LOCATION PROSPER SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Argiustolls
TYPICAL PEDON: Prosper loam - on a concave slope of 1 percent in a cultivated field. When described the soil was moist to 60 inches. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak fine granular structure; slightly hard, friable; neutral; abrupt smooth boundary.
A--6 to 9 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak medium subangular blocky structure parting to weak medium and fine granular; slightly hard, friable; neutral; clear wavy boundary. (Combined thickness of the A horizon is 7 to 15 inches.)
Bt1--9 to 18 inches; dark grayish brown (10YR 4/2) clay loam, very dark brown (10YR 2/2) moist; moderate medium prismatic structure parting to moderate medium and fine blocky; hard, friable, sticky; shiny film on faces of peds; neutral; clear wavy boundary.
Bt2--18 to 24 inches; grayish brown (2.5Y 5/2) clay loam, very dark grayish brown (2.5Y 3/2) moist; faces of peds dark grayish brown (2.5Y 4/2); moderate medium prismatic structure parting to moderate medium and fine blocky; hard, firm, sticky; shiny film on faces of peds; slightly alkaline; clear wavy boundary. (Combined thickness of the Bt horizon is 10 to 23 inches.)
Btk--24 to 30 inches; light brownish gray (2.5Y 6/3) clay loam, olive brown (2.5Y 4/3) moist; weak medium prismatic structure parting to weak medium blocky; hard, friable, sticky; shiny film on faces of peds; few fine accumulations of carbonate; strong effervescence; moderately alkaline; gradual wavy boundary. (0 to 12 inches thick)
Bk--30 to 45 inches; light brownish gray (2.5Y 6/3) clay loam, grayish brown (2.5Y 5/3) moist; few fine distinct gray (2.5Y 6/1) redox depletions; weak coarse blocky structure; hard, friable, slightly sticky; many medium and coarse accumulations of carbonate; strong effervescence; moderately alkaline; diffuse wavy boundary. (8 to 16 inches thick)
C--45 to 60 inches; light brownish gray (2.5Y 6/3) clay loam, dark grayish brown (2.5Y 4/3) moist; many coarse distinct gray (2.5Y 6/1) redox depletions and olive yellow (2.5Y 6/6) redox concentrations; weak coarse blocky structure; hard, friable, slightly sticky; common fine dark concretions (iron and manganese oxides); few fine and medium accumulations of carbonate; strong effervescence; moderately alkaline.
TYPE LOCATION: Davison County, South Dakota; 8 miles west and 1 mile south of Ethan; 520 feet north and 208 feet west of the southeast corner of sec. 21, T. 101 N., R. 61 W.
RANGE IN CHARACTERISTICS: Depth to carbonate ranges from 20 to 36 inches. The mollic epipedon ranges from 20 to 30 inches thick and extends into the Bt horizon. The soil contains 0 to 10 percent rock fragments by volume throughout. Some pedons have stones throughout.
The A horizon has value of 3 or 4 and 2 or 3 moist, and chroma of 1 or 2. It typically is loam but is silt loam in some pedons. It is moderately acid to slightly alkaline.
The Bt horizon has hue of 10YR or 2.5Y, value of 3 to 5 and 2 to 4 moist, and chroma of 1 to 3. It typically is clay loam but is silty clay loam in some pedons. Some pedons have thin horizons that exceed 35 percent clay, but the weighted average is between 27 and 35 percent clay. It is neutral or slightly alkaline.
The Btk, Bk, and C horizons have hue of 10YR or 2.5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. These horizons are loam or clay loam and are slightly or moderately alkaline. Carbonate is both disseminated and accumulated in the Btk, Bk, and C horizons. Gypsum crystals and other salts are below depths of 40 inches in some pedons.
COMPETING SERIES: These are the Albinas, Garrett, Haxtun, Jarita, Keya, Renner, Sampson, Tracylee, Vosburg, Wetterdon, Woodly, and Woonsocket soils in the same family. The well drained Albinas soils do not have redox features within depths of 40 inches. Garrett soils are redder with hues of 5YR through 10R. Haxtun soils do not have redox features within depths of 40 inches and typically have buried horizons within 25 inches. Jarita soils have limestone bedrock at depths between 20 and 40 inches and have argillic horizons with hues of 7.5YR or redder. Keya and Renner soils have carbonate at depths more than 36 inches. Sampson soils do not have low chroma redox features within a depth of 40 inches, and have more than 50 percent sand in the C horizon within depths of 40 inches. Tracylee and Wetterdon soils do not have carbonates and low chroma redox features within a depth of 40 inches. Vosburg soils do not have low chroma redox features within a depth of 40 inches and have a drier soil moisture control section. Woodly soils contain 18 to 27 percent clay in the series control section. Woonsocket soils contain 55 to 80 percent fine sand or coarser in the particle size control section.
GEOGRAPHIC SETTING: These soils are level and gently sloping on uplands. Slope gradients typically are 0 to 2 percent but range from about 0 to 6 percent. Surfaces typically are plane or slightly concave. These soils formed in loam or clay loam glacial till. The till commonly is mantled with local alluvium 1 to 3 feet thick. The mean annual air temperature ranges from 45 to 52 degrees F, and precipitation ranges from 17 to 26 inches. Growing season is about 130 to 165 days; average growing season precipitation is 13 to 20 inches; and growing degree days are about 2500 to 3500.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonilla, Clarno, Crossplain, Davison, Dudley, Ethan, Houdek, Stickney, and Tetonka soils. Bonilla soils do not have an argillic horizon and are on similar landscapes. Clarno, Houdek, and Ethan soils have a mollic epipedon less than 20 inches thick and are on the higher parts of the landscapes. The Crossplain soils are in more depressed swales and drainageways and have a fine textured series control section. Davison soils have a calcic horizon within 16 inches and are on slightly higher positions adjacent to swales. Dudley and Stickney soils have a natric horizon and are on the nearly level landscapes with microrelief. Tetonka soils are in shallow depressions, have a fine textured series control section, and have an E horizon.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is negigible to medium depending on slope. Permeability is moderate in the solum and moderately slow in the underlying material. Water table may rise to within 3 feet of surface during the spring and ranges from 3.5 to 5 feet.
USE AND VEGETATION: Most areas are cultivated; small grains, corn, alfalfa, and feed grains are the principal crops. Native vegetation is big bluestem, green needlegrass, sideoats grama, western wheatgrass, leadplant, sedges, and forbs.
DISTRIBUTION AND EXTENT: East-central South Dakota. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Davison County, South Dakota, 1971.
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 24 inches (Ap, A, Bt1, & Bt2 horizons); argillic horizon - the zone from about 9 to 30 inches (Bt1, Bt2 and Btk horizons).