LOCATION DEMPSTER SD+IA MNEstablished Series
TAXONOMIC CLASS: Fine-silty over sandy or sandy-skeletal, mixed, superactive, mesic Udic Haplustolls
TYPICAL PEDON: Dempster silt loam - on a 1 percent south-facing slope in a cultivated field. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, friable; slightly acid; abrupt smooth boundary.
A--6 to 10 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak coarse prismatic structure parting to weak coarse subangular blocky and weak fine granular; slightly hard, friable; slightly acid; clear wavy boundary. (Combined A horizon is 6 to 12 inches thick.)
Bw1--10 to 18 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) crushing to dark brown (10YR 4/3) moist; weak coarse and medium prismatic structure parting to weak coarse and medium subangular blocky; slightly hard, friable, slightly sticky; neutral; gradual wavy boundary.
Bw2--18 to 29 inches; brown (10YR 5/3) silty clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse and medium subangular blocky structure; slightly hard, friable, slightly sticky; neutral; clear wavy boundary. (Combined B horizon is 14 to 28 inches thick.)
Bk--29 to 36 inches; pale brown (10YR 6/3) loam, dark grayish brown (2.5Y 4/2) moist; weak very coarse and coarse subangular blocky structure; slightly hard, friable, slightly sticky; many fine and medium masses of carbonate; strong effervescence; moderately alkaline; clear smooth boundary. (0 to 9 inches thick)
2C--36 to 60 inches; brown (10YR 5/3) gravelly sand, dark brown (10YR 4/3) moist; single grain; loose; moderately thick carbonate crusts on undersides of pebbles; strong effervescence; moderately alkaline.
TYPE LOCATION: Lake County, South Dakota; about 2 miles west of Chester; 1,295 feet east and 725 feet north of the southwest corner of sec. 16, T. 105 N., R. 51 W.
RANGE IN CHARACTERISTICS: The depth to stratified sand and gravel ranges from 20 to 40 inches. Depth to carbonates ranges from 20 to 40 inches. Thickness of mollic epipedon ranges from 10 to 20 inches.
The A horizon has hue of 10YR, value of 3 or 4 and 2 or 3 moist, and chroma of 1 or 2. It typically is silt loam, but some pedons are silty clay loam. It ranges from moderately acid to neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 3 to 5 moist, and chroma of 2 to 4. It is silt loam or silty clay loam averaging between 24 and 30 percent clay. It is slightly acid or neutral.
The Bk horizon has hue of 10YR or 2.5Y, value of 5 or 6 and 4 or 5 moist, and chroma of 2 to 4. It is loam, silt loam, silty clay loam, or clay loam. It is slightly or moderately alkaline. Masses of carbonates are common or many.
The 2C horizon has hue of 7.5YR to 2.5Y. It is gravelly sand, gravelly loamy sand, very gravelly sand and very gravelly loamy sand and contains 15 to 50 percent pebbles. Pebbles and stones are coated on the undersides by carbonates, especially in the upper part of the horizon. It is slightly or moderately alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils are nearly level to moderately sloping on glacial stream terraces and outwash plains. Surfaces are plane or convex; and slope gradients range from 0 to 9 percent. Dempster soils formed in silty sediments overlying outwash sand and gravel. The mean annual precipitation ranges from 20 to 26 inches, and the mean annual temperature ranges from 45 to 54 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Egan, Graceville, Talmo, and Wentworth soils. Egan and Wentworth soils are on adjacent-higher upland positions in the landscape. They do not have sand and gravel above depths of 60 inches. The Graceville soils typically are on slightly lower positions or are on similar landscapes and have sand and gravel at depths of 40 to 60 inches. The Talmo soils are typically on crests and knolls and have sand and gravel within a depth of 14 inches.
DRAINAGE AND PERMEABILITY: Well drained; surface runoff is medium or low; permeability is moderate in the silty materials and moderately rapid or rapid in the sand and gravel.
USE AND VEGETATION: Most areas of these soils are used to grow corn and small grains. Native vegetation is big bluestem, little bluestem, needlegrasses, blue grama, and sideoats grama and sedges.
DISTRIBUTION AND EXTENT: East-central and southeastern South Dakota and northwest Iowa. It is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Lake County, South Dakota, 1970.
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 18 inches (Ap, A, Bw, horizons).