LOCATION COKATO MN+IAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Argiudolls
TYPICAL PEDON: Cokato loam, on a convex, south facing slope of 7 percent, in a cultivated field. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 12 inches; black (10YR 2/1) loam, very dark gray (10YR 3/1) dry; weak fine subangular blocky structure; friable; about 2 percent gravel; neutral; abrupt smooth boundary.
A--12 to 16 inches; very dark gray (10YR 3/1) loam, dark gray (10YR 4/1) dry; weak fine subangular blocky structure; friable; about 2 percent gravel; neutral; clear smooth boundary. (Combined thickness of the A horizon is 7 to 16 inches.)
Bt1--16 to 25 inches; dark yellowish brown (10YR 4/4) clay loam; moderate medium subangular blocky structure; friable; common very dark brown (10YR 2/2) clay films on faces of peds and in pores and few very dark brown (10YR 2/2) clay films in channels; about 2 percent gravel; neutral; clear smooth boundary.
Bt2--25 to 35 inches; light olive brown (2.5Y 5/4) clay loam; moderate coarse subangular blocky structure parting to moderate fine subangular blocky; friable; few very dark grayish brown (10YR 3/2) clay films in pores and on ped faces; about 2 percent gravel; neutral; clear smooth boundary.
Bt3--35 to 41 inches; light olive brown (2.5Y 5/4) clay loam; few fine distinct light brownish gray (2.5Y 6/2) relic Fe depletions; moderate coarse subangular blocky structure; friable; few very dark brown (10YR 2/2) clay films in pores, channels and on ped faces; about 2 percent gravel; about 1 percent cobbles; neutral; clear wavy boundary. (Combined thickness of the Bt horizon is 16 to 32 inches.)
Bk--41 to 60 inches; light olive brown (2.5Y 5/4) and light yellowish brown (2.5Y 6/3) loam; common medium prominent yellowish brown (10YR 5/8) relic Fe concentrations; weak coarse subangular blocky structure; friable; few fine irregular soft very pale brown (10YR 8/2) masses and threads of calcium carbonate distributed uniformly throughout; about 3 percent gravel; about 1 percent cobbles; slightly alkaline.
TYPE LOCATION: Meeker County, Minnesota; about 6.5 miles south of the city of Darwin; 1,000 feet east and 1,700 feet north of the southwest corner of section 26, T. 118 N., R. 30 W.; USGS Hutchinson West quadrangle; lat. 44 degrees 59 minutes 53 seconds N. and long. 94 degrees 24 minutes 57 seconds W., NAD83.
RANGE IN CHARACTERISTICS: Depth to free carbonates ranges from 18 to 48 inches. Rock fragments range from about 1 to 8 percent by volume throughout the profile. The thickness of the mollic epipedon is 7 to 16 inches.
The A or Ap horizon has hue of 10YR, value of 2 or 3 and chroma of 1 to 3. It is loam or clay loam. The reaction is moderately acid to neutral.
Some pedons have an E horizon as much as 3 inches thick.
The upper part of the Bt horizon has hue of 10YR, value of 4 or 5 and chroma of 3 or 4. It has thin to moderately thick coatings of very fine sand or silt that are light brownish gray or light gray when dry. Clay films are few to common. The lower part of the B horizon has hue of 10YR or 2.5Y, value of 4 or 5 and chroma of 3 or 4. The Bt horizon commonly is clay loam or loam but includes subhorizons of sandy clay loam. The B/A clay ratios range from 1.2 to 1.3. It is moderately acid to neutral.
The Bk horizon has hue of 10YR or 2.5Y, value of 5 or 6 and chroma of 3 or 4. It is loam. The reaction is slightly alkaline or moderately alkaline. The clay content ranges from 18 to 27 percent. The sand content ranges from 35 to 45 percent.
Some pedons have a C horizon with hue of 10YR or 2.5Y, value of 5 or 6 and chroma of 3 to 5. It is loam. The reaction is slightly alkaline or moderately alkaline. The clay content ranges from 18 to 27 percent. The sand content ranges from 35 to 45 percent.
COMPETING SERIES: These are the Atkinson, Barce, Burchard, Calmar, Corwin, Cresco, Durand, Foresman, Friesland, Griswold, Hitt, Hochheim, Jasper, Joslin, Keosauqua (T), La Rose, Linkville, Markesan, Moingona, Mona, Morrill, Pana, Parr, Plattville, Prairieville, Ringwood, Rockton, Rotamer, Schoolcraft, Shelby, Sibleyville, Symerton, Tippecanoe, Velma, Wea and Winnebago series. Barce soils have bulk density of more than 1.6 in the lower part of the series control section. Burchard, Cresco, Durand, Joslin, Mona, Prairieville and Shelby soils have more than 27 percent clay in the lower part of the series control section. Corwin soils have two chorma redox depletions within a depth of 36 inches. Foresman, Keosauqua, Tippecanoe and Wea soils have strata of sand in the lower part of the series control section. Friesland soils have silt loam or silty clay loam texture within the series control section. Griswold, Pana, Parr, Ringwood, Rotamer, and Schoolcraft soils have less than 18 percent clay in the lower part of the series control section. Atkinson, Calmar, Hitt, Plattville, Rockton, and Sibleyville soils have a lithic or paralithic contact within 60 inches. Hocheim and Markesan soils have more than 40 percent calcium carbonate equivalents in the lower part of the series control section. Jasper soils formed in stratified sediment and have more than 45 percent sand in the lower part of the series control section. Moingona soils do not have rock fragments in the upper part of the series control section. La Rose soils have hues that are redder than 10YR in the series control section. Linkville, Morrill and Winnebago soils have carbonates at depths greater than 48 inches. Smyerton soils have 10 to 35 percent sand in the lower part of the control section. Velma soils have strongly or very strongly reaction in the Bt horizon.
GEOGRAPHIC SETTING: Cokato soils are on convex and linear slopes on ground moraines. They formed in loamy, calcareous glacial till of the Late Wisconsin glaciation. Slopes range from 6 to 40 percent. Mean annual air temperature ranges from 45 to 50 degrees F. Mean annual precipitation ranges from 25 to 32 inches. Frost free days range from 125 to 180 days. The elevation above sea level ranges from 700 to 1600 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Cordova, Glencoe, Hamel, Le Sueur and Storden soils which formed in similar parent material. The well drained Storden soils are calcareous throughout and are on shoulders and backslopes. The moderately well drained Le Sueur soils are on summits. The poorly drained Cordova soils are on nearly level positions. The poorly drained Hamel soils are on footslopes. The very poorly drained Glencoe soils are in closed depressions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Saturated hydraulic conductivity, measured in inches per hour, is .6 to 2. Runoff is medium to very rapid.
USE AND VEGETATION: Most areas of these soils are used for cropland. A few areas are in pasture and woodland. Native vegetation is tall grass prairie and mixed northern hardwoods.
DISTRIBUTION AND EXTENT: MLRA-103. Central, South central Minnesota and North Central Iowa. Inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: McCleod County, Minnesota, 1993
REMARKS: Other features: mollic epipedon - the zone from the surface to 16 inches (Ap,A horizons); argillic horizon - the zone from 16 to 41 inches (Bt1,Bt2,Bt3 horizons); udic moisture regime. This soil was formerly included with the Clarion or Lester series.
ADDITIONAL DATA: Refer to Minnesota Agricultural Experiment Station, Central File Code numbers 4656, 4657, 4658, and 4659 for results of laboratory analyses of some pedons of this series. Soil Interpretation Record No. MN0684.