LOCATION LADELLE SD+MN NDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Cumulic Hapludolls
TYPICAL PEDON: LaDelle silt loam - on a 1 percent slope in a cultivated field. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated)
Ap--0 to 7 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; weak fine and medium granular structure; soft, very friable; slight effervescence; slightly alkaline, abrupt smooth boundary.
A--7 to 20 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; weak medium subangular blocky structure parting to weak fine and medium granular; slightly hard, very friable; strong effervescence; slightly alkaline; gradual wavy boundary. (Combined A horizons 12 to 25 inches thick)
Bk--20 to 35 inches; gray (2.5Y 5/1) silt loam, very dark gray (2.5Y 3/1) moist; weak medium and coarse subangular blocky structure; slightly hard, friable; common fine threads of calcium carbonate; strong effervescence; slightly alkaline; clear wavy boundary. (0 to 20 inches thick)
Akb--35 to 43 inches; dark gray (10YR 4/1) silty clay loam, black (10YR 2/1) moist; weak medium and coarse subangular blocky structure; slightly hard, friable; common fine and medium masses of calcium carbonate; strong effervescence; slightly alkaline, gradual wavy boundary.
C--43 to 60 inches; gray (10YR 5/1) silt loam, very dark gray (10YR 3/1) moist; common fine prominent dark brown (10YR 3/3) redox concentrations; massive; hard, friable; few to common fine and medium coats of calcium carbonate; strong effervescence; slightly alkaline.
TYPE LOCATION: Roberts County, South Dakota; about 3 miles north of Corona; 370 feet north and 270 feet west of the southeast corner, sec. 14, T. 122 N., R. 49 W.
RANGE IN CHARACTERISTICS: Depth to calcium carbonates ranges from 0 to more than 60 inches. Thickness of the mollic epipedon ranges from 17 to 50 inches. The control section is silt loam, silty clay loam or loam averaging between 25 and 35 percent clay and less than 15 percent fine and coarser sand. Buried horizons are below depths of 17 inches in most pedons. Some pedons have gypsum and other salts below 20 inches.
The A horizon has hue of 10YR or neutral, value of 3 or 4 and 2 or 3 moist, and chroma of 1 or less. It typically is silt loam or loam, but is silty clay loam in some pedons. It ranges from slightly acid to slightly alkaline. In some pedons the lower part of the A horizon has a value of 5 dry.
Bw or ABk horizons are in some pedons.
The Bk horizon has hue of 10YR or 2.5Y, value of 3 to 6 and 2 to 5 moist, and chroma of 3 or less. It is silt loam, silty clay loam, or loam and is neutral to moderately alkaline.
The C horizon has hue of 10YR or 2.5Y, value of 3 to 7 and 2 to 5 moist, and chroma of 1 to 4. It is silt loam, silty clay loam, or silty clay. Redox features are variable. It is slightly or moderately alkaline and has few to common fine threads or fine to coarse coats of carbonate. Some pedons have thin strata of sand, silt, clay loam, or clay below depths of 40 inches.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The LaDelle soils are on nearly level stream terraces and flood plains adjacent to major streams and tributaries within the glacial till plains. Slope gradients are less than 2 percent, except along terrace escarpments that range up to 9 percent. They formed in silty alluvial sediments. Mean annual air temperature ranges from 36 to 48 degrees F., and mean annual precipitation ranges from 15 to 24 inches. Growing season is about 105 to 155 days; average growing season precipitation from 14 to 18 inches; and growing degree days are about 2600 to 3300. Elevation above sea level ranges from 650 to 2350 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Divide, Forman, La Prairie, Lamoure, Ludden, Peever, and Poinsett soils. Divide soils have calcic horizons within a depth of 16 inches and are on similar landscape positions as the LaDelle soils. Forman and Peever soils have argillic horizons. Poinsett soils have mollic epipedons less than 16 inches thick. Forman, Peever, and Poinsett soils are on adjacent uplands. La Prairie soils have a fine-loamy series control section. La Prairie soils are on similar landscape positions as the LaDelle soils. Lamoure and Ludden soils have a wetter soil moisture control section. In addition, Ludden soils have a fine textured particle size control section. Lamoure and Ludden soils are on slightly lower landscape positions than the LaDelle soils.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is low to medium. Permeability is moderately slow or moderate. These soils are flooded for short periods from stream overflow. A seasonal high water table is at a depth of 3.5 to 5.0 feet at some time during the period of April through June.
USE AND VEGETATION: Largely used to grow corn, soybeans, small grains, and alfalfa. Native grasses are green needlegrass, big bluestem, switchgrass, indiangrass, and sedges.
DISTRIBUTION AND EXTENT: Northeastern South Dakota and adjacent parts of North Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Spink County, South Dakota, 1955.
REMARKS: Nonflooded and flooded phases recognized.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 43 inches (Ap, A, Bk, Akb horizons).