LOCATION BON SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Cumulic Haplustolls
TYPICAL PEDON: Bon loam - on plane slope of 1 percent in native grass. When described the soil was moist to a depth of 38 inches. (Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable; neutral; clear smooth boundary.
A2--6 to 10 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; soft, very friable; slight effervescence; slightly alkaline; clear smooth boundary. (Combined A horizons is 8 to 20 inches thick.)
Bw1--10 to 19 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak medium prismatic structure parting to weak medium and fine subangular blocky; soft, very friable; slight effervescence; slightly alkaline; clear smooth boundary.
Bw2--19 to 32 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak medium prismatic structure parting to weak medium subangular blocky; slightly hard, very friable; few fine threads of carbonates; strong effervescence; moderately alkaline; clear wavy boundary. (Combined Bw horizons is 10 to 30 inches thick.)
Bk--32 to 46 inches; grayish brown (10YR 5/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable; common fine threads of carbonate; strong effervescence; moderately alkaline; clear wavy boundary. (0 to 30 inches thick)
C1--46 to 58 inches; brown (10YR 5/3) loamy fine sand, dark brown (10YR 4/3) moist; single grained; loose; strong effervescence; moderately alkaline; clear wavy boundary. (0 to 14 inches thick)
C2--58 to 60 inches; pale brown (10YR 6/3) fine sandy loam, dark brown (10YR 4/3) moist; massive; slightly hard, very friable; few fine and medium accumulations of carbonate; strong effervescence; moderately alkaline.
TYPE LOCATION: Davison County, South Dakota; about 3 miles east and 4 1/2 miles north of Mount Vernon; 1885 feet south and 968 feet west of the northeast corner of sec. 36, T. 104 N., R. 62 W.
RANGE IN CHARACTERISTICS: Typically the depth to carbonates ranges from 6 to 20 inches, but some pedons contain carbonates throughout. Thickness of the mollic epipedon ranges from 20 to 50 inches or more. The control section is loam, clay loam or silt loam and typically averages between 20 and 30 percent clay. Buried A horizons are in some pedons.
The A horizon has hue of 10YR or 2.5Y, value of 3 to 5 and 2 to 3 moist, and chroma of 1 or 2. It is loam or silt loam but is very fine sandy loam in some pedons. It ranges from neutral to moderately alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 3 to 5 and 2 or 3 moist, and chroma of 1 to 3. It is loam or silt loam or very fine sandy loam. It ranges from neutral to moderately alkaline.
The Bk horizon has hue of 10YR or 2.5Y, value of 3 to 7 and 2 to 5 moist, and chroma of 1 to 3. It is loam, silt loam or fine sandy loam. Stratified fine sandy loam, silt loam, loam, clay loam, and silty clay loam are in some pedons. It is slightly or moderately alkaline. It has few to many accumulations of carbonates.
The C horizon has hue of 10YR, 2.5Y, or 5Y; value of 3 to 7 and 2 to 5 moist; and chroma of 1 to 3. It typically is stratified loam, fine sandy loam or sandy loam with layers of loamy fine sand, silt loam, silty clay loam and clay loam. It is slightly or moderately alkaline. Faint or distinct mottles are below depths of 30 inches in some pedons.
COMPETING SERIES: These are the Draper, Humbarger, Lynx, Manzano, Maskell, Merrick, Pack, Shanta, St. Onge, and Umbarg series. Draper and Pack soils are saturated with water within depths of 40 inches. Humbarger soils are stratified in the upper 20 to 30 inches and have a warmer soil temperature. The Lynx, Manzano, Shanta, and St. Onge soils have a drier soil moisture control section. In addition, the Lynx soils do not have carbonates. Maskell and Merrick soils do not have carbonates within depths of 40 inches. Umbarg soils have a consistent soil moisture control section.
GEOGRAPHIC SETTING: The Bon soils are nearly level to level on low stream terraces and high bottoms within the glacial till plain. Slope gradients are 0 to 2 percent. Bon soils formed in calcareous stratified alluvium. Mean annual air temperature ranges from 45 to 52 degrees F. Mean annual precipitation from 17 to 26 inches and most occurs from April to September.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Betts, Clamo, Davis, Ethan, Glenham, Houdek, Java, and Lamo soils. Betts soils do not have a mollic epipedon and are on steep adjacent slopes. Clamo and Lamo soils have a wetter soil moisture control section and are on slightly lower positions on similar landscapes. Davis soils have carbonates below depths of 20 inches and are on higher terraces and toe slopes. Ethan, Glenham, Houdek, and Java soils have mollic epipedons less than 20 inches thick and are on nearby uplands.
DRAINAGE AND PERMEABILITY: Well drained and moderately well drained. Runoff is neglible or low dependind on slope. Permeability is moderate. These soils are commonly flooded. Some pedons have a water table between depths of 3 and 5 feet in the spring in channeled areas.
USE AND VEGETATION: Small grains, corn, alfalfa, and feed grains are the principal crops. Narrow irregular shaped areas are in native range of big bluestem, needlegrass, switchgrass, western wheatgrass, and forbs. Trees are often near the channel.
DISTRIBUTION AND EXTENT: South-central and central South Dakota, east of the Missouri River. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Davison County, South Dakota, 1970.
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 32 inches (A1, A2, Bw1, Bw2 horizon).