LOCATION ROBERTSVILLE KY+MD PA TN VA WVEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, mesic Typic Fragiaqualfs
TYPICAL PEDON: Robertsville silt loam--wooded (Colors are for moist soil.)
A--0 to 2 inches; very dark gray (10YR 3/1) silt loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; very friable; many fine roots; few fine black (N2.5/0) iron and manganese concretions; common fine distinct pale brown (10YR 6/3) masses as iron accumulations; very strongly acid; abrupt smooth boundary. (1 to 4 inches thick)
Eg--2 to 6 inches; light brownish gray (2.5Y 6/2) silt loam; weak fine and medium granular structure; very friable; common fine roots; few fine black (N2.5/0) iron and manganese concretions; common medium prominent yellowish brown (10YR 5/6) masses as iron accumulations; very strongly acid; clear smooth boundary. (3 to 12 inches thick)
Bg--6 to 21 inches; light gray (10YR 7/1) silt loam; weak medium subangular blocky structure; friable; few fine roots and pores; few fine black (N2.5/0) iron and manganese concretions; common medium prominent yellowish brown (10YR 5/6) masses as iron accumulations; very strongly acid; clear wavy boundary. (0 to 20 inches thick)
Btxg--21 to 45 inches; light gray (10YR 7/1) silty clay loam; weak very coarse prismatic structure parting to weak fine and medium subangular blocky; very firm; few very fine roots between prisms in upper 10 inches; common fine discontinuous pores; many fine distinct gray (10YR 5/1) clay films on faces of prisms; common fine gray (10YR 6/1) silt coatings on prism faces and in vertical seams in upper 5 inches; few fine black (N2.5/0) iron and manganese concretions; many medium prominent yellowish brown (10YR 5/8) masses as iron accumulations; brittle in 60 percent of the mass; very strongly acid; gradual wavy boundary. (20 to 40 inches thick)
Cg--45 to 65 inches; light gray (10YR 7/1) silty clay; massive; firm; few fine black (N2.5/0) iron and manganese concretions; many medium prominent yellowish brown (10YR 5/8) masses as iron accumulation; strongly acid.
TYPE LOCATION: Nelson County, Kentucky, about 14 miles west of Bardstown; about 1.0 mile southwest of Boston; 1.6 miles south of intersection of U.S. Highway 62 and Kentucky Highway 52; 0.2 mile east of Kentucky Highway 52, 100 yards east of gravel road in field. USGS Quad: Lebanon Junction; (latitude: 37 degrees, 46 minutes, 14.5 seconds N; longitude: 85 degrees, 40 minutes, 52.8 degrees W)
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 5 to more than 20 feet. Depth to the fragipan ranges from 15 to 36 inches. Soil reaction ranges from strongly to extremely acid except where lime has been added. Fragments, mainly rounded pebbles, range from 0 to 5 percent in the A, Btg, and Btxg horizons and from 0 to 20 percent in the Cg horizon.
The A horizon has hue of 10YR or 2.5Y, value of 3 or 4, and chroma of 1 or 2. Texture is silt loam. The Ap horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 or 2. The horizon has none to common redoximorphic features in shades of brown or gray. Texture is silt loam.
The Eg horizon has hue of 10YR or 2.5Y, value of 4 to 7, and chroma of 1 or 2. The horizon has none to common redoximorphic features in shades of brown or gray. Texture is silt loam.
The Bg horizon has hue hue of 10YR to 5Y, value of 5 or 7, and chroma of 1 or 2. Redoximorphic features are in shades of brown, yellow, and gray. Texture is dominantly silt loam but the range allows silty clay loam.
The Btxg horizon has hue of 10YR to 5Y, value of 5 to 7, and chroma of 1 or 2, or is neutral. Few to many redoximorphic features are in shades of brown, yellow, or gray. Texture is silt loam or silty clay loam.
The Cg horizon has hue of 10YR to 5Y, value of 5 to 7, and chroma of 1 or 2, or is an evenly mottled pattern in these colors. Texture is commonly silt loam, silty clay loam, or silty clay. Some pedons have layers of sandy loam, loam, clay loam, or clay.
COMPETING SERIES: The Thorton series is the only ones in the same family. Thorton soils have a well developed argillic horizon above the fragipan.
GEOGRAPHIC SETTING: Nearly level strem terraces and concave upland areas. The soils developed in old, mixed alluvium or colluvium derived from soils formed from limestone, siltstone, sandstone, shales, and loess. Near the type location the mean annual air temperature is 56.2 degrees F. and the mean annual precipitation is 49.9 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: The somewhat poorly drained Lawrence soils in similar positions on uplands and stream terraces, Melvin and Newark soils on flood plains, and Crider, Lowell, Mercer, Teddy, Sano, and Nicholson soils on uplands. The Melvin and Newark soils lack a fragipan in the subsoil. The Crider and Lowell soils lack fragipans and are well drained. The Mercer, Sano, Teddy, and Nicholson soils are moderately well drained.
DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is negligible to very slow. Permeability is moderate above the fragipan and slow to very slow in the fragipan.
USE AND VEGETATION: Many areas are in forest, and cleared areas are used for hay or pasture where adequately drained. Soybeans and corn are the principal crops. Native forest is water-tolerant oaks, black willow, sweetgum, cottonwood, American sycamore, green ash, and maple as the major species.
DISTRIBUTION AND EXTENT: Kentucky, Arkansas, Tennessee, Maryland, Missouri, Ohio, and Virginia. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Franklin County, Missouri, 1911.
REMARKS: Diagnostic horizons recognized in this pedon are:
Ochric epipedon-from 0 to 6 inches.(A, Eg horizon)
Argillic horizon-from 21 to 45 inches.(Btxg horizon)
Fragipan-from 21 to 45 inches. (Btxg horizon)