LOCATION GRASSTON MNEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Oxyaquic Glossudalfs
TYPICAL PEDON: Grasston silt loam on a 3 percent convex slope on a glacial lake plain in a cultivated area. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 23 cm; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; weak medium granular structure; friable; strongly acid; abrupt smooth boundary. (8 to 25 cm thick)
B/E--23 to 36 cm; 60 percent brown (10YR 4/3) silty clay loam (Bt); 40 percent brown (10YR 5/3) silt loam (E); weak thick platy structure; friable; strongly acid; clear wavy boundary. (3 to 10 inches thick)
Bt1--36 to 74 cm; dark yellowish brown (10YR 4/4) silty clay; moderate medium prismatic structure parting to moderate fine and medium angular blocky; firm; faint discontinuous dark brown (10YR 3/3) clay films on faces of peds; strongly acid; gradual wavy boundary.
Bt2--74 to 107 cm; dark yellowish brown (10YR 4/4) silty clay loam; weak medium prismatic structure parting to weak medium angular blocky; friable; few distinct discontinuous very dark grayish brown (10YR 3/2) clay films on faces of peds and distinct discontinuous very dark brown (10YR 2/2) organic coats in root channels; common medium distinct yellowish brown (10YR 5/6) Fe concentrations and common fine and medium prominent grayish brown (2.5Y 5/2) Fe depletions; neutral; clear wavy boundary. (Combined thickness of the Bt horizon is 51 to 89 cm)
Bk--107 to 168 cm; light yellowish brown (10YR 6/4) silt loam; weak medium platy structure; friable; prominent discontinuous very dark brown (10YR 2/2) organic coats in root channels; many fine rounded light gray (10YR 7/2) soft masses of carbonate; common medium distinct yellowish brown (10YR 5/6) Fe concentrations and common medium and coarse distinct light brownish gray (2.5Y 6/2) Fe depletions; strongly effervescent; slightly alkaline; clear smooth boundary. (0 to 20 inches thick)
C--168 to 203 cm; light yellowish brown (10YR 6/4) silty clay loam; massive; friable; few fine rounded light gray (10YR 7/2) soft masses of carbonate; common medium distinct yellowish brown (10YR 5/6) Fe concentrations and common medium and coarse distinct light brownish gray (2.5Y 6/2) Fe depletions; strongly effervescent; slightly alkaline.
TYPE LOCATION: Kanabec County, Minnesota; about 3 miles southwest of Grasston; 2,300 feet north and 1,250 feet east of the southwest corner of sec. 16, T.38 N., R.23 W.; USGS Grasston topographic quadrangle; lat. 45 degrees 46 minutes 49 seconds N. and long. 93 degrees 13 minutes 09 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: Depth to free carbonates ranges from 64 to 127 cm. The series control section does not have rock fragments.
The A or Ap horizon has hue of 10YR, value of 3 or 4, and chroma of 1 or 2. It is silt loam, loam, silty clay loam, very fine sandy loam, or fine sandy loam. It is moderately acid to neutral.
Some pedons have an E horizon with hue of 10YR, value of 4 to 6, and chroma of 1 or 2. It is silt loam, loam, or very fine sandy loam. It is moderately acid to neutral.
The B/E or E/B horizon has colors and textures similar to the E and Bt horizons.
The Bt horizon has hue of 10YR, value of 4 or 5, and chroma of 3 or 4. A hue of 2.5Y occurs in the lower part of some pedons. It is silty clay, clay, or silty clay loam. It commonly has redoximorphic features in the lower part. It is strongly acid to neutral.
The Bk horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 3 or 4. It is silt loam or silty clay loam. It has soft threads or rounded masses of calcium carbonate. It is slightly alkaline or moderately alkaline.
Some pedons have a BC horizon.
The C horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 3 or 4. It is silt loam, silty clay loam, or very fine sandy loam. This horizon is varved in some pedons. It is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Lewis Lake and Suomi series. Lewis Lake soils have coarse textured outwash in the lower third of the series control section. Suomi soils have rock fragments throughout the profile and have more than 20 percent fine sand and coarser in the particle size control section.
GEOGRAPHIC SETTING: These soils have plane or convex slopes on glacial lake plains. Slope gradients range from 0 to 6 percent. They formed in calcareous, clayey and silty lacustrine sediments of Late Wisconsin Age. These sediments are primarily derived from the Des Moines lobe. Mean annual air temperature ranges from 2 to 7 degrees C. Mean annual precipitation ranges from 625 to 750 mm. Frost free days range from 90 to 140. Elevation above sea level ranges from 300 to 500 meters.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Debs, Foglake and Longsiding soils. The well drained Debs soils on higher lying positions. The poorly drained Foglake soils in swales and flats. The somewhat poorly drained Longsiding soils on less sloping, less convex areas.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. Surface runoff is negligible to low. Saturated hydraulic conductivity is 4.23 to 14.11 micrometers per second (.6 to 2.0 inches)in the upper part, .42 to 4.23 micrometers per second (.06 to .6 inches) in the middle part and 1.41 to 14.11 micrometers per second (.2 to 2.0 inches) in the lower part. Seasonal high saturation is at a depth as high as 61 cm below the surface during spring in normal years.
USE AND VEGETATION: The main use is cropland. Common crops grown include corn, soybeans, oats, and legume hay. A few areas are forested. Native vegetation is deciduous forest; ash, maple, basswood, and elm were the dominant species.
DISTRIBUTION AND EXTENT: MLRA-88, 90A and 93A. East-central and northeastern Minnesota. Minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Mille Lacs County, Minnesota, 2006.
REMARKS: Diagnostic horizons and features recognized in this pedon include: ochric epipedon - the zone from the surface to 23 cm (Ap horizon); glossic horizon - the zone from 23 to 36 cm (B/E horizon); argillic horizon - the zone from 23 to 107 cm (B/E, Bt1, and Bt2 horizons).
This soil was previously included with the Dalbo, silty substratum phase.
ADDITIONAL DATA: Refer to Minnesota Agricultural Experiment Station CFC # 4569 for data on a similar pedon.