LOCATION DULAC TN+AL MS
Established Series
Rev. DEL:JCJ
11/2015
DULAC SERIES
The Dulac series consists of moderately well drained soils that have a fragipan. They formed in a thin mantle of loess over clayey Coastal Plain sediment. Slopes range from 0 to 12 percent.
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Oxyaquic Fragiudalfs
TYPICAL PEDON: Dulac silt loam--cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; brown (10YR 5/3) silt loam; weak fine granular structure; friable; strongly acid; abrupt smooth boundary. (4 to 9 inches thick)
Bt1--6 to 20 inches; strong brown (7.5YR 5/6) silt loam; moderate medium subangular blocky structure; friable; common faint clay films on faces of peds; strongly acid; abrupt smooth boundary.
Bt2--20 to 23 inches; strong brown (7.5YR 5/6) silt loam; common coarse yellowish brown (10YR 5/4) and medium light gray (10YR 6/1) mottles; friable; few faint clay films on faces of peds; very strongly acid; clear smooth boundary. (Combined thickness of the Bt horizons range from 12 to 30 inches.)
Btx--23 to 37 inches; mottled yellowish brown (10YR 5/4), strong brown (7.5YR 5/6), and light gray (10YR 6/1) silt loam; moderate coarse and very coarse prismatic structure parting to moderate medium subangular blocky; prisms coated with light gray (10YR 6/1) silt; very firm and brittle in 90 percent of the soil mass; common faint clay films on faces of peds; very strongly acid; clear smooth boundary. (8 to 20 inches thick)
2Bt--37 to 60 inches; yellowish red (5YR 4/6) clay; common medium prominent dark gray (10YR 4/1) and light gray (10YR 6/1) mottles; moderate medium subangular blocky structure; firm, plastic and sticky when wet; many distinct clay films on faces of peds; very strongly acid; clear smooth boundary. (15 to 40 inches thick)
2C--60 to 72 inches; gray (10YR 5/1) clay; many coarse strong brown (7.5YR 5/6), yellowish red (5YR 4/6), and red (2.5YR 4/6) mottles; massive; firm, plastic and sticky when wet; few dark gray shaly clay fragments; very strongly acid.
TYPE LOCATION: Madison County, Tennessee; 1.1 miles north of Five Points and 200 feet east of Diamond Grove Road.
RANGE IN CHARACTERISTICS: Depth to the fragipan ranges from 16 to 34 inches. Depth to the 2Bt horizon ranges from 30 to 55 inches. The soil is strongly acid or very strongly acid throughout except the surface layer where limed.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 through 6. It is silt loam. In severely eroded areas the texture is silty clay loam.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 4 through 6, or rarely the hue is 5YR, value of 4 and chroma of 4 or 6. It is silt loam or silty clay loam averaging between 25 and 32 percent clay.
The Btx horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 through 8. Some pedons have common to many mottles in shades of yellow, brown, red, and gray. In some pedons, this horizon is mottled and lacks an evident matrix color. It is silt loam or silty clay loam.
The 2Bt and 2C horizons range from shades of red to shades of gray mottled with other colors. They are silty clay or clay.
COMPETING SERIES: These are the
Byram,
Gigger,
Loring and
Providence series in the same family. Closely related are the
Bude,
Dickson,
Grenada,
Olivier and
Paden series. Byram soils, in the lower part of the solum, contain less than 40 percent clay and are medium acid to neutral. Gigger, Loring, Providence, Bude, Grenada, Paden, and Olivier soils have loamy textures below the fragipan. In addition, Olivier soils have mottles of chroma 2 or less in the upper 10 inches of the argillic horizon. Dickson soils are siliceous.
GEOGRAPHIC SETTING: Dulac soils are on nearly level to sloping uplands. Slopes range from 0 to 12 percent. These soils formed in loess and in the underlying clayey Coastal Plain sediment. Near the type location, mean annual temperature is 60 degrees F., and mean annual precipitation is 53 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Boswell,
Calloway,
Falkner,
Henry,
Shubuta,
Silerton, and
Tippah series. Boswell, Falkner, Shubuta, Silerton, and Tippah soils do not have fragipans. Calloway and Henry soils are grayer and more poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium runoff; slow permeability. Dulac soils have a perched high water table between depths of 1 to 2 feet during the months of December to April.
USE AND VEGETATION: Much of the acreage is cropped to corn, cotton, soybeans, hay, and pasture. A large amount is idle. Native vegetation is forest of oak, gum, pine, hickory, beach, and elm.
DISTRIBUTION AND EXTENT: Tennessee and possibly Arkansas, Kentucky, and Mississippi. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AUBURN, ALABAMA
SERIES ESTABLISHED: Decatur County, Tennessee; l943.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 6 inches (Ap horizon).
Argillic horizon - the zone from 6 to 60 inches (Bt1, Bt2, Btx, 2Bt horizons).
Fragipan - the zone from 23 to 37 inches (Btx horizon).
Discontinuity - clayey Coastal Plain sediment - the zone from 37 to 72 inches (2Bt, 2C horizons).
Classification only was changed in 7/94. Competing series and other items will be updated later.
National Cooperative Soil Survey
U.S.A.