LOCATION OAK CENTER MNEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Mollic Hapludalfs
TYPICAL PEDON: Oak Center silt loam, on a linear slope of 1 percent, in a cultivated field, at an elevation of about 340 meters above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 23 centimeters; very dark grayish brown (10YR 3/2) silt loam, dark grayish brown (10YR 4/2) dry; moderate fine and very fine subangular blocky structure parting to moderate fine granular; very friable; few fine and medium roots, slightly acid; abrupt smooth boundary. (18 to 23 centimeters thick)
Bt1--23 to 91 centimeters; dark yellowish brown (10YR 4/4) silt loam; moderate medium subangular blocky structure; friable; few fine roots; common faint brown (10YR 4/3) clay films on faces of peds; moderately acid; gradual wavy boundary.
Bt2--91 to 137 centimeters; yellowish brown (10YR 5/4) silt loam; moderate medium subangular blocky structure; friable; few very fine roots; few faint brown (10YR 4/3) clay films on faces of peds; moderately acid; clear smooth boundary. (Combined thickness of the Bt horizon is 79 to 132 centimeters.)
2Bt3--137 to 142 centimeters; yellowish brown (10YR 5/4) fine sandy loam; weak coarse and medium subangular blocky structure; friable; few very fine roots; moderately acid; abrupt wavy boundary. (0 to 15 centimeters thick)
3C--142 to 157 centimeters; very pale brown (10YR 7/4) fine sand; single grain; loose; moderately acid; gradual wavy boundary.
3Cr--157 to 203 centimeters; very pale brown (10YR 8/2) weakly cemented sandstone; moderately acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 105-Northern Mississippi Valley Loess Hills, Wabasha County, Minnesota subset; about 2 1/2 miles northeast of Oak Center; located about 2,325 feet north and 1,985 feet west of the southeast corner of section 27, T. 111 N., R. 13 W.; USGS Lake City topographic quadrangle; lat. 44 degrees 23 minutes 19.8 seconds N. and long. 92 degrees 21 minutes 27.9 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of loess--100 to 150 centimeters
Depth to loamy fine sand or fine sand--100 to 150 centimeters
Depth to siliceous sandstone bedrock (paralithic contact)--100 to 200 centimeters
Depth to carbonates--greater than 200 centimeters
Clay content in the particle-size control section (weighted average)--18 to 28 percent
Sand content in the particle-size control section (weighted average)--less than 10 percent
Ap or A (when present) horizon:
Hue--10YR
Value--2 or 3, moist and 4 or 5, dry
Chroma--1 to 3
Texture--silt loam
Clay content--15 to 22 percent
Sand content--less than 10 percent
Rock fragment content--0 percent
Reaction--slightly acid or neutral
BE horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silt loam
Clay content--15 to 22 percent
Sand content--less than 10 percent
Rock fragment content--0 percent
Reaction--moderately acid or slightly acid
Thickness--0 to 15 centimeters
Bt horizon:
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--3 to 6
Texture--silt loam or silt clay loam
Clay content--18 to 28 percent
Sand content--less than 10 percent
Rock fragment content--0 percent
Reaction--strongly acid to slightly acid
Bw horizon (when present):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--3 or 4
Texture--silt loam
Clay content--18 to 24 percent
Sand content--less than 10 percent
Rock fragment content--0 percent
Reaction--slightly acid or neutral
2Bt horizon:
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--4 to 6
Texture--sandy loam, fine sandy loam, sandy clay loam, loam, clay loam or the gravelly analogs of these textures
Clay content--10 to 28 percent
Sand content--35 to 80 percent
Rock fragment content--0 to 35 percent
Reaction--strongly acid to slightly acid
3Bw horizon (when present):
Hue--7.5YR or 10YR
Value--4 to 6
Chroma--4 to 8
Texture--loamy fine sand or fine sand
Clay content--0 to 8 percent
Sand content--70 to 95 percent
Rock fragment content--0 to 10 percent (siliceous sandstone)
Reaction--strongly acid to slightly acid
3C horizon:
Hue--7.5YR to 2.5Y
Value--6 to 8
Chroma--2 to 8
Texture--fine sand
Clay content--0 to 8 percent
Sand content--85 to 100 percent
Rock fragment content--0 to 10 percent (siliceous sandstone)
Reaction--strongly acid to slightly acid
The underlying bedrock consists of siliceous sandstone and has color similar to the 3C horizon described above. Narrow joints containing residuum are common in the sandstone. In some pedons, the sandstone can be easily dug with a spade, but in other areas the sandstone is more consolidated and digging with a spade is difficult.
COMPETING SERIES: These are the
Batavia,
Bowes,
Churchtown,
Deroin,
Downs,
Ella,
Festina,
Frankville,
Gladek,
Greenbush,
Harvard,
Hersey,
Knox,
Luana,
Mannon,
Massbach,
Mellott,
Mt. Carroll,
Myrtle,
Nasset,
Newhouse,
Watkins,
Waubeek, and
Yutan series.
Batavia--have a clay content that averages 27 to 35 percent in the particle-size control section and have a sand content of less than 70 percent in the lower third of the series control section
Bowes--have a rock fragment (igneous) content of more than 15 percent and carbonates in the lower third of the series control section
Churchtown--have a sand content 10 to 55 percent in the upper half of the series control section
Deroin--have a clay content that averages 27 to 35 percent in the particle-size control section and have a sand content of less than 25 percent in the lower third of the series control section
Downs--have a sand content of less than 10 percent in the lower third of the series control section
Ella--have a frequently saturated zone at a depth of 1 meter during the wettest periods of normal years
Festina--have a sand content of less than 70 percent in the lower third of the series control section
Frankville--have a lithic contact with limestone within a depth of 100 centimeters
Gladek--have a sand content of less than 70 percent in the lower third of the series control section and have carbonates within a depth of 150 centimeters
Greenbush--have a frequently saturated zone at a depth of 1.2 meters during the wettest periods of normal years and have a sand content of less than 10 percent in the lower third of the series control section
Harvard--have a clay content that averages 27 to 35 percent and a sand content that averages more than 10 percent in the particle-size control section
Hersey--have a frequently saturated zone at a depth of 1 meter during the wettest periods of normal years and have a sand content of less than 50 percent in the lower third of the series control section
Knox--have a sand content of less than 5 percent in the lower third of the series control section
Luana--have a rock fragment (arenaceous limestone) content of 10 to 35 percent in the lower third of the series control section
Mannon--have a frequently saturated zone at a depth of 1.2 meters during the wettest periods of normal years and have a sand content of less than 10 percent in the lower third of the series control section
Massbach--have a paralithic contact with calcareous silty clay or clay shale within a depth of 150 centimeters and have a frequently saturated zone at a depth of 1 meter during the wettest periods of normal years
Mellott--have carbonates and a sand content of less than 65 percent in the lower third of the series control section
Mt. Carroll--have a sand content of less than 15 percent in the lower third of the series control section
Myrtle--have a sand content of less than 70 percent and a matrix hue of 2.5YR, 5YR or 7.5YR in the lower third of the series control section
Nassett--have a lithic contact with limestone within a depth of 150 centimeters
Newhouse--have a sand content of less than 70 percent and 5 to 35 percent chert and sandstone fragments in the lower third of the series control section
Watkins--have a clay content that averages 30 to 35 percent in the particle-size control section and have a sand content of less than 15 percent in the lower third of the series control section
Waubeek--have a sand content of less than 50 percent in the lower third of the series control section
Yutan--have a sand content of less than 15 percent in the lower third of the series control section
GEOGRAPHIC SETTING:
Parent material--100 to 150 centimeters of loess over siliceous sandy residuum and sandstone bedrock, St. Peter and New Richmond formations
Landform--linear and convex slopes on interfluves and side slopes on uplands
Slope--0 to 18 percent
Elevation--200 to 400 meters
Mean annual air temperature--6 to 10 degrees C
Mean annual precipitation--760 to 965 millimeters
Frost-free period--145 to 205 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Downs,
Hersey, and
Mt. Carroll soils.
Downs--are in landscape positions similar to those of the Oak Center soils and have a sand content of less than 10 percent in the lower third of the series control section
Hersey--are in landscape positions similar to those of the Oak Center soils, have a frequently saturated zone within a depth of 1 meter during the wettest periods of normal years, and have a sand content of less than 50 percent in the lower third of the series control section
Mt. Carroll--are in landscape positions similar to those of the Oak Center soils and have a sand content of less than 15 percent in the lower third of the series control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained--a frequently saturated zone does not occur within a depth of 1.8 meters in normal years
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second in the loess, 10.00 to 100.00 micrometers per second in the sandy residuum and 1.00 to 10.00 micrometers per second in the sandstone
Surface runoff potential--negligible to high
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and legume hays. The native vegetation is big bluestem, little bluestem, switchgrass, other grasses of the tall grass prairie and widely spaced oak trees.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Wisconsin driftless section
MLRA--Northern Mississippi Valley Loess Hills (105)
LRR M; southeastern Minnesota and southwestern Wisconsin
Extent--small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Goodhue County, Minnesota, 2007.
REMARKS:
Particle-size control section--the zone from a depth of 23 to 74 centimeters (Bt1 and Bt2 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (Ap, Bt1, Bt2, 2Bt3, and 3C horizons).
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 23 centimeters (Ap horizon);
argillic horizon--the zone from a depth of 23 to 137 centimeters (Bt1 and Bt2 horizons);
udic moisture regime.
In previously surveyed areas, these soils were included in soils associated with limestone bedrock.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.