LOCATION CAPE IL

Established Series
Rev. KCH-CCM-DRW
03/2011

CAPE SERIES

The Cape series consists of deep, poorly drained and very poorly drained soils formed in clayey slack water sediments on low lying flood plains. Slopes range from 0 to 2 percent. Mean annual precipitation is about 44 inches (1118 mm) and mean annual temperature is about 56 degrees F (13 degrees C).

TAXONOMIC CLASS: Fine, smectitic, acid, mesic Vertic Endoaquepts

TYPICAL PEDON: Cape silty clay loam - in a cultivated field at an elevation of about 375 feet (114 meters) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 10 inches (0 to 25 cm); dark gray (10YR 4/1) silty clay loam; weak medium angular blocky structure; very firm; neutral; abrupt smooth boundary. (6 to 10 inches or 15 to 25 cm thick)

Bg1--10 to 22 inches (25 to 56 cm); dark gray (10YR 4/1) silty clay loam; moderate coarse prismatic structure parting to weak medium angular blocky; very firm; common medium distinct brown (10YR 4/3) masses of oxidized iron; common prominent threadlike iron-manganese masses; strongly acid; clear smooth boundary.

Bg2--22 to 28 inches (56 to 71 cm); gray (10YR 5/1) silty clay; weak coarse prismatic structure parting to weak medium angular blocky; very firm; common medium distinct brown (10YR 4/3) masses of oxidized iron; few prominent threadlike iron-manganese masses on surfaces along root channels; strongly acid; clear smooth boundary.

Bg3--28 to 35 inches (71 to 89 cm); gray (10YR 5/1), dark gray (10YR 4/1) and gray (10YR 6/1) silty clay; weak coarse prismatic structure parting to weak medium and coarse angular blocky; very firm; common medium prominent dark reddish brown (5YR 3/3) masses of oxidized iron; few prominent threadlike iron-manganese masses on surfaces along root channels; strongly acid; clear smooth boundary.

Bg4--35 to 45 inches (89 to 114 cm); gray (10YR 5/1) and grayish brown (10YR 5/2) silty clay; weak coarse angular blocky structure; firm; common medium distinct pale brown (10YR 6/3) and faint dark grayish brown (10YR 4/2) masses of oxidized iron; common prominent threadlike iron-manganese masses; strongly acid; gradual smooth boundary. [Combined thickness of the Bg horizons is 34 to 50 (86 to 127 cm) or more inches.]

Cg--45 to 80 inches 114 to 203 cm); gray (10YR 6/1) light gray (10YR 7/1) and grayish brown (10YR 5/2) silty clay loam; massive; firm; common medium distinct pale brown (10YR 6/3) masses of oxidized iron; common prominent threadlike iron-manganese masses on surfaces along root channels; strongly acid.

TYPE LOCATION: Saline County, Illinois; about 2 miles southwest of Carrier Mills; 1,290 feet north and 660 feet west of the center of sec. 10, T. 10 S., R. 5 E.; USGS Carrier Mills, IL topographic quadrangle; lat. 37 degrees 40 minutes 08 seconds N. and long. 88 degrees 36 minutes 45 seconds W.; UTM Zone 16, Easting: 354838, Northing: 4170366, NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the solum: 40 to more than 60 inches (102 to more than 152 cm)
Particle-size control section: averages more 40 to 60 percent clay
Reaction: strongly acid to extremely acid, except where limed

Ap or A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 (5 or 6 dry)
Chroma: 1 or 2
Texture: silty clay loam, silty clay or clay

Bg horizon, upper part
Hue: 10YR, 2.5Y or N
Value: 4 to 6 (5 to 7 dry)
Chroma: 0 to 2
Redoximorphic features are present
Texture: silty clay loam, silty clay or clay

Bg horizon, lower part
Hue: 10YR, 2.5Y or N
Value: 4 to 6
Chroma: 0 to 2
Redoximorphic features are present
Texture: silty clay or clay

Cg horizon
Hue: 10YR, 2.5Y or N
Value: 4 to 7
Chroma: 0 to 2
Redoximorphic features are present
Texture: silty clay loam, silty clay or clay; silt loam strata exists in some pedons

COMPETING SERIES: This is the Salzer series in the same family. Other series in closely related families are Chequest, Jacob, Piopolis and Zipp soils. Salzer soils have a mean annual soil temperature of 47 to 51 degrees F (8 to 11 degrees C). Chequest and Zipp soils are non-acid and in addition, Chequest soils have a mollic epipedon. Jacob soils contain more clay in the upper part of the solum. Piopolis soils contain less clay in the series control section.

GEOGRAPHIC SETTING: Cape soils are on broad alluvial plains. Slopes are typically level or slightly concave and are typically less than 1 percent, but range to 2 percent. The Cape soils formed in slack-water silt and clay sediments. Summers are hot and winters are cold. The mean annual air temperature is 53 to 59 degrees F (11 to 15 degrees C) and mean annual precipitation is 35 to 45 inches (889 to 1143 mm).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonnie, Jacob, Karnak, Petrolia and Piopolis soils. Bonnie and Piopolis soils have less clay throughout the series control section. Jacob and Karnak soils contain more clay in the upper part of the solum. Karnak and Petrolia soils are less acid.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. The potential for surface runoff is low or negligible. Permeability is slow or very slow. Saturated hydraulic conductivity is low or moderately low (0.07 to 0.42 micrometers/sec) in the subsoil.

USE AND VEGETATION: Mostly cultivated to soybeans and corn; some is used for pasture and woods. Native vegetation is bottomland forest.

DISTRIBUTION AND EXTENT: Southern Illinois. The extent is moderate. The type location is in MLRA 120A. It is also in MLRAs' 113, 114B, 115B, 131A and 134.

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

SERIES ESTABLISHED: Alexander County, Illinois, 1967.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - - the zone from the surface to a depth of 10 inches or 25 cm (Ap horizon)
Cambic horizon - 10 to 45 inches or 25 to 114 cm (Bg1, Bg2, Bg3 and Bg4 horizons)
Redoximorphic features and aquic conditions in all layers below the Ap horizon

The NASIS Data Mapunit ID is: 137092. This data mapunit represents the OSD pedon for Cape.

The Cape soils were previously classified as:
1. Vertic Fluvaquents, fine, montmorillonitic, acid, mesic (classification adjusted to agree with ST Issue #17 on 23 Aug 94 by CLG)
2. Typic Fluvaquents, fine, montmorillonitic, acid, mesic, 1967.
3. Alluvial soils intergrading toward Low Humic Gley soil in the 1938 classification by great group system.

National Cooperative Soil Survey
U.S.A.