LOCATION HETLAND SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Pachic Vertic Argiudolls
TYPICAL PEDON: Hetland silty clay loam, on a southeast facing slope of less than 1 percent in a cultivated field. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 8 inches; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; weak fine granular structure; slightly hard, firm, sticky and plastic; common very fine roots; slightly acid; abrupt smooth boundary. (7to 15 inches thick)
Bt--8 to 23 inches; dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate coarse prismatic structure parting to moderate medium and fine subangular blocky; hard, very firm, sticky and plastic; few very fine roots; common distinct clay films on surface of peds; common dark gray (10YR 4/1) tongues 1/8 to 3/8 inch wide; neutral; clear wavy boundary. (9 to 22 inches thick)
Bk--23 to 41 inches; light brownish gray (2.5Y 6/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure parting to weak medium and fine subangular blocky; hard, firm, sticky and plastic; few very fine roots; few dark gray (10YR 4/1) fingers and tongues 1/8to 3/8 inch wide; few fine dark masses of iron and manganese oxides; common fine and medium prominent brownish yellow (10YR 6/8) Fe concentrations and common fine distinct light gray (2.5Y 7/2) Fe depletions; common fine and medium masses of calcium carbonate; strongly effervescent; slightly alkaline; gradual smooth boundary. (5 to 22 inches thick)
C--41 to 60 inches; light gray (2.5Y 7/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, firm, slightly sticky and slightly plastic; common fine dark masses of iron and manganese oxides; common fine to coarse prominent brownish yellow (10YR 6/8) Fe concentrations; few fine masses of calcium carbonate; strongly effervescent; moderately alkaline.
TYPE LOCATION: Kingsbury County, South Dakota; approximately 2 1/2 miles east and 1 1/2 miles south of Erwin; 96 feet west and 2508 feet south of the northeast corner of sec. 36, T. 112 N., R. 55 W.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon ranges from 16 to 30 inches. The mollic epipedon extends into or includes all of the Bt horizon. Depth to calcium carbonate ranges from 16 to 32 inches. The upper 2/3 of the series control section averages between 35 and 45 percent clay and contains less than 15 percent fine sand or coarser.
The A horizon has color value of 3 or 4 (2 or 3 moist) and chroma of 1 or less. It is silty clay loam or silty clay. It ranges from moderately acid to neutral.
The Bt horizon has hue of 10YR or 2.5Y, value of 3 to 6 (2 to 5 moist) and chroma of 1 to 3. It is silty clay or silty clay loam. Reaction ranges from moderately acid to neutral.
The Bk horizon has hue of 10YR, 2.5Y, or 5Y; value of 5 to 7 (4 to 6 moist); and chroma of 1 to 4. Most pedons have relic mottles with considerable variation in degree and intensity. Few or common, fine to coarse masses of calcium
carbonate are present. Texture is silty clay or silty clay loam. Reaction ranges from slightly alkaline to moderately alkaline.
The C horizon has hue of 10YR, 2.5Y, or 5Y; value of 5 to 7 (4 to 6 moist); and chroma of 1 to 4. Relic mottles vary in degree and intensity. Few to common fine masses of calcium carbonate are in the C horizon of most pedons. The C horizon typically is silty clay loam or silt loam, but some pedons contain thin strata of coarser material. Some pedons have distinct laminations. The reaction ranges from neutral to moderately alkaline.
COMPETING SERIES: These are Gwinner and Nabor soils. Gwinner soils have soil saturation in the lower third of the series control section. Nabor soils are from elevations above 7,700 feet and have a frost free period of 70 to 90 days.
GEOGRAPHIC SETTING: Hetland soils are on nearly level to gently sloping uplands having plane and convex surfaces with slope gradients of 6 percent or less. The soil formed in clayey glaciolacustrine sediments in ice-walled lakes on uplands. The mean annual air temperature ranges from 43 to 48 degrees F., and mean annual precipitation from 20 to 24 inches. Growing season is about 120 to 140 days; average growing season precipitation ranges from 15 to 18 inches; and growing degree days are about 2500 to 2900.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barnes, Buse, Poinsett, Sinai, and Waubay soils. All except the Sinai soils are on adjacent slopes and typically are at a lower elevation than the Hetland soils. The Barnes and Buse soils are fine-loamy. The Poinsett and Waubay soils are fine-silty. The Sinai soils have cracks in most years that are 1/2 inch or more wide at 20 inches, are at least 12 inches long, and extend upward to the base of the Ap horizon and are in positions on the landscape similar to those of the Hetland soils.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is low to high. Permeability is slow.
USE AND VEGETATION: Mostly used to grow corn, soybeans, small grain, and alfalfa. Native vegetation is little bluestem, big bluestem, green needlegrass, sideoats grama, blue grama, prairie junegrass, prairie dropseed, Kentucky bluegrass, sedges, and forbs.
DISTRIBUTION AND EXTENT: Eastern South Dakota and possibly parts of Minnesota and North Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Day County, South Dakota, 1990.
REMARKS: Diagnostic horizons and features recognized in the pedon are: mollic epipedon - the zone from the surface to a depth of 23 inches (Ap and Bt horizons); argillic horizon - 8 to 23 inches (Bt horizon); Pachic feature - a mollic over 16 inches thick, Vertic features - a linear extensibility of more than 6 cm in the upper 100 cm.
This soil may fit into the Oxyaquic Vertic subgroup if soil saturation occurs above a depth of 40 inches. Presently the redox features are considered as relic.