LOCATION COWPEN                  AL

Established Series
SP, JK, AW; GRB
12/2014

COWPEN SERIES


The Cowpen series consists of very deep, somewhat poorly drained, very slowly permeable soils on ridges, knolls, and side slopes on uplands of the Southern Coastal Plain. They formed in clayey Miocene-age sediments. Near the type location, the average annual air temperature is about 66 degrees F., and the average annual precipitation is about 58 inches. Slopes range from 2 to 15 percent.

TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Aquic Paleudults

TYPICAL PEDON: Cowpen loam, on a gently sloping ridge of mixed pine woodland at an elevation of about 220 feet above sea level. (Colors are for moist soil).

Ap--0 to 4 inches; brown (10YR 4/3) loam; weak fine subangular blocky structure; very friable; many very fine and fine and common medium and coarse roots; extremely acid; abrupt smooth boundary. (2 to 7 inches thick)

Bt1--4 to 12 inches; yellowish red (5YR 5/6) clay; strong medium angular blocky structure; firm; very sticky, moderately plastic; few very fine and fine roots and common medium and coarse roots; common distinct pressure faces on peds; common medium distinct light brown (7.5YR 6/4) and common medium prominent light yellowish brown (10YR 6/4) and red (2.5YR 4/6) masses of iron accumulation; very strongly acid; clear wavy boundary.

Bt2--12 to 26 inches; 35 percent red (2.5YR 4/6), 25 percent light yellowish brown (10YR 6/4), 25 percent light brownish gray (10YR 6/2) and 15 percent yellowish brown (10YR 5/6) clay in a variegated pattern; strong coarse subangular blocky structure parting to medium angular blocky; very firm; very sticky, moderately plastic; few very fine, fine and medium roots; common distinct and prominent pressure faces; few faint clay films on faces of peds; the areas of red, light yellowish brown and yellowish brown are areas of iron accumulations, and the areas of light brownish gray are areas of iron depletions; very strongly acid; gradual irregular boundary. (Combined thickness of the Bt horizon is 15 to 30 inches thick)

Btg--26 to 47 inches; light gray (10YR 7/2) clay; moderate very coarse subangular blocky parting to moderate coarse angular structure; firm; very sticky, moderately plastic; few very fine roots; common distinct pressure faces; common medium prominent strong brown (7.5YR 5/8) and reddish yellow (7.5YR 6/6) and few medium prominent yellow (10YR 7/6) masses of iron accumulation; very strongly acid; gradual wavy boundary. (7 to 24 inches thick)

2Btg1--47 to 61 inches; light gray (10YR 7/1) clay; strong coarse angular blocky structure; very firm; moderately sticky, slightly plastic; few very fine roots; common distinct pressure faces on peds; common medium prominent strong brown (7.5YR 5/6) masses of iron accumulation; very strongly acid; gradual wavy boundary.

2Btg2--61 to 85 inches; light gray (10YR 7/1) clay; weak coarse subangular blocky structure; very firm; moderately sticky, slightly plastic; common medium prominent brownish yellow (10YR 6/6) and strong brown (7.5YR 5/6) and few fine prominent red (2.5YR 4/8) masses of iron accumulation; many medium faint gray (10YR 6/1) areas of iron depletions; very strongly acid.

TYPE LOCATION: Washington County, Alabama; Approximately 6.5 miles east-southeast of Fruitdale; about 1600 feet north and 200 feet east of the southwest corner of sec 9, T. 4 N., R. 3 W.; Vinegar Bend topographic quadrangle; lat. 31 degrees 19 minutes 23.6 seconds N.; long. 88 degrees 17 minutes 43.1 seconds W.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 34 to more than 80 inches. Reaction ranges from extremely acid to very strongly acid in the A and Bt horizons and from extremely acid to strongly acid in the Btg or 2Btg and 2Cg horizons. Content of plinthite ranges from none to 4 percent and content of ironstone nodules ranges from 0 to 10 percent, by volume, in the subsoil.

The A or Ap horizon has hue of 10YR, value of 3 or 4, and chroma of 2 to 4. Texture is fine sandy loam or loam. Content of quartz pebbles range from 0 to 5 percent, by volume.

The E horizon, where present, has hue of 10YR, value of 4 or 5, and chroma of 4 to 8. Texture is fine sandy loam or loam. It is 6 to 15 inches thick where it occurs. Some pedons have a thin BA horizon with similar colors as the E horizon. Textures of the BA horizon are sandy clay loam or clay loam.

The Bt horizon has hue of 2.5YR to 10YR, value of 4 to 6, and chroma of 4 to 8; or it has no dominant matrix color and is multicolored in shades of red, brown, and gray. Content of plinthite ranges from 0 to 2 percent, by volume. Ironstone nodules 5 to 60 mm thick range from none to common. Redoximorphic features in shades of red, brown, yellow and gray range from few to many. Texture is dominantly silty clay or clay. Some pedons have a thin sub horizon of clay loam in the upper part.

The Btg or 2Btg horizon where present, has hue of 10YR to 5Y, value of 6 or 7, and chroma of 1 or 2. Content of plinthite ranges from 0 to 3 percent, by volume. Ironstone nodules 5 to 60 mm thick range from none to common. Redoximorphic features in shades of red, brown, yellow and gray range from common to many. Texture is silty clay or clay.

The 2Btg horizon, where present, has hue of 10YR or 2.5Y, value of 6 to 8, and chroma of 1 or 2. Redoximorphic accumulations in shades of red, yellow and brown range from common to many. Texture is silty clay or clay. Some pedons may have a 2C horizon that has no dominant matrix color and is multicolored in shades of red, brown, gray, and yellow.

COMPETING SERIES: These are the Angie, Chrysler, Mena, and Subran soils in the same family. These soils are all moderately well drained. In addition, Chrysler soils are on stream terraces. Mena soils are forming in old alluvium and pedisediments and are underlain by sandstone and shale. Subran soils occur on transitional landscapes of the Coastal Plain and Blackland Prairie.

GEOGRAPHIC SETTING: Cowpen soils are on uplands of the Southern Coastal Plain. Slopes range from 2 to 15 percent. They formed in clayey Miocene-age sediments. The climate is humid semitropical. The average annual air temperature ranges from 63 to 68 degrees F., and the average annual precipitation ranges from 48 to 60 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Atmore, Escambia, Pinebarren, Poarch and Tibbie series. Atmore, Escambia and Poarch soils have coarse-loamy control sections and have subsoil horizons with 5 percent or more plinthite. In addition, the poorly drained Atmore soils are on lower positions. Escambia soils are on similar to slightly lower positions. The moderately well drained Poarch soils are on higher positions. The somewhat poorly to poorly drained Pinebarren and Tibbie soils are on lower positions. They have a coarse-loamy and fine-loamy particle-size control section, respectively.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; very slow permeability.

USE AND VEGETATION: Most areas of Cowpen soils are used for woodland. Some areas are used for grazing. Common trees include longleaf pine, loblolly pine, water oak, post oak, turkey oak and sweetbay magnolia. The understory vegetation consists of huckleberry, gallberry, wax myrtle, smilax and broomsedge.

DISTRIBUTION AND EXTENT: Coastal Plain of Alabama, possibly Florida and Mississippi.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Auburn, Alabama.

SERIES PROPOSED: Washington County, Alabama; 2007.

REMARKS: Diagnostic horizons and features recognized in this pedon:

Ochric epipedon - the zone from the surface of the soil to a depth of 4 inches (Ap horizon).

Argillic horizon - the zone from 4 to 85 inches (Bt, Btg and 2Btg1 and 2Btg2 horizons).

Cowpen soils occur on landforms that were formerly mapped as Susquehanna in older soil surveys. Cowpen soils differ from Susquehanna in having mixed rather than smectitic mineralogy. In addition, Cowpen soils have a base saturation lower than 35 percent (by sum of cations) at a depth of 125 cm below the upper boundary of the argillic horizon.

Cowpen soils are saturated within a depth of 1.0 to 3.0 feet of the surface for short periods during the winter and spring.

Cowpen soils are in MLRA 133A.

ADDITIONAL DATA: Characterization Sample S07AL-129-003 (1-6). Sample analyzed by NSSL, Lincoln, NE.


National Cooperative Soil Survey
U.S.A.