LOCATION VIBORG SD+NDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Pachic Haplustolls
TYPICAL PEDON: Viborg silty clay loam - on a 1 percent southeast-facing plane slope in a cultivated field. When described the soils was dry. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark gray (10YR 4/1) silty clay loam, black (10YR 2/1) moist; weak coarse, medium and fine subangular blocky and weak fine granular structure; slightly hard, friable, slightly sticky; slightly acid; abrupt smooth boundary.
A--6 to 10 inches; dark gray (10YR 4/1) silty clay loam, black (10YR 2/1) moist; weak coarse and medium subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky; neutral; gradual wavy boundary. (Combined A horizons is 8 to 14 inches thick.)
BA--10 to 16 inches; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; weak medium and coarse prismatic structure parting to weak medium and coarse subangular blocky; slightly hard, friable, slightly sticky; neutral; gradual wavy boundary. (0 to 7 inches thick)
Bw1--16 to 21 inches; grayish brown (2.5Y 5/2) silty clay loam, very dark grayish brown (2.5Y 3/2) 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--21 to 29 inches; grayish brown (2.5Y 5/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; few fine faint mottles of light olive brown (2.5Y 5/3) moist; weak coarse prismatic structure parting to moderate coarse and medium subangular blocky; slightly hard, friable, slightly sticky; few very fine accumulations of calcium carbonate; slight effervescence; neutral; clear wavy boundary. (Combined Bw horizon is 12 to 19 inches thick)
Bk1--29 to 37 inches; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; few fine distinct gray (5Y 5/1) redox depletions, and few fine distinct stains of light olive brown (2.5Y 5/6) redox concentrations; moderate coarse, medium, and fine blocky structure; hard, friable, sticky; few fine irregular dark accumulations (iron and manganese oxides); many fine and medium accumulations of calcium carbonate; strong effervescence; moderately alkaline; gradual wavy boundary. (4 to 10 inches thick)
2Bk2--37 to 50 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; common fine and medium distinct gray (5Y 5/1) redox depletions; weak coarse, medium, and fine blocky structure; hard, firm, sticky; common fine stains (oxides) of yellowish brown (10YR 5/6) and strong brown (7.5YR 5/6) moist; common fine dark accumulations (iron and manganese oxides); common fine and medium accumulations of calcium carbonate; strong effervescence; moderately alkaline; gradual wavy boundary. (8 to 16 inches thick)
2C--50 to 60 inches; light brownish gray (2.5Y 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; common fine prominent black (10YR 2/1) and gray (5Y 5/1) redox depletions; massive; hard, firm, sticky; common to many fine stains (oxides) of yellowish brown (10YR 5/6) and yellowish red (5YR 4/6) redox concentrations; common fine dark (iron and manganese oxides); few fine accumulations of calcium carbonate; strong effervescence; moderately alkaline.
TYPE LOCATION: Lake County, South Dakota; about 1 mile east and 2 1/2 miles south of Nunda; 375 feet west and 1875 feet south of the northeast corner of sec. 31, T. 108 N., R. 51 W.
RANGE IN CHARACTERISTICS: Depth to free calcium carbonate ranges from 20 to 40 inches. The thickness of the mollic epipedon typically is 20 to 28 inches, but ranges from 20 to 36 inches and extends into the Bw horizon. The series control section is silty clay loam or silt loam averaging between 22 and 35 percent clay. Depth to firm clay loam glacial till or loamy drift ranges from 30 to 40 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 silty clay loam, but some pedons are silt loam. It is slightly acid or neutral. When present the BA horizon has colors and textures of the A horizons.
The Bw horizon has hue of 2.5Y or 10YR, value of 4 or 5 and 3 or 4 moist, and chroma of 2 or 3. Faint mottles are in the lower Bw horizon of most pedons are are few or common. It is neutral or slightly alkaline.
The Bk and 2Bk horizons have hue of 2.5Y or 10YR, value of 5 to 7 and 4 to 6 moist and chroma of 2 or 3. The Bk horizon typically is silty clay loam or silt loam. The 2Bk horizon is clay loam or loam. There are common or many, fine and medium accumulations of calcium carbonate in the Bk and 2Bk horizons. They are mildly alkaline or moderately alkaline. The 2C horizon has hue of 2.5Y or 10YR, value of 5 to 7 and 4 to 6 moist, and chroma of 2 or 3. Mottles and stains (oxides) are common in the 2C horizon. The Bk and 2Bk horizons are slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Duroc, Eltree, Graceville, Trent, and Yankton series. Similar soils are the Alcester, Bon, Bonilla, Chancellor, Davis, Egan, and Wentworth series. Duroc soils have a drier climate, and formed in sediments weathered from sedimentary rocks. Eltree and Yankton soils have free carbonate within depths of 20 inches. Graceville soils have sand and gravel at a depth between 20 and 60 inches. Trent soils do not have glacial sediments above a depth of 40 inches. Alcester and Bon soils have an irregular decrease in organic matter with depth. In addition, Bon soils are fine-loamy. Bonilla and Davis soils are fine-loamy. Chancellor soils are fine textured and are wetter. Egan and Wentworth soils have mollic epipedons less than 20 inches thick.
GEOGRAPHIC SETTING: Viborg soils are level or gently sloping and are in slight depressions, swales, and heads of drains. Surfaces are concave or plane and slope gradients typically are less than 3 percent, but range to 6 percent. These soils formed in silty materials over clay loam glacial till or loamy drift. Mean annual temperature is 45 to 49 degrees F, and mean annual precipitation ranges from 20 to 26 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chancellor, Egan, Wentworth Whitewood and Worthing soils. The well drained Egan and Wentworth soils are on convex slopes. The somewhat poorly drained and poorly drained Chancellor, Whitewood, and Worthing soils are in deeper swales and depressions. Worthing soils are fine textured.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is low or medium. Permeability is moderate in the solum and moderately slow in the underlying material. Soils in swales and along drainageways receive run-in water from adjacent slopes. A seasonal water table is at a depth of 4 to 6 feet.
USE AND VEGETATION: Most areas used to grow corn, but small grain and alfalfa are included in cropping sequence. Native vegetation is big bluestem, green needlegrass, little bluestem, western wheatgrass, sideoats grama, sedges, and forbs.
DISTRIBUTION AND EXTENT: East-central and southeastern South Dakota. Series 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 21 inches (Ap, A, BA and Bw1 horizons).