LOCATION WITTEN SD

Established Series
Rev. RFS-DLB-KJH
07/2013

WITTEN SERIES

The Witten series consists of very deep, moderately well drained soils formed in clayey alluvium in swales on uplands. Slopes range from 0 to 3 percent. Mean annual precipitation is about 51 centimeters (20 inches), and mean temperature is about 9 degrees C (48 degrees F).

TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Argiustolls

TYPICAL PEDON: Witten silty clay - on a north-facing slightly concave slope of 1 percent under cultivation. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 13 centimeters (0 to 5 inches); grayish brown (10YR 5/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; hard, friable, sticky and plastic; slight effervescence; neutral; abrupt smooth boundary.

A--13 to 23 centimeters (5 to 9 inches); dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate fine blocky structure and moderate medium subangular blocky; very hard, friable, sticky and plastic; slight effervescence; neutral; abrupt wavy boundary. [Combined A horizon depth is 20 to 38 centimeters (8 to 15 inches) thick.]

Bt1--23 to 36 centimeters (9 to 14 inches); dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure parting to strong medium blocky structure; very hard, very firm, sticky and plastic; slight effervescence; slightly alkaline; clear wavy boundary.

Bt--36 to 66 centimeters (14 to 26 inches); dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; strong fine and medium blocky structure; very hard, very firm, sticky and plastic; strong effervescence; slightly alkaline; clear irregular boundary. [Combined Bt horizon depth is 30 to 51 centimeters (12 to 20 inches) thick.]

BCss--66 104 centimeters (26 to 41 inches); grayish brown (2.5Y 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate medium blocky structure; extremely hard, extremely firm, very sticky and very plastic; few tongues, about .5 to 3 centimeters (1/4 to 1 inch) wide, of dark grayish brown (10YR 4/2); many pressure faces and common slickensides; strong effervescence; moderately alkaline; gradual wavy boundary. [0 to 46 centimeters (0 to 18 inches thick).]

Cy--104 to 152 centimeters (41 to 60 inches); grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; massive; very hard, firm, sticky and plastic; common fine nests of gypsum crystals; strong effervescence; moderately alkaline.

TYPE LOCATION: Tripp County, South Dakota; about 5 miles north of Winner; 1960 feet east and 120 feet south of the northwest corner of sec. 29, T. 100 N., R. 76 W.; latitude 43 degrees, 27 minutes, 29.844 seconds north and longitude 99 degrees, 47 minutes, 1.448 seconds west, NAD83.

RANGE IN CHARACTERISTICS:
Soil Moisture Control Section:
The soil moisture control section is moist in some parts from April to July; intermittently moist from October to March; driest in August and September; typic ustic moisture regime.

Soil Temperature: 8 to 11 degrees C (45 to 50 degrees F)

Particle Size Control Section:
Clay content: 50 to 60 percent
Sand content: 2 to 20 percent

Free carbonate is at or near the surface, but some pedons under native grass are leached of carbonate to depths of 38 centimeters (15 inches). The thickness of the mollic epipedon ranges from 51 to 86 centimeters (20 to 34 inches) and extends into the Bt horizon. Few to many tongues of A horizon extend into the solum.

A horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5 dry and 2 or 3 moist
Chroma: 1 or 2
Texture: silty clay but some pedons are clay
Clay content: 45 to 55 percent
Sand content: 3 to 15
Reaction: neutral or slightly alkaline

Bt horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 dry and 2 or 3 moist
Chroma: 1 or 2.
Texture: clay or silty clay
Clay content: 50 and 60 percent
Sand content: 3 to 15
Reaction: neutral or slightly alkaline

BC horizon:
Hue: 2.5Y or 10YR
Value: 5 or 6 dry and 4 or 5 moist
Chroma: 2 or 3
Texture: clay or silty clay
Clay content: 50 to 60 percent
Sand content: 3 to 15
Reaction: slightly or moderately alkaline
Ped surface features: common or many pressure faces and slickensides. Some pedons have a Bk horizon.

C horizon:
Hue: 2.5Y or 5Y
Value: 5 or 6 dry and 4 or 5 moist
Chroma: 2 or 3
Texture: clay or silty clay
Clay content: 50 to 60 percent
Sand content: 3 to 15 percent
Reaction: slightly or moderately alkaline
Concentrations: few to many accumulations of gypsum

COMPETING SERIES: These are the Oko and Okreek. Oko and Okreek soils have a mollic epipedon less than 20 inches thick. Oko soils contain less clay in the Bt horizon and Okreek soils have bedrock below depths of 40 inches.

GEOGRAPHIC SETTING:
Parent Material: locally transported clayey alluvium
Landscape: gently sloping uplands
Landform: broad to narrow, concave swales
Slope: 0 to 3 percent
Slope shape: concave
Mean annual air temperature: 7 to 10 degrees C (45 to 50 degrees F)
Mean annual precipitation: 410 to 610 millimeters (16 to 24 inches)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carter, Erd, Kolls, Millboro, and Promise soils. Carter and Erd soils are on similar landforms. Carter soils have a very fine textured argillic horizon and have 20 percent or more clay increase from the A horizon to the B horizon. Erd soils are somewhat poorly drained and have salts higher in the profile. Kolls soils are located below Witten in the wetter part of the swales. They have reduced matrix conditions that begin within 10 centimeters of the soil surface. Millboro and Promise soils typically are on nearby uplands above the Witten soils. Promise soils have a very fine textured control section and do not have an argillic horizon.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: moderately well drained
Saturated Hydraulic Conductivity: moderately low
Surface runoff: medium to very high depending on slope

USE AND VEGETATION: Mostly cropped to winter wheat, grain sorghum, oats, and alfalfa. Native vegetation is mainly western wheatgrass, green needlegrass, big bluestem, sideoats grama, blue grama, buffalograss, and sedges.

DISTRIBUTION AND EXTENT:
South-central South Dakota. It is of moderate extent in MLRA's 63A, 63B and 66.

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 66 centimeters [26 inches (Ap, A, Bt1, Bt2 horizons)]; argillic horizon - the zone from about 23 to 66 centimeters [9 to 26 inches (Bt1 & Bt2 horizons)]; slickensides - the zone from about 66 to 104 centimeters (26 to 41 inches); cracks - the zone from about 66 to 104 centimeters (26 to 41 inches).

NCJ 5/2013 - Overall update of Range in Characteristics, competing series, diagnostic features and change to tabular format.

National Cooperative Soil Survey
U.S.A.