LOCATION FOARD OK+TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Vertic Natrustolls
TYPICAL PEDON: Foard silt loam--cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 9 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable; few fine roots; slightly acid; abrupt smooth boundary. (5 to 12 inches thick)
Btss1--9 to 17 inches; brown (7.5YR 4/2) silty clay, dark brown (7.5YR 3/2) moist; moderate medium prismatic structure parting to moderate medium blocky; very hard, very firm; few fine roots; few fine pores; very dark brown (10YR 2/2) shiny surfaces on faces of peds; few silt coatings between peds; few non-intersecting slickensides; slightly alkaline; gradual wavy boundary. (5 to 18 inches thick)
Btss2--17 to 22 inches; brown (7.5YR 4/2) silty clay, dark brown (7.5YR 3/2) moist; moderate medium blocky structure; very hard, very firm; few fine roots; few fine pores; patchy shiny surfaces on faces of peds; common non-intersecting slickensides; slightly alkaline; clear wavy boundary. (0 to 12 inches thick)
Btnkss1--22 to 38 inches; brown (7.5YR 4/4) silty clay loam, dark brown (7.5YR 3/4) moist; weak medium blocky structure; very hard, very firm; few fine roots; few fine pores; few intersecting slickensides; few shiny surfaces on faces of peds; few medium soft masses of lime; few fine crystals of salt in the lower part; strongly effervescent, moderately alkaline; gradual smooth boundary. (12 to 30 inches thick)
Btnkss2--38 to 48 inches; brown (7.5YR 5/4) silty clay loam, brown (7.5YR 4/4) moist; ped faces are coated with dark brown (7.5YR 4/2) silt coatings; weak coarse blocky structure; very hard, very firm; few fine pores; few intersecting slickensides; few medium soft masses of lime; few crystals of salt; strongly effervescent, moderately alkaline; gradual smooth boundary. (0 to 15 inches thick)
BCnss--48 to 56 inches; yellowish red (5YR 5/6) silty clay loam, yellowish red (5YR 4/6) moist; common fine distinct gray redoximorphic depletion masses and brown redoximorphic concentration masses in lower part; weak coarse blocky structure; very hard, very firm; few intersecting slickensides; slightly effervescent; slightly alkaline; gradual smooth boundary. (5 to 12 inches thick)
Cn--56 to 66 inches; yellowish red (5YR 5/6) silty clay loam, yellowish red (5YR 4/6) moist; few fine distinct gray redoximorphic depletion masses and black redoximorphic concentration masses; massive; very hard, very firm; slightly effervescent; slightly alkaline.
TYPE LOCATION: Cotton County, Oklahoma; about 5 miles west and 2 1/4 miles north of Emerson, 100 feet east and 1,320 feet north of the southwest corner of sec. 11, T. 2 S., R. 13 W.
RANGE IN CHARACTERISTICS: Depth of solum ranges from 40 inches to more than 60 inches. Depth to soft secondary calcium carbonates ranges from 12 to 30 inches. Content of calcium carbonate as soft masses ranges from 2 to 10 percent by volume below a depth of 12 inches. This soil has cracks within 125 cm of the mineral soil surface that is 5 mm or more wide through a thickness of 30 cm or more for some time in most years, and slickensides 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 or more between the mineral soil surface and a depth of 100 cm.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 2 or 3. It is silt loam or silty clay loam and ranges from slightly acid through moderately alkaline. The lower boundary is clear or abrupt.
The Btss1 horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 2 or 3. Texture is silty clay loam, silty clay or clay. Clay content ranges from 35 to 45 percent. The exchangeable sodium percentage is less than 15. Reaction is slightly alkaline or moderately alkaline.
The Btss2 horizon has hue of 5YR through 10YR, value of 4 or 5, and chroma of 2 through 4. Texture is silty clay loam, silty clay or clay. Clay content ranges from 35 to 45 percent. The exchangeable sodium percentage is less than 15 to a depth of 20 inches from the soil surface. Reaction is slightly alkaline or moderately alkaline.
The Btnkss horizons have hue of 5YR through 10YR, value of 4 through 6, and chroma of 2 through 6. Texture is silty clay loam, silty clay, or clay. The exchangeable sodium percentage ranges from 15 to 25. Calcium carbonate in the form of soft masses ranges from 2 to 10 percent by volume. Reaction is slightly alkaline or moderately alkaline.
The BCnss horizon has color, texture, and reaction similar to the Btnkss horizons. Redoximorphic features are present in most pedons below 50 inches and range from few to common.
The Cn horizon has hue of 2.5YR through 7.5YR, value of 5 or 6, and chroma of 3 through 6. Texture is silty clay loam, silty clay, or clay. Reaction is slightly alkaline or moderately alkaline. Redoximorphic features are present in most pedons and range from few to common.
COMPETING SERIES: There are no known series in the same family. The closely competing Hinkle series has an ochric epipedon and an exchangeable sodium percentage of more than 15 percent within 20 inches of the soil surface. The closely competing Hollister series has mixed mineralogy and lacks a natric horizon.
GEOGRAPHIC SETTING: Foard soils are on nearly level to gently sloping broad summits and shoulder slopes of terrace pediments in the Central Rolling Red Plains (MLRA-78C) and Wichita Mountains (MLRA-82B). Foard soils formed in clayey material weathered from old alluvium of granitic outwash from the Wichita Mountains over clayey sediments of Permian age. The moisture regime is Typic-Ustic. The temperature regime is Thermic. The mean annual precipitation is 22 to 30 inches. The mean annual air temperature is 57 to 63 degrees F. The Thronthwaite annual PE indices range from 33 to 44. The frost free days range from 185 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Hinkle and Hollister series and the Lawton and Tillman series. Lawton and Tillman soils lack a natric horizon and have mixed mineralogy. All of these soils are intermingled with areas of Foard soils.
DRAINAGE AND PERMEABILITY: Well drained; runoff is moderate to high. Permeability is very slow.
USE AND VEGETATION: Mainly used for small grains and cotton. Some is in native range. Vegetation is sideoats grama, blue grama, western wheatgrass, little bluestem, and buffalograss.
DISTRIBUTION AND EXTENT: Southwestern Oklahoma and adjoining parts of Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Foard County, Texas; 1919.
ADDITIONAL DATA: The mineralogy of these soils is based on Lincoln Soil Survey Laboratory data on mineralogy-particle size analysis. Sample Numbers 72L1016-72L1018 and 72L1019-72L1020. Also sample numbers S59-OK-16-1 and S59-OK-17-2.
REMARKS: Soil Interpretation Record: OK0137 Series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of 22 inches (the A and Btss1 and Btss2 horizons).
Argillic horizon - the zone from a depth of 9 inches to a depth of 48 inches (Bt horizons).
Natric horizon - the zone from a depth of 22 inches to a depth of 66 inches (the Btn, BCn, and Cn horizons).
Vertic feature - contains cracks within 125 cm of the soil surface that are 5mm or more wide through a thickness of 30 cm or more, and slickensides in a layer 15 cm or more thick within 125 cm of the soil surface; or a linear extensibility of 6.0 or more between the mineral soil surface and a depth of 100 cm.