County, South Dakota, 1975.
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 13 inches (A1, A2, Bt, and Bt2 horizons); argillic horizon - the zone from about 8 to 22 inches (Bt1, Bt2, and Bt3 horizons).