LOCATION ALUSA OK+TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Vertic Albaqualfs
TYPICAL PEDON: Alusa loam, on a convex slope--in forest. (Colors are for moist soil unless otherwise stated.)
A--0 to 3 inches; grayish brown (10YR 5/2) loam; few fine faint yellowish brown redox iron concentrations; weak fine granular structure; friable; many roots; few fine brown and black concretions; medium acid; clear smooth boundary. (2 to 5 inches thick)
Eg--3 to 9 inches; light brownish gray (10YR 6/2) loam; common medium distinct light yellowish brown (10YR 6/4) redox iron concentrations; weak fine granular structure; friable; dark stains on faces of peds and in root channels; few fine brown and black redox concretions; medium acid; abrupt wavy boundary. (3 to 7 inches thick)
Btg1--9 to 20 inches; light brownish gray (10YR 6/2) clay; common medium and coarse distinct yellowish brown (10YR 5/4) and prominent yellowish red (5YR 5/8) redox iron concentrations; moderate medium blocky structure; very firm; pressure faces on peds; common silt coatings of light gray (10YR 7/2) on faces of peds and around voids; few fine brown redox concretions; very strongly acid; gradual wavy boundary. (8 to 30 inches thick)
Btg2--20 to 36 inches; gray (10YR 6/1) clay; common medium and coarse faint and prominent light brownish gray (10YR 6/2) redox iron depletions, and red (2.5YR 4/8) redox iron concentrations; moderate medium blocky structure; very firm; shiny faces of peds; few fine black and brown concretions; strongly acid; gradual smooth boundary. (10 to 35 inches thick)
Btg3--36 to 54 inches; gray (10YR 6/1) clay; many coarse distinct yellowish brown (10YR 5/4) and strong brown (7.5YR 5/6) redox iron concentrations; weak coarse blocky structure; very firm; few slickensides that do not intersect; many shiny pressure faces on peds; common fine brown and black concretions; neutral; gradual smooth boundary. (0 to 20 inches thick)
BCg--54 to 72 inches; gray (10YR 6/1) clay; many medium and coarse distinct yellowish brown (10YR 5/6) and strong brown (7.5YR 5/6) redox iron concentrations; weak coarse blocky structure; very firm; few intersecting slickensides; common fine and medium brown and black concretions and few calcium carbonate concretions; moderately alkaline.
TYPE LOCATION: McCurtain County, Oklahoma; about 2 miles east of Valliant, Oklahoma; 1520 feet east, 50 feet south of northwest corner of sec. 36, T. 6 S., R. 21 E.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 inches. Thickness of the A horizon and E horizon are 12 inches or less.
The Ap or A horizon has hue of 10YR, value of 4 or 5, and chroma of 1 or 2. Texture is loam or silt loam. Reaction ranges from medium acid to strongly acid.
The Eg horizon has hue of 10YR, value of 4 to 7, and chroma of 1 or 2. It has reddish or brownish redox concentrations of iron. Texture is loam or silt loam. Reaction is medium acid or strongly acid. The boundary between the Eg horizon and Btg horizon is abrupt and smooth or wavy.
The Btg horizon has hue of 10YR, value of 4 to 6, and chroma of 1 or 2, or hue of 2.5Y, value of 5, and chroma of 2, or hue of 5Y, value of 5, and chroma of 2. It has brownish, reddish, or grayish redox concentrations or depletions of iron. Texture is clay, silty clay, silty clay loam, or clay loam with the clay ranging from 35 to 55 percent. Reaction ranges from very strongly acid to neutral. Slickensides are at depths below 30 inches.
The BCg horizon has hue of 10YR, value of 4 to 6, and chroma of 1 or 2, or hue of 2.5Y, value of 6, and chroma of 2, or hue of 5Y, value of 4, and chroma of 1, or hue of N, value of 5, and chroma of 0. It has grayish, brownish, reddish, or yellowish redox concentrations or depletions of iron. The content of black and brown concretions ranges from few to many, and the carbonate concretions range from none to many. Reaction ranges from mildly alkaline or moderately alkaline.
COMPETING SERIES: These are the Arol, Corrigan, Crowley, Falba, Leaksville, and Meikle soils of the same family. Arol, Corrigan, Falba, and Leaksville soils have sola less than 40 inches thick. Crowley soils have sola less than 60 inches thick and have A horizons more than 12 inches thick. Meikle soils do not have a moisture deficit.
GEOGRAPHIC SETTING: Alusa soils are on nearly level uplands of the Western Coastal Plains. Slope gradients range from 0 to 1 percent. The soils formed in clayey sediments of Cretaceous age. The climate is humid. Mean annual temperature ranges from 57 degrees to 65 degrees F. Average annual precipitation ranges 40 to 50 inches. Thornthwaite P-E index ranges from 72 to 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bosville, Cadeville, Hollywood, and Panola soils. Bosville and Cadeville soils do not have dominant chroma of 2 or less in the Bt horizon. Hollywood soils have 30 percent or more clay in all horizons, intersecting slickensides below 20 inches in depth, and gilgai microrelief. Panola soils do not have an E horizon and have a gradual boundary between the A horizon and B horizon.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; very slow permeability. A perched water table is at a depth of 0 to 1.0 foot during November through April.
USE AND VEGETATION: The principal use is cropland, woodland, and tame or native pasture. Native vegetation is water oak, sweetgum, elm, hickory, and scattered shortleaf and loblolly pine.
DISTRIBUTION AND EXTENT: In the Western Coastal Plains of Oklahoma, possibly Arkansas and Texas. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: McCurtain County, Oklahoma; 1970.
REMARKS: Soil Interpretation Record: Alusa Series OK0128
These soils were formerly included in the Crowley series in McCurtain County, Oklahoma.
Diagnostic horizons and features in this pedon are:
Ochric epipedon - the zone from the surface to about 9 inches. (A, Eg horizons)
Albic horizon - the zone from 3 to 9 inches. (Eg horizon)
Argillic horizon - the zone from 9 to 54 inches. (Btg1, Btg2, Btg3 horizons)
Typic Albaqualfs features - soils with an aquic moisture regime; an ochric epipedon; have chroma of 2 or less immediately below any Ap horizon and have dominant chroma of 2 or less in coatings on the surface of peds and mottles within peds of the Btg; have an argillic horizon and a base saturation of 35 percent or more at a depth of 72 inches below the soil surface; and have an abrupt textural change between the Eg horizon and the Btg1 horizon and have a vertical saturated hydraulic conductivity of less than 10 cm per day.
Soil Interpretation Record: OK0128 Alusa Series