LOCATION SLACWATER          IL
Established Series
Rev.WMT-AAC-GRS
07/2009

SLACWATER SERIES


The Slacwater series consists of deep, poorly drained soils formed in calcareous, stratified silty alluvium on flood plains. These soils have moderate permeability. Slope ranges from 0 to 2 percent. Mean annual temperature is about 10 degrees C (50 degrees F), and mean annual precipitation is 864 millimeters (34 inches).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Mollic Fluvaquents

TYPICAL PEDON: Slacwater silt loam - on a nearly level slope in a wooded area near the Illinois River. (Colors are for moist soil conditions unless otherwise stated.)

A--0 to 15 cm (0 to 6 inches); very dark grayish brown (10YR 3/2) and dark grayish brown (2.5Y 4/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; many very fine and fine roots; strongly effervescent; slightly alkaline; abrupt smooth boundary. [0 to 25 cm (0 to 10 inches)]

Cg1--15 to 38 cm (6 to 15 inches); dark grayish brown (2.5Y 4/2) and light brownish gray (2.5Y 6/2) silt loam; massive; friable; many very fine and fine roots; few patchy prominent strong brown (7.5YR 4/6) iron stains throughout; few fine soft masses of iron accumulation; strongly effervescent; slightly alkaline; gradual smooth boundary.

Cg2--38 to 60 cm (15 to 22 inches); grayish brown (2.5Y 5/2), pale olive (5Y 6/3) and light olive brown (2.5Y 5/4) silt loam; massive; friable; common very fine and fine roots; few patchy prominent strong brown (7.5YR 4/6) iron stains throughout; few fine soft masses of iron accumulation; strongly effervescent; slightly alkaline; gradual smooth boundary.

Cg3--60 to 152 cm (22 to 60 inches); olive gray (5Y 4/2), pale olive (5Y 6/3), and light olive brown (2.5Y 5/6) silty clay loam; massive; friable; common very fine and fine roots; few prominent strong brown (7.5YR 4/6) iron stains throughout; strongly effervescent; slightly alkaline; gradual smooth boundary.

TYPE LOCATION: Woodford County, Illinois; about 2 miles northeast of Spring Bay: 1,660 feet north and 1,440 feet west of the southeast corner of sect. 30, T. 28 N., R. 3 W. ;USGS Germantown Hills Northwest Illinois topographic quadrangle; lat. 40 degrees 51 minutes 14.1seconds N. and long. 89 degrees 29 minutes 26.1 seconds W., UTM zone 16, 290065 easting and 4525527 northing, NAD 83.

RANGE IN CHARACTERISTICS: The depth to free carbonates is less than 25 cm (10 inches) and is commonly at the surface. The 25 to 102 cm (10 to 40 inches) particle-size control section averages from 18 to 27 percent clay.

The A horizon has hue of 10YR or 2.5Y; value of 2 to 4 and chroma of 1 to 3. It is silt loam or silty clay loam.
The C horizon has hue of 10YR, 2.5Y, or 5Y; value of 2 to 7 and chroma of 1 to 6. It is dominantly silt loam and silty clay loam, but includes strata of silt, loam, fine sandy loam, or loamy fine sand in some pedons.

COMPETING SERIES: These are the Blue Earth, Moundprairie, and Uturin series. Blue Earth soils have coprogenous earth in the series control section. Moundprairie and Uturin soils have buried A horizons at a depth of 20 to 60 inches.

GEOGRAPHIC SETTING: Slacwater soils are on flood plains and formed primarily from material washed from adjacent loess covered uplands.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Calco, Raveenwash, Jules and Lena soils. The poorly drained Calco soils have a thick dark surface. The somewhat poorly drained Raveenwash soils are coarse-loamy. The moderately well drained Jules soils are coarse-silty. The very poorly drained Lena soils are organic and are in depressions and toe slope seepy areas.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. The potential for surface runoff is low or negligible. Saturated hydraulic conductivity is moderately high to high (0.1417 to 1.417 micrometers per second). Permeability is moderate. Flooding is frequent and long to very long duration. Commonly the ground water is at the surface or within 0.46 meter (1.5 feet) of the surface during the late winter and spring or after a flooding event. Some areas of this soil have occasional brief to long periods of ponding, occurring during part or all of the same periods.

USE AND VEGETATION: Most undrained areas are wooded. Areas which are artificially drained are used for cultivated crops. Principal crops are corn and soybeans. Other crops include small grain.

DISTRIBUTION AND EXTENT: Along major streams and rivers in western Illinois. Extent is small.

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

SERIES ESTABLISHED: Woodford County, Illinois, 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 6 inches (A horizon); calcareous reaction class; an aquic moisture regime.


National Cooperative Soil Survey
U.S.A.