LOCATION HERDCAMP SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, mesic Vertic Endoaquolls
TYPICAL PEDON: Herdcamp silty clay - on a smooth slope of 1 percent under grass. (Colors are for moist soil unless otherwise stated)
Azg--0 to 6 inches; very dark gray (5Y 3/1) silty clay, dark gray (5Y 4/1) dry; many dark yellowish brown (10YR 4/4) iron stains, common olive brown (2.5Y 4/4) iron stains, common dark gray (10YR 4/1) mottles; moderate fine granular structure; hard, friable, slightly sticky and plastic; many roots; common fine nests of gypsum and other salts; strong effervescence; moderately alkaline; clear smooth boundary. (3 to 15 inches thick)
Cyzg1--6 to 20 inches; very dark gray (5Y 3/1) silty clay, dark gray (5Y 4/1) dry; many dark yellowish brown (10YR 4/4) iron stains, many dark gray (10YR 4/1) mottles; massive; slightly hard, firm, sticky and slightly plastic; common roots; common fine nests of gypsum and other salts; strong effervescence; moderately alkaline; clear wavy boundary.
Cyzg2--20 to 60 inches; dark gray (5Y 4/1) silty clay, gray (5Y 5/1) dry; common dark yellowish brown (10YR 4/4) iron stains, many olive brown (2.5Y 4/4) iron stains, common dark gray (N 4/0) mottles; massive; hard, firm, slightly sticky and plastic; common roots to 30 inches, few roots to 45 inches; common nests and striations of gypsum and other salts; slight effervescence; moderately alkaline.
TYPE LOCATION: Jones County, South Dakota; about 4 miles east of Okaton; 1970 feet east and 1370 feet north of the southwest corner of sec 7, T. 2 S., R. 28 E.
RANGE IN CHARACTERISTICS: Carbonates are typically at the soil surface but may be leached to a depth of 10 inches in some pedons. The mollic epipedon ranges from 7 to 24 inches in thickness. Clay content ranges from 35 to 55 percent. The series control section contains less than 10 percent sand. Mottles have hue of 2.5Y, 10YR, 7.5YR or are neutral, value of 3 to 5 and 4 to 6 moist, and chroma of 6 or less dry or moist. They occur throughout the profile.
The A horizon has hue of 5Y, 2.5Y, 10YR or is neutral, value of 2 or 3 and 3 or 4 dry, and chroma of 1 or less. It is silty clay loam, silty clay or clay. It is slightly or moderately alkaline. The electrical conductivity ranges from 1 to 3 mmhos/cm.
The C horizon has hue of 2.5Y or 5Y or is neutral, value of 3 or 4 and 4 or 5 moist, and chroma of 2 or less. It is silty clay loam, silty clay or clay. It is slightly or moderately alkaline. It contains many distinct or prominent mottles and few to common nests of gypsum and other salts. The electrical conductivity ranges from 2 to 8 mmhos/cm. Thin strata of coarser textured materials are below depths of 40 inches in some pedons.
COMPETING SERIES: These are the Egas, Knoke and Nishna series. Egas soils contain more than 10 percent sand in the series control section and have an EC of more than 8 mmhos/cm. Knoke and Nishna soils don not have gypsum in the series control section and formed in area with more than 25 inches of precipitation. In addition, Knoke soils have more than 15 percent sand in the particle-size control section.
GEOGRAPHIC SETTING: Herdcamp soils are on floodplains. Slopes are 2 percent or less. The soils formed in calcareous, clayey alluvium. The mean annual air temperature ranges from 45 to 50 degrees F, and the mean annual precipitation ranges from 15 to 24 inches. Growing season ranges from 125 to 150 days; growing season precipitation is about 12 to 17 inches; and growing degree days ranges from 2800 to 3300.
GEOGRAPHICALY ASSOCIATED SOILS: These are the Bullcreek, Lakoma, Opal, Ottumwa, Promise and Wendte soils. The moderately well or well drained Bullcreek soils contain more clay and are in slightly higher positions. The well drained Lakoma and Opal soils have bedded shale within depths of 20 and 40 inches and are on back slopes. The well drained Ottumwa and Promise soils are on adjacent foot slopes. The moderately well drained, stratified Wendte soils are mostly on the larger flood plains.
DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is low or medium depending on slope. Permeability is slow. These soils are subject to flooding and have a water table that fluctuates between depths of 0 and 1 foot.
USE AND VEGETATION: Herdcamp soils are used exclusively for native range. Native vegetation is dominantly prairie cordgrass, river bulrush, softstem bulrush, and common cattail.
DISTRIBUTION AND EXTENT: Central and west-central South Dakota. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Jones County, South Dakota, 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 20 inches (A and Cyzg1 horizons). vertic subgroup properties - linear extensibility of 6.0 cm or greater within a depth of 40 inches.