LOCATION WINNEBAGO IL+WIEstablished Series
TYPICAL PEDON: Winnebago silt loam on a southwest-facing, convex, 4 percent slope in a cultivated field at an approximate elevation of 256 meters (840 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 25 cm (0 to 10 inches); very dark grayish brown (10YR 3/2) silt loam with 10 percent fine sand, grayish brown (10YR 5/2) dry; moderate medium granular structure; friable; many fine roots; slightly acid; abrupt smooth boundary.
A--25 to 38 cm (10 to 15 inches); dark brown (7.5YR 3/2) silt loam with 20 percent fine sand, brown (7.5YR5/2) dry; weak very fine subangular blocky structure parting to moderate medium granular; friable; common fine roots; few rounded gravel 1 to 2 cm in diameter; strongly acid; clear smooth boundary. [combined thickness of the A horizon is 25 to 46 cm (10 to 18 inches) thick]
2BA--38 to 53 cm (15 to 21 inches); brown (7.5YR 4/4) loam; moderate medium subangular blocky structure; friable; few fine roots; few faint reddish brown (5YR 4/4) clay films on faces of peds; few distinct dark brown (7.5YR 3/2) organic stains on faces of peds and around rounded gravel; few rounded gravel 1 to 2 cm in diameter; strongly acid; clear smooth boundary. [10 to 30 cm (4 to 12 inches) thick]
2Bt1--53 to 86 cm (21 to 34 inches); reddish brown (5YR 4/4) clay loam; moderate medium subangular blocky structure; firm; few fine roots; common distinct dark reddish brown (5YR 3/4) clay films on faces of peds; common medium distinct yellowish red (5YR 4/6) masses of iron in the matrix; many rounded gravel 1 to 2 cm in diameter; strongly acid; clear smooth boundary.
2Bt2--86 to 127 cm (34 to 50 inches); strong brown (7.5YR 5/6) clay loam; weak coarse prismatic structure parting to weak medium and coarse subangular blocky; firm; few fine roots; common distinct dark brown (7.5YR 3/2) clay films on faces of peds; common medium distinct reddish brown (5YR 4/4) masses of iron in the matrix; many rounded gravel 1 to 2 cm in diameter; strongly acid; clear smooth boundary. [combined thickness of the 2Bt horizon is 46 to 112 cm (18 to 44 inches) thick]
2BC1--127 to 168 cm (50 to 66 inches); reddish brown (5YR 4/4) clay loam; weak coarse prismatic structure; friable; few faint dark reddish brown (5YR 3/4) clay films on pressure faces around rounded gravel; many rounded gravel 1 to 2 cm in diameter; moderately acid; abrupt smooth boundary. [25 to 61 cm (10 to 24 inches) thick]
2BC2--168 to 188 cm (66 to 74 inches); reddish brown (5YR 4/4) sandy loam; massive; friable; few faint dark reddish brown (5YR 3/4) clay films on pressure faces and around rounded gravel; many rounded gravel 1 to 2 cm in diameter; moderately acid.
TYPE LOCATION: Winnebago County, Illinois; about 7 miles northwest of Rockford; 405 feet east and 85 feet north of the southwest corner of sec. 11, T. 17 N., R. 11 E.; USGS Winnebago topographic quadrangle; lat. 42 degrees, 20 minutes, 58 seconds, N., and long. 89 degrees, 12 minutes, 11 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS: Sola commonly are 122 to 183 cm (4 to 6 feet) thick and range from 107 to 274 cm (3.5to 9 feet) thick. Loess mantle is less than 38 cm (15 inches) thick.
The Ap, A, and 2BA horizon has hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 1 to 3. It is normally silt loam, but it is loam or sandy loam in some pedons. Typically, reaction ranges from moderately acid to neutral depending on liming treatment.
The 2Bt horizon has colors in the major part of the matrix with hue of 7.5YR or 5YR, value of 3 to 6, and chroma of 3 or 4. Hue of 5YR or redder is present on ped surfaces or in the matrix in at least one subhorizon. Some subhorizons in some pedons have hue of 10YR, or chroma higher than 4, or both. It is loam in the upper part and heavy sandy loam, light clay loam or loam in the lower part. Reaction ranges from moderately acid to strongly acid. Some pedons range to very strongly acid in the middle part of the B horizon and to neutral in the lower part. A 2BC horizon darker colored than the Bt horizon is in some pedons.
The 2C horizon, where present, has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 4. It ranges from gravelly light sandy loam to loam where sola are thicker than 152 cm (5 feet); some pedons have stratified C horizons. Generally the upper part of the C horizon is neutral, but in some pedons the C horizon is moderately alkaline to the upper
boundary.
COMPETING SERIES: Other soils in the same family are
Atkinson,
Burchard,
Calmar,
Cokato,
Cresco,
Cresent,
Durand,
Friesland,
Griswold,
Hitt,
Jasper,
Joslin,
Keosauqua,
Kishwaukee,
Marbletown,
Moingona,
Morrill,
Nuxmaruhanixete,
Pana,
Parmod,
Penfield,
Reedslake,
Ringwood,
Rockton,
Schoolcraft,
Shelby,
Sibleyville, and
Velma series. All of these soils except Atkinson, Calmar, Durand, Joslin, Morrill, Pana, and Rockton lack hue as red as 5YR in the B horizon. Atkinson, Calmar, and Rockton soils have more clay in the lower part of the B horizon which formed in residuum weathered from limestone. In addition, limestone berock is at depths of less than 102 cm (40 inches) in Calmar and Rockton soils and greater than 102 cm (40 inches) in Atkinson soils. Durand soils formed in 38 to 64 cm (15 to 25 inches) of loess. Joslin soils contain more clay in the lower part of the sola which formed in reddish clayey lacustrine
deposits. Morrill soils have thinner sola and are underlain by Kansan or Nebraskan till that has a low content of illite. Pana soils contain more sand and gravel in the lower part of the sola, are more acidic, and are deeper to free carbonates.
GEOGRAPHIC SETTING: Winnebago soils are gently sloping to moderately steep on uplands. Slope ranges from 2 to 30 percent. Winnebago soils formed in layer of Wisconsin age loess less than 38 cm (15 inches) thick and in exhumed paleosols of Sangamon Age formed in sandy loam drift. The fresh glacial drift contains illite as the dominant clay mineral. It is believed that the part of the sola in drift was formed before the loess was deposited and that the climate may have been unlike the modern climate. The mean annual temperature ranges from 7 to 12 degrees C (45 to 53 degrees F), mean annual precipitation ranges from 760 to 1020 mm (30 to 40 inches), mean annual soil temperature is estimated to range between 8 and 13 degrees C (47 to 55 degrees F), and frost free period ranges from 140 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: The Durand soils are the closest associates. Others are the Argyle and Pecatonica soils. All these soils formed in a thicker mantle of loess. Westville soils are the Typic Hapludalf member of the biosequence. They formed in materials similar to those of the Winnebago soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff is low on the gentle slopes and high on the steeper slopes. Saturated hydraulic conductivity is 4.23 to 14.11 micrometers per second (moderate permeability).
USE AND VEGETATION: Mainly used for growing cultivated crops and pasture. Native vegetation was prairie grass.
DISTRIBUTION AND EXTENT: Northern Illinois and southern Wisconsin. LRR's K and M, MLRA's 95B, 105, and 108B. The extent is small.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Green County, Wisconsin, 1969.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from a depth of 0 to 38 cm (0 to15 inches) (Ap and A horizons)
Argillic horizon - from a depth of 53 to 127 cm (21 to 50 inches) (2Bt1 and 2Bt2 horizons)
Udic moisture regime; mesic temperature regime