LOCATION SMOKYHILL KSEstablished Series
TAXONOMIC CLASS: Clayey over loamy, mixed, superactive, mesic Cumulic Haplustolls
TYPICAL PEDON: Smokyhill silt loam - cultivated (Colors are for dry soil unless otherwise stated.)
Ap--0 to 15 centimeters (0 to 6 inches); dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots throughout; very slightly effervescent; slightly alkaline; clear smooth boundary.
A--15 to 36 centimeters (6 to 14 inches); dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; hard, friable, sticky and plastic; common very fine and fine roots throughout; slightly effervescent; slightly alkaline; clear smooth boundary. (Combined A horizons are 20 to 66 centimeters (8 to 26 inches) thick)
AC--36 to 76 centimeters (14 to 30 inches); dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; hard, firm, sticky and plastic; common very fine roots throughout; strongly effervescent; slightly alkaline; abrupt smooth boundary. (15 to 46 centimeters (6 to 18 inches) thick)
2C--76 to 183 centimeters (30 to 72 inches); pale brown (10YR 6/3) silt loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine tubular pores; strongly effervescent; slightly alkaline.
TYPE LOCATION: Geary County, Kansas; about 4 kilometers (2.5 miles) west and 8 kilometers (5 miles) south of Junction City; 792 meters (2,600 feet) south and 457 meters (1,500 feet) east of the northwest corner of section 33, T. 12 S., R. 5 E. USGS topographic quadrangle, Kansas Falls, Kansas; latitude 38 degrees, 57 minutes, 53 seconds north; longitude 96 degrees, 53 minutes, 6 seconds west.
RANGE IN CHARACTERISTICS:
Mollic epipedon: 51 to 86 centimeters (20 to 34 inches)
Depth to the 2C horizon: 51 to 102 centimeters (20 to 40 inches)
Free carbonates: throughout profile
A horizon:
Hue: 10YR
Value: 3 or 4, 2 or 3 moist
Chroma: 2 or 3
Texture: lower part of the A horizon averages 30 to 40 percent clay
Reaction: neutral or slightly alkaline.
AC horizon:
Hue: 10YR
Value: 3 to 5, 3 or 4 moist
Chroma: 2 or 3
Texture: silty clay loam or silty clay averaging 35 to 45 percent clay
Reaction: slightly or moderately alkaline
Some pedons have a Bw horizon.
2C horizon:
Hue: 10YR
Value: 5 to 7, 4 to 6 moist
Chroma: 2 or 3
Texture: silt loam or very fine sandy loam averaging 10 to 18 percent clay
Thin strata of finer or coarser sediments occur in some pedons.
Reaction: slightly or moderately alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform: drainageways and depressions on high floodplains of major streams
Slopes: dominantly less than 1 percent and generally concave
Parent material: clayey alluvium over lighter colored silty alluvium
Mean annual precipitation: 66 to 81 centimeters (26 to 32 inches)
Thornthwaites P-E Index: 44 to 54
Mean annual air temperature: 12 to 14 degrees C. (53 to 58 degrees F.)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
McCook soils.
McCook soils are coarse-silty and are on the same flood plain levels but in a slightly higher position.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: moderately well drained
Runoff: negligible
Saturated Hydraulic Conductivity: high in upper part and moderately high in lower part
Flooding: occasional
USE AND VEGETATION: Most areas are cultivated.
Principal crops are wheat and grain sorghum.
Native vegetation was tall prairie grasses.
DISTRIBUTION AND EXTENT: North central Kansas. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Geary County, Kansas, 1991. The name is coined from the Smoky Hill River in Geary County.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 76 centimeters (0 to 30 inches) (Ap, A, and AC horizons)
These soils were formally mapped as Sutphen soils or considered as inclusions in McCook soils.
06/2003 CEC activity class added, format changed to semi-tabular
ADDITIONAL DATA:
Kansas State University Soil Characterization Laboratory sample numbers 2430-2433 (pedon 89KS061070) from the type location.
Modified format by LRM in 3/2006 to include metric conversion and change permeability to saturated hydraulic conductivity.