LOCATION GROGAN MNEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Oxyaquic Hapludolls
TYPICAL PEDON: Grogan silt loam with a 3 percent convex east-facing slope on a delta in a glacial lake plain in a cultivated field. (Colors are for moist conditions unless otherwise stated.)
Ap--0 to 25 cm (0 to 10 inches); very dark brown (10YR 2/2) silt loam; weak fine subangular blocky structure; very friable; moderately acid; abrupt smooth boundary. [18 to 30 cm (7 to 12 inches thick)]
AB--25 to 33 cm (10 to 13 inches); dark brown (10YR 3/3) loam with very dark grayish brown (10YR 3/2) coatings on faces of peds; weak very fine subangular blocky structure; very friable; slightly acid; abrupt irregular boundary. [0 to 15 cm (0 to 6 inches thick)]
Bw1--33 to 41 cm (13 to 16 inches); brown (10YR 4/3) loam with very dark grayish brown (10YR 3/2) coatings on faces of peds; weak very fine subangular blocky structure; very friable; slightly acid; clear smooth boundary.
Bw2--41 to 56 cm (16 to 22 inches); dark yellowish brown (10YR 4/4) silt loam; weak very fine subangular blocky structure; very friable; slightly acid; clear wavy boundary.
Bw3--56 to 79 cm (22 to 31 inches); yellowish brown (10YR 5/4) loam; weak very fine and fine subangular blocky structure; very friable; neutral; abrupt wavy boundary. (Combined thickness of Bw horizon is 25 to 61 cm (10 to 24 inches.)
BC1--79 to 91 cm (31 to 36 inches); light olive brown (2.5Y 5/4) very fine sandy loam; weak fine and medium subangular blocky structure; very friable; few fine distinct gray (10YR 6/1) and common fine faint grayish brown (2.5Y 5/2) Fe depletions; strongly effervescent; slightly alkaline; gradual wavy boundary.
BC2--91 to 152 cm (36 to 60 inches); light yellowish brown (10YR 6/4) and brownish yellow (10YR 6/6) very fine sandy loam; weak thin to thick platy structure; few strong brown (7.5YR 5/8) iron oxide "pipes;" few thin strata of loamy very fine sand; many coarse prominent gray (10YR 6/1) Fe depletions; strongly effervescent; slightly alkaline.
TYPE LOCATION: Blue Earth County, Minnesota; about 2 miles west and 1 mile north of Garden City; 800 feet south and 2,440 feet west of the northeast corner of sec. 21, T. 107 N., R. 28 W., USGS Lake Crystal, MN quadrangle, latitude 44 degrees 03 minutes 47 seconds N., longitude 94 degrees 11 minutes 50 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: Depth to free carbonates range from 51 to 102 cm (20 to 40 inches). These soils do not have rock fragments in the series control section. The 25 to 102 cm (10 to 40 inch) control section averages between 8 and 18 percent clay and less than 15 percent of fine sand coarser particles. These soils commonly have evidence of stratification and the contents of the various sizes of particles change erratically with depth. The mollic epipedon ranges from 25 to 46 cm (10 to 18 inches) in thickness.
The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 to 3. It is silt loam or loam. It is moderately acid to neutral.
The B horizon has a matrix with hue of 10YR, value of 4 or 5, and chroma of 3 to 5. It typically is loam or silt loam, but it has subhorizons in some pedons that are very fine sandy loam or loamy very fine sand. It is slightly acid or neutral in the upper part and neutral or slightly alkaline in the lower part.
The BC or C horizon has a matrix with hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 3 to 6. It has Fe depletions in some part. It is very fine sandy loam or loamy very fine sand, but it has strata of silt loam of coarser textures in some pedons. It is slightly alkaline or moderately alkaline.
A 2C horizon of glacial till is at depths as shallow as 50 inches in some pedons.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils have plane or convex slopes with gradients of 0 to 6 percent primarily in glacial lake plains, glacial deltas, and stream terraces. . They formed in stratified, calcareous lacustrine sediments of the Des Moines lobe of the Late Wisconsinan glaciation. Mean annual air temperature is 7 to 10 degrees C (45 to 50 degrees F), and mean annual precipitation is 610 to 762 mm (24 to 30 inches). Frost free days range form 155 to 200 days. Elevation above sea level ranges from 242 to 427 m (800 to 1400 feet).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bold, Gardencity, Dickinson, Darfur and Fieldon soils. The well drained Bold soils are well drained and are on shoulder slopes. Gardencity soils are well drained and formed in sandy and silty material. The Dickinson soils are well drained. The Darfur and Fieldon soils are poorly drained and on lower lying positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. Surface runoff is low to medium. Saturated hydraulic conductivity is 4.23 to 14.11 micrometers per second (.6 to 2.0 inches per hour). Seasonal high saturation is as high as 2.5 feet from March through June in normal years.
USE AND VEGETATION: These soils are mostly cropped to corn and soybeans. Native vegetation is tall grass prairie.
DISTRIBUTION AND EXTENT: MLRA-103. Inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota.
SERIES ESTABLISHED: Blue Earth County, Minnesota, 1975.
REMARKS: Diagnostic horizons and properties recognized in this pedon are: mollic epipedon - the zone from the surface to a depth of 33 centimeters (13 inches) (Ap and AB and horizons), cambic horizon - the zone from 33 to 91 centimeters (13 to 36 inches) (Bw1, Bw2 and BC horizons).
Grogan was mapped on slopes over 6 percent in the past as a minor unit. These areas will need to be looked at on an update. They are likely well drained.
ADDITIONAL DATA: Refer to MAES Central File Code No. 974 for results of some laboratory analysis of the typical pedon.