LOCATION POLKTON            NC
Established Series
Rev. DGS-DTA-AG
01/2006

POLKTON SERIES


The Polkton series consists of moderately deep, moderately well drained, very slowly permeable soils on uplands of the Triassic Basins in the Southern Piedmont. They formed in residuum weathered from Triassic siltstone, mudstone, shale, and sandstone. Slope ranges from 2 to 25 percent. Mean annual precipitation is about 44 inches, and mean annual air temperature is about 61 degrees F. near the type location.

TAXONOMIC CLASS: Fine, mixed, active, thermic Oxyaquic Vertic Hapludalfs

TYPICAL PEDON: Polkton sandy clay loam--cultivated. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 7 inches; reddish brown (5YR 4/3) sandy clay loam; weak medium subangular blocky structure; friable, plastic, sticky; many fine roots; slightly acid; abrupt smooth boundary. (2 to 10 inches thick)

Btss1--7 to 18 inches; red (2.5YR 4/6) clay; weak coarse prismatic structure parting to moderate medium angular blocky structure; extremely firm, very plastic, very sticky; common fine roots; common nonintersecting slickensides; common distinct clay films on faces of peds; many fine prominent brown (7.5YR 5/4) iron depletions; very strongly acid; clear wavy boundary.

Btss2--18 to 24 inches; red (2.5YR 4/6) clay; weak coarse prismatic structure parting to moderate medium angular blocky structure; extremely firm, very plastic, very sticky; few fine roots; common nonintersecting slickensides; common distinct clay films on faces of peds; many fine prominent brown (7.5YR 5/4) and common fine prominent light gray (5YR 7/1) iron depletions; very strongly acid; clear wavy boundary. (Combined thickness of the Btss horizon is 12 to 25 inches)

BC--24 to 36 inches; dark reddish brown (2.5YR 3/4) clay loam; moderate medium subangular blocky structure; firm, plastic, sticky; few fine roots; 10 percent by volume rounded and angular weathered siltstone fragments; very strongly acid; clear wavy boundary. (0 to 10 inches thick)

Cr--36 to 52 inches; weathered, dark reddish brown (2.5YR 3/4) Triassic siltstone bedrock; partially consolidated but can be dug with difficulty with a spade.

R--52 inches; hard unweathered Triassic siltstone bedrock.

TYPE LOCATION: Anson County, North Carolina; 3.3 miles south of Polkton on Secondary Road 1250 (Poplar Hill Church Road), 100 feet north of road in field.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches. Depth to weathered bedrock is 20 to 40 inches. Depth to hard bedrock is 40 to 60 inches or more. Rock fragment content ranges from 0 to 10 percent by volume. Linear extensibility totals 6.0 cm or more between the surface and paralithic contact. Nonintersecting slickensides range from few to common in the Btss horizon. Base saturation by sum of cations increases with depth and ranges from 35 to 60 percent immediately above the paralithic contact. Exchangeable aluminum content of the Btss horizon is high (10 to 25 me/100g). The soil is very strongly acid to slightly acid in the A, Ap, and E horizons, and very strongly acid or strongly acid in the Btss, Bt, BC and C horizons.

The A or Ap horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 to 4. It is sandy clay loam, clay loam, silty clay loam, or clay. Where uneroded, it is sandy loam, fine sandy loam, loam, or silt loam.

The E horizon, where present, has hue of 5YR to 10YR, value of 4 to 6, and chroma of 3 to 6. It is sandy loam, fine sandy loam, loam, or silt loam.

The BE horizon, where present, has hue of 2.5YR to 10YR, value of 3 to 6, and chroma of 3 to 8. It is clay loam, sandy clay loam, silty clay, or silty clay loam.

The Bt horizon, if it occurs, has hue of 2.5YR to 10YR, value of 3 to 6, and chroma of 3 to 8. Iron depletions in shades of yellow and brown range from none to many. Texture is clay, silty clay, or sandy clay.

The Btss horizon has hue of 2.5YR to 10YR, value of 3 to 6, and chroma of 3 to 8. Iron depletions in shades of yellow and brown range from none to many. Iron depletions with chroma of 2 or less are below the upper 10 inches of the Btss horizon and within a depth of 40 inches. Texture is clay, silty clay, or sandy clay.

The BC horizon has hue of 2.5YR to 10YR, value of 3 to 6, and chroma of 3 to 8. Some pedons have masses of iron accumulation in shades of red, brown, or yellow, or iron depletions in shades of brown, yellow, or gray. Texture is silty clay loam, clay loam, or sandy clay loam.

The C horizon, where present, has hue of 2.5YR to 2.5Y, value of 3 to 7, and chroma of 1 to 8. Pedons may be mottled in shades of these colors or contain mottles in shades of red, brown, yellow, or gray. Texture is variable and ranges from sandy loam to clay saprolite.

The Cr horizon is weathered Triassic siltstone, mudstone, shale, sandstone, or conglomerate.

The R horizon is hard Triassic siltstone, mudstone, shale, sandstone, or conglomerate.

COMPETING SERIES: These are the Iredell and White Store series in the same family. Iredell soils formed in material weathered from diabase, diorite, gabbro, and other rocks high in ferro-magnesium minerals. White Store soils are deep to soft bedrock.

GEOGRAPHIC SETTING: Polkton soils are gently sloping to moderately steep and are on ridges and side slopes in thermic Triassic Basins of the Southern Piedmont. Slopes range from 2 to 25 percent. These soils formed in residuum weathered from Triassic siltstone, mudstone, shale, sandstone, or conglomerate. Mean annual air temperature ranges from 58 to 65 degrees F., and mean annual precipitation ranges from 43 to 48 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Iredell and White Store series, and the Brickhaven, Carbonton, Creedmoor, Green Level, Mayodan, Peakin, and Pinoka series. The Brickhaven and Carbonton soils lack vertic properties and have greater than 30% silt in the subsoil. The moderately well drained to somewhat poorly drained Creedmoor soils do not have vertic properties, and are on lower concave positions and adjacent to natural drainageways. The somewhat poorly drained Green Level soils do not have a depth to bedrock within 60 inches and have a base saturation of less than 35 percent. The well drained Mayodan soils do not have vertic properties and are on side slopes and gently sloping ridges. The well drained Peakin soils do not have vertic properties and have a perched water table at 3 to 6 feet. The well drained Pinoka soils have a loamy subsoil and are on similar landscape positions. White Store soils are on similar landscape positions.

DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; very slow permeability.

USE AND VEGETATION: About 20 percent of these soils are used for crops and pasture, and the rest is mainly in forests of hardwoods and pine. Common trees include loblolly pine, sweetgum, southern red oak, willow oak, and white oak. Understory plants include eastern red cedar, flowering dogwood, winged elm, eastern hophornbeam, eastern redbud, greenbrier, sassafras, honeysuckle, and poison ivy. The main crops are corn, small grain, and hay.

DISTRIBUTION AND EXTENT: Triassic Basins of the Southern Piedmont of North Carolina and possibly South Carolina and Virginia. The series has small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina

SERIES ESTABLISHED: Anson County, North Carolina; 1999. The name is from the community of Polkton in Anson County.

REMARKS: Polkton soils were formerly included with the White Store series. However, White Store soils are deep or very deep to bedrock.

Diagnostic features and diagnostic soil characteristics recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to a depth of 7 inches (Ap horizon)
Argillic horizon - the zone from 7 to 24 inches below the surface (Btss1 and Btss2 horizons)
Slickensides - presence of slickensides in the zone from 7 to 24 inches (Btss1 and Btss2 horizons)
Paralithic contact - the occurrence of weathered bedrock at a depth of 36 inches (upper boundary of the Cr horizon).
Lithic contact - the occurrence of hard bedrock at a depth of 52 inches (upper boundary of the R horizon)
Vertic feature: cracks within 50 inches of the soil surface that are 5 mm or more wide through a thickness of 12 inches or more for some time in normal years, and slickensides or wedge-shaped aggregates in a layer 6 inches or more thick that has its upper boundary within 50 inches of the soil surface; or a linear extensibility of 2.5 inches or more between the surface and either a depth of 40 inches or a paralithic contact, whichever is shallower
Oxyaquic feature: Saturation with water in one or more layers within 40 inches of the surface in normal years for either or both 20 or more consecutive days or 30 or more cumulative days.

ADDITIONAL DATA:
None

MLRA: 136 SIR: NC0285, NC0287 (Eroded)

TABULAR SERIES DATA:

SOI-5  Soil Name   Slope  Airtemp FrFr/Seas Precip  Elevation
NC0285 POLKTON     2- 25   58- 65  152-218  43- 48   180- 850 
NC0287 POLKTON     2- 25   58- 65  152-218  43- 48   180- 850 

SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness NC0285 NONE 1.5-2.5 PERCHED DEC-MAR 20-40 SOFT NC0287 NONE 1.5-2.5 PERCHED DEC-MAR 20-40 SOFT

SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- NC0285 0- 7 FSL SL 0-3 95-100 10-20 5-15 NC0285 0- 7 L SIL 0-3 95-100 7-27 5-15 NC0285 7-24 C SC SIC 0-3 90-100 35-70 20-40 NC0285 24-36 CL SCL SICL 0-3 95-100 20-40 10-25 NC0285 36-52 WB - - - - NC0285 52-62 UWB - - - - NC0287 0- 7 C 0-3 95-100 40-45 10-25 NC0287 0- 7 SCL CL SICL 0-3 95-100 27-40 5-15 NC0287 7-24 C SC SIC 0-3 90-100 35-70 20-40 NC0287 24-36 CL SCL SICL 0-3 95-100 20-40 10-25 NC0287 36-52 WB - - - - NC0287 52-62 UWB - - - -

SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll NC0285 0- 7 4.5- 6.5 .5-2. 0- 0 0.6- 2.0 LOW NC0285 0- 7 4.5- 6.5 .5-2. 0- 0 0.6- 2.0 LOW NC0285 7-24 4.5- 5.5 0.-.5 0- 0 0.0-0.06 VERY HIGH NC0285 24-36 4.5- 5.5 0.-.5 0- 0 0.06- 0.6 HIGH NC0285 36-52 - - - 0.00-0.06 NC0285 52-62 - - - 0.00-0.01 NC0287 0- 7 4.5- 6.5 .1-.5 0- 0 0.06- 0.2 HIGH NC0287 0- 7 4.5- 6.5 .2-1. 0- 0 0.2- 0.6 MODERATE NC0287 7-24 4.5- 5.5 0.-.5 0- 0 0.0-0.06 VERY HIGH NC0287 24-36 4.5- 5.5 0.-.5 0- 0 0.06- 0.6 HIGH NC0287 36-52 - - - 0.00-0.06 NC0287 52-62 - - - 0.00-0.01


National Cooperative Soil Survey
U.S.A.