LOCATION CORVUSO MN+IAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Calciaquolls
TYPICAL PEDON: Corvuso silty clay loam, on a slightly convex 1 percent slope on the rim of a depression in a cultivated field. (Colors are for moist soil unless otherwise noted).
Ap--0 to 18 cm (0 to 7 inches); black (N 2/0) silty clay loam; very dark gray (10YR 3/1) dry; moderate fine angular blocky structure; firm; few fine roots; about 1 percent gravel; strongly effervescent; moderately alkaline; abrupt smooth boundary.
Ak--18 to 38 cm (7 to 15 inches); black (10YR 2/1) silty clay loam; gray (10YR 5/1) dry; moderate fine and medium angular blocky structure; friable; few fine roots: carbonates disseminated throughout; about 1 percent gravel; violently effervescent; moderately alkaline; gradual wavy boundary. [Combined thickness of A horizon is 30 to 61 cm (12 to 24 inches.)]
ABkg--38 to 51 cm (15 to 20 inches); very dark gray (10YR 3/1) silty clay loam; dark gray (10YR 4/1) dry; moderate medium angular blocky structure; friable; carbonates disseminated throughout; about 1 percent gravel; violently effervescent; moderately alkaline; clear wavy boundary. [(Thickness of AB horizon is0 to 20 cm (0 to 8 inches.)]
Bkg--51 to 76 cm (20 to 30 inches); dark grayish brown (2.5Y 4/2) clay; weak medium angular blocky structure; firm; carbonates disseminated throughout; few fine distinct light olive brown (2.5Y 5/3) Fe concentrations; about 1 percent gravel; violently effervescent; moderately alkaline; clear wavy boundary. [Thickness of the Bkg horizon is 15 76 cm (6 to 30 inches.)]
2Bkg--76 to 119 cm (30 to 47 inches); olive gray (5Y 4/2) clay loam; weak coarse subangular blocky structure; firm; few medium distinct olive brown (2.5Y 4/4) Fe concentrations; few yellowish red Fe stains on ped exteriors; carbonates disseminated throughout; about 3 percent gravel; violently effervescent; moderately alkaline; clear wavy boundary. [Thickness of the 2Bk horizon is 0 to 76 cm (0 to 30 inches.)]
2BCg--119 to 203 cm (47 to 80 inches); olive gray (5Y 5/2) clay loam; moderate extremely coarse and coarse prismatic structure; firm; common medium distinct light olive brown (2.5Y 5/4) Fe concentrations; few yellowish red Fe stains on ped exteriors; carbonates segregated in few light gray (10YR 7/2) rounded soft masses; about 4 percent gravel, strongly effervescent; moderately alkaline.
TYPE LOCATION: Renville County, Minnesota; about 6.5 miles north and 1.1 miles north of Hector; about 663 m (2,175 feet) south and 61 m (200 feet) east of the northwest corner of section 22, T. 116 N., R. 32 W.; USGS Churchill quadrangle; lat. 44 degrees 50 minutes 30 seconds N and long. 94 degrees 41 minutes 26 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: The upper mantle is discontinuous over short distances but ranges up to127 cm (50 inches) in thickness. The mollic epipedon ranges in thickness from 30 to 61 cm (12 to 24 inches). 25 to 102 cm (The 10 to 40 inch) particle size control section averages between 35 and 60 percent clay and 5 to 20 percent fine sand and coarser. The lower part of the profile that formed in firm glacial till has 30 to 55 percent clay and 10 to 30 percent sand with a bulk density of 1.6 to 1.8 gm/cc. Rock fragments typically make up 0 to 2 percent of the upper mantle and 2 to 10 percent of the underlying material. Shale is a common component of the gravel size fraction.
The A, Ap and Ak horizons have hue of 10YR or is neutral, value of 2 or 3, and chroma of 0 through 2. It is silty clay loam, clay, silty clay or clay loam. Reaction is slightly alkaline or moderately alkaline
The AB horizons have hue of 10YR, value of 2 or 3, and chroma of 1 or 2. It is silty clay loam, clay, silty clay or clay loam. Reaction is slightly alkaline or moderately alkaline
The Bkg horizon has hue of 5Y or 2.5Y, value of 4 or 5 and chroma of 1 or 2. It is clay, silty clay, silty clay loam or clay loam. Ped exteriors have common to many coatings of organic matter that commonly are 1 value darker than ped interiors. Calcium carbonate is disseminated throughout or is in the form of threads and masses. Reaction is moderately alkaline.
The 2Bkg horizon has hue of 5Y or 2.5Y, value of 4 or 5 and chroma of 1 or 2. It is clay, silty clay, silty clay loam or clay loam. Calcium carbonate is disseminated throughout or is in the form of threads and masses. Reaction is moderately alkaline.
The 2BCg horizon has hue of 5Y or 2.5Y, value of 4 to 6 and chroma of 1 or 2. It is typically clay loam but includes clay or silty clay. It is slightly alkaline or moderately alkaline.
COMPETING SERIES: This is the Burr series. Burr soils do not have bulk densities greater than 1.6 gm/cc in the lower one third of the series control section.
GEOGRAPHIC SETTING: Corvuso soils are on plane and slightly convex positions on rims of closed depressions. Slopes range from 0 to 2 percent. Corvuso soils formed in a fine textured mantle over underlying firm till. The glacial till in Minnesota is thought to be pre-Wisconsin in age and referred to as Kandiyohi till. Mean annual air temperature ranges from 7 to 10 degrees C (45 to 50 degrees F). Mean annual precipitation is 660 to 813 mm (24 to 32 inches). The frost free days range from 155 to 200days. Elevation above sea level is from 320 to 381 m (1050 to 1250 feet).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arkton, Cosmos , Danielson , Kandiyohi , Lura, Newlondon , and Strout soils. Cosmos, Kandiyohi, Lura and Strout soils form a hydrosequence associated with Corvuso soils. The moderately well drained Arkton and Newlondon soils are calcareous throughout and are on shoulder slopes. The moderately well drained Strout soils are on summits, shoulders slopes, and back slopes. The somewhat poorly drained Kandiyohi soils are on summits and low rises. The poorly drained Cosmos soils do not have carbonates in the upper part of the profile. The poorly drained Danielson soils are on foot slopes and have a thicker mollic epipedon. The very poorly drained Lura soils are in closed depressions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. Surface runoff is low. . The saturated hydraulic conductivity is .42 to 1.41 micrometers per second (.06 to .2 inches per hour). Perched and apparent saturation is as high as 15 cm (0.5 foot) at some time from November through June in normal years. Perched conditions typically exist early in spring and/or during periods of heavy rainfall or snowmelt.
USE AND VEGETATION: Mostly used to grow corn and soybeans. A few areas are in pasture. Native vegetation is tall grass prairie.
DISTRIBUTION AND EXTENT: MLRA-103. Central and south-central Minnesota and north central Iowa. This series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Renville County, Minnesota, 1995
REMARKS: Diagnostic horizons and features recognized in this pedon: mollic epipedon - the zone from the surface to a depth of 20 inches (Ap, Ak, and ABkg horizons); calcic horizon - the zone from 7 to 47 inches (Ak, ABkg, Bkg, and 2Bkg horizons); other features: aquic moisture condition - low chroma below mollic epipedon.
ADDITIONAL DATA: Refer to Minnesota Agricultural Experiment Station Central File Code numbers 499 and 4529 for results of laboratory analyses of some pedons similar to this series. Soil Interpretation Record number MN0688.
Refer to the PhD thesis, 1984, by James Crum, University of Minnesota on the nature Kandiyohi till entitled "Soils and Till Stratigraphy of West-Central Minnesota."