LOCATION PADUCAH TXEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Typic Haplustalfs
TYPICAL PEDON: Paducah loam--cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 8 inches; reddish brown (5YR 5/4) loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; soft, friable; noneffervescent; slightly alkaline; abrupt smooth boundary. (6 to 14 inches thick)
Bt1--8 to 16 inches; reddish brown (5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; weak to moderate fine subangular blocky structure; slightly hard, friable; few distinct clay films on surfaces of peds; noneffervescent; slightly alkaline; gradual smooth boundary. (0 to 12 inches thick)
Bt2--16 to 27 inches; reddish brown (5YR 4/4) clay loam, dark reddish brown (5YR 3/4) moist; weak to moderate fine and medium subangular blocky structure; hard, friable; common distinct clay films on surfaces of peds; noneffervescent; slightly alkaline; gradual smooth boundary. (10 to 18 inches thick)
Bk1--27 to 44 inches; red (2.5YR 4/6) loam, dark red (2.5YR3/6) moist; weak fine and medium subangular blocky structure; slightly hard, friable; few films and threads of calcium carbonate; slightly effervescent; moderately alkaline; gradual smooth boundary. (12 to 20 inches thick)
Bk2--44 to 72 inches; light red (2.5YR 6/6) very fine sandy loam, red (2.5YR 5/6) moist; weak fine and medium subangular blocky structure; soft, very friable; contains few concretions of calcium carbonate and about 5 percent masses of calcium carbonate; strongly effervescent; moderately alkaline; diffuse wavy boundary. (4 to 32 inches thick)
Cd--72 to 90 inches; red (2.5YR 5/6) very weakly cemented stratified sandstone; massive; soft, very friable; slightly effervescent; moderately alkaline.
TYPE LOCATION: Cottle County, Texas; from the intersection of U.S. Highway 83 and U.S. Highway 70 in Paducah; 14.0 miles north on U.S. Highway 83; 2.75 miles west on Farm Road 1440; 100 feet north in a cultivated field.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. Depth to visible calcium carbonates ranges from 16 to 44 inches. The upper 20 inches of the argillic horizon has 18 to 35 percent clay and less than 15 percent sand coarser than very fine sand.
The A horizon has hue of 5YR or 7.5YR, value of 4 or 5, and chroma of 3 or 4. Mollic colors are less than 10 inches thick. Texture is silt loam, loam, or very fine sandy loam. Reaction is neutral or slightly alkaline
The Bt horizons have hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 3 to 6. Texture is loam, silt loam, clay loam, or silty clay loam. Effervescence ranges from noneffervescent to slightly effervescent and reaction is slightly alkaline to moderately alkaline.
The Bk horizons have hue of 2.5YR or 5YR, value of 4 to 6, and chroma of 3 to 8. Texture is loam, silt loam, or very fine sandy loam. Carbonates range from barely visible to about 15 percent by volume of masses and concretions. Effervescence ranges from slightly effervescent to violent and reaction is moderately alkaline.
The Cd horizon is weakly cemented stratified redbeds of sandstone or siltstone.
COMPETING SERIES: These are no other series in this family. Similar soils are the Bukreek, Carey, Decobb(T), Cobb, Madge, and St. Paul series. Bukreek, Cobb, Decobb and Madge soils have fine-loamy particle size control sections. Bukreek, Carey, Madge and St. Paul soils have a mollic epipedon.
GEOGRAPHIC SETTING: Paducah soils are on convex surfaces of dissected plains on uplands. Slopes range from 0 to 5 percent, but are mainly 1 to 3 percent. These soils formed in silty materials of the Permian system. The mean annual precipitation is 20 to 28 inches. The mean annual temperature is 59 degrees to 64 degrees F., and the Thornthwaite annual P-E indices of 32 to 40. Frost free days range from 210 to 230. Elevation ranges from 1400 to 2200 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Carey, and St. Paul series and the Lutie, Obaro, Quinlan and Woodward series. Lutie soils have a mollic epipedon. Obaro, Quinlan and Woodward soils do not have a argillic horizon and in addition Quinlan soils have sola less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability; runoff is negligible on slopes less than 1 percent, and low on 1 to 5 percent slopes.
USE AND VEGETATION: Mainly used for growing cotton, grain sorghums, and small grains. Native grasses are sideoatsgrama, blue grama, black grama, buffalograss, sand dropseed and Texas wintergrass. Mesquite is a common invader on some sites.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) in Texas and Oklahoma. The series extent is moderate.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Cottle County, Texas; 1970.
REMARKS: Paducah soils were formerly included in the Carey series.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the surface layer from 0 to 8 inches (the Ap horizon).
Argillic horizon - the zone from 8 to 27 inches (the Bt horizons).