LOCATION DENBY SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Torrertic Haplustepts
TYPICAL PEDON: Denby silty clay - on a south-facing slope of 1 percent in native grass. When described, the soil was moist to a depth of 3 inches. (Colors are for dry soil unless otherwise stated)
A--0 to 3 inches; light brownish gray (10YR 6/2) silty clay, grayish brown (10YR 5/2) moist; weak fine granular structure; hard, firm, sticky and plastic; strong effervescence; moderately alkaline; abrupt smooth boundary. (2 to 6 inches thick)
Bw1--3 to 6 inches; light brownish gray (10YR 6/2) silty clay, brown (10YR 5/3) moist; moderate medium subangular blocky structure; very hard, very firm, sticky and plastic; cracks 1/2 inch to 1 inch wide; strong effervescence; moderately alkaline; abrupt smooth boundary.
Bw2--6 to 22 inches; light brownish gray (10YR 6/2) silty clay, brown (10YR 5/3) moist; weak coarse and medium subangular blocky structure; very hard, very firm, sticky and plastic; cracks 1/2 inch to 1 inch wide; strong effervescence; strongly alkaline; clear smooth boundary. (Combined Bw horizons 10 to 24 inches thick)
BC--22 to 26 inches; light gray (10YR 7/2) clay loam, pale brown (10YR 6/3) moist; weak coarse subangular blocky structure; hard, firm, sticky and plastic; strong effervescence; strongly alkaline; clear wavy boundary.
2C--26 to 60 inches; light gray (10YR 7/2) silty clay loam with thin layers of silt loam and loam, pale brown (10YR 6/3) moist; massive; slightly hard, friable; weak bedding planes are evident; strong effervescence; strongly alkaline.
TYPE LOCATION: Pennington County, South Dakota; about 12 miles south and 2 miles east of Wall; 200 feet west and 175 feet south of the northeast corner of sec. 4, T. 3 S., R. 16 E.
RANGE IN CHARACTERISTICS: Carbonates are at or near the surface. The SAR of the A horizon ranges from 4 to 8 and is more than 10 within a depth of 10 inches of the surface.
The A horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 3 to 5 moist, and chroma of 2 or 3. It is silty clay or silty clay loam. It ranges from neutral to moderately alkaline.
The Bw horizon has hue of 2.5Y, 10YR, or 7.5YR; value of 5 to 8 and 4 to 7 moist; and chroma of 2 to 4. It is clay, silty clay, clay loam, or silty clay loam. It ranges from slightly to moderately alkaline.
The BC horizon has hue of 2.5Y, 10YR, or 7.5YR; value of 6 to 8 and 4 to 6 moist; and chroma of 2 to 4. It is clay, silty clay, or clay loam. It ranges from slightly to strongly alkaline.
The 2C horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 6 to 8 and 5 to 7 moist; and chroma of 2 to 4. It typically is silty clay loam or silt loam stratified with layers of very fine sandy loam to clay and contains less than 35 percent clay. Bedding planes are evident in most pedons. The 2C horizon ranges from slightly or strongly alkaline. Common fine nests of salts are in some pedons. Mudstone or siltstone is below a depth of 40 inches in some pedons.
COMPETING SERIES: These are the Dominguez, Heldt, Littlenan, and Lockerby series. Dominguez soils have a lower SAR than 10 and have redder than 7.5YR hues. Heldt soils have a lower SAR than 10 in the control section and have greater than 35 percent clay in the C horizon. Littlenan soils have weathered shale paralithic contact within depths of 20 to 40 inches. Lockerby soils do not have a cambic horizon and have shale bedrock within depths of 21 to 40 inches.
GEOGRAPHIC SETTING: Denby soils are on level to nearly level terraces, uplands, and alluvial fans. Slopes are plane or slightly concave and range from 0 to 4 percent. Denby soils formed in clayey over silty sediments weathered from sodium rich sedimentary rocks. Mean annual air temperature ranges from 45 to 53 degrees F, and the mean annual precipitation ranges from 12 to 16 inches. Growing season is about 120 to 150 days; average growing season precipitation ranges from 11 to 14 inches; and growing degree days are about 2500 to 3200.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cedarpass, Interior, Norrest, and Whitewater soils. Cedarpass and Interior soils have a fine-silty control section. Cedarpass soils are on similar landscapes as the Denby soils. Interior soils are in drainageways and on flood plains. Norrest and Whitewater soils have bedrock at a depth of 20 to 40 inches. They are slightly higher on the landscape.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low or medium depending on slope. Permeability is slow.
USE AND VEGETATION: Used primarily as range. The native vegetation dominantly is western wheatgrass, green needlegrass, blue grama, buffalograss, and pricklypear. Wheat, oats, and alfalfa are the principal crops.
DISTRIBUTION AND EXTENT: Southwestern South Dakota. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Jackson County, South Dakota, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of about 3 inches (A horizon); cambic horizon - the zone from a depth of 3 to 26 inches (Bw1, Bw2, and BC horizons).
ADDITIONAL DATA: NSSL Lab Data - 82P829.