LOCATION WEWELA SD+NEEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Argiustolls
TYPICAL PEDON: Wewela fine sandy loam - on a northeast-facing slope of 5 percent under cropland. When described the soil was dry to 13 inches and moist below. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 4 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure parting to moderate medium granular; hard, very friable; neutral; abrupt smooth boundary.
A--4 to 8 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse and medium subangular blocky structure; hard, very friable; neutral; clear smooth boundary. (Combined thickness of the A horizons is 7 to 12 inches.)
Bt--8 to 13 inches; light olive brown (2.5Y 5/4) sandy clay loam, olive brown (2.5Y 4/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, firm; coatings of dark colored A horizon material on sides of ped; neutral; gradual wavy boundary. (3 to 15 inches thick)
2BC--13 to 18 inches; light brownish gray (2.5Y 6/2) and olive yellow (2.5Y 6/6) clay, grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/8) moist; moderate coarse blocky structure; hard, firm; tonguing of A horizon in vertical cracks; neutral; gradual wavy boundary. (0 to 10 inches thick)
2C--18 to 26 inches; light brownish gray (2.5Y 6/2) and olive yellow (2.5Y 6/6) shaly clay, grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/8) moist; massive; hard, firm; neutral; gradual wavy boundary.
2Cr--26 to 60 inches; light brownish gray (2.5Y 6/2) and olive yellow (2.5Y 6/6) shale, grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/8) moist; platy; brittle; few fine accumulations of carbonate; strong effervescence on surface of shale fragments, interior does not effervesce; slightly alkaline.
TYPE LOCATION: Tripp County, South Dakota; about 19 miles south of Winner; 1850 feet south and 132 feet east of the northwest corner of sec. 29, T. 96 N., R. 76W.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon ranges from 7 to 15 inches and extends into the B horizons of some pedons. The depth to free carbonate ranges from 18 to 35 inches and the depth to shale ranges from 22 to 36 inches. Tongues of A horizon extend through the solum in most pedons.
The A horizon has hue of 10YR, value of 4 or 5 and 2 or 3 moist, and chroma of 1 or 2. It commonly is fine sandy loam, but is loam or loamy fine sand in some pedons. It is slightly acid or neutral.
The Bt horizon has hue of 10YR or 2.5Y, value of 5 or 6 and 3 to 5 moist, and chroma of 2 to 4. It is clay loam, loam, or sandy clay loam averaging between 20 and 35 percent clay. It is slightly acid or neutral.
The 2BC horizon has hue of 10YR or 2.5Y, value of 5 or 6 and 4 to 6 moist, and chroma of 2 to 8. It averages between 45 and 55 percent clay and is slightly acid or neutral.
Some pedons have a 2Bk horizon.
The 2C horizon has hue of 10YR, 2.5Y, and 5Y; value of 5 to 8 and 4 to 6 moist; and chroma of 2 to 8. It is clay or silty clay and neutral to moderately alkaline. It has up to 35 percent by volume fragments of shale.
The Cr horizon is bedded shale. Accumulations of carbonate are in the upper part of the shale in most pedons. It is neutral to moderately alkaline.
COMPETING SERIES: These are the Glenham, Gosper, Houdek, Ree, and Wineg series in the same family. Glenham and Houdek soils contain less sand and more pebbles and formed in glacial till. Gosper, Ree, Reventon, and Wineg do not have shale between depths of 20 and 40 inches. In addition, Reventon and Wineg soils have a drier climate.
GEOGRAPHIC SETTING: Wewela soils are on nearly level to sloping uplands. Slope gradients range from 0 to 9 percent and surfaces are plane or convex. These soils formed in loamy material over residuum from clayey shales. Mean annual air temperature ranges from about 46 to 50 degrees F, and mean annual precipitation ranges from 18 to 24 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anselmo, Boyd, Holt, Lakoma, Labu, and the Woodly soils. Anselmo and Holt soils generally are above the Wewela soils and are coarse-loamy and do not have shale above depths of 40 inches. Boyd, Lakoma, and Labu soils generally are below the Wewela soils and are fine-textured. Woodly soils are in concave positions and do not have shale above depths of 40 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low on the nearly level and medium on the sloping areas. Permeability is very slow.
USE AND VEGETATION: Used for native pasture, hayland or cropland. Alfalfa, corn, sorghum, and spring grains are the main crops. The dominant native vegetation is little bluestem, prairie sandreed, needleandthread, western wheatgrass, blue grama, switchgrass, big bluestem, forbs and sedges.
DISTRIBUTION AND EXTENT: South-central South Dakota and north-central Nebraska. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Tripp County, South Dakota, 1975.
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 8 inches (Ap & A horizons); argillic horizon - the zone from about 8 to 13 inches (Bt horizon).