LOCATION KONAWA OK+KS TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Ultic Haplustalfs
TYPICAL PEDON: Konawa fine sandy loam--bermudagrass pasture (Colors are for dry soil unless otherwise stated.)
A--0 to 9 inches; brown (7.5YR 5/2) fine sandy loam, dark brown (7.5YR 3/2) moist; weak fine granular structure; slightly hard, very friable; slightly acid; clear smooth boundary. (4 to 10 inches thick)
E--9 to 17 inches; light reddish brown (5YR 6/4) fine sandy loam, reddish brown (5YR 4/4) moist; weak fine granular structure; slightly hard, very friable; slightly acid; clear smooth boundary. (0 to 17 inches thick)
Bt--17 to 53 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; moderate medium subangular blocky structure; very hard, friable; thin discontinuous clay films on peds; moderately acid; gradual smooth boundary. (10 to 36 inches thick)
BC--53 to 72 inches; red (2.5YR 5/6) fine sandy loam, red (2.5YR 4/6) moist; weak coarse subangular blocky structure; very hard, friable; neutral.
TYPE LOCATION: Payne County, Oklahoma; about 8 miles west and 1 mile south of Perkins; 2000 feet north and 200 feet west of the southeast corner of sec. 10, T.17 N., R. 1 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 48 to more than 72 inches. Total thickness of the A horizon and E horizon is less than 20 inches.
The A horizon has hue of 5YR to 10YR, value of 4 to 7, and chroma of 2 to 6. It is fine sandy loam, loamy fine sand, and fine sand. Where the soil has not been limed, the reaction ranges from strongly acid to slightly acid. Thickness of the A horizon is less than 10 inches where the organic matter is 1 percent or more. The cation exchange capacity (CEC) ranges from 2 to 12 ME/100G.
The E horizon has hue of 5YR to 10YR, value of 5 to 8, and chroma of 2 to 6. Texture and reaction is the same as the Ap horizon or A horizon. The cation exchange capacity ranges from 2 to 10 me/100g. In some pedons there is no E horizon.
The Bt horizon has hue of 2.5YR to 7.5YR, value of 4 to 7, and chroma of 4 to 8. Texture is fine sandy loam or sandy clay loam and the clay content ranges from 18 to 30 percent. In a few pedons, this horizon and the lower horizons have gravel from 2 mm to 10 mm in diameter that make up 0 to 5 percent by volume. Reaction is strongly acid to neutral. Base saturation ranges from 50 to 70 percent. Cation exchange capacity ranges from 16 to 23 me/100g.
Some pedons have Bt2 and Bt3 horizons that are similar in color, texture and reaction to the Bt horizon.
The BC horizon has colors the same as the Bt horizon. Texture is fine sandy loam, sandy clay loam, or loamy fine sand. Reaction ranges from strongly acid to neutral. Base saturation ranges from 50 to 70 percent. Cation exchange capacity of this horizon ranges from 4 to 20 me/100g.
The C horizon where present, has colors and reaction the same as the BC horizon. A few pedons have mottles in shades of brown. Texture is fine sandy loam, loamy fine sand or fine sand. A few pedons have few, thin lamellae.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Konawa soils are on nearly level to moderately steep side slopes and broad flats of upland terraces in the Cross Timbers (MLRA 84A). These soils are usually near large streams. These soils formed in loamy and sandy stream terrace sediments of Pleistocene age. Slopes are 0 to 20 percent. The climate is subhumid. Mean Annual Precipitation: 30 to 40 inches. Mean Annual Temperature: 58 to 64 degrees F. Thornthwaite Annual P-E indices: 48 to 64. Frost Free Days: 200 to 230. Elevation: 500 to 1500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dougherty, Stidham, Bastrop, Eufaula, and Teller series. Dougherty and Stidham soils occur on similar areas of the landscape, but, in some places, are on slightly higher areas than Konawa soils. Bastrop soils have thicker argillic horizons that do not decrease in clay content and occur on broad flat landscapes that are slightly higher and farther from the stream channel. Eufaula soils have A horizons more than 20 inches thick, have a sandy control section, and occur on slightly higher landscapes. Teller soils have mollic epipedons and usually occur on similar landscapes farther from the stream channel.
DRAINAGE AND PERMEABILITY: Well drained; permeability is moderate; runoff is negligible on 0 to 1 percent slopes, low on 1 to 5 percent slopes and medium on 5 to 20 percent slopes.
USE AND VEGETATION: These soils are mainly cultivated to small grain, sorghum, and peanut. Some areas are used for tame pasture or range. Native vegetation is mainly postoak, blackjack oak, and hickory with an understory of grasses.
DISTRIBUTION AND EXTENT: Northern Cross Timbers (MLRA 84A) of Oklahoma, Kansas, and Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Pottawatomie County, Oklahoma; 1965.
REMARKS: Soil Interpretation Record No. OK0032
Konawa soils were formerly included in the Dougherty series.
Diagnostic horizons and features recognized for this series:
Ochric horizon: 0 to 9 inches of depth.
Argillic horizon: 17 to 53 inches of depth.
CEC less than 24.
Ustic moisture regime: control section is dry in some part from 90 to 150 days per year.
ADDITIONAL DATA: Oklahoma State University mineralogy data 69-OK-60-2 and Soil Survey Laboratory, Beltsville, Maryland mineralogy data 65-OK-63-51. Oklahoma State University data 80-OK-49-2-(1-4), 80-OK-49-3-(1-4), 73-OK-57-15-(1-5), 80-OK-49-1-(1-4), 80-OK-49-21-(1-6), and 80-OK-49-20-(1-6).