LOCATION KOROBAGO WI

Established Series
Rev. HFG-AAC
12/2010

KOROBAGO SERIES

The Korobago series consists of very deep, somewhat poorly drained soils formed in loamy outwash or lacustrine deposits and in the underlying clayey till on moraines. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 711 mm (28 inches). Mean annual air temperature is about 8.3 degrees C (47 degrees F).

TAXONOMIC CLASS: Coarse-loamy over clayey, mixed, active, mesic Aquic Eutrudepts

TYPICAL PEDON: Korobago silt loam - on a northwest-facing concave slope of 2 percent in a cultivated field at an elevation of about 238 meters (780 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 23 cm (0 to 9 inches); black (10YR 2/1) silt loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure; friable; many fine roots; slightly alkaline; abrupt smooth boundary. [18 to 23 cm (7 to 9 inches) thick]

Bw1--23 to 48 cm (9 to 19 inches); dark yellowish brown (10YR 4/4) silt loam; weak medium subangular blocky structure; friable; common fine roots; common worm casts; discontinuous bands of olive gray (5Y 5/2) silt loam in lower 2 inches; common medium distinct yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; common medium distinct grayish brown (10YR 5/2) iron depletions in the matrix; slightly alkaline; abrupt smooth boundary. [20 to 51cm (8 to 20 inches) thick]

Bw2--48 to 66 cm (19 to 26 inches); brown (7.5YR 4/3) loamy very fine sand; weak coarse subangular blocky structure; very friable; few fine roots; few worm casts; few thin strata of very fine sand and very fine sandy loam; many medium distinct strong brown (7.5YR 5/6) masses of oxidized iron in the matrix; many medium distinct grayish brown (10YR 5/2) iron depletions in the matrix; slightly alkaline; abrupt smooth boundary. [0 to 38 cm ( (0 to 15 inches) thick]

Bw3--66 to 79 cm (26 to 31 inches); brown (7.5YR 5/3) loam; weak medium prismatic structure; friable; few fine roots; few worm casts; few thin strata of very fine sand; many medium distinct strong brown (7.5YR 5/6) masses of oxidized iron in the matrix; many medium faint grayish brown (10YR 5/2) iron depletions in the matrix; about 3 percent very coarse sand and fine gravel; slightly effervescent; slightly alkaline; abrupt smooth boundary. [0 to 15 cm (0 to 6 inches) thick]

2Bw4--79 to 91 cm (31 to 36 inches); reddish brown (5YR 4/3) silty clay loam; moderate medium prismatic structure; firm; few fine roots; some grains of very fine sand along faces of prisms; many fine faint brown (7.5YR 4/4) masses of oxidized iron in the matrix; many fine faint brown (7.5YR 5/2) iron depletions in the matrix; about 5 percent gravel; slightly effervescent; slightly alkaline; gradual wavy boundary. [0 to 41 cm (0 to 16 inches) thick]

2C--91 to 152 cm (36 to 60 inches); reddish brown (5YR 5/3) silty clay loam; massive; firm; many fine faint brown (7.5YR 4/4) masses of oxidized iron in the matrix; many fine prominent light olive gray (5Y 6/2) iron depletions in the matrix; about 5 percent gravel; common medium pink (5YR 7/3) lime segregations in upper few inches, few below; strongly effervescent; moderately alkaline.

TYPE LOCATION: Winnebago County, Wisconsin; about 3 miles north of Oshkosh; 210 feet south and 1,530 feet west of the northeast corner of sec. 36, T. 19 N., R. 16 E. USGS Oshkosh Wisconsin topographic quadrangle; lat. 44 degrees 04 minutes 56 seconds N., and long. 88 degrees 31 minutes 54 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Depth to the base of soil development: 61 to about 114 cm (24 to about 45 inches)
Coarser-textured upper story thickness: 46 to 91 cm (18 to 36 inches)
Particle-size control section: averages less than 18 percent clay, more than 15 percent fine sand or coarser
Depth to carbonates: 51 to 102 cm (20 to 40 inches)
Reaction: slightly acid to slightly alkaline in the solum; slightly alkaline or moderately alkaline in the substratum
Redox features: redox accumulations typically throughout the soil below the A horizon; redox depletions with chroma of 2 or less and saturation within a depth of 61 cm (24 inches)

Ap horizon:
Hue: 10YR
Value: 2 or 3
Chroma: 2 or 3
Texture: silt loam or sandy loam

A horizon:
Hue: 10YR
Value: 2 or 3
Chroma: 1 or 2
Texture: silt loam or sandy loam

E horizon (where present):
Hue: 10YR
Value: 4 or 5
Chroma: 2 or 3
Texture: silt loam, loam, sandy loam or fine sandy loam

Bw horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5
Chroma: 2 to 4, matrix chroma of 2 at depths more than 51 cm (20 inches) below the surface
Texture: dominantly silt loam, loam, sandy loam or very fine sandy loam but subhorizons of very fine sand, loamy very fine sand, fine sand or loamy fine sand are in many pedons
Other features:
The thickness and sequence of layers of different texture have a wide range, often within short vertical distances

2Bw horizon:
Hue: 5YR
Value: 4 or 5
Chroma: 3 or 4
Texture: silty clay, clay, clay loam or silty clay loam
Clay content: averages 35 to 60 percent, less than 35 percent fine sand or coarser

2C horizon:
Hue: 5YR
Value: 4 or 5
Chroma: 3 or 4
Texture: silty clay, clay, clay loam or silty clay loam
Other features: clayey till that with gravel and stones

COMPETING SERIES: There are no competing series. Other series in closely related families are Fisk and Nebago. Fisk soils have carbonates below a depth of 102 cm (40 inches) and are sandy over loamy. Nebago soils are similar, but are sandy over clayey.

GEOGRAPHIC SETTING: Korobago soils are adjacent to drainageways in broad, concave areas between the more sloping rises of ground moraines. Slope ranges from 0 to 3 percent. These soils formed in medium or coarse-textured outwash or lacustrine deposits and in clayey till. Mean annual precipitation ranges from 635 to 737 mm (25 to 29 inches). Mean annual air temperature ranges from about 7.8 to 9.4 degrees C (46 to 49 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Keowns, Kewaunee, Manawa, and Wauseon soils. The poorly drained Wauseon soils are in a drainage sequence with the Korobago soils. Keowns soils are in lower-lying, contiguous areas that are not underlain by clayey deposits within a depth or 102 cm ( 40 inches). The well drained and moderately well drained Kewaunee soils occupy higher positions on the landscape where the clayey glacial till is not buried by lacustrine deposits. The somewhat poorly drained Manawa soils occupy similar positions on the landscape, but do not have the covering of lacustrine deposits.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. Internal drainage is restricted by the massive substratum. The potential for surface runoff is negligible or low. Saturated hydraulic conductivity is moderately high to high (4.23 to 14.11 micrometers per second) in the loamy upper story and moderately low to moderately high (0.42 to 1.41 micrometers per second) in the clayey till. Permeability is moderate in the loamy upper story and slow in the clayey till. These soils have a perched seasonal high water table at a depth of 31 to 61 cm (1 to 2 feet) for some time in most years.

USE AND VEGETATION: Most areas of this soil are used for cropland. Common crops are corn, oats, and hay. Some areas are used for woodland and some for pastureland. Native vegetation is mixed hardwood forest.

DISTRIBUTION AND EXTENT: East-central Wisconsin. The Korobago soils are inextensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Winnebago County, Wisconsin, 1977.

REMARKS:

1/05 This revision redefines the series concept to one of loamy sediments over clayey till only. A new series is needed for the 2300 acres correlated in Juneau County that are over clayey lacustrine deposits.

Diagnostic horizons and features recognized in this pedon are: ochric epipedon - 0 to 23 cm (0 to 9 inches) (Ap); cambic horizon - 23 to 91 cm (9 to 36 inches) (Bw1, Bw2, Bw3, 2Bw4); aquic feature - have redox depletions with chroma of 2 or less and saturation within 61 cm (24 inches) of the soil surface.

National Cooperative Soil Survey
U.S.A.