LOCATION KOLLS SDEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Typic Epiaquerts
TYPICAL PEDON: Kolls clay - in a level depression under native grass. When described the soil was dry to 60 inches. (Colors are for moist soil unless otherwise stated)
A--0 to 3 inches; very dark gray (10YR 3/1) silty clay, dark gray (10YR 4/1) dry; weak fine granular and weak fine subangular blocky structure; very hard, firm, sticky and plastic; common cracks about 0.5 inch wide; many roots; slight effervescence; neutral; clear wavy boundary. (2 to 5 inches thick)
Bg--3 to 12 inches; very dark gray (N 3/0) clay, dark gray (N 4/0) dry; weak coarse prismatic structure parting to moderate medium and coarse subangular blocky; extremely hard, very firm, sticky and plastic; common cracks about 0.5 inch wide; many roots; strong effervescence; slightly alkaline; clear wavy boundary. (8 to 30 inches thick)
Bssg--12 to 23 inches; dark gray (N 4/0) clay, gray (N 5/0) dry; weak very coarse subangular blocky structure parting to weak coarse subangular blocky; extremely hard, very firm, sticky and plastic; common cracks about 0.5 inch wide; many roots; many distinct intersecting slickensides; strong effervescence; moderately alkaline; gradual wavy boundary. (0 to 20 inches thick)
BCssyzg--23 to 31 inches; dark gray (N 4/0) clay, gray (N 5/0) dry; weak very coarse subangular blocky structure; extremely hard, very firm, sticky and plastic; common cracks about 0.5 inch wide; common roots; few distinct nonintersecting slickensides; common fine masses of gypsum and other salts; strong effervescence; strongly alkaline; gradual wavy boundary. (0 to 12 inches thick)
Cssyzg--31 to 42 inches; dark gray (5Y 4/1) clay, gray (5Y 5/1) dry, massive; extremely hard, very firm, sticky and plastic; few roots; few distinct nonintersecting slickensides; few fine masses of gypsum and other salts; strong effervescence; strongly alkaline; gradual wavy boundary.
Cyzg--42 to 60 inches; olive gray (5Y 4/2) clay, olive gray (5Y 5/2) dry; massive; extremely hard, very firm, sticky and plastic; few fine masses of gypsum and other salts; strong effervescence; strongly alkaline.
TYPE LOCATION: Jones County, South Dakota; about 8 miles north and 0.5 mile west of Draper; 350 feet east and 200 feet north of the southwest corner, sec. 18, T. 1 N., R. 30 E.
RANGE IN CHARACTERISTICS: The control section typically averages about 60 percent clay and ranges from 60 to 75 percent. When the soil is dry, cracks 1/2 to 2 inches wide and several feet long extend downward through the solum. Few or common brownish redoximorphic concentrations are in the upper 36 inches in some pedons. The thickness of the mollic epipedon typically is less than 20 inches, but exceeds 30 inches in some pedons. Carbonates are at or within a few inches of the surface.
The A horizon has hue of 10YR, 2.5Y or neutral, value of 2 or 3 and 4 or 5 dry, and chroma of 0 or 1. It typically is silty clay but is clay in some pedons. It ranges from neutral to moderately alkaline.
The Bg horizon has hue of 2.5Y, 5Y or neutral, value of 2 or 3 and 4 or 5 dry, and chroma of 0 or 1. It is slightly alkaline or moderately alkaline. Some pedons have a Bw horizon.
The Bssg horizon has hue of 2.5Y, 5Y or neutral, value of 4 or 5 and 5 or 6 dry, and chroma of 0 or 1. It is slightly alkaline or moderately alkaline.
The BCssyzg horizon has hue of 2.5Y, 5Y or neutral, value of 4 or 5 and 5 or 6 dry, and chroma of 0 or 1. It ranges from slightly alkaline to strongly alkaline. It has few to many accumulations of gypsum and other salts.
The Cssyzg and Cyzg horizons have hue of 2.5Y, 5Y or neutral, value of 3 to 5 and 4 to 6 dry, and chroma of 0 to 3. Chroma of 3 is below depths of 40 inches. It has fine accumulations of carbonates in some pedons. It does not have accumulations of gypsum in some pedons. Shale is between depths of 40 and 60 inches in some pedons. It ranges from slightly alkaline to strongly alkaline.
COMPETING SERIES: This is the Beauford soils which do not have carbonates within depths of 28 inches.
GEOGRAPHIC SETTING: The Kolls soils are in flat basins in the uplands. Microrelief is pronounced in some of the more depressed areas. Slopes are 0 to 1 percent. The basins range in size from a few yards in diameter to several hundred acres. The soils formed in local clayey alluvium. Mean annual air temperature ranges from about 45 to 50 degrees F, and mean annual precipitation ranges from 12 to 24 inches. Growing season ranges from 130 to 160 days; growing season precipitation is about 12 to 24 inches; and growing season degree days ranges from 2700 to 3300.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hurley, Kyle, Millboro, Opal, Pierre and Promise soils. Kyle, Millboro, Opal, Pierre and Promise soils are well drained soils on higher landscapes. The Hurley soils have a natric horizon and are at the edges of basins.
DRAINAGE AND PERMEABILITY: Poorly or very poorly drained. No surface runoff occurs unless artificially drained. These soils are ponded from surface runoff from surrounding soils for periods of 15 to 60 days in most years. These soils are saturated for 30 to 60 days or more to a depth of 3 feet or more in most years. Permeability is very slow except after periods of drought when initial intake may be rapid due to cracks.
USE AND VEGETATION: Mostly native range and hayland. Western wheatgrass is the principal native grass with smaller amounts of blue grama, buffalograss, and sedges. Ponded areas support a stand of spikesedge, reedgrass, cordgrass, and smartgrass.
DISTRIBUTION AND EXTENT: Central South Dakota, mostly west of the Missouri River. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bismarck, North Dakota
SERIES ESTABLISHED: Mellette County, South Dakota, 1971.
REMARKS: Revised 3/96.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 12 inches (A and Bg horizons); cambic horizon - the zone from about 12 to 31 inches (Bssg and BCssyzg horizons).