LOCATION HUGGINS SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Argiustolls
TYPICAL PEDON: Huggins silt loam - on a north facing slope of less than 2 percent under native grassland. When described the soil was moist below 10 inches. (Colors are for dry soil unless otherwise stated.)
A--0 to 5 inches; gray (10YR 5/1) silt loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure parting to weak medium granular; hard, friable; common fine roots; neutral; clear wavy boundary. (4 to 7 inches thick)
Bt1--5 to 10 inches; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak medium and coarse prismatic structure parting to weak medium subangular blocky; hard, firm, slightly sticky, slightly plastic; common fine roots; thin patchy films on faces of peds; slightly alkaline; clear wavy boundary.
Bt2--10 to 17 inches; grayish brown (10YR 5/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure parting to moderate medium blocky; very hard, firm, sticky, plastic; common fine roots; shiny film on faces of peds; slightly alkaline; clear wavy boundary.
Bt3--17 to 21 inches; grayish brown (10YR 5/2) gravelly silty clay, dark grayish brown (10YR 4/2) moist; weak medium and fine subangular blocky structure; very hard, firm, sticky, plastic; few fine flat roots; about 20 percent by volume fragments of siltstone 1 mm to 25 mm in diameter; thin patchy films on faces of peds; slightly alkaline; abrupt wavy boundary. (Combined Bt horizons is 7 to 21 inches thick).
BC--21 to 26 inches; pinkish gray (7.5YR 6/2) extremely gravelly clay loam, dark brown (7.5YR 4/3) moist; weak, medium and fine subangular blocky structure; very hard, friable; about 65 percent by volume fragments of siltstone; few fine roots; slightly alkaline; gradual smooth boundary. (4 to 14 inches thick)
Cr--26 to 60 inches; very pale brown (10YR 8/3) siltstone, brown (10YR 5/3) moist; slight effervescence; moderately alkaline.
TYPE LOCATION: Todd County, South Dakota; about 13 miles west of Mission; 2000 feet north and 900 feet east of the southwest corner of sec. 32, T. 39 N., R. 30 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 9 to 20 inches in thickness and extends into the Bt horizon. Depth to bedrock typically is 20 to 30 inches but ranges from 20 to 40 inches.
The A horizon has hue of 10YR, value of 4 or 5 and 2 or 3 moist and chroma of 1 or 2. It is silt loam or silty clay loam and slightly acid to slightly alkaline.
The Bt horizon has 10YR hue, value of 4 or 5 and 2 to 4 moist and chroma of 2 or 3. It is silty clay loam or silty clay averaging from 35 to 50 percent clay. It is neutral or slightly alkaline. The lower part of the Bt horizon contains 15 to 35 percent by volume fragments of hard siltstone.
The BC horizon has hue of 10YR or 7.5YR, value of 5 to 7 and 4 to 6 moist and chroma of 2 to 4. It is clay loam or silty clay loam and contains 35 to 80 percent by volume fragments of hard siltstone. It is slightly alkaline or moderately alkaline. Some pedons have C horizon. The underlying siltstone bedrock consists of strata of different hardness. Some strata do not have carbonate.
COMPETING SERIES: These are the Ashfork, Blackpipe, Boneek, Boquillas, Chapin, Collbran, Emigrant, Kube, Leyden, Loma, Nuncho, Nunn, Querc, Rednun, Richfield, Ryus, Savo, Showlow, Sofia, Standley, Thunderbird, Torreon, and Wormser. Ashfork and Chapin soils have a calcic horizon. Blackpipe soils have less coarse fragments in the lower Bt and Bk horizons and have carbonate above a depth of 25 inches. Boneek, Collbran, Kube, Loma, Nuncho, Nunn, Rednun, Richfield, Ryus, Savo, Showlow, Sofia, Standley, and Torreon are more than 40 inches deep to bedrock. Boquillas soils have a redder hue in the Bt horizon. Emigrant, Leyden, and Querc soils have more than 15 percent fine sand or coarser. Thunderbird soils have more clay in the A horizon and formed in material weathered from basalt or pyroclastics. Wormser soils have less coarse fragments in the lower part of the solum.
GEOGRAPHIC SETTING: Nearly level to sloping uplands with slope gradients ranging from 0 to 15 percent. Surfaces are plane or slightly convex. Huggins soils formed in residuum weathered from siltstone. The mean annual temperature is 45 to 48 degrees F, and precipitation ranges from 15 to 18 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Epping, Kadoka, Keya, Paka, Shena, Wanblee, and Wortman soils. Epping, Kadoka, Paka and Shena soils are on nearby landscapes. Epping and Shena soils are less than 20 inches to siltstone. Kadoka and Paka soils are fine-loamy. Keya soils have a mollic epipedons greater than 20 inches thick and are in swales. Wanblee and Wortman soils have a natric horizon. They are on nearly level areas of nearby landscapes.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to very high. Permeability is moderately slow.
USE AND VEGETATION: Most areas are used for rangeland. Small grains and alfalfa are the main crops grown, when cultivated. Western wheatgrass, green needlegrass, and blue grama are the main grasses.
DISTRIBUTION AND EXTENT: South-central and southwestern South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Tripp County, South Dakota, 1940.
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 17 inches (A, Bt1, and Bt2 horizons); argillic horizon - the zone from a depth of about 5 to 21 inches (Bt1, Bt2 and Bt3 horizons).