LOCATION HARRAH OKEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Ultic Paleustalfs
TYPICAL PEDON: Harrah fine sandy loam, on a 6 percent convex east facing slope, in a severely eroded field reseeded to native grasses. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 9 inches; brown (7.5YR 5/2) fine sandy loam, brown (7.5YR 4/2) moist; weak fine granular structure; soft, very friable; neutral; clear smooth boundary. (2 to 10 inches thick)
E--9 to 19 inches; light brown (7.5YR 6/4) loamy fine sand, brown (7.5YR 5/4) moist; weak fine granular structure; soft, very friable; neutral; clear smooth boundary. (0 to 20 inches thick)
Bt1--19 to 34 inches; red (2.5YR 5/6) sandy clay loam, red (2.5YR 4/6) moist; weak fine blocky structure; hard, firm; thin nearly continuous clay films on faces of peds; slightly acid; gradual wavy boundary. (10 to 25 inches thick)
Bt2--34 to 52 inches; red (2.5YR 5/8) sandy clay loam, red (2.5YR 4/8) moist; moderate medium prismatic structure parting to moderate medium blocky; hard, firm; thin nearly continuous clay films on faces of peds; about 5 percent by volume uncoated sand grains on vertical faces of peds and in pores; moderately acid; gradual wavy boundary. (12 to 45 inches thick)
Bt3b--52 to 76 inches red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; moderate medium prismatic structure parting to moderate medium blocky; hard, firm; thin continuous clay films on faces of peds; about 20 percent by volume of uncoated sand grains on vertical faces of peds and in pores; moderately acid; gradual wavy boundary. (0 to 28 inches thick)
Bt4b--76 to 86 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; moderate medium blocky structure; hard, firm; thin continuous clay films on faces of peds; few fine dark concretions; about 10 percent by volume of uncoated sand grains on vertical faces of peds and in pores; slightly acid.
TYPE LOCATION: Cleveland County, Oklahoma; about 10 miles east and 2.6 miles north of U.S. Highway 77 and Robinson Street intersection in Norman; about 2,350 feet south and 900 feet east of the northwest corner of sec. 12, T. 9 N., R. 1 W.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 inches. The base saturation, by sum of cations, ranges from 50 to 70 percent in the Bt horizons. Depth to a buried horizon ranges from 30 to more than 80 inches and averages 56 inches, but may be absent or below 80 inches in some pedons.
The Ap or A horizon has hue of 5YR or 10YR, value of 4 to 6, and chroma of 2 to 4. Texture is fine sandy loam or loamy fine sand. Where the texture is loamy fine sand, the combined thickness of the A and E horizons is less than 20 inches. Reaction ranges from very strongly acid to neutral.
The E horizon has hue of 2.5YR to 7.5YR, value of 5 to 7, and chroma of 4 to 6. Texture is fine sandy loam or loamy fine sand. Reaction ranges from very strongly acid to neutral.
The Bt horizons have hue of 10R to 5YR, value of 4 to 6, and chroma of 4 to 8. Texture is sandy clay loam or fine sandy loam and content of clay ranges from 18 to 35 percent. Skeletans or uncoated sand grains are mainly on vertical faces of peds or in old root channels and make up 0 to 20 percent by volume. Dark concretions from 2 to 76 mm in diameter make up 0 to 2 percent by volume. Reaction ranges from very strongly to neutral.
Some pedons have a Bt3 and Bt4 horizons where the Btb horizon is not within a depth of 80 inches. The Bt3 horizon has color and texture like the Bt2 horizon. Dark concretions from 2 to 76 mm in diameter make up 0 to 20 percent by volume. Reaction ranges from very strongly acid to neutral.
The Btb horizons have a hue of 10R or 2.5YR, value of 4 to 6, and chroma of 4 to 8. Texture is fine sandy loam or sandy clay loam and content of clay ranges from 18 to 35 percent. Skeletans or uncoated sand grains are mainly on vertical faces of peds or in old root channels and make up 0 to 40 percent by volume. Dark concretions from 2 to 76 mm in diameter make up 0 to 20 percent by volume. Barite rosettes, sandstone, or quartzite from 2 mm to 76 mm in diameter make up from 0 to 5 percent by volume. Reaction ranges from very strongly acid to neutral.
Some pedons have BC horizons when the Btb horizon is not present above 80 inches. It has hue of 2.5YR, value of 5, and chroma of 6 or 8. Texture is fine sandy loam and less often sandy clay loam. Reaction is slightly acid or neutral. Skeletans or uncoated sand grains are mainly on vertical faces of peds or old root channels and make up 0 to 5 percent by volume.
COMPETING SERIES: These are Gasil and Konsil series in the same family. Soils in similar families are Bastsil, Dougherty, Duffau, Galey, Heaton, Knolle, Konawa, Selden, Silawa, Silstid, Stephenville, Stidham, Styx and Weatherford series. Bastsil, Duffau and Selden soils have an argillic horizon that has base saturation of 75 percent or more in some part. Dougherty, Heaton, Silstid, Stidham, and Styx soils have loamy fine sand A horizons more than 20 inches thick. In addition, Dougherty and Stidham soils have mixed mineralogy and have an argillic horizon that decreases in clay content from the maximum by 20 percent or more within a depth of 60 inches. Galey and Gasil soils have an argillic horizon with hue of 7.5YR or yellower. Knolle, Konawa, and Silawa soils have an argillic horizon that decreases in clay content from the maximum by 20 percent or more within a depth of 60 inches. In addition, Konawa soils have mixed mineralogy. Konsil soils have a longer growing season and are warm for longer periods of time. Stephenville and Weatherford soils have sola less than 60 inches thick.
GEOGRAPHIC SETTING: Harrah soils are on gently sloping to sloping convex side slopes and foot slopes of uplands in the Cross Timbers. Slopes range from 3 to 45 percent. They formed in sandy and loamy colluvial material weathered from sandstone of Permian age.
Mean Annual Precipitation: 30 to 38 inches.
Mean Annual Temperature: 58 to 62 degrees F.
Thornthwaite Annual P-E indices: 48 to 64.
Frost free days: 190 to 220.
Elevation: 1000 to 1300 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Stephenville series and Darnell, Darsil, Pulaski, and Tribbey series. Darnell and Darsil soils lack an argillic horizon and are less than 20 inches thick over sandstone. Darnell and Darsil soils are mainly on ridge crest. Pulaski and Tribbey soils lack an argillic horizon, have an irregular decrease in organic carbon content, and have a coarse-loamy control section. In addition, Tribbey soils have a water table within 40 inches of the surface most of the time. Pulaski and Tribbey soils are on flood plains. Stephenville soils are on slightly higher areas.
DRAINAGE AND PERMEABILITY: Well drained; permeability is moderate; runoff is low on 3 to 5 percent slopes, medium on 5 to 20 percent slopes and high on slopes greater than 20 percent.
USE AND VEGETATION: Used mainly as rangeland or improved pasture. Some areas are cultivated and wheat and grain sorghum are the main crops. The native vegetation is Savannah consisting of post oak, blackjack oak, eastern red cedar, oak, and hickory with an understory of mid and tall grasses, primarily big bluestem and little bluestem.
DISTRIBUTION AND EXTENT: Northern Cross Timbers (MLRA 84A) of central Oklahoma. The series is moderate in extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Payne County, Oklahoma; 1983.
REMARKS: These soils were formerly included in the Dougherty, Konawa, and Stephenville series in earlier surveys.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface of the soil to a depth of 9 inches (A horizon).
Albic horizon - the zone from 9 inches to a depth of 19 inches (E horizon).
Argillic horizon - the zone from 19 inches to a depth of 86 inches (Bt horizons).
ADDITIONAL DATA: Laboratory data is available from Oklahoma State University, Stillwater, Oklahoma. Sample No. 78-OK-14-31 (1-8).