LOCATION STEFF KY+IN PAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Fluvaquentic Dystrudepts
TYPICAL PEDON: Steff silt loam--on a 1 percent slope in a cultivated area. (Colors are for moist soils unless otherwise stated.)
Ap--0 to 7 inches; brown (10YR 4/3) silt loam; weak fine granular structure; very friable; many fine roots; medium acid; clear smooth boundary. (6 to 10 inches thick)
Bw1--7 to 23 inches; brown (10YR 4/3) silt loam; few fine faint mottles of light brownish gray (10YR 6/2) and pale brown (10YR 6/3); weak fine granular structure; friable; many fine roots; common medium dark brown and black concretions; very strongly acid; clear smooth boundary. (14 to 20 inches thick)
Bw2--23 to 48 inches; light brownish gray (2.5Y 6/2) silt loam; common medium distinct mottles of dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/6); weak fine granular structure; friable; common medium dark brown and black concretions; very strongly acid; gradual smooth boundary. (4 to 20 inches thick)
C--48 to 65 inches; light brownish gray (2.5Y 6/2) silt loam; common medium distinct mottles of yellowish brown (10YR 5/4) and gray (N 5/0); massive; friable; few small black and brown concretions; very strongly acid.
TYPE LOCATION: Grayson County, Kentucky; 1 1/2 miles southeast of Goffs (Steff P.O.), 0.55 mile south of U.S. Highway 62, 150 yards north of Caney Creek.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 24 to 50 inches. Thickness of the alluvial deposit ranges from about 60 to 200 inches. Soil reaction is strongly acid or very strongly acid except where limed. The content of sandstone or siltstone pebbles ranges from 0 to about 5 percent to a depth of about 40 inches, and up to 50 percent below 40 inches.
The Ap horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 2 to 4. Some pedons have thin A1 horizons with value of 3. It is dominantly silt loam, but is loam in some pedons.
The Bw1 horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 4 or 5, and chroma of 3 to 6. Mottles are in shades of gray or brown. It is silt loam or silty clay loam. The Bw2 horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 2 to 4. Mottles are in shades of gray and brown. In some pedons the gray and brown colors in the Bw2 horizon are about evenly divided.
The C horizon matrix and mottles has hue of 7.5YR, 10YR, or 2.5Y, value of 4 to 6 and chroma 2 to 6. It is silt loam, loam, or very fine sandy loam. Below 50 inches stratified layers of sandy loam and gravelly modifiers of the C horizon textures are in some pedons.
COMPETING SERIES: These are Kauppi series. Kauppi soils are slightly to medium acid and are dry for less than 45 consecutive days.
GEOGRAPHIC SETTING: These soils are on level or nearly level flood plains. Slopes dominantly are from 0 to 2 percent, but range up to 4 percent. Steff soils developed in alluvium derived from acid siltstones, sandstones, shales, and loess. Mean temperature ranges from 53 to 57 degrees F, and the mean annual precipitation ranges from 42 to 50 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Bonnie, Clifty, Cuba, and Stendal series. Bonnie and Stendal soils are dominantly gray between the Ap horizon and a depth of 30 inches. Clifty soils have 5 to 30 percent gravel content. Cuba soils lack mottles in shades of gray in the upper sola.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow; permeability is moderate. Seasonal high water table rises to within 1 1/2 to 2 feet of the surface during winter and spring months. Subject to flooding.
USE AND VEGETATION: Most areas are used for growing corn, soybeans, hay, and pasture. The native vegetation is mixed hardwoods, such as river birch, sycamore, willow, water-tolerant oaks, poplar, shagbark hickory, and red maple; canebrakes in places.
DISTRIBUTION AND EXTENT: Kentucky, southern Indiana, Tennessee, and possibly Ohio, Pennsylvania, Virginia, and West Virginia. Extent is probably large.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: MO-18 Morgantown, West Virginia
SERIES ESTABLISHED: Grayson County, Kentucky; 1970.
REMARKS: Diagnostic horizons in the pedon are:
Ochric epipedon: 0 to 7 inches, Ap
Cambic horizon: 7 to 48 inches, Bw1, Bw2