LOCATION BORO SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Haplustepts
TYPICAL PEDON: Boro silty clay - on a northeast-facing, slightly convex slope of 6 percent in a cultivated field. When described the soil was moist throughout. (Colors are for dry conditions unless otherwise stated.)
Ap--0 to 3 inches; dark grayish brown (2.5Y 4/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; moderate medium granular structure; slightly hard, firm, sticky, plastic; slight effervescence; slightly alkaline; abrupt smooth boundary. (2 to 5 inches thick)
Bw--3 to 12 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; moderate coarse subangular blocky structure parting to moderate medium blocky and subangular blocky; very hard, firm, very sticky and very plastic; common tongues of dark grayish brown (2.5Y 4/2); few fine accumulations of carbonate; strong effervescence; moderately alkaline; clear wavy boundary. (8 to 15 inches thick)
Bk1--12 to 20 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; moderate medium blocky structure parting to moderate fine blocky; very hard, firm, very sticky and very plastic; few tongues of dark grayish brown (2.5Y 4/2); common fine accumulations of carbonate; strong effervescence; moderately alkaline; gradual wavy boundary.
Bk2--20 to 28 inches; olive (5Y 5/3) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse blocky structure; very hard, firm, very sticky and very plastic; few tongues of grayish brown (10YR 5/2); common fine accumulations of carbonate; strong effervescence; moderately alkaline; clear smooth boundary. (Combined Bk horizon is 7 to 20 inches thick.)
C--28 to 37 inches; olive (5Y 5/3) clay, dark grayish brown (2.5Y 4/2) moist; massive; hard, firm, very sticky and very plastic; strong effervescence; moderately alkaline; clear wavy boundary.
C2--37 to 50 inches; pale olive (5Y 6/3) silty clay, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; common fine gypsum and salt crystals; strong effervescence; moderately alkaline; clear wavy boundary.
C3--50 to 60 inches; pale olive (5Y 6/3) silty clay, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; few fine gypsum and salt crystals; strong effervescence; moderately alkaline.
TYPE LOCATION: Tripp County, South Dakota; about 5 miles north of Winner; 100 feet east and 1,120 feet north of the southwest corner of sec. 29, T. 100 N., R. 76 W.
RANGE IN CHARACTERISTICS: The carbonates typically are at the surface but some pedons are leached a few inches. It is mildly or moderately alkaline throughout. Tongues of A material extend into the C horizon in some pedons.
The A horizon has 10YR or 2.5Y hue, value of 4 or 5 and 3 or 4 moist, and chroma of 2 or 3. It is silty clay or clay.
The Bw horizon has 5Y or 2.5Y hue, value of 5 or 6 and 4 or 5 moist, and chroma of 2 or 3. It is silty clay or clay. It averages between 45 to 60 percent clay, with high content of silt. It typically has few accumulations of carbonate.
The Bk horizon has 5Y or 2.5Y hue, value of 5 or 6 and 4 to 5 moist, and chroma of 2 to 4. It is silty clay or clay. It typically has common to many accumulations of carbonate.
The C horizons have 2.5Y or 5Y hue, values of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It is silty clay or clay. Accumulations of carbonate and gypsum crystals typically range from few to many. Depth to shale is greater than 60 inches, however past correlations have recognized shale at 40 to 60 inches as phases.
COMPETING SERIES: These are the Labu series in the same family. Labu soils have shale between depths of 20 and 40 inches.
GEOGRAPHIC SETTING: Boro soils are on gently sloping to strongly sloping uplands. Slopes typically are convex and slopes range from 2 to 15 percent. They formed in clayey material from shale. Mean annual temperature ranges from about 45 to 50 degrees F, and annual precipitation 15 to 24 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Labu soils and the Boyd, Carter, Dupree, Kyle, Lakoma, Millboro, Okaton, Opal, Promise, Sansarc, and Witten soils. Boyd, Labu, Lakoma, and Opal have shale between depths of 20 and 40 inches and are on similar landscapes. In addition, Boyd and Opal soils have a mollic epipedon. Kyle, Millboro and Promise soils are on plane to concave slopes below the Boro soils in the landscape. Carter soils are in swales and on nearly level terraces below the Boro soils and have a mollic epipedon and an argillic horizon. Dupree, Okaton and Sansarc soils are on steeper, more dissected landscapes and have shale between depths of 10 to 20 inches. Witten soils are in swales and have a mollic epipedon greater than 20 inches thick.
DRAINAGE AND PERMEABILITY: Well drained; surface runoff is medium or high. Permeability is slow.
USE AND VEGETATION: Winter wheat, corn, grain sorghum, and alfalfa are the main crops. Native vegetation includes western wheatgrass, green needlegrass and lesser amounts of sideoats grama, blue grama, and little bluestem.
DISTRIBUTION AND EXTENT: South central South Dakota. The series is of moderate extent.
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: Ochric epipedon - the zone from the surface of the soil to a depth of about 3 inches (A horizon).