LOCATION COMBS              KY+IN MD TN VA WV
Established Series
Rev. RAH:WHC:JDM
05/2009

COMBS SERIES


The Combs series consists of very deep, well drained, alluvial soils on flood plains and terrace treads along rivers and major streams. Most areas are nearly level or gently sloping with slopes of 0 to 4 percent, but range to as much as 25 percent on riverbanks and risers.

TAXONOMIC CLASS: Coarse-loamy, mixed, active, mesic Fluventic Hapludolls

TYPICAL PEDON: Combs fine sandy loam--on a smooth 2 percent slope under corn stubble and weeds. (Colors are for moist soil.)

Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) fine sandy loam, moderate medium subangular blocky structure parting to moderate fine granular; very friable; common fine roots and pores; few wormcasts; 2 percent red sandstone fragments 2 to 5 cm across; moderately acid; clear smooth boundary. (6 to 12 inches thick)

A--8 to 23 inches; dark brown (10YR 3/3) loam; moderate medium subangular blocky structure parting to moderate fine granular; very friable; common fine roots; common fine pores; few wormcasts; 4 percent red sandstone fragments 2 to 5 cm across; moderately acid; clear smooth boundary. (0 to 18 inches thick)

Bw1--23 to 44 inches; dark yellowish brown (10YR 4/4) fine sandy loam; moderate coarse prismatic structure parting to weak medium subangular blocky; friable; few fine roots; common fine pores; nearly continuous coatings or flows on prisms and most pores; slightly acid; gradual smooth boundary.

Bw2--44 to 64 inches; yellowish brown (10YR 5/6) loam; weak coarse prismatic structure parting to weak medium subangular blocky; friable; few fine roots; common fine pores; nearly continuous thin coatings or flows on exteriors of prisms and in most pores; slightly acid; gradual smooth boundary.

Bw3--64 to 80 inches; yellowish brown (10YR 5/6) loam; moderate very coarse prismatic structure parting to weak medium subangular blocky; common fine pores; continuous coatings or flows on exteriors of prisms and in most pores; slightly acid. (Combined thickness of the Bw horizon is 16 to 50 inches or more)

TYPE LOCATION: Perry County, Kentucky; in a fallow field between the western shore of the North Fork of the Kentucky River and railroad tracks at the mouth of Oldhouse Branch about 1.3 miles south of Chavies; 37 degrees, 20 minutes, 01 second N. Latitude and 83 degrees, 21 minutes, 20 seconds W. Longitude; Krypton Topographic Quadrangle; NAD83.

RANGE IN CHARACTERISTICS: Solum thickness is more than 40 inches. Thickness of the mollic epipedon ranges from 10 to 24 inches. The soil ranges from moderately acid to neutral throughout. Coarse fragments are commonly lacking but range up to 15 percent.

The Ap or A horizon has hue of 10YR or 7.5YR, value of 3, and chroma of 2 or 3. Texture is silt loam, loam, sandy loam or fine sandy loam.

The AB horizon, where present, has hue of 10YR or 7.5YR, value of 3 or 4, and chroma of 2 or 3. Texture is similar to the Ap or A horizons.

The Bw horizon has hue of 10YR to 2.5Y, value of 4 or 5, and chroma of 4 to 6. In some pedons however, the upper part of the Bw has value of 3 and chroma of 2 or 3. Texture is loam, silt loam, sandy loam, or fine sandy loam. A few pedons have sandy clay loam texture below 40 inches.

The BC horizon, where present, has colors and textures similar to the Bw horizon, but it is commonly stratified.

The C horizon, where present, has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 3 to 6. Some pedons in swales or near drainageways display redox depletions and fe masses below 40 inches. Texture is loam, silt loam, sandy loam, or sandy clay loam and they also are commonly stratified.

COMPETING SERIES: There are no other series in this family. The Boonesboro, Broadway, Gladehill, Gullion, Huntington, Landes, Nomberville, Rossburg and Speedwell soils are close competitiors on similar alluvial landforms. Boonesboro, Rossburg, and Speedwell soils are in a fine-loamy family. Broadway, Gullion, Huntington, and Nomberville soils are in a fine-silty family. Gladehill, Landes, Rossburg, and Speedwell soils are in families with superactive cation-exchange activity Class. Braodway, Gladehill, Gullion, and Nomberville soils have siliceous mineralogy. In addition, Boonesboro soils are moderately deep to bedrock and Landes soils have solums less than 40 inches thick.

GEOGRAPHIC SETTING: These soils formed in alluvium washed chiefly from colluvial soils that weathered from interbedded sandstone, siltstone, shale and, in places, limestone. Near the official series sites, average annual air temperature ranges from 53 to 59 degrees F. with a mean of about 55 degrees. Average annual precipitation ranges from 40 to 50 inches annually with a mean of about 48 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Allegheny, Cutshin, Grigsby, Nelse, Nolin, Rowdy, and Shelbiana series. Grigsby soils lack mollic epipedons. Rowdy soils lack mollic epipedons and are on similar landscapes along smaller streams. Gilpin and Shelocta soils have argillic horizons and are on nearby steep mountain sides.

DRAINAGE AND PERMEABILITY: Well drained with moderate or moderately rapid permeability. Most areas are rarely flooded.

USE AND VEGETATION: Nearly all areas are cleared and used for growing cultivated crops and pasture. Crops include corn, small grains, tobacco, hay, and garden or truck crops. Native vegetation was a mixed mesophytic hardwood forest interspaced with cane breaks.

DISTRIBUTION AND EXTENT: The Cumberland-Allegheny Plateau in the Northern and Southern Appalachian Ridges and Valleys, and the Blue Ridge in Kentucky, Virginia, and possibly West Virginia.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia

SERIES ESTABLISHED: Perry County, Kentucky; 1979.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 23 inches (Ap & A horizons)
Cambic horizon - 23 to 80 inches (Bw horizons)

ADDITIONAL DATA: Characterization sample S77KY-193-6 (Typical Pedon). See Special Report 91-1 "Descriptions and Laboratory Data For Some Soils in Kentucky" (Section #5 "Mountains and Eastern Coalfields Region"), University of Kentucky College of Agriculture/Agricultural Experiment Station/Department of Agronomy: A.D. Karathansis, H.H. Bailey, R. I. Barnhisel, and R.L. Blevins, (January 1991).
Mineralogy Sample:S77KY-193-6


National Cooperative Soil Survey
U.S.A.