LOCATION DILLSBORO NCEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Humic Hapludults
TYPICAL PEDON: Dillsboro loam on a 5 percent slope in a hay field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 10 inches; dark reddish brown (5YR 3/3) loam; reddish brown (5YR 4/3) dry crushed; moderate medium granular structure; very friable; many fine and medium roots; few fine flakes of mica; moderately acid; clear smooth boundary. (7 to 15 inches thick)
Bt1--10 to 15 inches; yellowish red (5YR 4/6) clay loam; weak medium subangular blocky structure; friable; few fine and medium roots; few faint clay films on faces of peds and in pores; few fine flakes of mica; slightly acid; gradual smooth boundary.
Bt2--15 to 33 inches; yellowish red (5YR 4/6) clay; moderate medium subangular blocky structure; friable; few fine and medium roots; few faint clay films on faces of peds and in pores; 4 percent cobbles, 4 percent gravel by volume; few fine flakes of mica; slightly acid; diffuse smooth boundary.
Bt3--33 to 43 inches; yellowish red (5YR 5/6) clay; moderate medium subangular blocky structure; friable; few fine roots; few faint clay films on faces of peds and in pores; 6 percent gravel, 5 percent cobbles by volume; few fine flakes of mica; strongly acid; gradual wavy boundary. (Combined thickness of the Bt horizon is 19 to more than 50 inches.)
2Bt4--43 to 59 inches; strong brown (7.5YR 5/6) very cobbly clay; common fine distinct yellowish red (5YR 5/8) and strong brown (7.5YR 5/8) mottles; weak medium subangular blocky structure; friable; few faint clay films on faces of peds and in pores; common manganese nodules; 15 percent cobbles, 25 percent gravel by volume; few fine flakes of mica; strongly acid; gradual wavy boundary. (0 to 30 inches thick)
2BC--59 to 75 inches; yellowish brown (10YR 5/6) very cobbly clay loam; common medium distinct red (2.5YR 4/8) and few fine and medium distinct light yellowish brown (10YR 6/4) mottles; weak medium subangular blocky structure; friable; common manganese nodules; 20 percent gravel, 15 percent cobbles by volume; few fine flakes of mica; strongly acid. (0 to 30 inches thick)
TYPE LOCATION: Jackson County, North Carolina; 1.0 mile southwest of Webster on NC 116; 0.25 miles south of NC 116 in a hayfield on the Tom Kelley farm. State plane coordinates are: 604,000N; 738,000E.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 inches. Depth to bedrock is more than 72 inches. Content of mica flakes is few or common throughout. Reaction ranges from very strongly acid to moderately acid in all horizons unless the soil has been limed. Typically, the A and upper Bt horizons are moderately acid to neutral in areas that have been intensively cultivated and limed frequently. Content of water worn rock fragments by volume is 0 to 35 percent in the upper 40 inches and 0 to 60 percent below 40 inches. Rock fragments range from gravel to boulders in size.
The A or Ap horizon has hue of 5YR to 10YR, value of 2 or 3, and chroma of 1 to 4. It is fine sandy loam, sandy loam, loam, sandy clay loam, or clay loam in the fine-earth fraction. A thin BA horizon occurs in some pedons. It has hue of 5YR to 10YR, value of 4 to 6, and chroma of 4 to 8. It is sandy clay loam or clay loam in the fine-earth fraction.
The Bt horizon, and the 2Bt horizon, where present, have hue of 5YR to 10YR, value of 4 to 6, and chroma of 4 to 8. Mottles, if they occur, are in shades of red, brown, or yellow. Texture is clay loam or clay in the fine-earth fraction. The Bt horizon contains up to 35 percent rock fragments by volume. The 2Bt horizon contains 35 to 60 percent rock fragments by volume.
The BC and 2BC horizons, where present, are similar in color to the Bt and 2Bt horizons. They are loam, sandy clay loam or clay loam in the fine-earth fraction. The BC horizon contains up to 35 percent rounded rock fragments by volume. The 2BC contains 35 to 60 percent rounded rock fragments by volume.
C or 2C horizons occur in some pedons. They are loamy or sandy alluvial or colluvial material that is variable in color. Content of felsic, intermediate and mafic igneous or high-grade metamorphic rock fragments by volume ranges up to 35 percent in the C horizon, and up to 60 percent in the 2C horizon.
COMPETING SERIES: Alspaugh is the only other series in this family. It formed in alluvium and colluvium weathered from andesite and tuff and contains fragments of those rocks. It occurs on terraces at the edge of mountainous areas in Oregon. Braddock and Unison are soils in a closely related family of Typic Hapludults. Braddock soils have Bt horizons that have hue of 2.5YR or 10R. Braddock and Unison soils lack the dark color and thickness in the A horizon required for Humic Hapludults.
GEOGRAPHIC SETTING: Dillsboro soils are on gently sloping to steep high stream terraces, and on toe slopes, benches and fans in coves in the Blue Ridge (MLRA 130). Slope is commonly 2 to 15 percent, but ranges from 2 to 50 percent. Elevation ranges from about 1400 feet to 3600 feet. Dillsboro soils formed in old alluvium or colluvium derived from materials weathered from felsicto mafic rocks such as mica gneiss, granite, hornblende gneiss and hornblende schist. Mean annual air temperature ranges from 46 to 57 degrees F., and mean annual precipitation ranges from about 45 to 65 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Braddock, Clifton, Cowee, Dillard, Evard, Fannin, Hayesville, Hemphill Huntdale, Saunook Statler, and Trimont soils. Braddock soils have redder subsoils and occur on convex shaped stream terraces and colluvial fans. Clifton, Cowee, Evard, Fannin, Hayesville, Huntdale, and Trimont soils are on nearby mountain ridges and side slopes and formed in residuum with some soil creep, and have C horizons in saprolite. Cowee, Evard, Fannin, Huntdale and Trimont soils are fine-loamy. Cowee soils are moderately deep to weathered bedrock and Fannin soils have micaceous mineralogy. Dillard, Hemphill, and Statler soils occur on nearby low terraces. Dillard and Statler soils are fine-loamy. In addition, Dillard soils are moderately well drained. Hemphill soils are very poorly drained.. Saunook soils are fine-loamy, formed in colluvium, and are on slopes above stream terraces.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability. These soils receive surface and subsurface water from surrounding uplands especially in colluvial positions and seeps and springs are possible.
USE AND VEGETATION: Almost all of this soil has been cleared and used for row crops such as corn, tobacco, and tomatoes, and for specialty and horticultural crops, pasture and hayland. The remainder is used for residential housing and small woodlots of Virginia pine, shortleaf pine, eastern white pine, yellow poplar, northern red oak, white oak, scarlet oak, or black locust. Understory plants include flowering dogwood, mountain laurel, rhododendron, sourwood, switchcane, and Christmas fern.
DISTRIBUTION AND EXTENT: North Carolina, and possibly Georgia, Tennessee, and Virginia. This soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Macon County, North Carolina, 1990. The name is from the town of Dillsboro near the type location in Jackson County, North Carolina.
REMARKS: The Dillsboro series was formerly included with the Braddock and Unison soils. However, Braddock and Unison soils have ochric epipedons with higher color values. In addition, Braddock soils have hue of 2.5YR or 10R in the Bt horizon.
Diagnostic horizons and features in this pedon are:
Ochric epipedon - The zone from the surface to a depth of 10 inches (Ap horizon)
Humic Hapludult feature - Moist value of 3 in the Ap horizon (0 to 10 inches)
Argillic horizon - The zone from 10 to 59 inches (Bt1, Bt2, Bt3, and 2Bt4 horizons); CEC/100 g of clay(NH4OAC at pH 7) averages 17.
MLRA: 130 SIR: NC0236, NC0286 (Rarely Flooded)