LOCATION ROSCOE TX+OKEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Haplusterts
TYPICAL PEDON: Roscoe clay--cropland. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate fine angular blocky structure; surface mulch of very hard fine granules; very hard, firm, sticky, plastic; few fine roots; slightly alkaline; abrupt smooth boundary. (0 to 10 inches thick)
A--7 to 14 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate fine angular blocky structure; very hard, firm, sticky, plastic; shiny pressure faces on peds; few fine roots; slightly alkaline; diffuse wavy boundary. (8 to 18 inches thick)
Bss1--14 to 30 inches; gray (10YR 5/1) clay, dark gray (10YR 4/1) moist; moderate medium angular blocky structure; extremely hard, very firm, very sticky, plastic; contains wedge shaped peds have long axis tilted about 30 degrees from horizontal; few prominent slickensides in lower part; shiny pressure faces on peds; few very fine calcium carbonate concretions in lower part; noneffervescent in upper part, slightly effervescent in lower part; slightly alkaline in upper part, moderately alkaline in lower part; gradual wavy boundary. (10 to 25 inches thick)
Bss2--30 to 45 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; common medium to very fine redoximorphic concentrations of light brown (7.5YR 6/4); moderate medium blocky structure; extremely hard, very firm; wedge shaped peds have long axis tilted about 30 degrees from horizontal; common distinct slickensides; shiny pressure faces on peds; few very fine calcium carbonate concretions; strongly effervescent; moderately alkaline; gradual wavy boundary. (10 to 20 inches thick)
Bk1--45 to 60 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 4/4) moist; common vertically oriented streaks of grayish brown (10YR 5/2) depletion masses; weak coarse prismatic structure parting to moderate fine angular blocky; very hard, firm; about 10 percent by volume of concretions and masses of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (10 to 25 inches thick)
Bk2--60 to 75 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; weak coarse prismatic structure parting to moderate fine angular blocky; very hard, firm, few very fine concretions and masses of calcium carbonate decreasing with depth; strongly effervescent; moderately alkaline.
TYPE LOCATION: Nolan County, Texas; from the junction of Interstate 20 and U. S. Highway 84 at Roscoe, 1.1 miles west on Interstate 20 to junction of a north-south county road, 0.5 mile north on county road, 200 feet west in a cultivated field.
RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days but less than 150 cumulative days in normal years. November through March are the driest months, and April through October are the wettest.
Mean annual soil temperature: 61 to 67 degrees F.
Depth to secondary calcium carbonate: 28 to 73 inches
Depth to redox concentrations: 18 to 53 inches
Depth to redox depletions: 28 to 73 inches
Vertic features: 8 to 28 inches; undisturbed areas of this cyclic soil have gilgai microrelief in which microknolls are 6 to 20 inches higher than microdepressions. The distance between centers of the microknolls and the centers of the microdepressions range from about 4 to 12 feet. When dry, cracks 0.5 to 2 inches wide extend from the surface to a depth of 40 inches or more.
Thickness of the solum, is more than 80 inches
Particle-size control section (weighted average)
Total clay content:40 to 60 percent
Sand content: 10 to 20 percent
Coarse Fragments: 0 to 2 percent
Reaction: slightly alkaline or moderately alkaline
A Horizon
Hue: 10YR or 2.5Y
Value: 3 to 5 dry, 2 to 4 moist; Where moist color values are 4, they comprise less than one-half of the matrix.
Chroma: 0 to 2 dry; More than one-half of the surface layer has chroma of 1 or less; Thickness of chroma of 1 or less ranges from 18 inches on the microknolls to 44 inches in the microdepressions.
Texture: clay
Total clay content: 40 to 55 percent
Coarse fragments: 0 to 2 percent; siliceous gravel mainly less than 2 inches across long axis
Effervescence: noneffervescent to slightly effervescent
Reaction: neutral to slightly alkaline
Bss or Bkss Horizon(s)
Hue: 7.5YR to 10YR
Value: 3 to 5
Chroma: 0 to 4
Texture: clay
Total clay content: 40 to 60 percent
Pressure faces: 3 to 10 percent, prominent, throughout
Slickensides: 3 to 20 percent, prominent, throughout
Redox accumulations: 3 to 10 percent very fine to medium light brown (7.5YR 6/4)
Coarse fragments: 0 to 2 percent;siliceous gravel mainly less than 2 inches across long axis
Calcium carbonate equivalent: 0 to 15 percent
Identifiable secondary carbonate: 0 to 10 percent, very fine to fine as masses and concretions, throughout
Effervescence: slightly effervescent to strongly effervescent
Reaction: slightly alkaline or moderately alkaline
Bk Horizon
Hue: 7.5YR to 10YR
Value: 5 to 8
Chroma: 1 to 4
Texture: clay
Total clay content: 40 to 60 percent
Redox depletions: 3 to 10 percent, vertically oriented streaks of grayish brown (10YR 5/2) depletion masses
Coarse fragments: 0 to 2 percent; siliceous gravel mainly less than 2 inches across long axis
Calcium carbonate equivalent: 1 to 15 percent
Identifiable secondary carbonate: 1 to 12 percent, very fine to medium as masses and concretions, throughout
Gypsum: 0 to 3 percent
Effervescence: slightly effervescent to strongly effervescent
Reaction: slightly alkaline or moderately alkaline
COMPETING SERIES: These are the
Campwood,
Hollister,
Indiahoma,
Irion,
Leeray,
Lockney,
Teagard, and the similar
Kingco series.
Campwood: has 20 to 40 percent calcium carbonate equivalent in the upper subsoil and formed in clayey alluvium from Cretaceous age materials
Hollister: is well drained and are domininated by 2 chroma in the surface layer
Indiahoma: are well drained
Irion: has indurated platy limestone between 60 and 80 inches and formed in clayey from Cretaceous age materials
Kingco: has mixed clay mineralogy
Leeray: is saline in the lower part of the subsoil, and are dominated by 2 chroma in the surface layer
Lockney: occurs in areas above 2500 feet with mean annual temperature less than 62 degrees
Teagard: has shale at 20 to 40 inch depths and have mean annual temperatures less than 62 degrees
GEOGRAPHIC SETTING:
Parent material: calcareous clayey Pliestocene alluvium from Quaternary and Tertiary Age material
Landform and landscape: swale on alluvial plain remnants
Slope: 0 to 1 percent, dominantly less than 0.5 percent
Mean annual air temperature range: 59 to 65 degrees F.
Mean annual precipitation range: 18 to 25 inches
Precipitation Pattern: Precipitation falls mostly during the months of April through October. November through March are the driest months. Spring precipitation occurs during widely scattered intense thunderstorms.
Frost-free period: 200 to 240 days
Elevation: 1500 to 2850 feet
Thornthwaite annual P-E indices: 25 to 36
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Dermott,
Hermleigh,
Pyron,
Sagerton and
Snyder series.
Dermott: occurs higher in the landscape on shoulders, summits and breaks into valleys and drains. It is shallow to a petrocalcic.
Hermleigh: occurs lower in the landscape in depressions and are frequently ponded for more than 7 to more than 30 days following heavy rains
Pyron: occurs on similar to higher positions and is a Mollisol
Sagerton: occurs on similar to higher positions and is a Mollisol
Snyder: occurs on a higher position and is in a fine-loamy family
DRAINAGE AND PERMEABILITY: Moderately well drained; very slow permeability; runoff is medium to negligible. Ponding frequency is none to rare. These soils are ponded 0 to 5 times in 100 years.
USE AND VEGETATION: Mostly cultivated to cotton and grain sorghum. Rangeland areas support buffalograss, vine mesquite, white tridens, tobosa. Sedges are in the bottoms of microdepressions. Mesquite has invaded some areas.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) of north central Texas and southwest Oklahoma. The soil is moderately extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Reconnaissance Soil Survey of West Central Texas; 1922.
REMARKS: The soil was formerly classed in the Grumusol great soil group.
Diagnostic horizons and features recognized with this pedon are:
Mollic epipedon - the zone from 0 to 14 inches deep. (A horizons)
Vertisol features - slickensides in the zone from 14 to 45 inches (Bss horizons). Cracks that open and close periodically.