LOCATION SUMTER AL+AR GA MS OK TN TX
Established Series
Rev. PGM, SP, GRB
12/2014
SUMTER SERIES
The Sumter series consists of moderately deep, moderately well or well drained, slowly permeable soils of the Alabama and Mississippi Blackland Prairie (135A) and to a lesser extent in the Texas Blackland Prairie, Northern Part (86A) and the Cretaceous Coastal Plain (135B). They formed in loamy and clayey residuum and alkaline clays that weathered from chalk. Near the type location, the mean annual temperature is about 67 degrees F., and the mean annual precipitation is about 51 inches. Slope ranges from 1 to 40 percent.
TAXONOMIC CLASS: Fine-silty, carbonatic, thermic Rendollic Eutrudepts
TYPICAL PEDON: Sumter silty clay, in a pasture on a convex 3 percent slope (Colors are for moist soil).
Ap1--0 to 6 inches; grayish brown (2.5Y 5/2) silty clay; moderate medium granular structure; friable, common fine roots; moderately alkaline; strongly effervescent; clear smooth boundary. (3 to 10 inches thick)
Ap2--6 to 10 inches; light yellowish brown (2.5Y 6/4) and grayish brown (2.5Y 5/2) silty clay; moderate medium granular structure; friable; few fine roots; moderately alkaline; strongly effervescent; gradual wavy boundary.
Bk1--10 to 21 inches; light yellowish brown (2.5Y 6/4) silty clay; moderate medium subangular blocky structure; friable; few fine roots; few fine soft calcium carbonate; few fine distinct brownish yellow (10YR 6/6) masses of iron accumulation; moderately alkaline; strongly effervescent; gradual wavy boundary.
Bk2--21 to 28 inches; light yellowish brown (2.5Y 6/4) silty clay; moderate fine subangular blocky structure; friable; few fine soft calcium carbonate; few weathered platy fragments of chalk; common medium distinct light gray (2.5Y 7/2) areas of iron depletions and yellow (2.5Y 7/6) masses of iron accumulation; moderately alkaline; strongly effervescent; abrupt wavy boundary. (Combined thickness of the Bw horizon is 14 to 36 inches.)
Cr--28 to 60 inches; light gray (2.5Y 7/2) chalk; mottles and streaks of pale yellow (2.5Y 7/4) yellowish brown (10YR 5/8), white (5Y 8/1), and light olive gray (5Y 6/2) along cracks and seams; moderately alkaline, violently effervescent.
TYPE LOCATION: Dallas County, Alabama. Approximately 0.6 mile west of the Black Belt Substation office, about 1,000 feet east and 75 feet north of the SE corner of the SW1/4, Sec. 2, T. 17 N., R. 8 E.
RANGE IN CHARACTERISTICS: Solum thickness and depth to chalk ranges from 20 to 40 inches. The calcium carbonate equivalent ranges from 40 to 65 percent. Non-carbonatic clay content ranges from 18 to 35 percent. Reaction is neutral to moderately alkaline in the surface layer, and from slightly to moderately alkaline in the rest of the profile.
The A or Ap horizon has hue of 10YR to 5Y, value of 2 to 5, and chroma of 1 to 3. Some pedons have cobbly or very cobbly silt loam or silty clay loam surface layers with 7 to 74 percent by volume of cobbles 3 to 10 inches in size and 4 to 15 percent by volume of chalk fragments or calcium carbonate nodules smaller than 3 inches. Texture is silt loam, silty clay loam, silty clay, or clay with up to 10 percent by volume of chalk fragments. Soft masses and/or concretions and nodules of calcium carbonate range from few to many.
The Bw horizon, where present, has hue of 10YR to 5Y, value of 4 to 7, and chroma of 3 to 8. Iron accumulations in shades of yellow and brown range from none to common. Texture is silty clay loam, silty clay, or clay.
The upper part of the Bk horizon has hue of 10YR to 5Y, value of 4 to 7, and chroma of 3 to 6. Iron accumulations in shades of yellow and brown range from none to common. Soft masses and concretions of calcium carbonate range from few to many. Texture is silty clay loam, silty clay, or clay with 0 to 15 percent by volume of chalk fragments.
The lower part of the Bk horizon and the BC horizon, where present, has hue of 10YR to 5Y, value of 5 to 7, and chroma of 2 to 6. Redoximorphic features in shades of yellow, brown and gray range from few to many. Texture is silty clay loam, silty clay, or clay or their channery analogues with 2 to 25 percent by volume of chalk fragments and/or calcium carbonate nodules.
The BC or C horizon, where present, has the same range of colors and textures as the lower Bk horizon. Thin laminations of soft chalk may be present in some pedons.
The Cr horizon is composed of level-bedded chalk or soft limestone with platy rock structure. It can be excavated with difficulty with hand tools, and is rippable by mechanized equipment.
COMPETING SERIES: The
Keiffer series is the only known series in the same family. The well drained Keiffer soils are very deep to chalk.
GEOGRAPHIC SETTING: Sumter soils are on sloping topography in the Blackland Prairie, but slopes range to steep at its contact with the Southern Coastal Plain. Slopes range from 1 to 40 percent. They formed in marly clays and chalk. The climate is humid subtropical. Near the type location, the average annual temperature is about 67 degrees F. and average annual precipitation is about 51 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the
Binnsville,
Brooksville,
Demopolis,
Houston,
Kipling,
Maytag,
Okolona,
Oktibbeha,
Vaiden, and
Watsonia series. The well drained Binnsville, Demopolis, and Watsonia soils have sola less than 20 inches thick to chalk. Brooksville, Houston and Okolona series have less than 40 percent calcium carbonate in the profile. In addition, the very poorly drained Brooksville series is on lower positions and is very deep. The moderately well drained Houston soils are on less sloping areas and have more clay in the control section. The well drained Okolona soils are on less sloping areas, are very deep and have intersecting slickensides in the solum. Kipling, Oktibbeha, and Vaiden soils have acid subsoils, are very deep and have more clay in the control section. In addition, the somewhat poorly drained Kipling soils are on similar positions, the moderately well drained and poorly drained Oktibbeha and Vaiden soils are on less sloping areas. The well drained Maytag soils are on less sloping areas, have vertic properties and more clay in the subsoil.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Most of the less sloping areas of Sumter soil
are cleared and used for growing pasture, hay, and small grain. Some areas are in red cedar. Steeper areas are in native woodland, mainly oaks and red cedar.
DISTRIBUTION AND EXTENT: Blackland Prairies of Alabama, Arkansas, Georgia, Mississippi, and eastern Texas. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Auburn, Alabama.
SERIES ESTABLISHED: Sumter County, Georgia; 1910.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from the surface to a depth of 10 inches (Ap1 and Ap2 horizons).
Accumulation of carbonates - the zone from 10 inches to a depth of 28 inches (Bk1 and Bk2 horizons).
Rendollic features - have greater that 40 percent carbonates in and below the cambic horizon (Bk1 and Bk2 horizons).
Sumter soils are in MLRAs 135A and to a lesser extent in 86A and 135B.
ADDITIONAL DATA: Laboratory data is available on the National Soil Survey website at: http://ncsslabdatamart.sc.egov.usda.gov/querypage.aspx
Laboratory data was provided by Auburn University, Soil Characterization Laboratory, Auburn AL and the National Soil Survey Laboratory, Lincoln, NE.
National Cooperative Soil Survey
U.S.A.