LOCATION GRACEVILLE SD+IA MNEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Pachic Haplustolls
TYPICAL PEDON: Graceville silty clay loam - on 1 percent, south-facing concave slope in a cultivated field. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) silty clay loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, slightly sticky; moderately acid; abrupt smooth boundary.
A--8 to 20 inches; dark grayish brown (10YR 4/2) silty clay loam, black (10YR 2/1) crushing to very dark brown (10YR 2/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky; moderately acid; gradual wavy boundary. (Combined thickness of the A horizons is 12 to 24 inches.)
Bw1--20 to 27 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark gray (10YR 3/1) crushing to very dark grayish brown (10YR 3/2) moist; weak coarse prismatic structure parting to weak coarse and medium subangular blocky and weak fine granular; slightly hard, friable, slightly sticky; slightly acid; clear wavy boundary.
Bw2--27 to 39 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; weak coarse and medium prismatic structure parting to moderate coarse, medium and fine subangular blocky; slightly hard, friable, slightly sticky; slightly acid; gradual wavy boundary.
Bw3--39 to 53 inches; light yellowish brown (10YR 6/4) silty clay loam, brown (10YR 4/3) moist; few fine distinct olive brown (2.5Y 4/4) redox concentrations; moderate coarse and medium prismatic structure parting to moderate coarse, medium and fine subangular blocky; slightly hard, friable, slightly sticky; slightly acid; abrupt smooth boundary. (Combined thickness of the Bw horizons is 12 to 40 inches.)
2C--53 to 60 inches; brown (10YR 4/3) gravelly sand, dark brown (10YR 3/3) moist; single grain; loose; slightly acid.
TYPE LOCATION: Lake County, South Dakota; about 11/2 miles west and 1 mile north of Chester; 330 feet north and 2,300 feet west of the southeast corner, sec. 9, T. 105 N., R. 51 W.
RANGE IN CHARACTERISTICS: The depth to sand and gravel ranges from 40 to 60 inches and it is typically stratified. Thickness of mollic epipedon ranges from 20 to 48 inches and extends into the Bw horizon of most pedons. Depth to calcium carbonate ranges from 25 to 60 inches. The control section is silty clay loam or silt loam and averaging between 25 and 35 percent clay and between 3 and 15 percent fine or coarser sand.
The A horizon has hue of 10YR, value of 3 or 4 and 2 or 3 moist, and chroma of 1 or 2. It is silty clay loam, or silt loam. It ranges from moderately acid to neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 2 to 4 moist, and chroma of 1 to 4. It is silty clay loam or silt loam but is loam in the lower part in some pedons. It ranges from moderately acid to slightly alkaline.
A Bk or C horizon is present in some pedons.
The 2C or 2Bk horizon typically has hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 1 to 4. It is gravelly loamy sand, gravelly sand, very gravelly loamy sand, or very gravelly sand but is loamy sand or sand in some pedons and contains 10 to 50 percent gravel by volume. It ranges from slightly acid to slightly alkaline. When present, the 2Bk horizon is charaterized by having carbonate coatings on the underside of pebbles.
COMPETING SERIES: These are the Duroc, Eltree, Trent, and Viborg, and Yankton series. Similar soils are the Alcester, Bon, Brocksburg, Davis, Dempster, Enet, Flandreau, and Hord series. Duroc soils are dry for longer periods. Eltree soils have free calcium carbonate within 15 inches of the surface. Trent soils have distinct or prominent mottles between depths of 20 and 40 inches. Viborg soils contain more fine or coarser sand in the lower part of the control section. Yankton soils do not have sand and gravel in the substratum. Alcester and Hord soils have an irregular decrease in organic matter. Bon and Davis soils have a fine-loamy control section. Brocksburg soils have sand and gravel at depths of 20 to 40 inches and have an argillic horizon. Dempster and Enet soils have sand and gravel at depths of 20 and 40 inches. Flandreau soils have a mollic epipedon less than 20 inches thick and have a fine-loamy control section.
GEOGRAPHIC SETTING: Graceville soils are nearly level in swales or in slightly depressed flats that have concave or plane surfaces. Slopes range from 0 to 6 percent. These soils formed in silty alluvium overlying outwash sand and gravel on glacial stream terraces and outwash plains. The mean annual precipitation ranges from 18 to 26 inches, and the mean air annual temperature ranges from 45 to 55 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Delmont, Dempster, Egan, Enet, and Wentworth soils. These soils are on slightly higher to similar landscapes as the Graceville soils. Delmont soils have sand and gravel between depths of 14 and 20 inches. Egan and Wentworth have mollic epipedons less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Well and moderately well drained. Surface runoff is slow. Permeability is moderate in the solum and rapid in the underlying material.
USE AND VEGETATION: These soils are used primarily as cropland. Corn and small grain are the main crops. Native vegetation includes big bluestem, green needlegrass, little bluestem, sedges, and forbs.
DISTRIBUTION AND EXTENT: East central and southeastern South Dakota and northwestern Iowa. The Graceville soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Lake County, South Dakota, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to a depth of about 39 inches (Ap, A, Bw1, Bw2 horizon).