LOCATION TETONKA SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Argiaquic Argialbolls
TYPICAL PEDON: Tetonka silt loam - in a level enclosed depression in native grass. When described the soil was moist throughout. (Colors are for moist soil unless otherwise stated)
A--0 to 8 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; few fine brownish yellow (10YR 6/6) dry mottles; weak thin platy structure parting to weak fine and medium granular; slightly hard, very friable; few fine accumulations and concretions (iron and manganese oxides); slightly acid; clear irregular boundary. (6 to 12 inches thick)
E--8 to 14 inches; dark gray (10YR 4/1) silt loam, gray (10YR 5/1 & 6/1) dry; common medium brownish yellow (10YR 6/6) dry redox concentrations; weak thin platy structure parting to weak fine granular; slightly hard, very friable; common fine and very fine pores; common medium accumulations and common fine concretions (iron and manganese oxides); slightly acid; clear wavy boundary. (4 to 12 inches thick)
E/B--14 to 16 inches; dark gray (10YR 4/1) silty clay loam (E), gray (10YR 5/1 & 6/1) dry, very dark gray (10YR 3/1) clay (B), dark gray (10YR 4/1) dry; many medium prominent brownish yellow (10YR 6/6) dry redox concentrations; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few accumulations and common fine and medium concretions (iron and manganese oxides); slightly acid; clear smooth boundary. (0 to 4 inches thick)
Bt1--16 to 22 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; weak medium and coarse prismatic structure parting to moderate fine and medium subangular blocky; extremely hard, firm, sticky and plastic; few fine concretions (iron and manganese oxides); thin continuous shiny film on vertical faces of peds; neutral; gradual wavy boundary.
Bt2--22 to 44 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; weak coarse prismatic structure parting to weak medium subangular blocky; extremely hard, very firm, sticky and plastic; few fine concretions (iron and manganese oxides); faint patchy shiny film on faces of peds; neutral; gradual wavy boundary.
Btg--44 to 50 inches; dark gray (5Y 4/1) and olive gray (5Y 4/2) clay loam, light olive gray (5Y 6/2) dry; few medium distinct light brownish gray (2.5Y 6/2) redox depletions; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky and plastic; few fine concretions (iron and manganese oxides); faint continuous shiny film on surfaces of peds; moderately alkaline; gradual wavy boundary. (Combined Bt horizons 14 to 40 inches thick)
Bg--50 to 56 inches; dark gray (5Y 4/1) and olive gray (5Y 4/2) clay loam, gray (5Y 6/1) and light olive gray (5Y 6/2) dry; common medium distinct brownish yellow (10YR 6/6) and light yellowish brown (2.5Y 6/4) dry redox concentrations; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few fine concretions (iron and manganese oxides); slightly alkaline; clear wavy boundary. (0 to 16 inches thick.)
Bkg--56 to 60 inches; gray (5Y 5/1) and olive gray (5Y 5/2) clay loam, light gray (5Y 7/1 & 7/2) dry; many medium distinct brownish yellow (10YR 6/6) dry redox concentrations; weak coarse platy structure; hard, firm, sticky and plastic; few medium concretions (iron and manganese oxides); few fine accumulations of carbonate; slight effervescence; moderately alkaline. (0 to 30 inches thick)
TYPE LOCATION: Davison County, South Dakota; about 2 miles south of Ethan, 207 feet north of right of way fence and 1105 feet west of the southeast corner of sec. 26, T. 101 N., R. 60 W.
RANGE IN CHARACTERISTICS: Depth to carbonate ranges from 30 to more than 60 inches. The maximum thickness of mollic colors ranges from 24 to 50 inches.
The A horizon has value of 2 or 3 and 4 or 5 dry, and chroma of 1 or 2. It commonly is silt loam or silty clay loam, but some pedons are coarser textured when mantled by sandy eolian material. It ranges from moderately acid to neutral. Few to many, distinct to prominent redox features are in some pedons. The lower boundary ranges from abrupt wavy to clear wavy or irregular with tongues of A extending into the E horizon 1 or 2 inches in most pedons. Some pedons have A/E horizons.
The E horizon has value of 3 to 5 and 5 to 7 dry, and chroma of 1 or 2. It typically is silt loam, but also included is loam and silty clay loam. Bright brownish redox features are in some pedons. It ranges from moderately acid to neutral.
The E/B horizon has colors and textures similar to the E and Bt horizons. It ranges from moderately acid to neutral. Some pedons have a B/E horizon.
The Bt horizon has hue of 10YR, 2.5Y, or 5Y; value of 2 to 4 and 4 to 6 dry; and chroma of 2 or less. It is clay, silty clay, silty clay loam, or clay loam. It ranges from slightly acid to slightly alkaline.
The Bg and Bkg horizons have hue of 2.5Y or 5Y, value of 4 or 5 and 5 to 7 dry, and chroma of 2 or less. They are clay loam, silty clay loam, clay, or silty clay and range from neutral to moderately alkaline.
Where present, the C horizon has hue of 2.5Y or 5Y, value of 4 to 6 and 5 to 7 dry, and chroma of 1 to 4. It is silty clay, silty clay loam, clay, and clay loam. Some pedons are underlain by stratified lenses of sandy loam or loam. The C horizon has few or common, fine to coarse accumulations of carbonate in most pedons. It is neutral to moderately alkaline. Accumulations of gypsum are in the Bg, Bkg, and C horizons of some pedons.
COMPETING SERIES: These are Arbela, Humeston, and Leslie series in the same family. Arbela, Humeston, and Leslie soils are more acid throughout.
GEOGRAPHIC SETTING: The Tetonka soils are in flat closed depressions and in wide flat-bottomed drainageways in the glacial till plains. Slopes are less than 2 percent. They formed in local alluvial sediments overlying glacial till. The mean annual air temperature ranges from 45 to 52 degrees F, and mean annual precipitation ranges from 17 to 26 inches. Growing season is about 120 to 155 days; average growing season precipitation ranges from 13 to 20 inches; and growing degree days are about 2700 to 3500.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chancellor, Clarno, Crossplain, Davison, Egan, Ethan, Harps, Houdek, Onita, Prosper, Stickney, Viborg, Wakonda, Wentworth, and Worthing soils. Chancellor and Crossplain soils do not have E horizons and are in slightly higher positions. The well drained Clarno, Egan, Ethan, Houdek, and Wentworth soils are on steeper higher positions. Prosper and Onita soils do not have E horizons and are in swales and shallow drainageways. In addition, Prosper soils are fine-loamy. Stickney soils have a natric horizon and are on slightly higher positions. The moderately well drained, fine-silty Viborg soils are in slight depressions and swales. Davison, Harps, and Wakonda soils have a calcic horizon within depths of 16 inches and are at edges of depressions. Worthing soils do not have E horizons and are in the lower, more poorly drained positions.
DRAINAGE AND PERMEABILITY: Poorly drained. These soils are ponded after heavy rains and melt waters from snow. Surface drainage is ponded. These soils typically are wet except in late summer and fall unless they have been drained. Permeability is slow. Water tables range from 1 foot above the surface to 4 feet below the surface in the spring of most years.
USE AND VEGETATION: Largely cropped when drained. Small grain, tame grasses, corn, and sorghum are the most common crops. Native vegetation is mainly prairie cordgrass, western wheatgrass, sedges, reedgrasses, bluegrasses, and forbs.
DISTRIBUTION AND EXTENT: Central and southeastern South Dakota east of the Missouri River. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Spink County, South Dakota, 1951.
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 and 14 to about 44 inches (A, E/B, Bt1, and Bt2 horizons); albic horizon - the zone from about 8 to 14 inches (E horizon); argillic horizon - the zone from about 14 to 50 inches (E/B, Bt1, Bt2, and Btg horizons).