LOCATION TARA MN
Established Series
Rev. RTD-TWN-JJB
05/2016
TARA SERIES
The Tara series consists of very deep, moderately well drained soils that formed in 50 to 100 centimeters of glaciolacustrine sediments or loess and in the underlying till of Late Wisconsin Age. These soils are on glacial lake plains and moraines on till plains. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 645 millimeters (about 25 inches). Mean annual air temperature is about 6 degrees C (about 43 degrees F).
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Aquic Pachic Hapludolls
TYPICAL PEDON: Tara silt loam, from an area of Balaton-Tara complex, 1 to 3 percent slopes, on a 1 percent, slightly concave west-facing slope, on a ground moraine, in a cultivated field. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 18 centimeters (0 to 7 inches); black (10YR 2/1) silt loam, very dark gray (10YR 3/1) dry; weak very fine subangular blocky structure; friable; pH 7.0 (neutral); abrupt smooth boundary.
A--18 to 38 centimeters (7 to 15 inches); black (10YR 2/1) silt loam, very dark gray (10YR 3/1) dry; weak and moderate very fine subangular blocky structure; friable; pH 7.0 (neutral); clear smooth boundary.
AB--38 to 48 centimeters (15 to 19 inches); very dark gray (10YR 3/1) silt loam, very dark gray (10YR 3/1) and dark gray (10YR 4/1) dry; moderate very fine and fine subangular blocky structure; friable; few masses of dark grayish brown (2.5Y 4/2); pH 7.0 (neutral); clear wavy boundary.
Bw--48 to 69 centimeters (19 to 27 inches); dark grayish brown (2.5Y 4/2) silt loam; weak medium and coarse prismatic structure parting to weak fine and medium subangular blocky; friable; pH 7.0 (neutral); gradual wavy boundary.
2Bk--69 to 84 centimeters (27 to 33 inches); light olive brown (2.5Y 5/4) loam; weak fine subangular blocky structure; friable; few threads and masses of lime; few fine distinct grayish brown (2.5Y 5/2) iron depletions and few fine prominent dark yellowish brown (10YR 4/4) iron concentrations; about 2 percent rock fragments; strongly effervescent; pH 8.2 (moderately alkaline); gradual wavy boundary. (0 to 20 inches thick)
2C1--84 to 97 centimeters (33 to 38 inches); light olive brown (2.5Y 5/4) loam; massive; friable; common medium distinct grayish brown (2.5Y 5/2) iron depletions; about 4 percent gravel; strongly effervescent; pH 7.6 (slightly alkaline); gradual smooth boundary. (0 to 20 inches thick)
2C2--97 to 152 centimeters (38 to 60 inches); grayish brown (2.5Y 5/2) loam; massive; friable; many coarse distinct light olive brown (2.5Y 5/4) iron concentrations; few iron oxide and manganese oxide stains; about 5 percent rock fragments; strongly effervescent; pH 7.6 (slightly alkaline); gradual smooth boundary.
2C3--152 to 203 centimeters (60 to 80 inches); light olive brown (2.5Y 5/4) loam; massive; friable; many coarse distinct light grayish brown (2.5Y 5/2) iron depletions; few iron oxide and manganese oxide stains; about 5 percent rock fragments; strongly effervescent; pH 7.6 (slightly alkaline).
TYPE LOCATION: Major Land Resource Area (MLRA) Rolling Till Prairie (102A); Swift County, Minnesota subset; located about 9 miles north of Holloway; located about 1,850 feet north and 80 feet west of the southeast corner of section 14, T. 122 N., R. 42 W;, USGS Hancock SW, Minnesota topographic quadrangle; lat. 45 degrees 22 minutes 28.6 seconds N., lon. 95 degrees 53 minutes 29.9 seconds W., NAD83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness--40 to 75 centimeters
Thickness of glaciolacustrine sediments--50 to 100 centimeters
Depth to carbonates--50 to 100 centimeters
Clay content of the particle-size control section (weighted average)--18 to 27 percent
Sand content of the particle-size control section (weighted average)--5 to 15 percent fine sand and coarser
Ap and A horizon:
Hue--10YR or 2.5Y
Value--2 or 3
Chroma--1 or 2
Texture--silt loam, loam, or silty clay loam
Clay content--20 to 35 percent
Sand content--5 to 35 percent
Rock fragment content--0 percent
Reaction--pH 6.1 to 7.3
Thickness--40 to 60 centimeters
AB horizon:
Hue--10YR or 2.5Y
Value--2 to 4
Chroma--1 or 2
Texture--silt loam, loam, or silty clay loam
Clay content--18 to 30 percent
Sand content--5 to 35 percent
Rock fragment content--0 percent
Reaction--pH 6.1 to 7.3
Thickness--0 to 15 centimeters
Bw horizon:
Hue--10YR or 2.5Y
Value--3 to 5
Chroma--2 to 4
Texture--silt loam, loam, or silty clay loam
Clay content--18 to 27 percent
Sand content--5 to 37 percent
Rock fragment content--0 percent
Reaction--pH 6.6 to 7.8
Thickness--10 to 25 centimeters
Some pedons have a Bk horizon
Some pedons have a thin 2Bw horizon
Some pedons have a thin stone line with as much as 30 percent rock fragments at the contact of the glaciolacustrine sediments and the till material
2Bk horizon:
Hue--2.5Y
Value--4 to 6
Chroma--2 to 4
Texture--loam or clay loam
Clay content--20 to 30 percent
Sand content--20 to 50 percent
Rock fragment content--1 to 10 percent
Reaction--pH 7.4 to 8.4
Thickness--0 to 50 centimeters
2C horizon:
Hue--2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--loam or clay loam
Clay content--20 to 30 percent
Sand content--20 to 50 percent
Rock fragment content--1 to 10 percent
Reaction--pH 7.4 to 8.4
COMPETING SERIES: There are no competing series. A closely related series is McIntosh.
McIntosh--have a mollic epipedon 18 to 39 centimeters thick and have a calcic horizon with a depth of 40 centimeters
GEOGRAPHIC SETTING:
Parent material--50 to 100 centimeters of glaciolacustrine sediments or loess and in the underlying till of Late Wisconsin Age
Landform--concave to slightly convex slopes on lake plains and moraines on till plains
Slope--0 to 3 percent
Elevation--280 to 650 meters above sea level
Mean annual air temperature--3 to 8 degrees C
Mean annual precipitation--550 to 780 millimeters
Frost-free period--120 to 160 days
GEOGRAPHICALLY ASSOCIATED SOILS: At the type location, these are the
Balaton,
Byrne,
Parnell, and
Winger soils.
Balaton--are on higher landscape positions on convex slopes and have a rock fragment content of 1 to 10 percent throughout the series control section
Byrne--are on higher landscape positions on convex slopes and do not have a frequently saturated zone with a depth of 1.0 meter during the wettest periods of most years
Parnell--are in lower landscape positions in depressions and are frequently saturated at the soil surface during the wettest periods of most years
Winger--are in lower landscape positions in swales and have a frequently saturated zone within a depth of 0.15 meters during the wettest periods of most years
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs between depths of 0.5 and 0.75 meters during the wettest periods of normal years
Saturated hydraulic conductivity--1.41 to 14.11 micrometers per second (moderately high)
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, and small grains. The native vegetation is big bluestem, indiangrass, switchgrass, western wheatgrass, sideoats gramma, and other grasses of the tall grass prairie, upland sedges, and forbs.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Western lake section
MLRA--Rolling Till Prairie (102A)
LRR--Central Feed Grains and Livestock Region (M); western Minnesota
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Stevens County, Minnesota, 1978.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface of the soil to a depth of 150 centimeters.
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface of the soil to a depth of 48 centimeters (0 to 19 inches) (Ap, A, and AB horizons);
cambic horizon--the zone from a depth of 48 to 69 centimeters (19 to 27 inches) (Bw horizon);
calcic horizon--the zone from a depth of 69 to 84 centimeters (27 to 33 inches) (2Bk horizon);
udic moisture regime.
Classification subgroup changed 2/2016 as the zone from the soil surface to a depth of 48 centimeters meets the criteria for a mollic epipedon. Most of the correlated and published county subset taxonomic unit descriptions for the Tara series support the classification change to Aquic Pachic subgroup.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, Twelfth Edition, 2014.
ADDITIONAL DATA:
Laboratory data--Kellogg Soil Survey Laboratory, Lincoln, Nebraska; User Pedon IDs 1978MN012-000 (2841) and 75MN023(1986).
National Cooperative Soil Survey
U.S.A.