LOCATION DUNBAR NC+AL FL GA SC VAEstablished Series
TAXONOMIC CLASS: Fine, kaolinitic, thermic Aeric Paleaquults
TYPICAL PEDON: Dunbar sandy loam - cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; dark gray (10YR 4/1) sandy loam; weak medium and fine granular structure; very friable; many fine roots; strongly acid; clear smooth boundary. (5 to 12 inches thick)
Bt--8 to 14 inches; light olive brown (2.5Y 5/4) clay loam; moderate medium subangular blocky structure; hard, firm, plastic, sticky; many fine roots; few fine pores; thin patchy clay films; few medium distinct dark gray (10YR 4/1) iron depletions in the matrix; very strongly acid; gradual wavy boundary. (5 to 10 inches thick)
Btg1--14 to 20 inches; grayish brown (2.5Y 5/2) sandy clay; moderate medium subangular blocky structure; firm, hard, plastic, sticky; few fine roots and pores; thin continuous clay films on faces of peds; many medium distinct light olive brown (2.5Y 5/4) masses of iron accumulation on faces of peds; very strongly acid; gradual wavy boundary.
Btg2--20 to 42 inches; gray (10YR 5/1) sandy clay; moderate medium subangular blocky structure; hard, firm, sticky, plastic; few fine roots and pores; thin patchy clay films on faces of peds; common medium distinct yellowish brown (10YR 5/8) and yellowish red (5YR 5/8) masses of iron accumulation on faces of peds; very strongly acid; gradual wavy boundary.
Btg3--42 to 62 inches; gray (10YR 6/1) sandy clay; moderate medium subangular blocky structure; firm; few fine roots and pores; thin patchy clay films on faces of peds; few medium distinct yellowish brown (10YR 5/4) and brown (10YR 5/3) masses of iron accumulation on faces of peds; very strongly acid; gradual wavy boundary. (Combined thickness of the Btg horizon is 40 to 75 inches.)
Cg--62 to 92 inches; light gray (10YR 7/1) sandy clay with a few pockets of sandy clay loam; massive; firm; very strongly acid.
TYPE LOCATION: Robeson County, North Carolina; 4 miles south of Red Springs; 1/4 mile east on NC 2ll; 40 feet south of state road 1507.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 inches. The soil is strongly or very strongly acid unless limed.
The A or Ap horizon has hue of 10YR to 5Y, value of 4 or 5, and chroma of 1 or 2. Where the A or Ap horizon is less than 10 inches thick, colors include value of 2 or 3. The A or Ap horizon is sandy loam, fine sandy loam, or loam.
The E horizon, where present, has hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 to 4, or is neutral. It is sandy loam, fine sandy loam, or loam.
The Bt horizon has hue of 7.5YR to 5Y, value of 4 to 6, and chroma of 3 to 8. Iron accumulations and depletions in shades of red, yellow, brown or gray are present. The Bt horizon is sandy clay, clay loam, or clay. The clay content averages between 35 and 55 percent, and silt content is less than 30 percent.
The Btg horizon has hue of 7.5YR to 5Y, value of 4 to 6, and chroma of 1 or 2, or is neutral. Iron accumulations in shades of red, yellow, or brown are present. The Btg horizon is sandy clay, clay loam, or clay. The clay content averages between 35 and 55 percent, and silt content is less than 30 percent.
The BCg horizon, where present, has hue of 7.5YR to 5Y, value of 4 to 6, and chroma of 1 or 2, or is neutral. Iron accumulations in shades of red, yellow, or brown are present. The BCg horizon is sandy clay, sandy clay loam, clay loam, or clay.
The Cg horizon is gray or light gray loamy sand, sandy loam, sandy clay loam, or sandy clay.
COMPETING SERIES: These are the Bethera, Bladen, Cantey, Coxville, Craven, Duplin, Exum, Grady, Leaf, Lenoir, Lynchburg, Nahunta, Persanti, Rains, and Wahee series. Bethera, Bladen, Cantey, Coxville, Grady, Leaf, and Rains soils lack dominant chromas of 3 or more between the A1 or Ap and thirty (30) inches of the soil surface. In addition, Bethera, Bladen, and Leaf soils have mixed mineralogy. Craven, Duplin, Exum, and Persanti soils have better drainage, and in addition Craven soils have mixed mineralogy and Exum soils are fine-silty. Lenoir, Lynchburg, Nahunta, and Wahee soils have similar drainage. Lenoir and Wahee soils have mixed mineralogy, and in addition Wahee soils contain more than 10 percent weatherable minerals in the sand and silt fraction. Lynchburg and Nahunta soils have 18 to 35 percent clay.
GEOGRAPHIC SETTING: Dunbar soils are on broad, smooth interstream divides mainly in the middle and upper Coastal Plains. Slope gradients are 0 to 5 percent. They formed in clayey Coastal Plain deposits. Near the type location the mean annual temperature is 63 degrees F., and mean annual precipitation is 46 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing Coxville, Duplin, Lynchburg, and Rains series, these are the Faceville, Goldsboro, Marlboro, Norfolk, and Wagram series. Faceville, Marlboro, Norfolk, and Wagram soils are well drained and are on the dryer parts of the landscape. In addition, Wagram soils have thick sandy surface layers. Goldsboro soils also have better drainage than the Dunbar soils, and they occur in intermediate positions between the Dunbar soils and the well drained soils on the landscape.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderately slow permeability. The water table is 1 to 2.5 feet from the soil surface for significant periods of the year.
USE AND VEGETATION: About 60 percent is in cropland and the remainder is in forest. Principal crops are corn, soybeans, truck crops, cotton, tobacco, peanuts, small grain, and grasses. Forests consist of oaks, sweetgum, blackgum, dogwood, elm, longleaf and loblolly pines, and an understory of gallberry and other shrubs.
DISTRIBUTION AND EXTENT: Alabama, Florida, Georgia, North Carolina, South Carolina, and Virginia. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Marlboro County, South Carolina; 1917.
REMARKS: The Dunbar series formerly was classified as Red-Yellow Podzolic soils intergrading toward Low-Humic Gley soils.
ADDITIONAL DATA: None
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation
NC0046 DUNBAR 0- 5 59- 66 190-240 38- 50 25- 450
SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness NC0046 NONE 1.0-2.0 APPARENT NOV-MAY 60-60SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- NC0046 0- 8 SL FSL L 0- 0 100-100 5-27 2- 7 NC0046 0- 8 LS LFS 0- 0 90-100 10-15 3- 6 NC0046 8-14 L SCL CL 0- 0 0- 0 0- 0 2- 5 NC0046 14-80 SC CL C 0- 0 0- 0 0- 0 4- 7
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll NC0046 0- 8 4.5- 5.5 2.-4. 0- 0 2.0- 6.0 LOW NC0046 0- 8 4.5- 5.5 2.-4. 0- 0 6.0- 20 LOW NC0046 8-14 4.5- 5.5 0.-1. 0- 0 0.2- 0.6 LOW NC0046 14-80 4.5- 5.5 0.-.5 0- 0 0.2- 0.6 MODERATE