LOCATION PIEDMONT OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Udertic Argiustolls
TYPICAL PEDON: Piedmont silt loam-bermudagrass pasture. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 4 inches; brown (7.5YR 5/3) silt loam, dark brown (7.5YR 3/3) moist; moderate fine and medium platy structure parting to weak very fine granular; hard, friable; many very fine and fine roots; common very fine and fine pores; moderately acid; clear smooth boundary. (3 to 9 inches thick)
BA--4 to 8 inches; dark reddish gray (5YR 4/2) silty clay loam, dark reddish brown (5YR 3/2) moist; weak medium platy structure parting to weak fine subangular blocky; hard, friable; many very fine and fine roots; many very fine and fine pores; silt coatings light brown (7.5YR 6/3) on ped surfaces; slightly acid; clear smooth boundary. (0 to 4 inches thick)
Btss--8 to 16 inches; reddish brown (5YR 4/3) silty clay, dark reddish brown (5YR 3/3) moist; moderate medium prismatic structure parting to moderate medium blocky; extremely hard, extremely firm; common very fine and fine roots; many very fine and common fine pores; common non-intersecting slickensides; continuous clay films on vertical and horizontal facces; common pressure faces; neutral; gradual wavy boundary. (5 to 17 inches thick)
Btkss1--16 to 21 inches; reddish brown (5YR 5/3) silty clay, reddish brown (5YR 4/3) moist; weak medium prismatic structure parting to moderate medium blocky; extremely hard, extremely firm; common very fine and fine roots; common very fine and fine pores; common slickensides; continuous clay films on vertical and horizontal faces; common pressure faces; few fine and medium calcium carbonate concretions; moderately alkaline; gradual wavy boundary. (0 to 17 inches thick)
Btkss2--21 to 30 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; weak medium prismatic structure parting to weak medium blocky; extremely hard, extremely firm; common very fine and few fine roots; common very fine and fine pores; few slickensides; patchy clay films on faces of peds; common coarse soft masses of calcium carbonate; few fine and medium calcium carbonate concretions; violently effervescent; moderately alkaline; gradual wavy boundary. (0 to 14 inches thick)
BCk--30 to 35 inches; yellowish red (5YR 5/6) silty clay loam, yellowish red (5YR 4/6) moist; weak medium subangular blocky structure; very hard, very firm; few very fine and fine roots; common very fine and fine pores; common fine threads and medium soft masses of calcium carbonate; few black stains on faces of peds; red (2.5YR 5/6) soft shale fragments 10 to 14 percent by volume; violently effervescent; moderately alkaline; clear wavy boundary. (0 to 5 inches thick)
Cr1--35 to 52 inches; red (2.5YR 5/6) clayey and silty soft shale, red (2.5YR 4/6) moist; few very fine and fine roots in fractures; strongly effervescent; moderately alkaline; gradual wavy boundary. (12 to 17 inches thick)
Cr2--52 to 59 inches; red (2.5YR 5/6) laminated siltstone, red (2.5YR 4/6) moist; strongly effervescent; moderately alkaline.
TYPE LOCATION: Oklahoma County, Oklahoma; about 8 miles west and 3 3/4 miles north of Edmond, Oklahoma; about 1,300 feet south and 2000 feet west of the northeast corner of sec. 9, T. 14 N., R. 4 W.
RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock ranges from 20 to 40 inches. Depth to secondary carbonates ranges from 10 to 30 inches. It has cracks within 125 cm of the mineral soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some tine in most years, and slickensides or wedge shaped aggregates in a layer 15 cm or more thick that has its upper boundary within 125 cm of the mineral soil surface, or a linear extensibility of 6.0 cm or more between the mineral soil surface and either a depth of 100 cm or a patalithic contact. The clay content is greater than 35 percent within 15 inches of the soil surface.
The A horizon or Ap horizon has hue of 2.5YR, 5YR or 7.5YR, value of 4 or 5 and chroma of 2 or 3. Texture is silt loam, silty clay loam and clay loam. Reaction ranges from moderately acid to neutral. Electrical conductivity of the saturation extract ranges from 0 to 1 mmhos/cm.
The BA horizon has hue of 2.5YR or 5YR, value of 4 or 5, chroma of 2 to 4. Texture is silty clay loam or clay loam and the clay content ranges from 27 to 40 percent. This horizon is absent in most cultivated areas where moderate erosion has removed much of the original A horizon and this horizon is mixed with the A horizon and now designated as an Ap horizon. Reaction ranges from moderately acid to slightly alkaline. Electrical conductivity of the saturation extract ranges from 0 to 1 mmhos/cm.
The Btss horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 3 to 6. Dark soil materials in vertical streaks occur in some pedons as a result of cracking. Texture is silty clay loam, silty clay, or clay. Clay content ranges from 35 to 55 percent. Reaction ranges from neutral to moderately alkaline. Most pedons are noncalcareous. Electrical conductivity of the saturation extract ranges from 0 to 1 mmhos/cm.
The Btkss1 horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 to 6. Dark soil materials in vertical streaks occur in some pedons as a result of cracking. Texture is silty clay loam, silty clay, or clay. Clay content ranges from 35 to 55 percent. Slickensides occur in most pedons. Calcium carbonate occurs as masses, mycelia and as concretions. Reaction is moderately alkaline. Electrical conductivity of the saturation extract ranges from 0 to 1 mmhos/cm. Sodium adsorption ratio ranges from 0 to 8.
The Btkss2 horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 to 8. Dark soil materials in vertical streaks occur in some pedons as a result of cracking. Texture is silty clay loam, silty clay, or clay. Clay content ranges from 35 to 55 percent. Fragments of soft shale 2mm to 76mm in diameter make up from 0 to 15 percent by volume. Slickensides occur in some pedons. Calcium carbonate occurs as masses or mycelia, and as concretions. Reaction is moderately alkaline. Electrical conductivity of the saturation extract ranges from 0 to 4. Sodium adsorption ratio ranges from 0 to 12.
The BCk horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 to 8. Dark soil materials in vertical streaks occur in some pedons as a result of cracking. Texture is silty clay loam, silty clay, or clay. Clay content ranges from 35 to 55 percent. Fragments of soft shale 2mm to 76mm in diameter make up from 0 to 35 percent by volume. Calcium carbonate occurs as masses or mycelia, and as concretions. Reaction is moderately alkaline. Electrical conductivity of the saturation extract ranges from 0 to 8 mmhos/cm. Sodium adsorption ratio ranges from 0 to 12.
The Cr horizon has hue of 2.5YR, value of 4 to 6, and chroma of 6 to 8. Some pedons have streaks or rounded splotches in hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 2 to 4. The shale is calcareous in most pedons, but some are only calcareous in seams or fractures. Electrical conductivity of the saturation extract ranges from 0 to 8 mmhos/cm. Sodium adsorption ratio ranges from 0 to 16. This material is non paralithic with low to moderate excavation difficulty. Fractures are greater than 10 cm apart. Most of this material slakes in water within 15 hours.
COMPETING SERIES: These are the Brewer, Brewless, Dilworth, Renthin, Westsum and Wetbeth series. The Brewer and Brewless soils are very deep and are on flood plains. The Dilworth soils have control section of 10YR to 5Y and were developed from gray shale bedrock. The Renthin soils have solum 40 to 60 inches thick over bedrock. The Westsum and Wetbeth soils are very deep. In addition Wetbeth soils developed in alluvium.
GEOGRAPHIC SETTING: Piedmont soils are on very gently sloping to gently sloping broad and smooth convex ridges, side slopes and foot slopes of uplands in the Central Rolling Red Prairies (MLRA-80A). Slopes range from 1 to 5 percent. These soils formed in material weathered from clayey and silty shale of Permian age. The climate is dry or moist subhumid. The mean annual temperature ranges from 59 to 63 degrees F. The mean annual precipitation ranges from 28 to 38 inches. The Thornthwaite annual PE indices range from 44 to 64. The frost free period ranges from 200 to 230 days. Elevation ranges from 700 to 1600 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bethany, Grainola, Grant, Huska, Kingfisher, Kirkland, Lucien, Norge, Renfrow, Renthin, and Zaneis series. Renthin soils occur on similar landscapes, but at higher elevations and are 40 to 60 inches deep. Bethany, Kirkland, and Renfrow soils on higher positions and Norge soils on lower positions have a solum more than 60 inches thick. Also, they have an argillic horizon that does not decrease in clay content from the maximum by more than 20 percent at a depth of 60 inches. In addition, Bethany and Kirkland soils have a mollic epipedon more than 20 inches thick and Norge soils have a fine-silty control section. Grainola soils on lower positions do not have a mollic epipedon and are calcareous. Grant and Kingfisher soils on similar landscapes have a fine-silty control section. In addition, Grant soils have a solum 40 to 60 inches thick. Huska soils on similar landscapes, do not have a mollic epipedon and have a natric horizon. Lucien soils on similar positions have a solum 10 to 20 inches thick and have a loamy control section. Zaneis soils on higher positions, have a fine-loamy control section, solum 40 to 60 inches thick, and do not have secondary calcium carbonate accumulations.
DRAINAGE AND PERMEABILITY: Well drained; runoff is very high; very slow permeability.
USE AND VEGETATION: Some areas are cultivated to wheat or other small grains; lesser amounts are in hybrid forage sorghums. Many old fields have been sprigged to bermudagrass or seeded to old world bluestems and used for hay or tame pasture. Native vegetation consists mostly of tall and mid grasses.
DISTRIBUTION AND EXTENT: Central Rolling Red Prairies of Oklahoma.The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas.
SERIES ESTABLISHED: Logan County, Oklahoma 1994.
REMARKS: This series was formally included in the Renfrow, Vernon and Zaneis series in earlier surveys. Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface of the soil to a depth of approximately 16 inches.
Argillic horizon - The zone from approximately 8 to 30 inches.
Slickensides - The zone from 8 to 30 inches.
Accumulation of carbonates - The zone from 16 to 35 inches.
Ustolls - Moisture control section dry in some part more than 90 days.
Udertic - Cracks within 125 cm of the mineral soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some tine in most years, and slickensides or wedge shaped aggregates in a layer 15 cm or more thick that has its upper boundary within 125 cm of the mineral soil surface, or a linear extensibility of 6.0 cm or more between the mineral soil surface and either a depth of 100 cm or a paralithic contact, which ever is shallower.
Cr horizon - the non paralithic rock like material encountered at a depth of 35 inches.
Soil Interpretation Record: OK0347 Piedmont Series