LOCATION BOMAR ALEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Typic Fragiudults
TYPICAL PEDON: Bomar silt loam--cultivated.(Colors are for moist soils unless otherwise stated.)
Ap--0 to 7 inches; brown (10YR 4/3) silt loam; weak fine granular structure; very friable; common fine roots; moderately acid; clear smooth boundary.(3 to 10 inches thick)
Bt1--7 to 18 inches; yellowish brown (10YR 5/6) silty clay loam; moderate medium subangular blocky structure; friable; common fine roots; very thin patchy clay films on faces of most peds; very strongly acid; clear wavy boundary.
Bt2--18 to 33 inches; yellowish brown (10YR 5/6) silty clay; moderate medium subangular blocky structure; friable; very thin patchy clay films on faces of most peds; common medium distinct light yellowish brown (10YR 6/4) iron depletions and common medium prominent yellowish red (5YR 5/8) iron accumulations; few fine roots; very strongly acid; clear wavy boundary. (combined thickness of the Bt horizon is 16 to 33 inches)
Btx--33 to 73 inches; mottled strong brown (7.5YR 5/6), yellowish brown (10YR 5/6), and pale brown (10YR 6/3) silty clay; common nearly vertical streaks or crevices of light gray (10YR 7/2) up to 1 inch wide; weak coarse blocky structure parting to moderate medium platy structure; firm and brittle in about 80 percent of the horizontal area, the light gray and some pale brown areas being friable; few fine roots in the light gray streaks; common fine voids lined with clay; nearly continuous clay films on faces of peds; common black concretions and ped coatings; very strongly acid; clear irregular boundary.(22 to 42 inches thick)
BC--73 to 100 inches; mottled brownish yellow (10YR 6/6), red (2.5YR 4/6), and light gray (10YR 7/2) clay loam; weak medium subangular blocky structure; friable; extremely acid.
TYPE LOCATION: Cherokee County, Alabama; 2.0 miles south of Centre and 0.5 mile southwest of Terrapin Creek Bridge. NW1/4NW1/4 sec. 3, T. 11 S., R. 9 E.
RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock is more than 60 inches. Reaction ranges from strongly acid to very strongly acid in the A and Bt horizons, except where limed, and from very strongly acid to extremely acid in the Btx and BC horizons. Depth to the fragipan ranges from 19 to 40 inches.
The A horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 4 or 5, and chroma of 2 through 6. Texture is silt loam, loam, or silty clay loam.
The Bt horizon has hue of 5YR through 2.5Y, value of 5 through 8, and chroma of 4 through 8. In most pedons the lower Bt horizon has few to common mottles in shades of yellow, brown, gray, and red. Texture is clay loam, silty clay loam, silty clay, or clay with 35 to 50 percent clay and more than 30 percent silt.
The Btx horizon is mottled in shades of yellow, red, brown, and gray or it has a matrix hue of 5YR through 2.5Y, value of 5 through 8, and chroma of 3 through 8 with common to many mottles of chroma 2 or less. Percent brittleness is 60 to 90. Texture is clay loam, silty clay loam, or silty clay.
The BC horizon has the same hue, value, chroma, and texture as the Btx horizon.
COMPETING SERIES: There are no known series in the same family, competing series in related families include the Captina, Cataula, Gilead, Pelzer, Lax, and Leadvale series. Captina, Lax, and Leadvale soils contain less than 35 percent clay in their control sections. Cataula, Gilead, and Pelzer soils have kaolinitic mineralogy.
GEOGRAPHIC SETTING: Bomar soils are on nearly level to gently sloping toe slopes, stream terraces, and upland depressions. Slopes range from 0 to 3 percent with 1 to 2 percent being dominant. The soil formed in clayey alluvium or old valley fill or residuum weathered from shale. Average annual rainfall is 55 inches near the type location.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Chewacla, McQueen, Firestone, and Ellisville series. McQueen and Firestone soils lack fragipans. Chewacla and Ellisville soils lack argillic horizons and fragipans.
DRAINAGE AND PERMEABILITY: These soils are moderately well drained. Runoff is moderate or slow. Permeability is moderately slow in solum above the fragipan and slow in the fragipan.
USE AND VEGETATION: Corn, soybeans, pasture, cotton, and woodland. Forests are chiefly hardwoods, dominated by oaks, hickory, maple, beech, and elm with some shortleaf and loblolly pines.
DISTRIBUTION AND EXTENT: The Southern Appalachian Valleys of Alabama, Tennessee, and Georgia. The series is inextensive. Over 3,000 acres were mapped in the county of type location.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Cherokee County, Alabama; 1973.
REMARKS: Data is available on 2 pedons. Bomar soils were formerly included in the Leadvale series.
Diagonistic horizons recognized in this pedon are:
Ochric epipdon - 0 to 7 inches (Ap horizon)
Argillic horizon - 7 to 73 inches (Bt and Btx horizons)
Fragipan horizon - 33 to 73 inches (Btx horizon)