LOCATION ROTHSAY MNEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, frigid Calcic Hapludolls
TYPICAL PEDON: Rothsay silt loam with a 4 percent convex slope on a glacial lake plain in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; black (10YR 2/1) silt loam, very dark gray (10YR 3/1) dry; weak fine subangular blocky structure; friable; many roots; neutral; abrupt smooth boundary.
A--8 to 13 inches; very dark gray (10YR 3/1) silt loam, dark gray (10YR 4/1) dry; weak medium subangular blocky structure; friable; many roots; neutral; clear irregular boundary. (Combined thickness of A horizons is 7 to 15 inches thick)
Bw1--13 to 16 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) coatings on peds; weak medium prismatic structure parting to weak medium subangular blocky; friable; common roots; neutral; clear wavy boundary.
Bw2--16 to 22 inches; dark yellowish brown (10YR 4/4) silt loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; common roots; neutral; gradual wavy boundary. (Combined thickness of the Bw horizons is 4 to 24 inches.)
Bk--22 to 30 inches; light olive brown (2.5Y 5/4) silt loam; weak fine subangular blocky structure; friable; few roots; few soft accumulations of carbonates: strong effervescence; moderately alkaline; gradual smooth boundary. (0 to 20 inches thick)
BC--30 to 60 inches; light yellowish brown (2.5Y 6/4) silt loam; weak fine subangular blocky structure; friable; slight effervescence; moderately alkaline.
TYPE LOCATION: Swift County, Minnesota; about 5 miles east of Benson; about 2,420 feet south and 50 feet east of the northwest corner of sec. 6, T. 121 N., R 38 W.
RANGE IN CHARACTERISTICS: Depth to free carbonates is 12 to 36 inches. A zone of carbonate accumulation occurs in most pedons but does not qualify for a calcic horizon. The mollic epipedon is 7 to 16 inches thick. The control section has 10 to 18 percent clay and less than 15 percent fine sand, and coarser particles.
The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2. Texture is silt loam, loam, or very fine sandy loam. Reaction is neutral or slightly alkaline.
The Bw horizon has hue of 10YR, value of 3 to 5 and chroma of 2 to 4. It has the lower value or chroma only in the upper part if at all. Texture is silt loam, loam, or very fine sandy loam. Reaction is neutral or slightly alkaline.
The C horizon has hue of 10YR or 2.5Y, value of 5 or 6 and chroma of 2 to 4. Texture is silt loam, loam, or very fine sandy loam. Reaction is slightly or moderately alkaline.
A 2C horizon of loamy glacial till begins at depths as shallow as 40 inches in some pedons.
COMPETING SERIES: This is the Eckman series. Eckman soils have a calcic horizon.
GEOGRAPHIC SETTING: Rothsay soils are on convex or plane slopes with gradients of 1 to 18 percent. These soils formed in silty calcareous deposits 4 to 10 feet thick that are of lacustrine or eolian origin. These sediments are underlain by loamy calcareous glacial till within depths of 60 inches in some pedons. The mean annual temperature ranges from about 38 to 46 degrees F. Mean annual precipitation from about 22 to 27 inches. Frost-free days range from 90 to 150. Elevation above sea level ranges from 700 to 1950 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hantho soils and Perella, Quam, and Zell soils, which are members of a toposequence with Rothsay soils. Somewhat excessive drained Zell soils are mapped adjacent to Rothsay on slightly higher terrain or steep slopes. Moderately well drained Hantho soils are on less sloping terrain and have a thicker mollic epipedon. Poorly drained Perella soils are on nearly level lower-lying terrain. Very poorly drained Quam soils are in depressions.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium; permeability is moderate.
USE AND VEGETATION: Most areas of this soil are used to grow corn, soybeans, and small grains. Native vegetation is tall grass prairie plant association.
DISTRIBUTION AND EXTENT: Western Minnesota and perhaps northeastern South Dakota, and eastern North Dakota. Small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Douglas County, Minnesota, in February l971.
REMARKS: Diagnostic horizon and features recognized in this pedon are: mollic epipedon - from the surface to 13 inches (Ap and A horizons); cambic horizon - 13 to 22 inches (Bw1 and Bw2 horizons).