LOCATION TOKO SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Argiaquic Argialbolls
TYPICAL PEDON: Toko fine sandy loam - on a concave slope of less than 1 percent in a depression in a formerly cultivated field. When described the soil was moist to 28 inches and saturated below. (Colors are for moist soil unless otherwise stated)
Ap--0 to 8 inches; black (10YR 2/1) fine sandy loam, dark gray (10YR 4/1) dry; few fine prominent dark yellowish brown (10YR 4/6) redox concentrations; weak fine granular structure; soft, very friable; many very fine and fine roots throughout; common very fine tubular pores; neutral; abrupt smooth boundary. (Combined A horizons 4 to 15 inches thick)
E--8 to 11 inches; dark grayish brown (10YR 4/2) sandy loam, light brownish gray (10YR 6/2) dry; common fine prominent dark yellowish brown (10YR 4/6) redox concentrations; weak thin platy structure; soft, very friable; common very fine and fine roots throughout; common very fine and fine tubular pores; few fine iron-manganese concretions; slightly alkaline; clear smooth boundary. (3 to 10 inches thick)
Bt1--11 to 18 inches; very dark gray (10YR 3/1) sandy clay loam, gray (10YR 5/1) dry; few fine prominent dark yellowish brown (10YR 4/6) redox concentrations; moderate medium and coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots throughout; few very fine tubular pores; few manganese or iron-manganese stains throughout and clay films on vertical faces of peds; few fine iron-manganese concretions; slightly alkaline; clear wavy boundary.
Bt2--18 to 28 inches; very dark grayish brown (10YR 3/2) sandy clay loam, grayish brown (10YR 5/2) dry; few fine prominent dark yellowish brown (10YR 4/6) redox concentrations; moderate medium and coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, firm, slightly sticky and slightly plastic; few very fine roots throughout; few very fine tubular pores; common manganese or iron-manganese stains throughout and clay films on vertical faces of peds; few fine iron-manganese concretions; slightly alkaline; clear wavy boundary. (Combined Bt horizons 10 to 25 inches thick)
Bk--28 to 38 inches; grayish brown (2.5Y 5/2) sandy loam, light gray (2.5Y 7/2) dry; common fine and medium prominent dark yellowish brown (10YR 4/6) redox concentrations; weak fine subangular blocky structure; soft, very friable; few very fine roots throughout; few very fine tubular pores; common manganese or iron-manganese stains throughout; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 30 inches thick)
C1--38 to 56 inches; olive brown (2.5Y 4/3) loamy sand, light yellowish brown (2.5Y 6/3) dry; many fine and medium distinct dark yellowish brown (10YR 4/4) redox concentrations and common fine prominent gray (10YR 5/1) redox depletions; single grain; loose; common manganese or iron-manganese stains throughout; strongly effervescent; moderately alkaline; gradual wavy boundary.
2C2--56 to 80 inches; grayish brown (2.5Y 5/2) clay loam, light gray (2.5Y 7/2) dry; common fine and medium prominent dark yellowish brown (10YR 4/4) redox concentrations and many fine and medium distinct gray (10YR 5/1) redox depletions; massive; hard, firm, slightly sticky and slightly plastic; few very fine tubular pores; few fine masses of iron-manganese; strongly effervescent; 2 percent gravel; moderately alkaline.
TYPE LOCATION: Spink County, South Dakota; about 2 miles west of Tulare; 380 feet north and 325 feet east of the southwest corner of Sec. 29, T. 115 N.- R. 64 W.; USGS Topographical Quadrangle - TULARE, S. DAK.; Latitude: 44 degrees, 44 minutes, and 7 seconds N.; Longitude: 98 degrees, 33 minutes, and 46 seconds W.
RANGE IN CHARACTERISTICS: The depth to the till typically is greater than 40 inches, but ranges from 30 to greater than 60 inches. Mollic colors ranges to a maximum depth of 15 to 40 inches. The mollic epipedon may include the E and Bt horizons. The depth to carbonates is 25 to greater than 60 inches and is associated with the depth to till.
The A horizon has hue of 10YR, value of 2 or 3 and 3 to 5 dry, and chroma of 1. It typically is fine sandy loam but is loam or sandy loam in some pedons. It has few to common, faint or distinct redox features in some pedons. It is moderately acid to neutral.
The E horizon has hue of 10YR, value of 3 to 5 and 5 to 7 dry, and chroma of 1 or 2. It is fine sandy loam, sandy loam, loamy fine sand, or loamy sand. The E horizon extends into the Bt horizon in some profiles and bleached sand and silt grains coat faces of peds in the Bt horizon. Redox features range from few to many and faint to prominent. It is moderately acid to slightly alkaline.
The Bt horizon has hue of 2.5Y or 10YR, value of 3 to 5 and 4 to 7 dry, and chroma of 1 or 2. It is sandy clay loam, sandy loam, fine sandy loam, loam, or clay loam and the percent clay ranges from 18 to 35 percent. Few or common, faint or distinct redox features are in most pedons. It is slightly acid to slightly alkaline. Some pedons have a Btk horizon.
The Bk horizon has a hue of 5Y to 10YR, value of 4 to 6 and 5 to 8 dry, and chroma of 1 to 4. It is loam, fine sandy loam, sandy loam, loamy sand, loamy fine sand, sandy clay loam, or clay loam. It is slightly alkaline to strongly alkaline. Redox features range from common to many and faint to prominent. Some pedons have a 2Bk horizon. Some pedons do not have a C horizon above the 2C horizon.
The 2C horizon has hue of 5Y to 10YR, value of 4 to 6 and 6 to 8 dry, and chroma of 1 to 4. It is clay loam or loam. It is slightly alkaline to strongly alkaline. Redox features range from common to many and faint to prominent.
COMPETING SERIES: There are no other series in the same family.
GEOGRAPHIC SETTING: Toko soils are in depressions on till plains. Slope gradients are 1 percent or less. The soils formed in glaciofluvial deposits overlying till. Mean annual air temperature ranges from 45 to 48 degree F, and mean annual precipitation ranges from 18 to 21 inches.
GEOGRAPHICAL ASSOCIATED SOILS: These are the Blendon, Carthage, Elsmere, Forestburg, Hand, Henkin, Lawet, Overshue and Shue soils. The well drained Blendon, Hand and Henkin soils and moderately well drained Carthage and Forestburg soils are on nearby uplands. In addition the Blendon, Carthage and Henkin soils are coarse-loamy and the Forestburg soils are sandy over loamy. The somewhat poorly drained Elsmere soils are in nearby swales and are sandy. Lawet soils have a calcic horizon within depths of 16 inches and are at edges of the depressions. The poorly drained Overshue and Shue soils are in shallow and commonly smaller depressions and do not have an albic horizon. In addition, the Overshue soils are coarse-loamy and the Shue soils are sandy over loamy.
DRAINAGE AND PERMEABILITY: Very poorly drained or poorly drained. Surface runoff is ponded. Permeability is slow. A seasonal water table ranges from 1 foot above the surface to 3 feet below the surface at some time during the period March through June in most years. It is from 2 feet above the surface to 1 foot below the surface at some time during the period of March to July in the very poorly drained phase.
USE AND VEGETATION: Mostly cropped, however, excess moisture prevents cultivation in some years. Corn and tame grasses are the most common crops. Cottonwoods and Willow trees are common in uncultivated areas. Native vegetation is mainly prairie cordgrass and sedges.
DISTRIBUTION AND EXTENT: East central South Dakota. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Spink County, South Dakota, 1997.
REMARKS: Diagnostic horizons and features recognized in the pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 8 inches (Ap horizon) ; albic horizon - the zone from 8 to 11 inches (E horizon); argillic horizon - the zone from about 11 to 28 inches (Bt1 and Bt2 horizons).
ADDTIONAL DATA; Laboratory characterization data (NSSL) - S96SD115-010