LOCATION WILKES NC+AL GA SC VA
Established Series
RAG-DTA/Rev. RBT
01/2021
WILKES SERIES
MLRA(s): 136
SSRO Responsible: Raleigh, North Carolina
Depth class: Shallow
Agricultural Drainage Class: Well drained
Permeability: Moderately slow to slow
Index Surface Runoff: High to very high
Parent Material: Residuum weathered from intermediate and mafic crystalline rocks
Shrink-swell potential: High
Slope: 4 to 60 percent
TAXONOMIC CLASS: Loamy, mixed, active, thermic, shallow Typic Hapludalfs
TYPICAL PEDON: Wilkes sandy loam--wooded. (Colors are for moist soil unless otherwise stated.)
Oi--0 to 2 inches (0 to 5 centimeters); slightly decomposed plant material (mixed hardwood and pine forest litter).
Oe--2 to 3 inches (5 to 8 centimeters); moderately decomposed plant material.
A--3 to 6 inches (8 to 15 centimeters); grayish brown (2.5Y 5/2) sandy loam; moderate medium granular structure; very friable; common fine and medium roots; common fine and medium quartz pebbles; strongly acid; abrupt smooth boundary. (2 to 6 inches, 5 to 15 centimeters thick)
E--6 to 9 inches (15 to 23 centimeters); light brownish gray (2.5Y 6/2) sandy loam; moderate medium and coarse granular structure; very friable; common fine and medium roots; common fine strong brown fragments of weathered rocks; common fine and medium pebbles; strongly acid; abrupt smooth boundary. (0 to 5 inches, 0 to 13 centimeters thick)
Bt--9 to 13 inches (23 to 33 centimeters); yellowish brown (10YR 5/6) clay; common fine prominent black, green, and faint strong brown bodies, all of which are assumed to be partially weathered primary minerals; weak coarse angular blocky structure; firm, sticky, plastic; few fine roots; few fine pores; common faint clay films on faces of peds; few medium pebbles; A horizon material in old root channels; slightly acid; clear wavy boundary. (3 to 8 inches, 8 to 20 centimeters thick)
Bt/C--13 to 16 inches (33 to 41 centimeters); yellowish brown (10YR 5/6) clay loam; weak coarse subangular blocky structure; firm, sticky, plastic; common faint clay films on faces of peds(Bt part); common fine prominent black and few fine distinct gray bodies and common thin green bands of partially weathered primary minerals; relic platy structure (C part); common hard schist fragments; slightly acid; abrupt wavy boundary. (0 to 6 inches, 0 to 15 centimeters thick.)
Cr--16 to 51 inches (41 to 130 centimeters); soft, yellowish brown, green, black, and gray saprolite which crushes to loam; relic platy rock structure; firm; few fine roots in upper part; few large roots in rock fractures; few distinct clay films line vertical cracks; common fine and medium schist fragments; neutral; abrupt wavy boundary. (24 to 42 inches, 61 to 107 centimeters thick)
R--51 inches (130 centimeters); hard schist bedrock.
TYPE LOCATION: Durham County, North Carolina; 1,915 feet southeast of the intersection of Route 98 and Boyce Mill Road near the Durham-Wake County line and 2,060 feet northwest of the road intersection of Boyce Mill Road and Old Creedmor Road and 90 feet due east off Boyce Mill Road in a wooded area; USGS Bayleaf topographic quadrangle; Latitude 35 degrees 58 minutes 40.90 seconds N., and Longitude 78 degrees 42 minutes 52.65 seconds W.
RANGE IN CHARACTERISTICS:
Solum thickness: 10 to 25 inches (25 to 64 centimeters)
Depth to soft bedrock: 10 to 20 inches (25 to 50 centimeters)
Depth to hard bedrock: 40 to more than 60 inches (100 to 150+ centimeters)
Content and size of rock fragments: 0 to 50 percent in the A horizon consisting of gravel, cobble and stone size fragments and 0 to 35 percent in the Bt horizons.
Dark concretions: none to common.
Soil reaction: strongly acid through slightly acid in the A and E horizons if present, and moderately acid through mildly alkaline in the lower horizons
Clay content: averages 18 to 35 percent
Range of Individual Horizons:
The A or Ap horizon:
Color = hue of 7.5YR to 2.5Y, value of 3 to 5, and chroma of 2 to 6
Texture (fine earth fraction) = sandy loam, fine sandy loam, or loam (some eroded mapunit phases are sandy clay loam or clay loam)
E horizon, where present:
Color = hue of 10YR to 2.5Y, value of 4 to 6, and chroma of 2 to 8
Texture (fine earth fraction) = sandy loam, fine sandy loam, or loam
Bt horizon:
Color = hue of 5YR to 2.5Y, value of 4 to 6, and chroma of 4 to 8. Mottles, bodies, or streaks of black, greenish, grayish, or whitish saprolite or primary minerals are few to common in most pedons
Texture (fine earth fraction) = loam, sandy clay loam, clay loam, or clay
Thin transitional horizons are present in most pedons.
BC or CB horizon:
Color = hue of 5YR to 2.5Y, value of 4 to 8, and chroma of 3 to 8. Mottles, bodies, or streaks of black, greenish, grayish, or whitish saprolite or primary minerals are none to common.
Texture (fine earth fraction) = loam, sandy clay loam, clay loam, or clay
C horizon (if it occurs):
loamy saprolite of intermediate or mafic crystalline rock. It is black, greenish, brownish, or grayish in color
Cr horizon:
Type of bedrock - soft, weathered highly fractured intermediate or mafic crystalline rock
R layer (if it occurs):
Type of bedrock - hard unweathered to slightly weathered intermediate or mafic crystalline rock
COMPETING SERIES:
There are no known competing series in this family. Similar soils in related families include the
Goldston,
Louisa,
Louisburg,
Montevallo, and
Poindexter.
Goldston soils have more than 35 percent rock fragments in the control section.
Louisa soils have cyclic pedons, have lower base saturation and contain more mica throughout the solum.
Louisburg soils are very deep to bedrock.
Montevallo soils have more than 35 percent rock fragments in the control section.
Poindexter soils have a paralithic contact at depths of more than 20 inches (50 centimeters).
GEOGRAPHIC SETTING:
Landscape: Piedmont
Landform: Narrow ridges, steep ridge sides, and hills
Hillslope position: Summit, shoulder, back slope, and footslope
Parent Material: Residuum weathered from diorite, hornblende, schist, and related intermediate and mafic crystalline rocks
Elevation (type location): 393 feet
Mean Annual Air Temperature: 58 - 65 degrees F. (14 - 18 degrees C.)
Mean Annual Precipitation: 37 - 60 inches (94 - 152 centimeters)
Frost Free period: 180 to 240 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Coronaca - are deep soils with 35 to 60 percent clay throughout.
Crawfordville - are moderately deep soils with clay content of 35 to 60 percent.
Cullen - have 60 percent or more clay throughout the particle size control section.
Enon - soils are very deep to weathered bedrock.
Gaston - soils are very deep to weathered bedrock.
Iredell - have soils with paralithic contacts 40 inches (100 centimeters) or more deep.
Mecklenburg - soils are very deep to bedrock and have 35 to 60 percent clay in the particle size control section.
Mocksville - soils are very deep to bedrock.
Pittsboro - soils are moderately deep to weathered bedrock.
Poindexter - soils are moderately deep to weathered bedrock.
Sedgefield - soils are very deep to bedrock and have 35 to 60 percent clay in the particle size control section.
Virgilina - have smectitic mineralogy and have 35 to 60 percent clay in the particle size control section.
Winnsboro - soils have a paralithic contact between 40 to 60 inches (100 to 150 centimeters).
Wynott - soils have a paralithic contact between 40 to 60 inches (100 to 150 centimeters).
DRAINAGE AND PERMEABILITY:
Drainage Class (Agricultural): Well drained
Surface runoff: High to very high
Permeability: Moderately slow to slow
USE AND VEGETATION:
Major Uses: Woodland, pasture and cropland (mainly small grain, lespedeza, corn and tobacco).
Dominant trees are shortleaf, loblolly, and Virginia pines, eastern red cedar, blackjack oak, and post oak.
DISTRIBUTION AND EXTENT:
Distribution: Thermic Piedmont area of Alabama, North Carolina, Georgia, South Carolina, and Virginia.
Extent: Moderate The series is of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Jasper County, Georgia; 1916.
REMARKS: Diagnostic horizons and features recognized in the typical pedon are:
This revision included horizon depth changes to include O horizons for the type location.
Ochric epipedon-the zone from the soil surface to a depth of 9 inches (0 to 23 centimeters) (O, A, and E horizons).
Argillic horizon--the zone between depths of 9 and 13 inches (23 to 33 centimeters) (Bt horizon).
Paralithic contact--the upper boundary of the Cr horizon at a depth of 16 inches (41 centimeters).
ADDITIONAL DATA:
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation NC0031 WILKES 2-60 57-65 180-240 37-60 250-900
NC0134 WILKES 2-60 57-65 180-240 37-60 250-900
SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness NC0031 NONE >6.0 - 10-20 SOFT
NC0134 NONE >6.0 - 10-20 SOFT
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC-
NC0031 0-9 SL L FSL 0-10 80-100 5-20 3-15
NC0031 0-9 SCL CL 0-10 90-100 20-35 10-25
NC0031 0-9 GR-SL GR-L GR-FSL 5-15 60- 75 5-20 3-15
NC0031 9-16 CL C SCL 0-10 80-100 20-45 10-30
NC0031 16-51 WB - - - -
NC0134 0-9 STV-SL STV-L 3-15 60-75 5-20 3-15
NC0134 0-9 STX-SL STX-L 10-20 60-75 5-20 3-15
NC0134 9-16 SICL ST-C ST-SCL 10-25 80-100 20-45 10-30
NC0134 16-51 WB - - - -
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll
NC0031 0-9 5.1-6.5 0.5-2.0 0-0 2.0-6.0 LOW
NC0031 0-9 5.1-6.5 0.5-1.0 0-0 0.6-2.0 LOW
NC0031 0-9 5.1-6.5 0.5-2.0 0-0 2.0-6.0 LOW
NC0031 9-16 6.1-7.8 0.0-0.5 0-0 0.2-0.6 MODERATE
NC0031 16-51 - - - -
NC0134 0-9 5.1-6.5 0.5-2.0 0-0 2.0-6.0 LOW
NC0134 0-9 5.1-6.5 0.5-2.0 0-0 2.0-6.0 LOW
NC0134 9-16 5.6-7.8 0.0-0.5 0-0 0.2-0.6 MODERATE
NC0134 16-51 - - - -
National Cooperative Soil Survey
U.S.A.