LOCATION RUSTON LA+AL AR FL KY MS NC OK TN TX VAEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, semiactive, thermic Typic Paleudults
TYPICAL PEDON: Ruston fine sandy loam--forest. (Colors are for moist soil.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) fine sandy loam; weak fine granular structure; friable; many coarse, medium and fine roots; very strongly acid; abrupt smooth boundary. (3 to 6 inches thick)
E--4 to 7 inches; pale brown (10YR 6/3) fine sandy loam; common medium faint light yellowish brown mottles; massive; firm; common fine and medium roots; few yellowish red (5YR 5/6) bodies of B horizon material in lower part; few channels filled with dark grayish brown (10YR 4/2) material; strongly acid; abrupt smooth boundary. (0 to 15 inches thick)
Bt1--7 to 18 inches; red (2.5YR 4/6) clay loam; moderate medium subangular blocky structure; friable; few fine roots; few fine pores; common, distinct, continuous clay films on surfaces of peds and in pores; strongly acid; gradual wavy boundary.
Bt2--18 to 26 inches; yellowish red (5YR 5/8) fine sandy loam; weak medium subangular blocky structure; friable; few fine roots; few fine pores; common, thin, patchy clay films on faces of peds and walls of pores; strongly acid; gradual wavy boundary. (Combined thickness of the Bt horizons is 10 to 40 inches)
Bt/E--26 to 39 inches; 70 percent yellowish red (5YR 5/6) and 30 percent light yellowish brown (10YR 6/4) fine sandy loam; weak coarse prismatic structure; friable; few fine roots; few fine pores; discontinuous bands of firm and brittle material up to 5 cm. thick make up 30 percent of horizon; common clay bridges between sand grains in Bt part; few red (2.5YR 4/8) sandy clay loam bodies of Bt material up to 7 cm in diameter; few black accumulations; strongly acid; gradual wavy boundary. (4 to 20 inches thick)
B't1--39 to 52 inches; red (2.5YR 4/8) fine sandy loam; few fine distinct dark yellowish brown (10YR 4/6) mottles; weak coarse prismatic strucutre parting to weak medium subangular blocky; firm; few fine roots; few fine pores; common, distinct, discontinuous red (2.5YR 4/6) clay films on ped surfaces and in pores; thin patches and streaks of pale brown (10YR 6/3) sand; few fine chert gravel; strongly acid; gradual wavy boundary.
B't2--52 to 67 inches; red (2.5YR 5/8) sandy clay loam; weak coarse prismatic structure parting to weak medium subangular blocky; friable; few fine roots; few fine pores; common thin discontinuous distinct clay films on ped surfaces and in pores; few thin patches and streaks of pale brown (10YR 6/3) sand, few chert gravel up to 2 cm. in diameter; about 30 percent by volume firm and brittle material up to 10 cm. in diameter; very strongly acid; gradual wavy boundary.
B't3--67 to 85 inches; red (2.5YR 5/8) fine sandy loam, weak coarse prismatic structure; friable; few fine roots; common thin distinct clay films on prism faces; few thin patches of light yellowish brown (10YR 6/4) sand; very strongly acid. (Combined thickness of the B't horizons is 10 to 50 inches)
TYPE LOCATION: Rapides Parish, Louisiana; approximately 3 miles northwest of Woodworth; 150 feet northeast of gravel road; NE1/4NE1/4 sec. 11, T. 2 N., R. 2 W. USGS Woodworth west topographic quadrangle; lat. 31 degrees 10 minutes 01.66 seconds N. and long. 92 degrees 32 minutes 14.19 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness exceeds 60 inches. The Bt/E and B't horizons are definitive for the series. Calcium-magnesium ratios are variable in the Bt horizons, but typically are less than 1 in the B't horizons.
The A horizon has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 2 to 4. It is fine sandy loam, sandy loam, very fine sandy loam, loamy fine sand, gravelly fine sandy loam, or gravelly sandy loam. The A horizon ranges from very strongly acid to slightly acid.
The Ap horizon in severely eroded areas has colors and textures similar to the upper part of the Bt horizon.
The E horizon and E part of the Bt/E horizon have hue of 10YR, value of 5 or 6, and chroma of 3 or 4. Texture is fine sandy loam, loamy sand, or sandy loam and occurs in streaks and pockets that make up as much as 50 percent of the horizon. Small dark colored bodies that are compact and brittle make up as much as 10 percent by volume of the Bt/E horizon in some pedons.
A thin BA or BE horizon is in some pedons. The Bt, Bt part of the Bt/E, and B't horizons have hue of 5YR or 2.5YR, value of 4 to 6, and chroma of 4 to 8. They are sandy clay loam, fine sandy loam, loam, or clay loam. The B't horizon, in most pedons is mottled with shades of gray, brown, red, or yellow. Clay content of the Bt horizon averages between 18 and 30 percent in the upper 20 inches and the silt content ranges from 20 to 50 percent. The Bt and B't horizons are very strongly acid to medium acid. As much as 15 percent by volume of ironstone fragments or quartz gravel are present within the solum of some pedons. The clay content decreases from the upper Bt horizons to the Bt/E horizon and increases again in the B't horizons.
COMPETING SERIES: These are the Allen, Etowah, Holston, Sailes, and Silsbee series in the same family, and the Addielou, Avilla, Bama, Dubach, Ironcity, Leesburg, Lytle, Minvale, Nella, Noboco, Octavia, Pikeville, and Warnock series in closely related families. Allen, Etowah, Sailes, and Silsbee soils soils do not have a bisequal profile. Holston soils have color hues of 7.5YR and 10YR throughout. Addielou soils have an A horizon greater than 20 inches thick. Bama, Ironcity, Minvale, and Noboco soils have a CEC to clay ratio less than.24 in the upper 20 inches of the argillic horizon. In addition, Bama, Octavia, and Pikeville soils do not have a bisequal profile; Avilla, Ironcity, and Nella soils contain more than 10 percent coarse fragments throughout; Minvale soils contain less than 20 percent fine and coarser sand in the control section; and Dubach, Leesburg, Noboco, and Warnock soils have color hues of 7.5YR and 10YR throughout. Lytle soils have a surface mantle of loess that is 2 to 3 feet thick.
GEOGRAPHIC SETTING: These soils are on nearly level to moderately sloping uplands of the Western and Southern Coastal Plains on slope gradients of 0 to 8 percent. The soil formed in marine or stream deposits of Pleistocene age. The climate is warm and humid with mean annual temperature of 65 degrees F., and mean annual precipitation of 59 inches near the type location.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Sailes and Lytle series, and the Beauregard, Betis, Boykin, Mahan, Malbis, McLaurin, Ora, Savannah, Sawyer, Smithdale, and Tangi series. Beauregard and Malbis soils contain more than 5 percent plinthite. Sawyer and Mahan soils are finer textured. Betis, Boykin, and McLaurin soils are coarser textured. Ora, Savannah, and Tangi soils have a fragipan. Smithdale soils are not bisequal and are Hapludults.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Principal use is woodland consisting of southern pine and some hardwoods with understories of shrubs or grasses. A small acreage is used for cotton, corn, soybeans, small grain, truck crops, and pasture. A considerable portion of the acreage formerly cultivated has been converted to pasture or southern pine woodland
DISTRIBUTION AND EXTENT: Coastal Plains of Alabama, Arkansas, Louisiana, Mississippi, Oklahoma, Tennessee, and Texas. The series is of large extent, with an area of more than 1,000,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Lincoln Parish, Louisiana; 1909.
REMARKS: The concept of the series limits the series to a bisequal profile. Soils formerly included in Ruston but having low silt content are excluded.
Diagnostic horizons and features recognized are:
Ochric epipedon..0 to 7 inches (A and E horizons)
Albic horizon 4 to 7 inches (E horizon)
Argillic horizon..7 to 85 inches (Bt, Bt/E, and B't horizons).
ADDITIONAL DATA: NSSC data are available for the type location (S87LA-079-001), and other pedons in Louisiana, Mississippi, and Alabama (S71AL-097-013, S88LA-013-013, S57LA-015-001, S57LA-015-002, S81LA-027-001, S87LA-059-001, S87LA-073-001, S81LA-079-001, S81LA-111-001, S87LA-119-008, S55MS-059-003, S55MS-059-004). Engineering test data are available for Dale County, Alabama; Escambia County, Florida, Schley, Sumter, Thomas Counties, Georgia; Covington County Mississippi; Duplin County, North Carolina; Bambery County, South Carolina, Fayette and Henderson Counties, Tennessee.