LOCATION ALLISON IL+IN

Established Series
Rev. GOW-LMK-JWS-AAC
03/2011

ALLISON SERIES

The Allison series consists of deep, well drained and moderately well drained, moderately permeable soils that formed in stratified moderately fine and medium textured alluvium on flood plains. Slope ranges from 0 to 7 percent. Mean annual temperature is about 12.2 degrees C (54 degrees F), and mean annual precipitation is about 1041 mm (41 inches).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Hapludolls

TYPICAL PEDON: Allison silty clay loam on a northwest-facing concave slope of one percent in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 cm (0 to 8 inches); very dark grayish brown (10YR 3/2) silty clay loam, dark grayish brown (10YR 4/2) dry; weak fine and medium granular structure; firm; many fine roots; neutral; abrupt smooth boundary.

A3--20 to 43 cm (8 to 17 inches); very dark grayish brown (10YR 3/2) silty clay loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure; firm; many fine roots; many very dark gray (10YR 3/1) organic coatings on faces of peds; neutral; diffuse smooth boundary. [Combined thickness of the A horizon is 25 to 51 cm (10 to 20 inches).]

Bw1--43 to 89 cm (17 to 35 inches); dark brown (10YR 3/3) silty clay loam, brown (10YR 5/3) dry; weak medium and coarse subangular blocky structure; firm; common fine roots; very dark grayish brown (10YR 3/2) organic coatings on faces of peds and worm casts; neutral; diffuse smooth boundary.

Bw2--89 to 127 cm (35 to 50 inches); dark brown (10YR 3/3) silty clay loam, brown (10YR 5/3) dry; weak coarse prismatic structure parting to weak medium subangular blocky; firm; few fine roots; very dark grayish brown (10YR 3/2) organic coatings on faces of peds; neutral; diffuse smooth boundary.

Bw3--127 to 152 cm (50 to 60 inches); brown (10YR 4/3) silty clay loam; weak coarse prismatic structure parting to weak medium subangular blocky; firm; thin dark brown (10YR 3/3) organic coatings on faces of peds; neutral; diffuse smooth boundary. (Combined thickness of the B2 horizon is 20 to 45 inches.)

C--152 to 178 cm (60 to 70 inches0; brown (10YR 4/3) silty clay loam; weak coarse prismatic structure; firm; few dark brown (10YR 3/3) organic coatings on vertical cleavage planes; neutral.

TYPE LOCATION: Gallatin County, Illinois; about 12 miles east of Ridgway; 450 feet east and 550 feet north of the center of sec. 25, T. 8 S., R. 10 E.

RANGE IN CHARACTERISTICS:
Thickness of the solum: 76 to greater than 152 cm (30 to greater than 60 inches)
Thickness of the mollic epipedon: typically greater than 91 cm (36 inches) and ranges from 61 to 152 cm (24 to 60 inches) Series control section: averages between 27 and 35 percent clay
Reaction: slightly acid to mildly alkaline throughout
Free carbonates: do not have above depths of 102 cm (40 inches)

A horizon:
Hue: 10YR
Value: 2 or 3 moist and 4 or 5 dry
Chroma: 1 to 3
Texture: dominantly silty clay loam but includes silt loam in some pedons.

Bw horizon:
Hue: commonly 10YR
Value: 2 to 4
Chroma: 2 to 4
Texture: typically silty clay loam and in many pedons contains strata of silt loam, loam, clay loam, or sandy loam below depths of 30 inches
Other features: Some pedons have hue of 7.5YR. Some pedons contain mottles below the mollic epipedon or in the lower part of the B horizon. They have hue of 10YR or 7.5YR, value of 4 through 6, and chroma of 2 through 4.

Some pedons have a BC horizon. It has properties in the same range as the Bw horizon.

C horizon:
Hue: 10YR or 7.5YR
Value: 4 to 6
Chroma: 3 to 6
Texture: commonly silty clay loam with thin strata with textures that range from fine sand to silt loam.
Reaction: slightly acid to mildly alkaline

COMPETING SERIES: These are the Anthon, Huntsville, Ivan, Judson, Kahola, Kennebec, Kenridge, Lindstrom, Napier, Rossville, Sturkie, and Worthen series. Anthon soils have more than 5 percent rock fragments throughout the series control section. Huntsville, Lindstrom, Napier, and Worthen soils contain less than 27 percent clay in the control section. Ivan soils are calcareous throughout. Judson soils have more strongly developed structure and lack strata or lenses of coarser textured material in the lower part of the B horizon. Kahola soils are calcareous in the lower part of the mollic epipedon and within the control section. Kennebec soils lack a B horizon and have chroma of 1 or 2 to depths of 152 cm (5 feet) or more. Kenridge soils have less than 40 percent sand in the lower part of the series control section. Sturkie soils contain more sand in the upper part of the control section. Rossville soils have less than 27 percent clay content in the lower part of the series control section.

GEOGRAPHIC SETTING: Allison soils are on slightly elevated parts of flood plains. Slope ranges from 0 to 7 percent. These soils formed in stratified moderately fine and medium textured alluvium. Mean annual temperature varies from 10.6 to 13.9 degrees C (51 to 57 degrees F), and mean annual precipitation varies from 890 to 1143 mm (35 to 45 inches).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beaucoup, Comfrey, Emma, Karnak, Tice, and Sawmill soils. The poorly drained Beaucoup, Comfrey, Karnak, and Sawmill soils have grayer colors throughout and are lower on the flood plains. In addition, Karnak soils contain more clay in the control section and Comfrey soils contain more sand in the control section. The somewhat poorly drained Tice soils are on slightly lower parts of the flood plain and have mottles within 41 cm (16 inches) of the soil surface or gray colors within 15 cm (6 inches) below the mollic epipedon and have a mollic epipedon less than 61 cm (24 inches) thick. Emma soils are on similar nearby landscapes, lack mollic epipedons and have more acid reaction throughout the solum.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained and moderately well drained. Runoff is slow or medium. Saturated hydraulic conductivity is moderately high to high (4.23 to 14.11 micrometers per second). Permeability is moderate.

USE AND VEGETATION: Most areas of Allison soils are cultivated. Corn and soybeans are the principal row crops. Small areas are in woodland. Native vegetation was mixed hardwoods and grasses.

DISTRIBUTION AND EXTENT: Illinois and Indiana in MLRAs 108A, 110, 111D, 113, and 115A. The extent is moderate.

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

SERIES ESTABLISHED: Lawrence County, Illinois, 1952.

REMARKS: All the published typical pedons have silty clay loam texture in the A horizon. The data from the type location is just over the line into silty clay but the difference is within the range of normal error.

National Cooperative Soil Survey
U.S.A.