LOCATION WILNO MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Hapludolls
TYPICAL PEDON: Wilno loam on a foot slope of about 13 percent in a cropped field. (Colors are for moist soil unless otherwise indicated.)
Ap--0 to 9 inches; black (10YR 2/1) loam, very dark gray (10YR 3/1) dry; weak fine subangular blocky structure; friable; many fine roots; about 2 percent gravel; neutral; abrupt smooth boundary.
A--9 to 42 inches; black (10YR 2/1) loam, very dark gray (10YR 3/1) dry; weak fine subangular blocky structure; friable; many fine roots; about 2 percent gravel; neutral; gradual smooth boundary. (Combined thickness of the A horizons is 20 to 50 inches)
AB--42 to 52 inches; very dark brown (10YR 2/2) loam, very dark grayish brown (10YR 3/2) dry; weak medium subangular; blocky structure; friable; many fine roots; about 2 percent gravel; neutral; gradual smooth boundary. (0 to 15 inches thick)
Bw1--52 to 70 inches; dark grayish brown (10YR 4/2) loam; weak medium subangular blocky structure; friable; common fine roots; about 2 percent gravel; neutral; gradual smooth boundary.
Bw2--70 to 80 inches; olive brown (2.5Y 4/3) loam; weak medium subangular blocky structure; friable; common fine roots; about 2 percent gravel; neutral.
TYPE LOCATION: Lincoln County, Minnesota; 690 feet north and 123 feet east of the southwest corner of section 13, T. 112 N., R. 46 W. USGS Canby SE quadrangle, latitude 44 degrees 30 minutes 16 seconds N., longitude 96 degrees 20 minutes 32 seconds W., NAD83.
RANGE IN CHARACTERISTICS: Loamy colluvial sediments are typically 40 to over 80 inches thick, however loamy glacial till can occur at depths of 40 inches. Free carbonates are at depths of 40 to over 80 inches. Sand content in the 10 to 40 inch particle size control section is typically between 30 and 45 percent, but ranges from 25 to 50 percent. Clay content ranges from 18 to 30 percent. The mollic epipedon is 24 to 60 inches thick and does not contain fine strata or an irregular decrease in organic carbon. Below depths of 60 inches, the organic carbon content is less than .3 percent. Rock fragments of mixed lithology, by volune, range from 0 to 5 percent in the colluvial sediments and 2 to 8 percent in the underlying till.
The A horizon has hue of 10YR, value of 2 or 3 and chroma of 1 or 2. Some pedons have surface horizons with recent erosional sediments. The A horizon is loam or clay loam. Reaction is slightly acid or neutral.
The AB horizon has hue of 10YR, value of 2 or 3 and chroma of 2 or 3. It is loam or clay loam. Reaction is slightly acid or neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 3 or 4 and chroma of 2 to 4. It is loam, clay loam or less commonly sandy loam. Reaction is slightly acid or neutral.
Some pedons have a Bt horizon with few to common clay films. However the B/A clay ratio is less then 1.2 required for an argillic.
The C horizon has hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 3 or 4. It is loam, clay loam or less commonly sandy loam. Reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Aastad, Lankin, Svea and Walsh series. The Walsh soils formed in glacial alluvium derived from shale and have a high shale content. The Aastad, Lankin and Svea soils have water tables within six feet of the surface.
GEOGRAPHIC SETTING: Wilno soils are on slightly concave foot slopes and backslopes. Slope gradients are between 6 and 45 percent. The soils formed in loamy local colluvium derived from glacial till and glacial till of mixed mineralogy. Mean annual air temperature ranges from 38 to 45 degrees F., and
mean annual precipitation is 19 to 27 inches. Annual frost free days are 120 to 170 days. Elevation ranges from 890 to 1950 feet above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: Associated soils are commonly the well drained
Buse,
Langhei and
Barnes soils. The Barnes, Langhei and Buse soils are upland soils formed in glacial till, and they are on slopes above the Wilno soils. In some places they are associated with the poorly drained
Lakepark soils.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to high. Permeability is moderate.
USE AND VEGETATION: Many areas are non-cropped escarpments, either in woods or permanent pasture. Other areas are cultivated with corn, soybeans, and small grain being the main crops. Native vegetation is mixed prairie grasses with scattered hardwood trees on steep escarpments along river
valleys.
DISTRIBUTION AND EXTENT: MLRA-102A Southwestern Minnesota and possibly southeastern South Dakota.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Pipestone County, Minnesota, 2005
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to a depth of 52 inches (Ap,A, and AB horizons); Udic moisture regime.
This series replaces the Darnen soils, where correlated on steeper slopes, as the concept of Darnen has changed to having saturation in the lower third of the series controls section.