LOCATION POINSETT SD+MNEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Calcic Hapludolls
TYPICAL PEDON: Poinsett silty clay loam - on a northeast facing, 3 percent slope in a cultivated field. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 20 centimeters (0 to 8 inches); black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; moderate medium subangular blocky structure parting to moderate medium granular; hard, friable; moderately sticky and moderately plastic; common very fine roots; few very fine pores; slightly acid (pH 6.1); abrupt smooth boundary. [Ap horizon thickness is 15 to 25 centimeters (6 to 10 inches).]
Bw1--20 to 33 centimeters (8 to 13 inches); very dark grayish brown (10YR 3/2) silty clay loam, dark grayish brown (10YR 4/2) dry; weak medium prismatic structure parting to weak fine and medium subangular blocky; slightly hard, friable; moderately sticky and moderately plastic; few very fine roots; few very fine pores; neutral (pH 7.0); gradual wavy boundary.
Bw2--33 to 58 centimeters (13 to 23 inches); dark grayish brown (10YR 4/2) silty clay loam, brown (10YR 5/3) dry; weak medium prismatic structure parting to weak fine and medium subangular blocky; slightly hard, friable; moderately sticky and moderately plastic; few very fine roots; common very fine pores; neutral (pH 7.2) clear wavy boundary. [Combined thickness of the Bw horizon is 20 to 51 centimeters (8 to 20 inches).]
Bk1--58 to 89 centimeters (23 to 35 inches); olive brown (2.5Y 4/3) silty clay loam, light brownish gray (2.5Y 6/2) dry; weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine pores; common fine and medium accumulations of calcium carbonate; violent effervescence; moderately alkaline (pH 8.2); clear wavy boundary.
Bk2--89 to 117 centimeters (35 to 46 inches); dark grayish brown (2.5Y 4/2) silty clay loam, light brownish gray (2.5Y 6/2) dry; few fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations; weak coarse prismatic structure; hard, friable, moderately sticky and moderately plastic; few very fine pores; common fine and medium accumulations of calcium carbonate; violent effervescence; moderately alkaline (pH 8.4); clear wavy boundary.
Bk3--117 to 157 centimeters (46 to 62 inches); grayish brown (2.5Y 5/2) silty clay loam, light gray (2.5Y 7/2) dry; common medium and coarse prominent yellowish red (5YR 4/6) and yellowish brown (10YR 5/6) redoximorphic concentrations and few fine faint light brownish gray (2.5Y 6/2) redoximorphic depletions; weak coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine pores; strata of loam to silty clay loam; common fine accumulations of calcium carbonate; strong effervescence; moderately alkaline (pH 8.4); clear wavy boundary. [Combined thickness of the Bk horizon is 15 to 102 centimeters (6 to 40 inches).]
2C1--157 to 173 centimeters (62 to 68 inches); light olive brown (2.5Y 5/4) clay loam, light yellowish brown (2.5Y 6/4) dry; common medium and coarse prominent yellowish brown (10YR 5/6) redoximorphic concentrations and few fine distinct light brownish gray (2.5Y 6/2) redoximorphic depletions; few fine prominent very dark gray (10YR 3/1) Fe concretions; massive; hard, firm, slightly sticky and slightly plastic; few very fine pores; 3 percent gravel; few fine accumulations of calcium carbonate; strong effervescence; moderately alkaline (pH 8.0); gradual wavy boundary.
2C2--173 to 203 centimeters (68 to 80 inches); light olive brown (2.5Y 5/4) clay loam, light yellowish brown (2.5Y 6/4) dry; few fine and medium prominent yellowish brown (10YR 5/6) redoximorphic concentrations and common fine distinct light brownish gray (2.5Y 6/2) redoximorphic depletions; few fine prominent very dark gray (10YR 3/1) Fe concretions; massive; hard, firm, slightly sticky and slightly plastic; few very fine pores; 3 percent gravel; strong effervescence; moderately alkaline (pH 8.0).
TYPE LOCATION: Brookings County, South Dakota; about 2 miles north and 11 miles west of Bruce; 460 meters (1,510 feet) south and 46 meters (150 feet) west of the northeast corner of sec. 31, T. 112 N., R. 52 W. USGS Arlington NE, S. Dak. topographical quadrangle; latitude 44 degrees 27 minutes 59.8 seconds N. and longitude 97 degrees 6 minutes 31.9 seconds W., NAD 83
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon ranges from 18 to 41 centimeters (7 to 16 inches). Some pedons have a few granitic cobbles and pebbles on the surface and throughout the solum. The particle size control section averages between 18 and 32 percent clay. Typically there are strata in the horizon above the glacial till. Strata ranges in texture from loam to silty clay loam and are 10 to 50 mm in thickness. Clay loam glacial till is between depths of 102 and 152 centimeters (40 and 60 inches) in some pedons.
The A horizon has value of 2 or 3 and 3 or 4 dry and chroma of 1. It typically is silty clay loam, but is silt loam or clay loam in some pedons. Reaction is slightly acid or neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 2 to 4 and 4 to 6 dry, and chroma of 1 to 4. It typically is silty clay loam or silt loam. Reaction is slightly acid or neutral in the upper part and neutral or slightly alkaline in the lower part. Some pedons have a thin BC horizon.
The Bk horizon has hue of 2.5Y or 10YR, value of 4 to 6 and 5 to 7 dry, and chroma of 2 to 4. It is silty clay loam or silt loam. It has common or many accumulations of carbonates. It is slightly or moderately alkaline.
The C horizon, where present, has hue of 2.5Y or 10YR, value of 4 to 6 and 5 to 7 dry, and chroma of 2 to 4. It is silt loam or silty clay loam. It is slightly alkaline or moderately alkaline.
The 2C horizon has hue of 2.5Y or 10YR, value of 4 to 6 and 5 to 7 dry, and chroma of 2 to 4. It is clay loam. It is slightly alkaline or moderately alkaline. Some pedons do not have a 2C horizon.
COMPETING SERIES: These are the Brandt, Great Bend, Kings Lake, Kranzburg, Putney and Still Lake series. Brandt soils have a 2C horizon with more than 15 percent gravel. Great Bend soils are varved with thin layers of sand to clay at a depth of 102 to 152 centimeters (40 to 60 inches). Varves range from less than 1 mm to 10 mm in thickness. Kings Lake and Kranzburg soils have glacial till between depths of 51 and 102 centimeters (20 and 40 inches).Kranzburg and Still Lake soils also do not have the strata above the glacial till. Putney soils have gypsum and other salts within depths of 51 centimeters (20 inches).
GEOGRAPHIC SETTING: Poinsett soils are nearly level to gently rolling on uplands having plane to convex slopes with gradients of 0 to 15 percent. Poinsett soils formed in calcareous silty glacial drift. Mean annual air temperature ranges from 4 to 7 degrees C (38 to 45 degrees F), and mean annual precipitation ranges from 485 to 735 millimeters (19 to 29 inches). Growing season is about 120 to 160 days; average growing season precipitation ranges from 330 to 457 millimeters (13 to 18 inches); and growing degree days are about 2500 to 3000. Elevation ranges from 1000 to 2150 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Badger, Barnes, Buse, Cubden, Forman, Hetland, Kings Lake, Oldham, Parnell, Rusklyn, Sinai, Tonka, and Waubay soils. The somewhat poorly drained Badger soils have a fine textured control section and are in deeper swales. The well drained Barnes and Forman soils are fine-loamy and are on adjacent till plains. In addition, Forman soils also have an argillic horizon. The well drained Buse and Rusklyn soils are on shoulder slopes and do not have a cambic horizon. The somewhat poorly drained Cubden soils have a calcic horizon within 41 centimeters (16 inches) of the surface and are along the edges of deeper swales and closed depressions. The well drained Hetland and Sinai soils have a fine textured control section and are on higher lying ice-walled lake positions in the silty drift landscape. The well drained Kings Lake soils have glacial till between 51 and 102 centimeters (20 and 40 inches) and are on similar landscape positions as the Poinsett soils. The very poorly drained Oldham and Parnell soils and the poorly drained Tonka soils have fine textured control sections and are in closed depressions. Waubay soils have mollic epipedons more than 41 centimeters (16 inches) thick and are on footslopes and in swales.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Surface runoff is low or medium. Saturarted hydraulic conductivity, measured in cm per hour, is 1.52 to 5.10 (.6 to 2.0 inches). Occasional saturation occurs as high as 102 to 152 centimeters (40 to 60) inches during the months April through June in years of above normal precipitation. In years with normal rainfall, saturation typically does not occur for periods of 1 month or more within a depth of 152 centimeters (60 inches).
USE AND VEGETATION: Principal crops are corn, small grains, and alfalfa. Small areas are in native range of big bluestem, little bluestem, needlegrass, blue grama, sideoats grama, Kentucky bluegrass, forbs, and sedges.
DISTRIBUTION AND EXTENT: MLRA-102A. Northeastern South Dakota and adjacent areas in Minnesota. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Brookings County, South Dakota, 1956.
REMARKS: Diagnostic horizons and textures recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 33 centimeters (13 inches) (Ap and Bw1 horizons); cambic horizon - the zone from 33 to 58 centimeters (13 to 23 inches) (Bw2 horizon). calcic horizon - the zone from 58 to 157 centimeters (23 to 62 inches) (Bk1, Bk2, Bk3).