LOCATION SOUTHBROOK MNTentative Series
TAXONOMIC CLASS: Fine, smectitic, mesic Cumulic Vertic Endoaquolls
TYPICAL PEDON: Southbrook silty clay loam, on a slope of 1 percent, in a CRP field, at an elevation about 424 m (1,390 feet) above sea level. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 25 cm (0 to 10 inches); black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1) dry; weak fine granular and weak fine subangular blocky structure; friable; many very fine roots; neutral; abrupt smooth boundary.
A1--25 to 69 cm (10 to 27 inches); black (2.5Y 2.5/1) silty clay, very dark gray (10YR 3/1) dry; moderate very fine subangular blocky structure; firm; common fine prominent dark reddish brown (5YR 3/4) Fe concentrations; few very fine roots; neutral; gradual smooth boundary.
A2--69 102 cm (27 to 40 inches); black (2.5Y 2/1) silty clay, very dark gray (10YR 3/1) dry; moderate medium subangular blocky structure; firm; sheen on faces of peds; slightly acid; gradual wavy boundary. [Combined thickness of the A horizon is 66 to 102 cm (26 to 40 inches)]
Bg--102 to 109 cm (40 to 43 inches); very dark gray (2.5Y 3/1) sandy clay loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure; friable; about 2 percent gravel; neutral; gradual wavy boundary. [0 to 15 cm (0 to 6 inches thick)]
2Cg--109 to 203 cm (43 to 80 inches); dark gray (5Y 4/1) coarse sand; single grain; loose; about 10 percent gravel; slightly effervescent; slightly alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 103); Cottonwood County, Minnesota; about 1 mile north and 4 miles east of Dundee; about 320 m ( 1,050 feet) north and 23 m ( 75 feet) west of the southeast corner of section 27, T. 105 N., R. 38 W; USGS Dundee quadrangle; lat. 43 degrees 51 minutes 56 seconds N. and long. 95 degrees 22 minutes 54 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:Thickness of the upper mantle and depth to the 2C horizon typically is 102 to 122 cm (40 to 48 inches) but ranges from 127 to 152 cm (50 to 60 inches). The upper mantle typically averages about 35 to 45 percent clay and 0 to 15 percent fine sand or coarser. However, in some pedons, the lower part of the solum is about 12 to 18 percent clay and 50 to 60 percent fine sand or coarser. Free carbonates are absent in the upper mantle and commonly to a depth of 152 cm (60 inches) or more, but pedons with carbonates as shallow as 102 cm (40 inches) are within the range. The mollic epipedon typically is 76 to 127 cm (30 to 50 inches) thick.
The A horizon has hue of 10YR through 5Y or is neutral, value of 2 or 3, and chroma of 0 or 1. The A horizon typically is silty clay loam or silty clay. It is neurtral to slightly alkaline.
Some pedons have a thin AB or BA horizon.
The Bg horizon typically has hue of 2.5Y, 5Y or is neutral, value of 4 or 5, and chroma of 0 thhrough 2. The Bg horizon is typically silty clay or silty clay loam. The lower part o f the Bg horizon in some pedons is sandy loam or sandy clay loam. Reaction is slightly acid or neutral.
The 2Cg horizon typically is coarse sand, sand, loamy sand or their gravelly analogues. Reaction is neutral to moderately alkaline.
COMPETING SERIES: These are the Chehalem, Clamo, Derrynane, Okoboji, Peotone, Rantoul, Shiloh, Wabash, and Zoe series. All of these do not have coarse textures in the lower third of the series.
GEOGRAPHIC SETTING: Southbrook soils are in concave areas or flats on flood plains and stream terraces. Slope gradient is 0 to 2 percent. The soils formed in mostly deep alluvial sediments that overlie coarse-textured sediments. The mean annual air temperature ranges from about 7 to 10 (45 to 50 degrees F), and the mean annual precipitation ranges from 660 to 813 mm 26 to 32 inches. Frost-free days range from155 to 200 days. Elevation is 305 to 479 m (1000 to 1570 feet) above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Biscay, Dickman Estherville, Mayer, Minneopa, and Shandep soils. These soils, except Shandep have mollic epipedons less than 61 cm (24 inches) thick and coarse-textured substrata above a depth of 102 cm (40 inches). Dickman, Estherville and Minneopa soils are better drained and typically are at higher elevations. Mayer soils have free carbonates throughout the solum. Biscay and Mayer soils typically are slightly higher on the landscape. Shandep soils are poorly drained and occupy similar position.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained--a saturated zone occurs within a depth of 30 cm (1 foot) during March to June in most years and is considered apparent
Saturated hydraulic conductivity in the upper part is 0.42 to 1.41 micrometer per second (.06 to .20 inches) moderately low or 1.41 to 4.23 micrometer per second (.20 to .60 inches) moderately high. In the lower part is 42.34 to 705.00 micrometer per second (6 to 99.90 inches)
Surface runoff potential--low or very low
Flooding--rare to frequent flooding for brief to long periods during the months of February to November from precipitation events and snowmelt
USE AND VEGETATION: Where drained, most areas are cultivated. The principal crops are corn and soybeans. The native vegetation is big bluestem, western wheatgrass, sedges, blue grama and other species of the tall grass prairie that are tolerant of excessive wetness.
DISTRIBUTION AND EXTENT: Southern Minnesota and probably northern Iowa. These soils are inextensive.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES PROPOSED: Cottonwood County, Minnesota, 2005.
REMARKS: Particle-size control section--the zone from a depth 25 to 100 cm (10 to 40 inches) (A1, A2 horizons);
series control section--the zone from the surface to a depth of 152 centimeters (60 inches) (Ap, A1, A2, Bg, and 2Cg horizons).
Diagnostic horizons and features recognized in this pedon: mollic epipedon--the zone from the surface to a depth 109 centimeters (43 inches) (Ap, A1, A2, and Bg horizons); aquic moisture regime. Vertic subgroup based on linear extensibility greater than 6.0 centimeters between the surface and a depth of 100 centimeters (39 inches).
Taxonomy version--Keys to Soil Taxonomy, 10th edition, 2006.