LOCATION CENTER TN+KY

Established Series
Rev. RPS:MAV
02/2013

CENTER SERIES

The Center series consists of very deep, moderately well drained soils that have moderately slow permeability. These soils formed in loess on broad level and gently sloping stream terraces. Slopes range from 0 to 3 percent.

TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Aquic Hapludalfs

TYPICAL PEDON: Center silt loam--cultivated.

Ap--0 to 8 inches; dark grayish brown (10YR 4/2) silt loam; weak fine granular structure; very friable; many fine roots; moderately acid; clear smooth boundary. (5 to 10 inches thick)

BA--8 to 14 inches; yellowish brown (10YR 5/4) silt loam, common medium distinct gray (10YR 5/1) mottles; weak fine subangular blocky structure; friable; many fine roots; few fine black concretions; moderately acid; gradual smooth boundary. (0 to 9 inches thick)

Bt--14 to 30 inches; yellowish brown (10YR 5/4) silty clay loam, many medium distinct mottles of gray (10YR 5/1), light brownish gray (10YR 6/2), and light yellowish brown (10YR 6/4); weak fine amd medium subangular blocky structure; friable; common fine roots; few thin discontinuous clay films on faces of peds; few fine black concretions; moderately acid; gradual smooth boundary. (Combined thickness of the Bt horizon is 12 to 55 inches)

Btg--30 to 44 inches; light brownish gray (10YR 6/2) silt loam, many medium distinct yellowish brown (10YR 5/4) mottles; weak medium subangular blocky structure; friable; few thin clay films on faces of peds; few fine black concretions; slightly acid; gradual smooth boundary. (0 to 20 inches thick)

C--44 to 72 inches; mottled yellowish brown (10YR 5/6) and grayish brown (10YR 5/2) silt loam; massive; friable; neutral.

TYPE LOCATION: Obion County, Tennessee; 1/2 mile south of Union City, 300 feet west of U. S. Highway 51.

RANGE IN CHARACTERISTICS: Thickness of the solum is more than 60 inches. Reaction ranges from slightly acid to strongly acid except the C horizon and BC horizon, where present, ranges from medium acid to mildly alkaline.

The A horizon has hue of 10YR, value of 4 or 5, and chroma of 2 to 4. The E horizon, where present, has a hue of 10YR, value of 5, and chroma of 2 or 3 or value of 6 and chroma of 3. The A and E horizons are silt loam.

The BA horizon has hue of 10YR, value of 4 to 6, and chroma of 4 to 6. Mottles range from none to common in shades of gray and brown. It is silt loam.

The Bt horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 4 or 6. Mottles of chroma 2 or less range from few to many within the upper 10 inches. The Btg horizon, where present, has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 2 or less. Mottles of higher chroma range from few to many. Structure of the Bt and Btg horizons are dominantly subangular blocky, but some pedons have weak prismatic structure parting to subangular blocky. They are silt loam or silty clay loam.

The C horizon or BC horizon, where present, has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 2 to 6. In some pedons where this horizon is in Roxana loess, it has hue of 7.5YR, value of 4, and chroma of 4 or 6.

COMPETING SERIES: Askew is the only other series in the family. Similar soils in other families are Calhoun, Calloway, Dundee, Grenada and Routon. Askew soils have thinner sola and higher sand content in the lower part of the B and C horizons. The poorly drained Calhoun and Routon soils are dominantly gray. Calloway and Grenada soils are bisequal and have a fragipan and glossic horizon. Dundee soils have a chroma of 2 or less in the major part of the argillic horizon.

GEOGRAPHIC SETTING: Broad level and gently sloping stream terraces. Slopes range from 0 to 3 percent. The soil formed in loess ranging from about 4 to 20 or more feet in thickness. At the type location, the mean annual precipitation is 40 inches, and the mean annual temperature is about 59 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Calhoun, Calloway, Grenada and Routon series and the Dekoven and Kurk series. Dekoven soils have thick black A horizons and are poorly drained. Kurk soils are somewhat poorly drained with chroma 2 in the upper part of the subsoil.

DRAINAGE AND PERMEABILITY: Moderately well drained and somewhat poorly drained; slow runoff; moderately slow permeability. Some areas are subject to flooding during the months of December through March.

USE AND VEGETATION: Practically all of the soil is cleared. The main crops are soybeans, cotton, and corn. The original vegetation was chiefly oaks, sweetgum, American elm, and maples.

DISTRIBUTION AND EXTENT: Western Tennessee, western Kentucky, and possibly western Mississippi. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AUBURN, ALABAMA

SERIES ESTABLISHED: Henry County, Tennessee; 1950.

REMARKS: Active CE activity class assigned in 2002. Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from the surface of the soil to approximately 8 inches (Ap horizon).

Argillic horizon - the zone from approximately 14 to 44 inches (Bt and Btg horizons).

Aquic subgroup features - the occurrence of mottles of chroma 2 or less in the upper 10 inches of the argillic horizon.

National Cooperative Soil Survey
U.S.A.