LOCATION BUFTON NE+SDEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Vitrandic Haplustepts
TYPICAL PEDON: Bufton silty clay loam - rangeland (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; grayish brown (10YR 5/2) silty clay loam, dark grayish brown (10YR 4/2) moist; moderate medium and fine subangular blocky structure parting to moderate fine granular; hard, firm, strong effervescence; moderately alkaline; clear smooth boundary. (2 to 7 inches thick)
Bw1--6 to 15 inches; light brownish gray (10YR 6/2) silty clay loam, grayish brown (10YR 5/2) moist; moderate medium and coarse prismatic parting to moderate medium and fine subangular blocky; very hard, very firm; violent effervescence; moderately alkaline; clear smooth boundary. (0 to 10 inches thick)
Bw2--15 to 26 inches; light gray (10YR 7/2) silty clay loam, grayish brown (10YR 5/2) moist; moderate medium and coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, very firm; violent effervescence; moderately alkaline; clear wavy boundary. (6 to 14 inches thick)
BCk--26 to 36 inches; light gray (10YR 7/2) silty clay loam, grayish brown (10YR 5/2) moist; moderate coarse prismatic structure parting to weak coarse subangular blocky; hard, firm; many threads and soft masses of lime; violent effervescence; moderately alkaline; gradual wavy boundary. (5 to 12 inches thick)
C--36 to 72 inches; light gray (2.5Y 7/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, firm; violent effervescence; moderately alkaline.
TYPE LOCATION: Dawes County, Nebraska; 10 miles east and 4 miles north of Crawford; 2400 feet west and 200 feet north of the southeast corner, sec. 17, T. 32 N., R. 50 W.
RANGE IN CHARACTERISTICS: The solum thickness ranges from 13 to 43 inches. Typically, these soils contain free carbonates at the surface but the surface few inches are leached in some pedons. Glass shards are present throughout the profile but are most abundant in the residual shale material in the C horizon, and comprise from 20 to 80 percent by volume of the very fine sand and coarse silt fraction. The glass shards have abnormally high values for cation exchange and 15-bar water; the l5-bar water/clay ratio often exceeds 1. The soil has an ustic moisture regime that borders on aridic.
The A horizon has hue of 10YR, value of 4 through 6 and 3 or 4 moist, and chroma of 2. Horizons having values of less than 5.5 and 3.5 moist are less than 7 inches thick. It is silty clay loam, clay loam or silty clay. It is neutral to moderately alkaline.
The Bw horizon has hue of 10YR, value of 5 through 8 and 4 through 7 moist, and chroma of 2 through 4. It is clay loam, silty clay loam, or silty clay averaging between 35 and 45 percent clay. Thin layers exceed 50 percent clay in some pedons. It is slightly alkaline to strongly alkaline.
The BCk horizon has hue of 2.5Y or 10YR, value of 6 through 8 and 5 through 7 moist, and chroma of 2 through 4. Soft masses and threads of secondary calcium carbonates are throughout this horizon. It is typically silty clay loam, clay loam, or silty clay and is moderately alkaline or strongly alkaline.
The C horizon has colors and reaction like the BCk. It is typically silty clay loam, but the range includes silt loam to silty clay.
COMPETING SERIES: The Calendar series is the only competing series in the same family. Calendar soils are moderately deep over shale.
GEOGRAPHIC SETTING: Bufton soils have nearly level to steep slopes. Slopes range from 0 to 20 percent. The Bufton soils formed in material weathered from clayey or silty shales in upland positions, and in colluvial and alluvial material on foot slopes and stream terraces. In some areas these soils are formed in loess-like material that originated from the shales. The mean annual precipitation ranges from 14 to 18 inches, and the mean annual temperature from 46 to 52 degrees
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buffington, Kadoka, Keith, Kyle and Orella soils. The Buffington soils are lower on the landscape, have a mollic epipedon and do not have a cambic horizon. The Kadoka soils are fine silty and have an argillic horizon. Kadoka soils are moderately deep over siltstone and are higher on the landscape. Keith soils have mollic epipedons, formed in loess and are higher on the landscape. Kyle soils have more clay in the series control section and Orella soils are shallow over shale. Kyle and Orella soils are lower on the landscape.
DRAINAGE AND PERMEABILITY: Well drained. Runoff ranges from slow on nearly level areas to rapid on steep slopes. Permeability is moderately slow or slow.
USE AND VEGETATION: Mostly used as rangeland. Native vegetation is primarily western wheatgrass and blue grama. A few areas are cultivated with alfalfa and small grains being the principal crops.
DISTRIBUTION AND EXTENT: Northwestern Nebraska and South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Dawes County, Nebraska, 1972.
REMARKS: The Bufton series was formerly classified as fine, mixed, mesic Ustollic Camborthids. The soil was determined to have an aridic-ustic moisture regime rather than an ustic-aridic regime.
Diagnostic horizons and features recognized in the pedon:
Ochric epipedon - the zone from the surface to a depth of 6 inches. Cambic horizon - the zone from a depth of 6 to 26 inches (Bw horizon). These soils were included in the Buffington series in older surveys.