LOCATION DUDLEY SD+NEEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Natrustolls
TYPICAL PEDON: Dudley silt loam - with a slope of 1 percent in native grass. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
A--0 to 7 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable; slightly acid; clear wavy boundary. (4 to 8 inches thick)
E--7 to 9 inches; gray (10YR 6/1) silt loam, very dark gray (10YR 3/1) moist; weak thin platy structure parting to weak fine granular; soft, very friable; neutral; clear wavy boundary. (0 to 3 inches thick)
Btn1--9 to 12 inches; dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; moderate and strong medium columnar structure parting to moderate and strong medium blocky; extremely hard, very firm, sticky, and plastic; thin nearly continuous light gray (10YR 6/1) coatings on tops of columnar peds; thin continuous clay films on faces of peds; neutral; clear wavy boundary.
Btn2--12 to 20 inches; dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; moderate medium prismatic structure parting to strong medium blocky; very hard, very firm, sticky, and plastic; thin continuous clay films on faces of peds; moderately alkaline; clear wavy boundary. (Combined Btn horizons is 11 to 24 inches thick.)
Bz1--20 to 25 inches; dark grayish brown (2.5Y 4/2) clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, firm, sticky, and plastic; continuous shiny films on vertical faces of peds; many fine and medium accumulations and threads of gypsum and other salts; strongly alkaline; clear wavy boundary.
Bz2--25 to 30 inches; grayish brown (2.5Y 5/2) clay loam, very dark grayish brown (2.5Y 3/2) and dark grayish brown (2.5Y 4/2) crushing to dark grayish brown (10YR 4/2) moist; weak medium prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky, and plastic; common fine and medium nests of gypsum and other salts; slight effervescence; moderately alkaline; gradual wavy boundary. (Combined Bz horizons is 0 to 12 inches thick.)
Bkz--30 to 36 inches; grayish brown(2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; hard, firm, sticky, and plastic; common fine and medium nests of gypsum and other salts; few fine accumulations of carbonate; strong effervescence; moderately alkaline; gradual wavy boundary. (4 to 24 inches thick)
C--36 to 60 inches; light yellowish brown (2.5Y 6/4) clay loam, light olive brown (2.5Y 5/4) moist; many fine faint of light gray (2.5Y 7/1) and few fine distinct yellowish brown (10YR 5/6) mottles; massive; hard, friable sticky and plastic; few fine nests of gypsum and other salts; common fine and medium accumulations of carbonate; strong effervescence; moderately alkaline.
TYPE LOCATION: Davison County, South Dakota; about 8 miles south of Mount Vernon; 375 feet west and 315 feet north of the southeast corner, sec. 33, T. 102 N., R. 62 W.
RANGE IN CHARACTERISTICS: Depth to carbonates ranges from 16 to 35 inches. Thickness of the mollic epipedon ranges from 20 to 40 inches. Depth to gypsum and other salts typically is 16 to 25 inches and ranges from 16 to 40 inches. Depth to salts or gypsum are above free carbonates in most pedons. The natric horizon typically has exchangeable magnesium plus sodium that is greater than calcium plus exchangeable acidity and the SAR and ESP ranges from 10 to 20.
The A horizon has value of 3 to 5 and 2 or 3 moist, and chroma of 1 or 2. It is silt loam or loam and is moderately acid to neutral.
The E horizon has value of 5 to 7 and 3 to 5 moist, and chroma of 1 or 2. In most cultivated areas, it is mixed with the A horizon. The E horizon is silt loam or loam and is moderately acid to neutral.
The Btn horizon has hue of 10YR or 2.5Y, value of 3 to 5 and 2 or 3 moist, and chroma of 1 or 2. It is silty clay loam, clay loam, silty clay or clay and averages between 35 and 50 percent clay and has more than 15 percent fine sand or coarser. It is slightly acid to slightly alkaline in the upper part and neutral to moderately alkaline in the lower part. Btnz or Btnkz horizons are in some pedons.
The Bz and Bkz horizons have hue of 10YR, 2.5Y, or 5Y; value of 4 to 6 and 3 to 5 moist; and chroma of 2 to 4. They have few to many fine to coarse mottles in some pedons. They are clay loam, silty clay loam, or clay and are slightly alkaline to strongly alkaline. It contains 1 to 10 percent coarse fragments. Bk horizons are in some pedons.
The C horizon has hue of 2.5Y or 5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It is loam or clay loam and is slightly to strongly alkaline. It contains 1 to 10 percent coarse fragments. Mottling is mostly inherent to the parent material.
COMPETING SERIES: These are the Cavo, DeGrey, Dwight, Farmsworth, Mosher, and Wood River series. Cavo, DeGrey, Mosher and Wood River soils have mollic epipedons less than 20 inches thick. Dwight soils are moist for longer periods in the SMCS and have mean annual soil temperatures of more than 52 degrees F. Farmsworth soils have less than 15 percent fine sand or coarser.
GEOGRAPHIC SETTING: The Dudley soils formed in calcareous glacial till on upland till plains and in upland foot slopes. Surfaces typically are plane to slightly concave. Slope gradients typically are 0 to 3 percent but range from 0 to 6 percent. Mean annual air temperature ranges from 45 to 52 degrees F, and the mean annual precipitation ranges from 17 to 26 inches. Growing season is about 130 to 160 days; average growing season precipitation ranges from 13 to 20 inches; and growing degree days are about 2800 to 3500.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beadle, Clarno, Crossplain, Davison, Houdek, Hoven, Jerauld, Prosper, Stickney, and Tetonka soils. Beadle, Clarno, Crossplain, Davison, Houdek, Prosper, and Tetonka soils do not have a natric horizon. Beadle, Clarno, and Houdek soils are on higher upland landscapes. Crossplain and Prosper soils are on toe slopes and foot slopes, respectively. Davison soils are in slightly higher positions. Hoven soils are saturated for 30 to 60 days or more to a depth of 3 feet or more in most years. The poorly drained Hoven and Tetonka soils are in closed depressions. Jerauld soils have a thinner mollic epipedon, salts within 16 inches, and are in similar landscapes positions. Stickney soils do not have columnar structured Btn horizons and are in similar landscapes.
DRAINAGE AND PERMEABILITY: Moderately well or somewhat poorly drained. Runoff is low or very high depending on slope. Permeability is slow or very slow. Somewhat poorly drained soils are in swales and receive common flooding from run-in water from adjacent slopes. A water table may be within 2 feet of the surface for short periods in the spring of the year.
USE AND VEGETATION: These soils are used for native range and cultivated crops. Small grain, alfalfa, and tame grasses are major crops. Native vegetation is mainly western wheatgrass, switchgrass, blue grama, green needlegrass, buffalograss, big bluestem, sedges, and forbs.
DISTRIBUTION AND EXTENT: South-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: Hutchinson County, South Dakota, 1974.
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 7 inches and from 9 to 25 inches (A, Btn1, Btn2, Bz1 horizons); albic horizon- the zone from 7 to 9 inches (E horizon); argillic (Natric) horizon - the zone from a depth of about 9 to 20 inches (Btn1 and Btn2 horizons).
ADDITIONAL DATA: Reference Lincoln Sample No. 71L333-41.