LOCATION HOKANS MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcic Hapludolls
TYPICAL PEDON: Hokans loam, in a cultivated field. (Colors are for moist soil unless otherwise stated)
Ap--0 to 9 inches; black (10YR 2/1) loam, very dark gray (10YR 3/1) dry; weak medium subangular blocky structure; friable; common fine roots throughout; about 2 percent gravel; slightly alkaline; abrupt smooth boundary.
A--9 to 15 inches; black (10YR 2/1) loam, very dark gray (10YR 3/1) dry; weak fine and medium subangular blocky structure; friable; common fine roots throughout; about 2 percent gravel; slightly alkaline; clear smooth boundary.
Bw--15 to 22 inches; brown (10YR 4/3) loam; weak fine and medium subangular blocky structure; friable; common fine roots throughout; about 2 percent gravel; slightly alkaline; clear smooth boundary.
Bk--22 to 40 inches; light yellowish brown (2.5Y 6/4) loam; weak medium subangular blocky structure; friable; common fine roots throughout; carbonates disseminated throughout; about 2 percent gravel; violently effervescent; moderately alkaline; gradual smooth boundary.
C--40 to 80 inches; light olive brown (2.5Y 5/4) loam; massive; friable; few medium distinct light brownish gray (2.5Y 6/2) Fe depletions and few medium distinct light olive brown (2.5Y 5/6) Fe concentrations; about 3 percent gravel; strongly effervescent; slightly alkaline.
TYPE LOCATION: Swift County, Minnesota; about 1 mile west of Kerkhoven; located about 100 feet east and 300 feet north of the southwest corner of section 20, T. 120 N., R. 37 W.; USGS Kerkhoven topographic quadrangle; lat. 45 degrees 10 minutes 57 seconds N. and long. 95 degrees 20 minutes 57 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The mollic epipedon is 7 to 16 inches thick. Depth to carbonates ranges from 20 to 30 inches. The 10 to 40 inch particle-size control section is loam or clay loam and contains from 1 to 10 percent, by volume, of rock fragments. It has more than 30 percent total sand and more than 20 percent fine sand and coarser sand.
The Ap or A horizon has hue of 10YR, value of 2 or 3 and chroma of 1 or 2. It is loam. It is moderately acid to slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 3 to 5 and chroma of 3 or 4. It is loam or clay loam. It is slightly acid to slightly alkaline.
The Bk horizon has hue of 2.5Y or 10YR, value of 4 to 6 and chroma of 3 or 4. It is loam or clay loam. It has 15 to 30 percent calcium carbonate equivalent. It is slightly alkaline or moderately alkaline.
The C horizon has hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 3 or 4. It is loam or clay loam. It has 10 to 20 percent calcium carbonate equivalent It is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Barnes, Byrne, Doland, Formdale, Venagro, and Vienna series. Barnes soils do not have soil saturation in the lower third of the series control section. Doland and Byrne soils have less than 20 percent fine sand and coarser sand in the upper part of the series control section. Formdale soils contain less than 30 percent total sand in the particle-size control section. Vienna soils have silty upper horizons. Venagro soils do not have coarse fragments above a depth of 40 inches.
GEOGRAPHIC SETTING: Hokans soils are on nearly level to gently undulating till plains and moraines. Slope gradients are 1 to 6 percent. The soils formed in loamy glacial till. The mean annual air temperature is 38 to 45 degrees F. and the mean annual precipitation is 22 to 29 inches. Frost-free period ranges from 120 to 160 days. Elevation is 990 to 1950 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Balaton, Buse, Langhei, Parnell, and Vallers soils. Buse and Langhei soils are on steeper convex slopes. Balaton, Vallers and Parnell soils are on lower lying foot slopes and flats, and in depressions. They are wetter and have soil saturation at a shallower depth.
DRAINAGE AND PERMEABILITY: Well drained. These soils have a seasonally high water table between 48 and 72 inches in normal years. Moderately slow or moderate permeability.
USE AND VEGETATION: Cultivated areas are used mostly for corn and soybeans. Native vegetation is tall grass prairie.
DISTRIBUTION AND EXTENT: These soils are extensive throughout southwestern Minnesota, primarily in the eastern part of MLRA 102A.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Swift County, Minnesota. 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon include: mollic epipedon - the zone from the surface of the soil to a depth of 15 inches (Ap and A horizons); cambic horizon - the zone from 15 to 22 inches (Bw horizon); calcic epipedon-the zone from 22 to 40 inches (Bk horizon), soil saturation based on redoximorphic features below a depth of 40 inches.
These soils were formerly included with the Barnes soils. In the eastern part of MLRA 102A soil saturation occurs at about depths of 4 feet in normal years.