Established Series


The Wakulla series consists of very deep, somewhat excessively drained, rapidly permeable soils that formed in sandy Coastal Plain sediments on uplands and stream terraces. Near the type location, mean annual air temperature is 62 degrees F. and mean annual precipitation is 49 inches. Slopes range from 0 to 15 percent.

TAXONOMIC CLASS: Siliceous, thermic Psammentic Hapludults

TYPICAL PEDON: Wakulla sand--on a 3 percent slope in cultivated field at an elevation of 170 feet. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 7 inches; dark grayish brown (10YR 4/2) sand; single grained; loose; few medium and fine roots; moderately acid; abrupt wavy boundary. (3 to 10 inches thick)

E--7 to 24 inches; light yellowish brown (10YR 6/4) sand; single grained; loose; few fine roots; strongly acid; clear wavy boundary. (10 to 25 inches thick)

Bt--24 to 42 inches; strong brown (7.5YR 5/8) loamy sand; weak fine granular structure; very friable; few fine roots; grains of sand bridged with clay; strongly acid; gradual wavy boundary. (6 to 30 inches thick)

C1--42 to 56 inches; yellowish brown (10YR 5/8) sand; single grained; loose; very strongly acid; gradual wavy boundary.

C2--56 to 83 inches; yellow (10YR 7/6) sand; single grained; loose; about half of the sand grains are uncoated; very strongly acid.

TYPE LOCATION: Robeson County, North Carolina; 2 1/4 miles west of St. Pauls; 1 1/2 miles west of Interstate 95 on SR 1006; 3/8 mile north.

RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 28 to 60 inches but is commonly 38 to 48 inches. Reaction ranges from very strongly acid to moderately acid unless limed.

The A or Ap horizons have hue of 10YR, value of 4 or 5, and chroma of 2 to 4. They are sand, loamy sand, fine sand, or loamy fine sand.

The E horizon has hue of 10YR or 2.5Y, value of 4 to 7, and chroma of 4 to 8. It has the same texture range as the A horizon.

The Bt horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 6 to 8. Texture is loamy sand or loamy fine sand with a silt plus clay content of 10 to 20 percent.

The C horizons have hue of 7.5YR to 10YR, value of 5 to 7, and chroma of 1 to 8. Streaks or mottles in shades of yellow or brown are present in some pedons. The C horizon is sand, fine sand, or coarse sand.

COMPETING SERIES: There are no other known series in this family. Alaga, Blanton, Buncombe, Eustis, Galestown, Kenansville, Lakeland, Molena, Tarboro, and Troup series are in closely related families. Alaga, Buncombe, and Lakeland soils lack argillic horizons. In addition, Lakeland soils contain 5 to 10 percent clay plus silt in the 10- to 40-inch control section and Buncombe soils have mixed mineralogy. Blanton and Troup soils have sandy loam or sandy clay loam Bt horizons 40 to 80 inches below the surface. Eustis soils have argillic horizons that extend to depths of 60 inches or more. Galestown soils have average annual soil temperature of less than 59 degrees F. Kenansville soils have sandy loam Bt horizons. Molena and Tarboro soils have mixed mineralogy.

GEOGRAPHIC SETTING: Wakulla soils are nearly level to strongly sloping and are on broad landscapes of the Coastal Plain uplands and stream terraces. Slope is generally 0 to 6 percent but may ranges to 15 percent. The soil formed in sandy marine, aeolian, or fluvial Coastal Plain sediments. Average annual precipitation is 49 inches and mean annual air temperature 62 degrees F. near the type location.

GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing Alaga, Eustis, Kenansville, Lakeland, and Troup series, these are Kalmia, Norfolk, Orangeburg, Rains, and Wagram series. All of these soils are on lower positions on the landscape and have finer textured Bt horizons. In addition, Wagram soils have loamy argillic horizons and Rains soils are poorly drained.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; rapid permeability.

USE AND VEGETATION: About one half of the acreage of Wakulla soils is used for cultivated crops and pasture. Corn, peanuts, peas, soybeans, tobacco, watermelons, and coastal bermudagrass are common crops. Native forests are principally loblolly pine, longleaf pine, and hardwoods. The hardwoods are mainly turkey, bluejack, white, post, and blackjack oaks with a few hickories, blackgum, and dogwood.

DISTRIBUTION AND EXTENT: The Atlantic Coastal Plain of North and South Carolina and possibly Virginia. The series is of moderate extent.


SERIES ESTABLISHED: Robeson County, North Carolina; 1972.

REMARKS: Wakulla soils were formerly included in the Alaga series or the Eustis series, but these soils do not have argillic horizons.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from the surface to a depth of 24 inches (Ap and E horizons)

Argillic horizon - the zone from a depth of 24 inches to 42 inches (Bt horizon)

ADDITIONAL DATA: North Carolina State University Soils Department.

Horizon Depth % Sand % Silt % Clay

E 7-24" 91.5 5.5 3.0

Bt 24-42" 85.9 5.1 9.0

C1 42-56" 91.3 2.9 5.7

MLRA(S): 133A, 153A, 137, 153B


SOI-5  Soil Name   Slope  Airtemp FrFr/Seas Precip  Elevation
NC0068 WAKULLA     0- 15   59- 68  190-240  38- 52    30- 300 

SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness NC0068 NONE 6.0-6.0 - 60-60

SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- NC0068 0-24 LS LFS 0- 0 100-100 2- 8 1- 2 NC0068 0-24 S FS COS 0- 0 100-100 2- 8 1- 2 NC0068 24-42 LS LFS LCOS 0- 0 100-100 5-12 0- 2 NC0068 42-80 S FS COS 0- 0 100-100 2- 8 0- 2

SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll NC0068 0-24 4.5- 6.0 .5-1. 0- 0 6.0- 20 LOW NC0068 0-24 4.5- 6.0 .5-1. 0- 0 6.0- 20 LOW NC0068 24-42 4.5- 6.0 0.-.5 0- 0 6.0- 20 LOW NC0068 42-80 4.5- 6.0 0.-.5 0- 0 6.0- 20 LOW

National Cooperative Soil Survey