LOCATION CACTUSFLAT SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Torrertic Haplustolls
TYPICAL PEDON: Cactusflat silty clay - on a south-facing slope of 1 percent in native grass. When described the soil was dry throughout. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure parting to weak fine and medium granular; soft, friable, sticky and plastic; many fine and medium roots; slight effervescence; slightly alkaline; clear smooth boundary. (1 to 5 inches thick)
Bw1--4 to 11 inches; grayish brown (10YR 5/2) silty clay, very dark grayish brown (10YR 3/2) moist; weak medium and coarse prismatic structure parting to weak medium subangular blocky; very hard, very firm, sticky and plastic; cracks 1/2 to 1 inch wide; common fine and medium roots; slight effervescence; slightly alkaline; clear smooth boundary.
Bw2--11 to 19 inches; light brownish gray (10YR 6/2) silty clay, dark brown (10YR 3/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; very hard, very firm, sticky and plastic; cracks 1/2 to 1 inch wide; common fine and medium roots; slight effervescence; slightly alkaline; gradual wavy boundary. (Combined thickness of the Bw horizons is 8 to 26 inches thick.)
Bk--19 to 25 inches; pale brown (10YR 6/3) silty clay, brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, firm, sticky and plastic; cracks 1/2 to 1 inch wide; few fine and medium roots; common fine and medium accumulations of carbonate; strong effervescence; slightly alkaline; gradual wavy boundary. (0 to 15 inches thick)
2Cz--25 to 31 inches; light gray (10YR 7/2) and very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; massive; hard, friable, sticky and slightly plastic; thin bedding planes evident; common fine and medium accumulations of salts and carbonate; strong effervescence; slightly alkaline; gradual wavy boundary.
2C--31 to 60 inches; light gray (10YR 7/2) clay loam with thin layers of fine sandy loam and silty clay loam, brown (10YR 5/3) moist; massive; hard, friable, sticky and slightly plastic; thin bedding planes evident; strong effervescence; moderately alkaline.
TYPE LOCATION: Jackson County, South Dakota; about 3 miles west and 1 1/2 miles north of Cactus Flat; 2105 feet north and 810 feet west of the southeast corner of sec. 21, T. 2 S., R. 18 E.
RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 0 to 6 inches. The thickness of the mollic epipedon typically is 9 to 12 inches but ranges from 7 to 19 inches. The series control section averages 35 to 50 percent clay and contains much coarse silt and very fine sand.
The A horizon has hue of 10YR, value of 3 to 5 and 2 or 3 moist, and chroma of 1 or 2. It is clay loam, silty clay loam, silty clay or clay. It ranges from neutral to moderately alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 2 to 4 moist, and chroma of 1 to 3. It is clay or silty clay and averages 40 to 60 percent clay. It is slightly alkaline or moderately alkaline and has a SAR of 5 to 25 in some part.
The Bk horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 5 to 8 and 4 to 6 moist; and chroma of 1 to 4. It is silty clay, clay, silty clay loam, or clay loam. It is slightly alkaline and moderately alkaline and has a SAR of 10 to 30.
Some pedons have a BC horizon and it has colors and texture of the Bk horizon.
The 2C horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 5 to 8 and 4 to 6 moist; and chroma of 1 to 4. It typically is clay loam, silty clay loam or loam and is stratified with layers of very fine sandy loam to clay in some part. Stratification is evident. It typically has few to many accumulations of salts in some parts. It ranges from mildly alkaline to strongly alkaline. Mudstone or siltstone are below a depth of 40 inches in some pedons.
COMPETING SERIES: There are no competing series. The Blackpipe, Buffington, Huggins, Kube, Nunn, and Savo series are similar. Blackpipe and Huggins soils have bedrock at a depth of 20 to 40 inches. Buffington soils have less salts and a low SAR. Kube, Nunn, and Savo soils have an argillic horizon and have a low SAR.
GEOGRAPHIC SETTING: The Cactusflat soils are on nearly level to gently sloping concave foot slopes, terraces, uplands, and alluvial fans. Slopes are long and smooth and range from 0 to 6 percent. The soils formed in materials weathered from sodium rich sedimentary rocks. The mean annual temperature ranges from 45 to 53 degrees F, and mean annual precipitation ranges from 12 to 16 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Blackpipe, Nunn, and Savo soils and the Absted, Norrest, and Weta soils. Blackpipe, Nunn, and Savo soils are on the high parts of the landscape. Absted and Weta soils have a natric horizon and are in slightly lower positions on the landscape. Norrest soils do not have a mollic epipedon and are above the Cactusflat soils.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium. Permeability is slow in the solum and moderately slow or moderate in the underlying material.
USE AND VEGETATION: Used primarily as rangeland. Native grasses are western wheatgrass, green needlegrass, buffalograss, and blue grama. Wheat, oats, sorghum, and alfalfa are the principal crops.
DISTRIBUTION AND EXTENT: Southwestern South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Jackson County, South Dakota, 1984.
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 19 inches (A, Bw1, and Bw2 horizons)
ADDITIONAL DATA: NSSL Lab Data 82P828 is for the typical pedon. Other NSSL Lab Data is 82P824.