LOCATION SMITHBORO SCEstablished Series
TAXONOMIC CLASS: Fine, kaolinitic, thermic Aeric Paleaquults
TYPICAL PEDON: Smithboro silt loam--cultivated (Colors are for most soils, unless otherwise indicated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, grayish brown (10YR 5/2), dry; weak fine granular structure; very friable; many fine and medium roots; strongly acid; abrupt smooth boundary. (2 to 10 inches thick)
Bt--6 to 17 inches; variegated brownish yellow (10YR 6/6) and light brownish gray (10YR 6/2) clay loam; few medium distinct yellowish red (5YR 4/6) masses of iron accumulation; strong medium subangular blocky structure; very firm; moderately sticky, moderately plastic; common fine roots; few fine pores; 55 percent prominent light brownish gray (10YR 6/2) clay films on faces of peds; very strongly acid; gradual wavy boundary. (5 to 18 inches thick)
Btg1--17 to 31 inches; gray (10YR 6/1) clay loam; moderate medium subangular blocky structure; firm, moderately sticky, moderately plastic; few fine roots; few fine pores; 35 percent faint light brownish gray (10YR 6/2) clay films on faces of peds; many medium and coarse distinct yellowish brown (10YR 5/6), common medium prominent red (2.5YR 4/8), and few medium faint pale brown (10YR 6/3) masses of oxidized iron; very strongly acid; gradual wavy boundary.
Btg2--31 to 44 inches; gray (10YR 6/1) clay loam; moderate medium subangular blocky structure; firm, moderately sticky, moderately plastic; few fine roots; few fine pores; 15 percent faint light brownish gray (10YR 6/2) clay films on faces of peds; very strongly acid; gradual wavy boundary.
Btg3--44 to 62 inches; variegated gray (10YR 6/1) and yellowish brown (10YR 5/8) clay; moderate medium subangular blocky structure; firm, moderately sticky, moderately plastic; few fine pores; 15 percent faint light brownish gray (10YR 6/2) clay films on faces of peds; common medium distinct strong brown (7.5YR 5/6) and few medium prominent yellowish red (5YR 4/6) masses of oxidized iron; few fine flakes of mica; few fine concretions; extremely acid; gradual wavy boundary.
Btg4--62 to 80 inches; variegated gray (10YR 6/1) and yellowish brown (10YR 5/8) clay; weak coarse subangular blocky structure; firm, moderately sticky, moderately plastic; 1 percent faint light brownish gray (10YR 6/2) clay films on faces of peds; few faint clay films on faces of peds; common medium faint light brownish gray (10YR 6/2) masses of iron accumulation; extremely acid.
TYPE LOCATION: Marion County, South Carolina; about 2 miles west of Marion in idle field about 400 feet north of U. S. Highway 76.
RANGE IN CHARACTERISTICS:
Thickness of the surface and subsurface layers: 4 to 19 inches
Depth to top of the argillic horizon: 4 to 19 inches
Depth to the base of the argillic horizon: 60 to more than 80 inches
Depth to bedrock: Greater than 80 inches
Depth to seasonal high water table: 6 to 18 inches, December to March
Rock Fragment content: 0 to 5 percent, by volume
Soil reaction: Extremely acid to strongly acid throughout, unless limed
Other features--Averages more than 30 percent silt in the particle-size control section
RANGE OF INDIVIDUAL HORIZONS:
Ap horizon or A horizon (where present):
Color--hue of 10YR, value of 3 to 5, chroma of 1 or 2
Texture--sandy loam, fine sandy loam, very fine sandy loam, loam, or silt loam
E horizon (where present):
Color--hue of 10YR or 2.5Y, value of 4 to 6, chroma of 1 to 3
Texture--sandy loam, fine sandy loam, very fine sandy loam, loam, or silt loam
BA or BE horizon (where present):
Color--hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 3 to 6
Texture--loam, sandy clay loam, clay loam, or silty clay loam
Redoximorphic features (where present)--masses of oxidized iron in shades of red, yellow, or brown and iron depletions in shades of brown, yellow, olive, or gray
Bt horizon:
Color--hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 3 to 6, or is variegated in shades of these colors
Texture--clay loam, silty clay loam, silty clay, or clay
Redoximorphic features--masses of oxidized iron in shades of red, yellow, or brown and iron depletions in shades of brown, yellow, olive, or gray
Btg horizon:
Color--hue of 10YR or 2.5Y, value of 5 to 7, chroma of 1 or 2, or is neutral with value of 4 to 8, or is variegated in shades of these colors
Texture--clay loam, silty clay loam, silty clay, or clay
Redoximorphic features--masses of oxidized iron in shades of red, yellow, or brown and iron depletions in shades of brown, yellow, olive, or gray
Cg horizon (where present):
Color--hue of 10YR to 5Y, value of 4 to 8, chroma of 1 or 2, or is neutral with value of 4 to 8, or is variegated in shades of these colors
Texture--loam, clay loam, or silty clay loam
Redoximorphic features--masses of oxidized iron in shades of red, yellow, or brown and iron depletions in shades of brown, yellow, olive, or gray
COMPETING SERIES:
Dunbar soils--have less than 30 percent silt in the particle-size control section
GEOGRAPHIC SETTING:
Landscape: Lower and middle coastal plain
Landform: Marine terraces, flats
Geomorphic Component: treads, talfs
Parent Material: Marine deposits, fluviomarine deposits
Slope: 0 to 2 percent
Elevation (type location): 40 to 170 feet
Mean Annual Air Temperature: 57 to 70 degrees
Mean Annual Precipitation: 35 to 55 inches
Frost Free Period: 190 to 245 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Byars soils--have an umbric epipedon
Cantey soils--do not have chroma of 3 or more within 30 inches of the soil surface
Coxville soils--do not have chroma of 3 or more within 30 inches of the soil surface
Dothan soils--have 18 to 35 percent clay in the particle-size control section
Dunbar soils--have less than 30 percent silt in the particle-size control section
Duplin soils--have a dominant chroma higher than 2 between the base of the A horizon and 30 inches
Goldsboro soils--have 18 to 35 percent clay in the particle-size control section
Lynchburg soils--have 18 to 35 percent clay in the particle-size control section
Persanti soils---have a dominant chroma higher than 2 between the base of the A horizon and 30 inches
Summerton soils--soils do not have chroma 2 mottles within 30 inches of the surface
Varina soils--soils do not have chroma 2 mottles within 30 inches of the surface
DRAINAGE AND PERMEABILITY:
Depth Class: Very deep
Drainage Class (Agricultural): Somewhat poorly drained
Internal Free Water Occurrence: Very shallow or shallow, transitory to common
Flooding Frequency and Duration: None
Ponding Frequency and Duration: None
Index Surface Runoff: Negligible to medium
Permeability: Slow
Shrink-swell Potential: Low
USE AND VEGETATION:
Major Uses: About 60 percent of the area is in woodland and the remainder is in pasture or cropland
Dominant Vegetation: Where cultivated--corn, soybeans, small grain, cotton, and tobacco. Where wooded--loblolly and longleaf pine, oaks, sweet gum, black gum, and hickory.
DISTRIBUTION AND EXTENT:
Distribution: South Carolina and Virginia, and possibly Georgia and North Carolina
Extent: Moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Marion County, South Carolina; 1975
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--the zone from the surface of the soil to 6 inches (Ap horizon)
Argillic horizon--the zone from 6 to 75 inches (Bt, Btg1, Btg2, Btg3, and Btg4 horizons)
ADDITIONAL DATA: Smithboro soils were formerly mapped as Lenoir or Wahee. Both of these soils have mixed mineralogy. Laboratory data from Clemson University indicates kaolinitic mineralogy for the series.
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation SC0040 SMITHBORO 0-2 57-70 190-245 38-52 40-170SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness SC0040 NONE 0.5-1.5 APPARENT DEC-MAR >80 -
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- SC0040 0-6 SL FSL 0- 0 98-100 5-15 1-3 SC0040 0-6 L 0- 0 100-100 10-20 2-4 SC0040 0-6 SIL VFSL 0- 0 100-100 10-20 2-4 SC0040 6-75 C CL SIC 0- 0 100-100 35-60 3-8
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll SC0040 0-6 3.5-5 0.5-3.0 0-0 0.6-2.0 LOW SC0040 0-6 3.5-5.5 0.5-3.0 0-0 0.6-2.0 LOW SC0040 0-6 3.5-5.5 0.5-3.0 0-0 0.6-2.0 LOW SC0040 6-75 3.5-5.5 0.0-0.5 0-0 0.06-0.2 MODERATE