LOCATION IHLEN MN+SDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Udic Haplustolls
TYPICAL PEDON: Ihlen silty clay loam on a west-facing slightly convex slope of 3 percent on a loess mantled bedrock high in a pasture field. (Colors are for dry soil unless otherwise stated.)
A--0 to 8 inches; very dark brown (10YR 2/2) silty clay loam, black (10YR 2/1) moist; weak fine and medium subangular blocky structure; slightly hard, friable; slightly acid; gradual smooth boundary. (7 to 14 inches thick)
Bw1--8 to 15 inches; brown (10YR 4/3) silty clay loam, dark brown (10YR 3/3) moist, very dark grayish brown (10YR 3/2) moist coatings on faces of peds; moderate medium and coarse prismatic structure parting to weak moderate fine and medium subangular blocky; slightly hard, friable; a few very dark gray (10YR 3/1) moist worm casts; slightly acid; gradual smooth boundary.
Bw2--15 to 23 inches; brown (10YR 5/3) silty clay loam, brown (10YR 4/3) moist, dark grayish brown (10YR 4/2) moist coatings on faces of peds; weak medium and coarse prismatic structure parting to weak fine and medium subangular blocky; slightly hard, friable; neutral; abrupt smooth boundary. (Combined thickness of Bw horizons is 8 to 20 inches.)
BC--23 to 29 inches; light olive brown (2.5Y 5/4) silt loam, dark grayish brown (10YR 4/2) moist; weak medium and coarse prismatic structure parting to very weak medium subangular blocky; slightly hard, friable; neutral; abrupt smooth boundary. (0 to 10 inches thick)
C--29 to 31 inches; light olive brown (2.5Y 5/4) silt loam, dark grayish brown (10YR 4/2) moist; weak medium and coarse subangular blocky structure; slightly hard, friable; few hard and soft white limy masses; slight effervescence; moderately alkaline; abrupt smooth boundary. (0 to 12 inches thick)
R--31 inches; red, pale red, and weak red Sioux quartzite.
TYPE LOCATION: Pipestone County, Minnesota; about 2 1/2 miles southeast of Ihlen; 133 feet south and 100 feet west of northeast corner of sec. 27, T. 105 N., R. 46 W.
RANGE IN CHARACTERISTICS: The thickness of solum ranges from 20 to 38 inches. Depth to bedrock ranges from 20 to 40 inches. Free carbonates are lacking in pedons that have bedrock at depths of less than 28 inches and typically are in the C horizon where it extends below depths of about 28 inches. Some of the carbonates are in the form of soft masses. The solum and the C horizon typically lack coarse fragments but the horizon that overlies the bedrock has up to 10 percent of coarse fragments, mostly quartzite in some pedons. The A horizon and B horizon is neutral or slightly acid and the BC horizon is neutral or mildly alkaline. The mollic epipedon ranges from 10 to 20 inches in thickness. Between depths of 10 inches and the top of the bedrock the soil averages between 24 and 32 percent clay and less than 5 percent of fine sand and coarser. The highest content of clay is in the A horizon and the content of clay decreases uniformly with depth.
The A horizon has hue of 10YR, value of 2 through 4 and 2 or 3 moist, and chroma of 1 or 2, dry or moist. It typically is silty clay loam but includes silt loam. Some pedons have an AB horizon ranging to as much as 6 inches in thickness.
The Bw horizon has hue of 10YR in the upper part and 10YR or 2.5Y in the lower part, value of 4 through 6 and 3 or 4 moist, and chroma of 2 through 4 dry or moist. The lower chroma primarily is on faces of peds. It is silty clay loam or silt loam.
The C horizon has hue of 2.5Y, value of 5 or 6 and 4 or 5 moist, and chroma of 2 through 4 dry or moist. It is silt loam or silty clay loam. This horizon ranges from slightly alkaline to moderately alkaline.
COMPETING SERIES: These are the Egan, Moody, Nora, and Wentworth soils in the same family. All of these soils lack a lithic contact above depths of 40 inches.
GEOGRAPHIC SETTING: These soils have long convex slopes with uniform gradients of 0 to 35 percent. The Ihlen soils formed in 20 to 40 inches of loess that is underlain by Sioux quartzite on uplands. Mean annual air temperature is about 45 to 47 degrees F, and mean annual precipitation is about 22 to 26 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: The main ones are the well drained Moody soils and the moderately well drained Trent soils. These soils lack bedrock above depths of 40 inches and commonly are on lower lying terrain.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is slow to rapid. Permeability is moderate.
USE AND VEGETATION: The major acreage of the soil is cropped to corn, soybeans, and hay. A significant part of this soil is used for pasture. Native vegetation was tall and mid grass prairie.
DISTRIBUTION AND EXTENT: Southwestern Minnesota. Inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Rock County, Minnesota, 1945.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from 0 to 8 inches (A horizon); cambic horizon - the zone from 8 to 29 inches (Bw1, Bw2, BC horizons); ustic moisture regime, grading toward Udic.
ADDITIONAL DATA: Refer to MAES Central File Case No. 1083 for results of some laboratory analysis of the typical pedon.