LOCATION WILBANKS NC
Established Series
Rev. DLN
10/2021
WILBANKS SERIES
The Wilbanks series consists of very poorly drained slowly permeable soils in the Middle and Lower Coastal Plain. These soils formed in stratified clayey and loamy fluvial or marine sediments. They have a thin grayish brown silt loam horizon over thick black and very dark gray clay and silty clay subsurface layers and grayish stratified C horizons. Slopes are less than 2 percent.
TAXONOMIC CLASS: Fine, mixed, semiactive, acid, thermic Cumulic Humaquepts
TYPICAL PEDON: Wilbanks silt loam--forested. (Colors are for moist soils unless otherwise stated.)
Oi--0 to 1 inch; organic litter of deciduous trees and shrubs.
A1--1 to 6 inches; grayish brown (10YR 5/2) silt loam; few fine prominent yellowish red mottles; weak medium subangular blocky structure; friable; many fine, medium, and coarse roots and pores; very strongly acid; abrupt smooth boundary. (0 to 10 inches thick)
A2--6 to 17 inches; black (N 2/0) clay; common coarse distinct dark grayish brown (10YR 4/2) mottles; weak medium subangular blocky structure; firm, sticky, and plastic; many fine and medium roots and pores; very strongly acid; gradual wavy boundary. (8 to 16 inches thick)
A3--17 to 23 inches; very dark gray (10YR 3/1) silty clay; weak medium subangular blocky structure; firm, slightly sticky, plastic; many fine and medium roots and pores; very strongly acid; gradual smooth boundary. (5 to 12 inches thick)
A4--23 to 40 inches; black (N 2/0) clay; weak medium subangular blocky structure in upper part grading to massive in lower part; firm, slightly sticky, plastic; common fine and medium roots and pores; very strongly acid; clear smooth boundary. (11 to 20 inches thick)
2Cg1--40 to 53 inches; grayish brown (10YR 5/2) loam; common fine and medium distinct reddish brown (5YR 4/4) mottles; massive, friable; few fine and medium roots and pores; very strongly acid; clear smooth boundary. (5 to 20 inches thick)
2Cg2--53 to 59 inches; dark grayish brown (10YR 4/2) sandy clay loam; massive; friable; few fine and medium roots and pores; very strongly acid; clear smooth boundary. (5 to 20 inches thick)
2Cg3--59 to 64 inches; grayish brown (10YR 5/2) sandy loam; common medium and coarse distinct black (10YR 2/1) mottles; massive; friable; few fine and medium roots and pores; very strongly acid; clear smooth boundary. (5 to 20 inches thick)
2Cg4--64 to 73 inches; grayish brown (10YR 5/2) loamy sand; massive; very friable; neutral; abrupt smooth boundary. (5 to 20 inches thick)
3Cg5--73 to 79 inches; greenish gray (5G 5/1) silty clay loam; massive; firm; neutral.
TYPE LOCATION: Wilson County, North Carolina; 1.25 mile west of intersection of U.S. 30l and NC 42 on NC 42 to intersection of NC 42 Bypass; 0.95 mile north on NC Bypass; 600 feet east of NC 42 Bypass on dirt road; 25 feet south of dirt road.
RANGE IN CHARACTERISTICS: The soil ranges from strongly acid to extremely acid in the 10 to 40 inch control section and in the surface layer except where the soil has been limed. The C horizons below 40 inches range from very strongly acid to neutral. Organic matter content in the umbric epipedon ranges from 2 to 12 percent. The 10 to 40 inch control section averages more than 35 percent clay.
The A1 horizon, where present, has hue of 10YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 1 or 2. It is loam, silt loam, or fine sandy loam.
The A2, A3, and A4 horizons have hue of 10YR, 2.5Y, or 5Y, value of 2 or 3, and chroma of 1 or 2; or hue of N, value of 2 or 3. It is clay loam, silty clay, or clay and ranges in thickness from 24 to 48 inches.
An AC horizon, where present, has hue of 10YR, value of 3 or 4, and chroma of 1 or 2. Mottles are in shades of gray or brown. It is loamy sand, loamy fine sand, or sandy loam in addition to the named textures for the umbric epipedon.
The Cg horizon is stratified grayish or brownish sand, loamy sand, sandy loam, loam, sandy clay loam, clay loam, silty clay loam, silty clay, sandy clay, or clay. Buried A horizons are common. Marl deposits, where present, are 5 to 8 feet below the surface of the soil.
COMPETING SERIES: These are the
Ballahack,
Cape Fear,
Chastain,
Johnston,
Santee,
Toxaway, and
Wasda series. Ballahack, Johnston, and Toxaway soils have less than 35 percent clay in the 10 to 40 inch control section. In addition, Toxaway soils have temperatures less than 59 degrees F. Cape Fear and Santee soils have argillic horizons and umbric epipedons that are less than 24 inches thick. Chastain soils are kaolinitic and lack umbric epipedons. Wasda soils have histic epipedons and they contain less clay.
GEOGRAPHIC SETTING: Wilbanks soils are on flood plains, low-lying terraces, and in old estuaries in the Middle and Lower Coastal Plain. These soils formed in stratified clayey and loamy fluvial or marine sediments. Slopes are less than 2 percent. Mean annual temperature is 60 degrees F. and average annual precipitation is about 47 inches near the type location.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing
Ballahack,
Cape Fear, and
Johnston series, these are the
Bibb,
Leaf, and
Myatt series. Bibb soils lack umbric epipedons. Leaf and Myatt soils have argillic horizons and lack umbric epipedons.
DRAINAGE AND PERMEABILITY: Very poorly drained; slow to ponded runoff; slow permeability. The water table is at or near the surface for three to five months in most years. Wilbanks soils are flooded frequently for brief periods.
USE AND VEGETATION: Most of the known areas of this soil are in forests of water tolerant hardwoods. Native species include southern baldcypress, sweetgum, water oak, red maple, green ash, swamp white oak, and willow oak. Some understory plants are greenbrier, switchcane, honeysuckle, sweetbay magnolia, and sourwood. A few areas have been cleared, drained, and are used mainly for growing corn, soybeans, and pasture
DISTRIBUTION AND EXTENT: Coastal Plain of North Carolina and possibly Virginia and South Carolina. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Wilson County, North Carolina, 1980.
REMARKS: The Wilbanks series was formerly mapped in the Johnston series and classified in the Humic Gley great soil group. The soil horizon depths were revised on 10/2021 to ensure the description began at the soil surface.
TABULAR SERIES DATA:
ADDITIONAL DATA: Laboratory Data, North Carolina State University, one pedon from Wilson County, North Carolina.
3 Sand Silt
Clay O.C.
A2 5-16@ 10.9 21.4
67.7 2.90
A3 16-22@ 13.3 42.6
44.1 4.29
A4 22-39@ 25.3 26.1
48.5 1.73
Cg1 39-52@ 25.6 48.2
26.2 .85
Mineralogy:
VFS Quartz Mica Feldspar
HVY+Opg Other
Cg1 39-52@ 83.1 5.3 10.2
0.6 0.8
CLAY
X-ray diffraction traces were interpreted as 50% kaolinite and 50%
slightly interlayered vermiculite.
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation
NC0101 WILBANKS 0- 2 59- 65 190-250 45- 58 5- 170
SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness
NC0101 FREQ 0-1.0 APPARENT NOV-MAY 60-60
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC-
NC0101 0- 6 L SIL FSL 0- 0 100-100 5-25 3- 10
NC0101 6-40 SIC C CL 0- 0 100-100 35-55 8- 15
NC0101 40-79 VAR - - - -
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll
NC0101 0- 6 3.5- 5.5 2.-5. 0- 0 0.6- 2.0 LOW
NC0101 6-40 3.5- 5.5 1.-3. 0- 0 0.06- 0.6 MODERATE
NC0101 40-79 - - - -
National Cooperative Soil Survey
U.S.A.