LOCATION KRATKA MN+ND SD WIEstablished Series
TAXONOMIC CLASS: Sandy over loamy, mixed, superactive, frigid Typic Endoaquolls
TYPICAL PEDON: Kratka fine sandy loam, in a slightly concave area, on a glacial lake plain, in a cultivated field, at an elevation of about 1,072 feet above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; weak fine and medium subangular blocky structure parting to weak fine granular; friable; few medium and common very fine and fine roots; about 5 percent gravel; slightly alkaline; abrupt smooth boundary.
A--6 to 11 inches; black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; weak moderate subangular blocky structure parting to weak fine granular; friable; few fine and common very fine roots; about 5 percent gravel; slightly alkaline; clear smooth boundary. (Combined thickness of the A horizon is 6 to 18 inches.)
Bg1--11 to 14 inches; dark grayish brown (2.5Y 4/2) fine sandy loam; weak medium subangular blocky structure; very friable; few very fine and fine roots; about 5 percent gravel; common medium distinct light olive brown (2.5Y 5/4) Fe concentrations; slightly alkaline; clear smooth boundary.
Bg2--14 to 18 inches; dark grayish brown (2.5Y 4/2) loamy fine sand; weak fine and medium subangular blocky structure; very friable; about 8 percent gravel; common medium distinct light olive brown (2.5Y 5/4) and yellowish brown (10YR 5/6) Fe concentrations; slightly alkaline; clear wavy boundary. (Combined thickness of the Bg horizon is 0 to 32 inches.)
Cg1--18 to 25 inches; grayish brown (2.5Y 5/2) fine sand; single grain; loose; about 10 percent gravel; many coarse distinct light olive brown (2.5Y 5/6) Fe concentrations and common medium faint light brownish gray (2.5Y 6/2) Fe depletions and few medium prominent yellowish brown (10YR 5/6) Fe concentrations; slightly alkaline; abrupt wavy boundary. (0 to 12 inches thick)
2Cg2--25 to 31 inches; olive gray (5Y 5/2) loam; massive; friable; about 5 percent gravel; common medium prominent light olive brown (2.5Y 5/4) Fe concentrations; slightly effervescent; slightly alkaline; clear wavy boundary.
2Cg3--31 to 39 inches; olive gray (5Y 5/2) loam; massive; friable; about 5 percent gravel; common medium prominent light olive brown (2.5Y 5/4) and few fine prominent yellowish brown (10YR 5/6) Fe concentrations; strongly effervescent; slightly alkaline; clear smooth boundary.
2Cg4--39 to 80 inches; olive gray (5Y 5/2) clay loam; massive; friable; about 5 percent gravel; few medium prominent yellowish brown (10YR 5/6) and common medium prominent light olive brown (2.5Y 5/6) Fe concentrations; strongly effervescent; slightly alkaline.
TYPE LOCATION: Pennington County, Minnesota; about 11 miles northwest of Thief River Falls; located about 1,420 feet north and 250 feet east of the southwest corner of section 12, T. 154 N., R. 45 W.; USGS Viking topographic quadrangle; lat. 48 degrees 10 minutes 16 seconds N. and 96 degrees 23 minutes 23 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon typically is 6 to 18 inches. The depth to loamy glacial till or lacustrine sediments ranges from 20 to 40 inches. Some pedons have stratified sediments below 40 inches. The depth to carbonates typically ranges from 16 to 45 inches but ranges to more than 60 inches in some pedons. The upper sediments have 0 to 5 percent gravel and the 2C horizon contains 0 to 8 percent by volume of gravel of mixed lithology. In pedons that have lacustrine sediments in the 2C horizons, rock fragments may not be present. A thin lag line ranging to as much as 6 inches in thickness and containing as much as 35 percent by volume of gravel is at the contact between the upper and lower material. The reaction ranges from moderately acid to slightly alkaline in the A and Bg horizons, slightly acid to slightly alkaline in the Cg horizons and slightly acid to moderately alkaline in the 2Cg horizons.
The A or Ap horizon has hue of 10YR or 2.5Y, value of 2 or 3, chroma of 1 or 2 or is neutral. It is loamy sand, loamy fine sand, sandy loam, or fine sandy loam.
Some pedons have an ABg horizon.
The Bg or Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 or 2 in the upper part, and includes chroma of 3 or 4 in the lower part. It is loamy fine sand, fine sand, loamy sand, sand or fine sandy loam.
Some pedons have Bkg or 2Bkg horizons with 2.5Y or 5Y hue. They are slightly alkaline or moderately alkaline.
Some pedons have 2Bg horizons with hue of 2.5Y or 5Y, value of 4 to 6 and chroma of 1 to 3. Textures include loam or clay loam.
The Cg horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 2 to 4. Texture is sand, fine sand, loamy fine sand or loamy sand.
Some pedons have thin Ab horizons.
The 2Cg horizon has hue of 10YR to 5Y; value of 4 to 6; and chroma of 1 to 3. It is loam, clay loam, sandy loam, or fine sandy loam in the glacial till and silt loam, silty clay loam, or very fine sandy loam, with thin strata of loamy fine sand or fine sand in the lacustrine material.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils have plane or slightly concave slopes on flats or in shallow depressions on stream terraces, glacial lake plains, glacial deltas of former glacial lakes, and glacial moraines. Slopes range from 0 to 2 percent. Kratka soils formed in a sandy mantle of lacustrine glacial outwash over loamy glacial till or lacustrine sediments of Late Wisconsinan Age. Mean annual air temperature ranges from 37 to 45 degrees F. Mean annual precipitation ranges from 19 to 33 inches. Frost-free period ranges from 88 to 150 days. Elevation ranges from 700 to 1,500 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These typically include the Foldahl, Grimstad, Rockwell, Strathcona and Towner soils which formed in similar materials. The Foldahl and Grimstad soils are moderately well drained to somewhat poorly drained. Rockwell and Strathcona soils have a calcic horizon and the Towner soils are moderately well drained. They are also associated with Blomford and Braham soils in a few places. Blomford are poorly drained soils on plane slopes and Braham are well drained and moderately well drained soils on plane and convex slopes.
DRAINAGE AND PERMEABILITY: Poorly and very poorly drained. Permeability is moderately rapid or rapid in upper part and moderately rapid to moderately slow in the lower part. Surface runoff is negligible. Depth to an apparent seasonal high water table is 0.5 to 1.5 feet at some time from April to July in normal years for the poorly drained phases and at plus 1 to 0.5 feet at some time from March to August in normal years for the very poorly drained phase.
USE AND VEGETATION: Most areas of the Kratka series are used for hay and pasture or are cropped with small grains. Native vegetation is wet tall grass prairie and sedges with some scattered shrubs.
DISTRIBUTION AND EXTENT: Primarily northwestern Minnesota in the Glacial Lake Agassiz Plain and in eastern North Dakota, but is also recognized in other parts of northern Minnesota and Wisconsin. Moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Norman County, Minnesota, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon include: mollic epipedon - from the surface to 11 inches (A horizons); aquic features per low chroma below mollic epipedon. Typical pedon was revisited 9/97 and described to 80 inches.
ADDITIONAL DATA: Refer to Minnesota Agricultural Experiment Station Central File Code number 3006 for laboratory data of the typical pedon. See also MAES CFC numbers 802 and 883 and NSSL S92MN-113-3 for laboratory data of representative pedons and Minnesota Department of Transportation data for SS81369-370 for engineering test data.
SIR #MN0072; MN0419, Depressional phase; MN0640, Stratified substratum phase; MN0641, Stratified substratum, depressional phase; MN0618, thick solum phase.