LOCATION BLUEGRASS KYEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Typic Paleudalfs
TYPICAL PEDON: Bluegrass silt loam--cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 12 inches; dark grayish brown (10YR 4/2) silt loam; moderate medium granular structure parting to moderate fine granular structure; very friable; common fine roots throughout; neutral; gradual smooth boundary. (4 to 15 inches thick)
Bt1--12 to 26 inches; dark yellowish brown (10YR 4/6) silt clay loam; moderate medium subangular blocky structure parting to moderate fine subangular blocky structure; very friable; few fine roots throughout; 30 percent discontinuous faint clay films on vertical faces of peds; 1 percent fine prominent spherical weakly cemented black (7.5YR 2.5/1) iron-manganese nodules with sharp boundaries in matrix; slightly acid; clear smooth boundary.
Bt2--26 to 35 inches; strong brown (7.5YR 5/6) silty clay loam; moderate medium subangular blocky structure; friable; few fine roots throughout; 45 percent discontinuous distinct clay films on vertical faces of peds; 1 percent fine prominent spherical weakly cemented black (7.5YR 2.5/1) iron-manganese nodules with sharp boundaries in matrix and 1 percent fine prominent irregular black (7.5YR 2.5/1) iron-manganese masses with sharp boundaries in matrix; slightly acid; clear smooth boundary. (combined thickness of the Bt horizon ranges from 20 to 40 inches)
2Bt3--35 to 63 inches; yellowish red (5YR 4/6) silty clay loam; strong medium subangular blocky structure; firm; 45 percent discontinuous distinct clay films on vertical faces of peds; 1 percent fine prominent spherical weakly cemented black (7.5YR 2.5/1) iron-manganese nodules with sharp boundaries in matrix and 1 percent fine prominent irregular black (7.5YR 2.5/1) iron-manganese masses with sharp boundaries between peds; very strongly acid; clear smooth boundary.
2Bt4--63 to 84 inches; yellowish red (5YR 4/6) silty clay loam; 5 percent medium prominent irregular light yellowish brown (2.5Y 6/4) mottles; moderate medium subangular blocky structure; firm; 45 percent discontinuous distinct clay films on vertical faces of peds; 1 percent fine prominent spherical weakly cemented black (7.5YR 2.5/1) iron-manganese nodules with sharp boundaries in matrix and 1 percent fine prominent irregular black (7.5YR 2.5/1) iron-manganese masses with sharp boundaries between peds; strongly acid; clear smooth boundary. (combined thickness of the 2Bt horizon ranges from 40 to 60 inches)
2BC--84 to 96 inches; yellowish red (5YR 4/6) silty clay; 20 percent medium prominent irregular light yellowish brown (2.5Y 6/4) mottles; weak medium subangular blocky structure; very firm; 20 percent discontinuous distinct clay films on vertical faces of peds; 25 percent fine prominent spherical weakly cemented black (7.5YR 2.5/1) iron-manganese nodules with sharp boundaries in matrix and 25 percent fine prominent irregular black (7.5YR 2.5/1) iron-manganese masses with sharp boundaries between peds; moderately acid. (10 to 30 inches or more thick)
TYPE LOCATION: Fayette County, Kentucky; 500 feet east of James Lane, 0.75 miles southwest of the intersection of James Lane and Military Pike, and 0.75 mile southeast of Little Texas. USGS Versailles Quadrangle (Latitude: 38 degrees, 00 minutes, 2.40 seconds North; Longitude: 84 degrees, 38 minutes, 37.20 seconds West; UTM Easting 706892 UTM Northing 4208509).
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 60 to 120 inches or more. Thickness of the argillic horizon ranges from 50 to 100 inches. Depth to bedrock ranges from 60 to 200 inches or more. Chert fragments, less than 3 inches in diameter, range from 0 to 5 percent in the 2Bt, 2BC and 2C horizons. The reaction of the Ap, A and Bt horizons range from neutral to strongly acid; the 2Bt, 2BC and 2C horizons range from slightly acid to strongly acid. The phosphate content in the solum is variable but is typically medium or high.
The Ap or A horizons, have hue of 10YR or 7.5YR, value of 4, and chroma from 2 to 4. Some pedons have Ap or A horizons less than 7 inches thick with a value of 3 after mixing.
The AB or BA horizons, where present, have hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 2 to 4.
The Bt horizons, have hue of 7.5YR or 5YR, value of 4 or 5, and chroma of 4 to 6. Texture is silt loam, or light silty clay loam.
The 2Bt, 2BC and 2C horizons have hue of 7.5YR to 2.5YR, value of 4 or 5, and chroma of 4 to 6. Texture is heavy silty clay loam to clay. Some pedons are mottled in shades of red, brown or yellow, or are a variegation of these colors.
Some pedons in the transition zone between the Inner and Outer Bluegrass Physiographic Regions have 2BC and 2C horizons with hue of 10YR, value of 3 to 5, and chroma of 3 to 6.
Many pedons have few to many, fine to coarse, black iron and manganese oxide nodules, masses or concretions.
COMPETING SERIES: Crider is the only competing series. Crider soils formed in a loess mantle and the underlying residuum from limestone. The Sandview and Shelbyville soils are in related families. Sandview soils formed in a thin mantle of silty material and residuum weathered from limestone. Shelbyville soils formed in loess and the underlying limestone residuum, and have a dark colored surface layer. The limestone residuum of the Crider, Sandview, and Shelbyville soils are not phosphatic.
GEOGRAPHIC SETTING: Bluegrass soils are on nearly level to moderately steep uplands. Slopes are commonly 0 to 12 percent, but range up to 20 percent. The underlying limestone is cavernous and some areas have karst topography. The upper 20 to 40 inches of the solum formed in silty material and the lower part formed in residuum weathered from phosphatic limestone. The phosphatic limestone members include the Lexington and Cynthiana Limestone Formations of the Inner Bluegrass Physiographic Region. The mean annual precipitation is about 45 inches and the mean annual temperature is about 54 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashton, Caleast, Donerail, Elk, Fairmount, Faywood, Loradale, Lowell, Maury, McAfee, and Nicholson series. Ashton soils are located on low stream terraces and alluvial fans, have a dark colored surface layer, and have a solum thickness of 40 to 60 inches. Caleast soils formed in residuum weathered from limestone interbedded with thin strata of calcareous shale and siltstone, have a dark colored surface layer, have an average of more than 35 percent clay in the particle size control section, and have a solum thickness of 40 and 60 inches. Donerail soils have a dark colored surface layer, are moderately well drained, have an average of more than 35 percent clay in the particle size control section, and have hues of 10YR or yellower in the subsoil. Elk soils are located on stream terraces, and are typically more acid. Fairmount soils formed in limestone residuum interbedded with thin layers of calcareous shales, have a solum thickness and depth to bedrock from 10 to 20 inches, have a dark colored surface layer, have more than 35 percent clay in the particle size control section, and do not have argillic horizons. Faywood soils have hues of 7.5YR yellower in the Bt horizon and are moderately deep. Loradale soils formed in residuum or old alluvium from limestone and thin layers of calcareous shale, have a dark colored surface layer, and have hues of 10YR or yellower in the subsoil. Lowell soils formed in residuum weathered from limestone interbedded with thin layers of shale, have more than 35 percent clay in the particle size control section, have a solum thickness of 30 to 60 inches, and have hues of 7.5YR or yellower in the lower part of the subsoil. Maury soils have more than 35 percent clay in the particle size control section. McAfee soils have a solum thickness and depth to bedrock from 20 to 40 inches, have a dark colored surface layer, and have an average of more than 35 percent clay in the particle size control section. Nicholson soils are moderately well drained with a slowly permeable fragipan in the subsoil.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to slow and permeability is moderate to moderately rapid.
USE AND VEGETATION: Most areas are used for crops; such as burley tobacco, corn, small grains, alfalfa, and for pasture. Bluegrass and white clover are the most common pasture plants. Native vegetation was dominated by oaks, elm, ash, black walnut, black and honey locust, hackberry, black cherry, and Kentucky coffee tree. Glades of native grasses and canes were reported by early settlers.
DISTRIBUTION AND EXTENT: The Inner Bluegrass Region of Kentucky.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Fayette County, Kentucky; 2008.
REMARKS: The Bluegrass series was previously included with the Maury or Sandview phosphatic substratum series.
Diagnostic horizons in the pedon are:
Ochric epipedon 0 to 9 inches (Ap)
Argillic horizon 9 to 53 inches (Bt1, Bt2, Bt3)
Lithologic discontinuity @ 35 inches
ADDITIONAL DATA: Characterization sample 07KY-067-02-(1-6) by the University of Kentucky.