LOCATION CALHOUN                 LA+AR KY MO MS TN TX

Established Series
Rev. JLD
02/2013

CALHOUN SERIES


The Calhoun series consists of level, poorly drained, slowly permeable soils. These soils formed from loess or loess-like material with low sand content. They mainly are at low local elevations on Pleistocene age terraces, and less commonly on flood plains. Slopes range from 0 to 1 percent. Mean annual temperature is 67 degrees F., and the average annual rainfall is 58 inches near the type location.

TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Typic Glossaqualfs

TYPICAL PEDON: Calhoun silt loam - pasture.
(Colors are for moist soil unless otherwise stated.)

A--0 to 3 inches; dark brown (10YR 4/3) silt loam; moderate fine granular structure; friable; strongly acid; abrupt smooth boundary. (0 to 8 inches thick)

Eg1--3 to 12 inches; light brownish gray (10YR 6/2) silt loam; common fine distinct light yellowish brown (10YR 6/4) mottles; massive; friable; few soft reddish brown bodies; strongly acid; gradual wavy boundary.

Eg2--12 to 17 inches; light gray (10YR 7/2) silt loam; common fine distinct yellowish brown (10YR 5/4) mottles; massive; friable; few fine black concretions; very strongly acid; clear irregular boundary. (Combined thickness of E horizons is 9 to 24 inches.)

Btg--17 to 30 inches; gray (10YR 6/1) silty clay loam; common fine distinct yellowish brown (10YR 5/4) mottles; weak coarse subangular blocky structure; firm; thin light gray silt coatings around peds in upper few inches; silt tongues of E horizon 1/2 inch to 2 inches wide extend to the lower boundary of the horizon and make up 15 to 20 percent of the mass in the upper part of the horizon; few faint clay films on faces of peds; common fine brown and black concretions; very strongly acid; gradual wavy boundary. (10 to 40 inches thick)

BC--30 to 48 inches; light brownish gray (2.5YR 6/2) silt loam; common fine distinct brownish yellow (10YR 6/6) mottles and common fine faint light gray mottles; weak coarse subangular blocky structure; firm; few fine brown and black concretions; strongly acid. (10 to 20 inches thick)

Cg--48 to 72 inches; light brownish gray (2.5Y 6/2) silt loam; common medium distinct brownish yellow (10YR 6/6) mottles; massive; firm; small pockets or veins of light brownish gray silt; few fine brown concretions; strongly acid.

TYPE LOCATION: East Baton Rouge Parish, Louisiana; 0.6 mile east of Deerford behind Mose Chapel Church; northwest 1/4 southeast 1/4, sec. 2, T. 5 S., 1 E.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 80 inches. Calcium-magnesium ratios are 1 or more in most horizons. Sand content is less than 10 percent in the upper 60 inches of the solum. The glossic horizon extends deeply into the B horizon. Exchangeable sodium percentage ranges from 0 to 6 percent. In at least one subhorizon within a depth of 30 inches, exchangeable aluminum makes up 20 to 70 percent of the effective cation-exchange capacity. Common fine brown and black concretions are throughout the solum in most pedons, but are not diagnostic.

The A horizon has value of 4 to 6 and chroma of 1 to 3. Reaction ranges from extremely acid to medium acid, unless limed.

The E horizon has hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 1 or 2. Reaction ranges from medium acid through extremely acid.

The Btg horizon has hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 1 or 2. Mottles, in shades of brown, yellow, and gray range from common to many. Texture is silt loam or silty clay loam. Clay content ranges from 22 to 35 percent. Reaction is typically strongly acid to extremely acid but ranges through neutral in the lower part of some pedons. Fine veins of black staining (manganese-oxide) are on surfaces of peds in the B horizon of some pedons.

The BC and Cg horizons have hue of 10YR, 2.5Y, or 5Y, value of 5 or 6, and chroma of 1 to 4. Reaction ranges from mildly alkaline through extremely acid.

COMPETING SERIES: These are the Basile, Fountain, Frost, Gilbert, and Leton series in the same family and the Amagon, Caddo, Crowley, Foley, Guyton, Henry, Lafe, Routon, Wrightsville, and Zachary series. Amagon soils lack tonguing of the E horizon into the B horizon and contain more than 15 percent sand. Basile and Leton soils have more than 10 percent sand. Caddo soils contain more than 15 percent sand and mineralogy is siliceous. Crowley soils have finer textures and an abrupt textural change from the A to the B horizon. Foley soils are more alkaline and have a natric horizon. Fountain soils have mildly to moderately alkaline B horizons. Frost soils have B horizons that have peds coated with dark gray or black. Gilbert soils have more than 15 percent exchangeable sodium in the lower B horizon. Guyton soils have more than 10 percent sand. Henry soils have fragipans and the horizon of maximum clay content is below depths of 36 inches. Lafe soils are browner and have a natric horizon. Routon soils lack a glossic horizon. Zachary soils have an abrupt textural change from the A to B horizon. Wrightsville soils have finer textures in the B horizon.

GEOGRAPHIC SETTING: Calhoun soils are dominantly on nearly level areas and depressions on Pleistocene terraces, and less commonly on flood plains. The soil formed from loess or loess-like material more than 5 feet thick. The climate is warm and humid. Mean annual temperature ranges from about 60 to 70 degrees F., and the average annual rainfall ranges from about 45 to 55 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Henry series and the Calloway, Grenada, Loring, and Oliver series all of which have fragipans. In addition, Calloway, Grenada, Loring, and Oliver soils have browner colors.

DRAINAGE AND PERMEABILITY: Poorly drained; slow to very slow runoff; very slow internal drainage; slow permeability. Soils on flood plains are subject to occasional or frequent flooding.

USE AND VEGETATION: Mostly in pasture or woodland; some areas are used to grow soybeans or other cultivated crops. Dominant forest species are loblolly and slash pine, water oak, and sweetgum.

DISTRIBUTION AND EXTENT: Arkansas, Kentucky,Louisiana, Mississippi, Missouri, and Tennessee. This series is of large extent.

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

SERIES ESTABLISHED: Prairie County, Arkansas; 1906.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon.................0 to 17 inches (A,E)
Albic horizon.....................3 to 17 inches (E)
Argillic horizon...............17 to 30 inches (Btg)
Glossic horizon................17 to 30 inches (Btg)


ADDITIONAL DATA: NSSL Sample Nos. S61LA-033-008, S75LA-041-018, S75LA-041-019. Louisiana Agricultural Experiment Station Sample No. S5, East Baton Rouge Parish, Louisiana, Published Soil Survey Report, pp. 72-76.


National Cooperative Soil Survey
U.S.A.