LOCATION IRENE OKEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Pachic Argiustolls
TYPICAL PEDON: Irene silt loam--on ridge crest of 2 percent slope -- rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 9 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; slightly hard, friable; common fine roots; neutral; clear smooth boundary. (8 to 14 inches thick)
Bt--9 to 22 inches; brown (10YR 4/3) silty clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm; common fine roots; common distinct clay films on faces of peds; neutral; gradual smooth boundary. (9 to 22 inches thick)
Btk--22 to 44 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm; few fine roots; common distinct clay films on faces of peds; few threads and films of calcium carbonate; voids coated with thin films of calcium carbonate; strongly effervescent; strongly alkaline; gradual smooth boundary. (8 to 30 inches thick)
BCk--44 to 59 inches; yellowish brown (10YR 5/6) silty clay loam, dark yellowish brown (10YR 4/6) moist; weak coarse subangular blocky structure; hard, firm; few fine roots; few coarse rounded fragments less than 76 mm in diameter; common threads and films of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (10 to 23 inches thick)
2C--59 to 80 inches; brownish yellow (10YR 6/6) loam, yellowish brown (10YR 5/6) moist; massive; slightly hard, friable; films and masses of calcium carbonate make up about 10 percent by volume; violently effervescent; moderately alkaline.
TYPE LOCATION: Woods County, Oklahoma; about 29 miles west and 12 miles north of Alva, Oklahoma; about 1,100 feet north and 600 feet west of the southeast corner of sec. 19, T. 29N., R. 18W.
RANGE IN CHARACTERISTICS: Solum thickness is 40 to more than 60 inches. The mollic epipedon is more than 20 inches thick. Depth to secondary calcium carbonates ranges from 21 to 30 inches.
The A horizon has hue of 10YR, value of 4 or 5, and chroma of 2. Texture is silt loam or silty clay loam. Clay content ranges from 15 to 30 percent. Reaction ranges from neutral to moderately alkaline.
Some pedons have AB horizons that are similar to the A horizon in color, texture, and reaction.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 2 or 3. Texture is silty clay loam and clay content ranges from 27 to 35 percent. Reaction ranges from neutral to moderately alkaline.
The Btk horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 2 to 4. Texture is silty clay loam or clay loam. Clay content ranges from 27 to 35 percent. Visible calcium carbonate in forms of films and threads range from 1 to 5 percent by volume. Calcium carbonate equivalent is less than 15 percent. Reaction is moderately alkaline.
The BCk horizon has hue of 5YR to 10YR, value of 5 or 6, and chroma of 2 to 6. Texture is silty clay loam or clay loam. Clay content ranges from 27 to 35 percent. Visible calcium carbonate in forms of threads, films, and masses range from 1 to 10 percent by volume. Calcium carbonate equivalent is less than 15 percent. Rounded coarse fragments less than 76 mm in diameter range from 0 to 5 percent by volume.
The 2C horizon has hue of 5YR to 10YR, value of 5 to 7, and chroma of 3 to 6. Texture is loam, clay loam, or sandy clay loam. Clay content ranges from 15 to 30 percent. Visible calcium carbonate in forms of threads, films, and masses range from 1 to 30 percent by volume. Rounded coarse fragments less than 76 mm in diameter range from 0 to 10 percent by volume.
Some pedons have buried horizons similar to the 2C horizon in texture and reaction.
COMPETING SERIES: These are the Braman (OK), Corbin (KS), Lawrie (OK), Pond Creek (OK), St. Paul (OK), and Westview (OK) in the same family. Soils in similar families are the Abilene (TX), Altus (OK), Blanket (TX), Carey (TX), Dodson (TX), Smithville (TX), Selman (OK), Texroy (TX), and Tipton (OK) series. Corbin soils have more than 35 percent clay content in the lower part of the solum. Pond Creek and St. Paul soils do not have secondary carbonates within 30 inches of the soils surface. In addition, Braman, Lawrie, and Pond Creek, soils are moist for longer periods of time. Westview soils typically have hue of 5YR in the Bt horizon and do not have 2C horizons. Abilene, Blanket and Dodson soils have a fine control section. Altus, Smithville, Texroy, and Tipton soils have a fine-loamy control section. Carey and Selman soils have mollic epipedon less than 20 inches thick.
GEOGRAPHIC SETTING: Irene soils are on nearly level to gently sloping broad flats or ridge crests of uplands in the Southern High Plains Breaks (MLRA-77E). Slopes range from 0 to 5 percent. They formed in calcareous alluvium of the Ogallala formation of Tertiary age. Climate is subhumid dry. Mean annual precipitation ranges from 20 to 26 inches. Mean annual air temperature ranges from 57 to 59 degrees F. Thornthwaite annual P-E indices ranges from 32 to 40.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abbie, Farry, Fortyone, Mansic, and Oklark series. Abbie soils occur on similar landscapes and have a fine-loamy control section and have mollic epipedons less than 20 inches thick. Fortyone soils occur on similar landscapes and have mollic epipedons less than 20 inches thick and have a coarse-loamy control section. Mansic soils occur on lower landscapes and have a fine-loamy control section and have mollic epipedons less than 20 inches thick. Oklark soils occur on lower landscapes and have a coarse-loamy control section, have mollic epipedons less than 20 inches thick, and do not have argillic horizons. Farry soils occur on similar landscapes and have a fine-loamy control section and have mollic epipedons less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Irene soils are well drained; runoff is very low to low; permeability is moderately slow.
USE AND VEGETATION: Used mainly for rangeland. Some areas are cultivated to small grains and grain sorghum. Native vegetation is short and mid grasses.
DISTRIBUTION AND EXTENT: Southern High Plains Breaks (MLRA-77E) of Oklahoma and possibly Kansas and Texas. The series is of minor extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Woods County, Oklahoma; 1995; name is from a small community.
REMARKS: Irene soils were formerly included in the Abilene series in the earlier soil survey of Woods County, Oklahoma; 1939 series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of approximately 44 inches (A, Bt, Btk horizons).
Argillic horizon - the zone from approximately 9 to 44 inches (Bt, Btk horizons).
Moisture Regime: Aridic ustic.
ADDITIONAL DATA: Oklahoma State University; lab sample 82-OK-151-007.
Soil Interpretation Record Number: Series OK0340