LOCATION BOYD SD+NEEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Leptic Haplusterts
TYPICAL PEDON: Boyd silty clay - on a south-facing slope of 7 percent in native grass. When described the soil was moist throughout. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 5 inches; dark gray (10YR 4/1) silty clay, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to moderate fine granular; very hard, very firm, very sticky and very plastic; slight effervescence; slightly alkaline; abrupt smooth boundary. (3 to 7 inches thick)
Bw--5 to 13 inches; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; very hard, very firm, very sticky and very plastic; slight effervescence; slightly alkaline; clear wavy boundary.
Bss--13 to 23 inches; dark gray (10YR 4/1) clay, dark grayish brown (10YR 4/2) moist; weak coarse blocky structure; extremely hard, extremely firm, very sticky and very plastic; few non-intersecting slickensides; few fine accumulations of carbonates; strong effervescence; slightly alkaline; clear wavy boundary. (Combined Bw and Bss horizons 12 to 26 inches thick)
BCss--23 to 27 inches; dark gray (10YR 4/1) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse and medium blocky structure; extremely hard, extremely firm, very sticky and very plastic; few non-intersecting slickensides; 10 percent by volume of shale fragments; few fine gypsum crystals; strong effervescence; neutral; clear wavy boundary. (0 to 15 inches thick)
C--27 to 31 inches; grayish brown (2.5Y 5/2) clay, olive gray (5Y 4/2) moist; olive brown (2.5Y 4/4) mottles; weak coarse blocky and platy structure; very hard, very firm, very sticky and very plastic; 30 percent by volume of shale fragments; few fine accumulations of carbonates in seams of shale; slight effervescence; neutral; clear wavy boundary. (0 to 8 inches thick)
Cr--31 to 60 inches; gray (5Y 5/1) bedded shale, olive gray (5Y 4/2) moist; olive brown (2.5Y 4/4) mottles; brittle; many fine accumulations of carbonates in cracks and seams of shale; slight effervescence; neutral.
TYPE LOCATION: Charles Mix County, South Dakota; about 3 miles south of Lake Andes; 1850 feet east and 750 feet south of the northwest corner of sec. 21, T. 96 N., R. 65 W.
RANGE IN CHARACTERISTICS: Depth to shale ranges from 20 to 40 inches. Depth to carbonates ranges from 0 to 18 inches. Thickness of the mollic epipedon ranges from 7 to 15 inches and extends into the Bw horizon. Cracks 1/2-inch to 1-inch wide and several feet long commonly extend through the solum when dry. Tongues of the A horizon material are common in the Bw, Bss and BCss horizons, and some extend into the C horizon. The soil has an EC of 2 mmhos/cm or less throughout.
The A horizon has hue of 2.5Y or 10YR, value of 4 or 5 and 2 or 3 moist, and chroma of 1 or 2. It is silty clay or clay. It ranges from neutral to moderately alkaline.
The Bw and Bss horizons have hue of 2.5Y or 10YR, value of 4 to 6, and 3 to 5 moist, and chroma of 1 to 3. They are silty clay or clay and averages from 45 to 60 percent clay. They range from neutral to moderately alkaline and have few fine accumulations of carbonate in the lower part.
The BCss horizon has hue of 10YR, 2.5Y, or 5Y; value of 4 to 6 dry or moist; and chroma of 3. It is silty clay or clay and averages from 45 to 60 percent clay. It ranges from neutral to moderately alkaline. Some pedons have Bk or By horizons.
The C horizon has hue of 10YR, 2.5Y, or 5Y hue; value of 4 to 6 and 4 or 5 moist; and chroma of 2 or 3. It ranges from neutral to moderately alkaline. Some pedons contain few to many nests of gypsum and other salts. It contains 5 to 50 percent shale fragments.
The Cr horizon has hue of 2.5Y or 5Y, value of 4 to 7 (dry or moist), and chroma of 1 to 3. It ranges from neutral to moderately alkaline. Some pedons contain few to common nests of gypsum and other salts in the upper part.
COMPETING SERIES: This is the Opal series. Opal soils have more than 60 percent clay in the Bss horizon.
GEOGRAPHIC SETTING: Boyd soils are gently sloping to steep on uplands. Slope gradients range from 3 to 30 percent. Boyd soils formed in residuum weathered from clay shale. The annual precipitation ranges from 18 to 26 inches, and the mean annual air temperature ranges from 44 to 52 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boro, Lakoma, Millboro, Promise, Reliance, Sansarc and Witten soils. Boro, Lakoma, Millboro, Promise and Reliance soils are on similar landscapes. Boro soils lack a mollic epipedon and have shale at greater depths. Lakoma soils do not have mollic epipedons. Millboro soils have argillic horizons and have shale at depths below 40 inches. Promise soils are very fine textured and are deeper to shale. Reliance soils have an argillic horizon and contain less clay. Sansarc soils are on steep nearby landscapes, lack a mollic epipedon, and have shale within depths of 20 inches. Witten soils are in swales and have mollic epipedons greater than 20 inches thick and have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to very high depending on slope. Permeability is slow or very slow, except after dry periods when initial intake in cracks is rapid.
USE AND VEGETATION: In cropland and rangeland. Small grain, sorghum, and alfalfa are the main crops. Native grasses are western wheatgrass, blue grama, green needlegrass, and some sideoats grama.
DISTRIBUTION AND EXTENT: South-central South Dakota and north-central Nebraska. The Boyd soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Cedar County, Nebraska, 1928.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - zone from the surface of the soil to a depth of 13 inches (Ap and Bw horizons).
The site will be redescribed in the field to better document the Vertisol criteria.