LOCATION SAMBA AREstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Umbric Endoaqualfs
TYPICAL PEDON: Samba silt loam, 0 to 1 percent slopes in a
meadow. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; very dark brown (10YR 2/2) silt loam,
grayish brown (10YR 5/2) when dry; weak medium granular structure; friable; many roots; moderately acid; abrupt smooth boundary. (0 to 8 inches thick)
A--6 to 12 inches; very dark gray (10YR 3/1) silty clay
loam, grayish brown (10YR 5/2) when dry; moderate medium angular blocky structure; friable; many roots; few dark iron-manganese concretions; moderately acid; gradual irregular boundary. (6 to 10 inches thick)
Btg1--12 to 31 inches; dark gray (10YR 4/1) silty clay, gray (10YR 6/1) when dry; moderate medium angular blocky structure; firm, plastic; few roots; few faint clay films; common medium distinct yellowish brown (10YR 5/6) and prominent yellowish red (5YR 4/6) iron accumulations in matrix; few soft iron-manganese nodules in matrix; strongly acid; diffuse wavy boundary. (10 to 25 inches thick)
Btg2--31 to 52 inches; dark gray (10YR 4/1) silty clay, gray (10YR 6/1) when dry; moderate medium angular blocky structure; firm, plastic; few roots; few faint clay films; common coarse distinct dark yellowish brown (10YR 4/4) iron accumulations in matrix; many dark iron-manganese concretions; moderately acid; clear wavy boundary. (10 to 25 inches thick)
Cg--52 to 66 inches; dark gray (10YR 4/1) and dark brown
(7.5YR 4/4) channery silty clay; massive; firm; few roots; about 20 percent by volume shale channers; many dark soft iron-manganese nodules in matrix; slightly acid.
TYPE LOCATION: Washington County, Arkansas; at northwest corner of Fayetteville Airport. NW1/4NE1/4NW1/4 sec. 4, T. 15 N., R. 30 W.
RANGE IN CHARACTERISTICS: Depth to bedrock exceeds 72 inches. Reaction is slightly acid or moderately acid in the A horizon and ranges from strongly acid to neutral in the B and C horizons.
The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2. Texture is silt loam, loam, or silty clay loam.
The B horizon has hue of 10YR, value of 4 or 5, and chroma of 1; or hue of 2.5Y, value of 5 or 6, and chroma of 2, Redoximorphic accumulations are in shades brown or red. Texture is silty clay loam, silty clay, or clay.
The C horizon has hue of 10YR, value of 4 or 5, and chroma of 1; or hue of 2.5Y, value of 5 or 6, and chroma of 2, Redoximorphic accumulations are in shades brown or red. Texture of the fine earth is silty clay loam, silty clay, clay. Some pedons are stratified clay, silty clay, and gravel. Coarse fragments range from 0 to 25 percent.
COMPETING SERIES: These are no other series in this family.
GEOGRAPHIC SETTING: The level to depressional Samba soils are in upland valleys along the north escarpment of the Boston Mountains; MLRA 117. They formed in silty and clayey old alluvium and pedisediments from calcareous sandstones and shales. Average annual temperature is about 60 degrees F. Average annual rainfall is about 45 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Cherokee, Johnsburg and Summit series. Cherokee soils do not have an umbric epipedon and have an abrupt texture change between the ochric epipedon and underly ing argillic horizon. Johnsburg soils have fragipans. Summit soils are better drained and have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow to ponded runoff; very slow permeability. Usually saturated with water for several months during the year.
USE AND VEGETATION: Most areas are cleared and used for pasture or hay. Native vegetation was hardwood forest consisting mainly of water tolerant oaks and elm, with thick undergrowth of vines, brambles, and cane.
DISTRIBUTION AND EXTENT: Arkansas, Missouri, and Oklahoma. The series is of moderate extent, probably in excess of 15,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Washington County, Arkansas; 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon-surface to a depth of 12 inches.
Argillic horizon-depth of 12 to 52 inches.
Aquic conditions-throughout.
The Samba series formerly would have been classified in the Humic-Gley great soil group. Description of the typical pedon of this series is published in the unedited text of Soil Taxonomy, 8-16, as representative of the central concept of Umbraqualfs.