LOCATION BULLCREEK SDEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Typic Haplusterts
TYPICAL PEDON: Bullcreek clay - on a slope of 1 percent in native grass. (Colors are for dry soil unless otherwise stated)
A--0 to 2 inches; grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; hard, firm, sticky and plastic; common fine roots; cracks 1 inch wide; slightly alkaline; clear smooth boundary. (1 to 4 inches thick)
Bss--2 to 12 inches; grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure parting to weak medium subangular blocky; extremely hard, firm, sticky and plastic; few fine roots; cracks 1 inch wide; few intersecting slickensides; strongly alkaline; gradual wavy boundary. (5 to 15 inches thick)
Bssyz--12 to 24 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure parting to weak medium subangular blocky; extremely hard, firm, sticky and plastic; few fine roots; cracks 1/2 inch wide; few intersecting slickensides; many fine and medium nests of gypsum and other salts; moderately alkaline; gradual wavy boundary. (4 to 15 inches thick)
Byz1--24 to 42 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure; very hard, firm, sticky and plastic; few fine roots; common fine and medium nests of gypsum and other salts; strongly alkaline; gradual wavy boundary.
Byz2--42 to 51 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure; very hard, firm, sticky and plastic; many fine to coarse nests of gypsum and other salts; strongly alkaline; gradual wavy boundary. (Combined Bssyz and Byz horizons 4 to 45 inches thick)
C--51 to 60 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; massive; very hard, firm, sticky and plastic; moderately alkaline.
TYPE LOCATION: Buffalo County, South Dakota; about 2 miles south and 5 miles west of Gann Valley; 500 feet south and 125 feet east of the northwest corner, sec. 11, T. 106 N., R. 69 W.
RANGE IN CHARACTERISTICS: Depth to visible salts ranges from 6 to 20 inches. The surface generally is dispersed and crusted. Below the A horizon, the SAR ranges from 10 to 15 and EC ranges from 4 to 16. When the soil is dry, cracks 1/2 inch to 2 inches wide and several feet long extend downward through the B horizon. The dark colors typically extend into the B horizon.
The A horizon has hue of 10YR, 2.5Y or 5Y, value of 4 or 5 and 2 or 3 moist, and chroma of 1 to 3. It is clay or silty clay. It ranges from neutral to moderately alkaline.
The B horizon has hue of 10YR, 2.5Y or 5Y, value of 4 to 6 and 3 or 4 moist, and chroma of 2 or 3 moist. It typically has accumulations of gypsum and other salts in the lower part. It ranges from slightly alkaline to strongly alkaline. Some pedons have a Bk horizon.
The C horizon has hue of 10YR, 2.5Y or 5Y, value of 5 or 6 and 4 or 5 moist, and chroma of 1 to 4. It ranges from slightly alkaline to strongly alkaline. Accumulations of gypsum crystals and other salts range from few to many.
COMPETING SERIES: These are the Promise soils. Promise soils do not have salts in the B horizon.
GEOGRAPHIC SETTING: Bullcreek soils are on level to moderately sloping upland valleys, alluvial fans and stream terraces. Many areas have slight gilgai microrelief. Slopes typically are less than 3 percent but range from 0 to 9 percent. They formed in dense clayey alluvium. Mean annual air temperature ranges from 45 to 50 degrees F, and the mean annual precipitation ranges from 15 to 24 inches. Growing season is about 130 to 160 days; average growing season precipitation ranges from 13 to 16 inches; and growing degree days are about 3000 to 3300.
GEOGRAPHIC ASSOCIATED SOILS: These are the competing Promise soils and the Chantier, Opal, Sansarc and Wendte soils. Promise, Chantier, Opal and Sansarc soils are on adjacent higher uplands. Chantier and Sansarc soils have bedded shale within a depth of 20 inches. Opal soils have bedded shale within depths of 20 to 40 inches. Wendte soils have a fine-textured control section and are adjacent to larger drainageways below areas of Bullcreek soils.
DRAINAGE AND PERMEABILITY: Moderately well or well drained. Runoff is medium to very high depending on slope. Permeability is very slow, except after dry periods when initial intake may be rapid due to cracking of the surface. Flooding is none or rare. Some pedons have a seasonal water table at a depth of 4 to 6 feet.
USE AND VEGETATION: Used almost entirely for rangeland. Principal grasses occur as a thin stand of western wheatgrass and green needlegrass.
DISTRIBUTION AND EXTENT: Central and south-central South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Brule and Buffalo Counties, South Dakota, 1983.
REMARKS: These soils were previously correlated as Swanboy in Dewey, Hughes, Stanley, Tripp and Walworth Counties, South Dakota.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 2 inches (A horizon); Vertisol criteria - cracks to a depth of 24 inches (A, Bss and Bssyz horizons) and intersecting slickensides (Bss and Bssyz horizons).