LOCATION TILLMAN                 TX OK

Established Series
Rev. CRC:DDR:TGM
09/2016

TILLMAN SERIES

The Tillman series consists of very deep, well drained, slowly permeable soils. These soils formed in loamy and clayey alluvium derived from redbed clays and claystone sediments of Permian age. These soils are on nearly level to gently sloping alluvial plains and alluvial plain remnants of the Central Rolling Red Plains (MLRA-78C) and the Rolling Limestone Prairie (MLRA-78D). Slope ranges from 0 to 5 percent. The mean annual air temperature is 16 degrees C (61 degrees F) and the mean annual precipitation is 660 mm (26 in).

TAXONOMIC CLASS: Fine, mixed, superactive, thermic Vertic Paleustolls

TYPICAL PEDON: Tillman loam-rangeland, at an elevation of 370.2 m (1214 ft). (Colors are for dry soil unless otherwise stated.)

A1--0 to 8 cm (0 to 3 in); brown (7.5YR 5/3) loam, dark brown (7.5YR 3/3) moist and crushed; moderate medium subangular blocky structure; very firm, very hard; many fine roots and few medium roots; common fine and medium pores; few worm casts and channels; strongly acid; clear smooth boundary. (Thickness of the A horizon is 10 to 40 cm [4 to 16 in])

A2--8 to 18 cm (3 to 7 in); brown (7.5YR 4/3) clay loam, dark brown (7.5YR 3/3) moist; moderate fine and medium subangular blocky structure; very firm, very hard; many fine roots and few medium roots and many very fine roots; common fine and medium pores; few worm casts and channels; moderately acid; clear smooth boundary. (Thickness of the A horizon is 8 to 40 cm [3 to 16 in])

Bt1--18 to 43 cm (7 to 17 in); reddish brown (5YR 4/3) clay, dark reddish brown (5YR 3/3) moist; moderate coarse prismatic structure parting to strong medium angular blocky structure parting to strong fine angular blocky structure; very firm, extremely hard; common very fine roots, common fine roots, few medium roots, and few course roots; common fine and medium pores; few worm casts and channels; 30 percent distinct clay films on surface of peds; slightly acid; gradual smooth boundary. (6 to 12 inches thick)

Bt2--43 to 69 cm (17 to 27 in); reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate coarse prismatic structure parting to strong medium angular blocky structure parting to strong fine angular blocky structure; very firm, extremely hard; few very fine roots, few fine roots, few medium roots; common fine and medium pores; few worm casts and channels; 30 percent distinct clay films and 30 percent distinct pressure faces on surface of peds; slightly alkaline; gradual smooth boundary. (Combined thickness of the Bt horizon is 25 to 80 cm [10 to 32 in])

Btk1--69 to 102 cm (27 to 40 in); reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; weak coarse prismatic structure parting to moderate medium angular blocky structure parting to moderate fine angular blocky; very firm, extremely hard; few fine roots and few medium roots; 20 percent distinct clay films; 5 percent fine carbonate masses and 5 percent fine carbonate concretions; violent effervescence; moderately alkaline; gradual smooth boundary.

Btk2--102 to 135 cm (40 to 53 in); reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; weak coarse prismatic structure parting to moderate medium angular blocky structure parting to moderate fine angular blocky; very firm, extremely hard; few fine roots and few medium roots; 15 percent distinct clay films; 5 percent fine carbonate masses and 5 percent fine carbonate concretions; violent effervescence; moderately alkaline; gradual smooth boundary. (8 to 20 inches thick)

Btk3--135 to 168 cm (53 to 66 in); reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; fine distinct reddish brown (2.5YR 4/4) mottles; weak coarse prismatic structure parting to moderate medium angular blocky structure parting to moderate fine angular blocky; very firm, extremely hard; few fine roots and few medium roots; 10 percent distinct clay films; 7 percent coarse carbonate masses and 7 percent coarse carbonate concretions; violent effervescence; moderately alkaline; gradual smooth boundary. (Combined thickness of the Btk horizon is 30 to 76 cm [12 to 30 in])

2BCk--168 to 203 cm (66 to 80 in); reddish brown (2.5YR 4/4) clay, dark reddish brown (2.5YR 3/4) moist; weak coarse prismatic structure parting to moderate medium subangular blocky structure; very firm, extremely hard; few fine roots and few medium roots; 3 percent medium carbonate masses and 3 percent medium carbonate concretions; violent effervescence; moderately alkaline; gradual smooth boundary. (Thickness of the BCk horizon is 0 to 46 cm [0 to 18 in])

2Cr--203 to 216 cm (80 to 85 in); red (2.5YR 4/8) clay loam, red (2.5YR 4/6) moist; massive; very firm, extremely hard; horizon has rock structure with cleavage planes. Some clay coatings on cleavage planes; violent effervescence; moderately alkaline.

TYPE LOCATION: Wilbarger County, Texas; from the intersection of Farm Road 433 and U. S. Highway 70 in Lockett; 3.6 miles southwest on U. S. Highway 70; 5.0 miles south on Farm Road 1207; 0.05 mile west on county road, 4.9 miles south, 0.1 mile southwest, 5.3 miles southeast and south to gate to fenced enclosure and 160 feet east from gate into rangeland enclosure.

USGS topographic quadrangle: Santa Rosa Lake, Texas
Latitude: 33 degrees, 53 minutes, 15.32 seconds N
Longitude 99 degrees, 19 minutes, 30.91 seconds W
Datum: WGS84

Decimal Degrees:
Latitude: 33.8875889
Longitude: -99.3252527

UTM Easting: 469924 m
UTM Northing: 3749740 m
UTM Zone: 14N

RANGE IN CHARACTERISTICS:
Thickness of the solum: 152 to 203 cm (60 to more than 80 in) over dense clay or clay loam, or claystone
Thickness of the mollic epipedon: 25 to 50 cm (10 to 20 in) and usually extends into the argillic horizon
Depth to secondary calcium carbonate: 0 to 60 cm (0 to 24 in)
Depth to a calcic horizon (where present): 100 cm (more than 40 in)
Depth of cracks: 121 cm (more than 48 in) deep
COLE:; more than 0.06 in the upper 100 cm (40 in)
Some pedons have a few siliceous gravel or cobbles on the surface

Particle-size control section (weighted average):
Clay content: 35 to 50 percent
Coarse fragments: amount-0 to 5 percent; size-2 to 250 mm; kind-quartzite
CEC/clay ratio: 0.6 or more

A horizon:
Hue: 5YR or 10YR
Value: 3 to 5, 2.5 to 4 moist
Chroma: 2 or 3
Texture: loam, silt loam, silty clay loam, or clay loam
Clay content: 18 to 35 percent, but averages 30 percent or less
Calcium carbonate equivalent: 0 to 2 percent
Electrical Conductivity (mmhos/cm): 0 to 2
Sodium Adsorption Ratio: 0 to 1
Effervescence: none to slight
Reaction: slightly acid to moderately alkaline (6.1 to 8.4)

Bt horizon:
Hue: 2.5YR or 5YR
Value: 3 to 5, 2.5 to 4 moist
Chroma: 2 to 6; with 5 or more in some part of the horizon
Texture: clay loam, silty clay loam, silty clay, or clay
Other features: Some pedons have a few slickensides
Calcium carbonate equivalent: 0 to 5 percent
Identifiable secondary carbonate: none to a few fine or medium concretions
Electrical Conductivity (mmhos/cm): 0 to 2
Gypsum: 0 to 1 percent
Sodium Adsorption Ratio 0 to 2
Effervescence: none to strong
Reaction: slightly alkaline or moderately alkaline (7.4 to 8.4)

Btk horizon:
Hue: 2.5YR or 5YR
Value: 3 to 5, 2.5 to 4 moist
Chroma: 4 to 6; with 5 or more in some part of the horizon
Texture: clay loam, silty clay loam, silty clay, or clay
Other features: Some pedons have a few slickensides
Calcium carbonate equivalent: 5 to 30 percent
Identifiable secondary carbonate: few to many, fine to coarse, concretions, films, threads, or masses
Electrical Conductivity (mmhos/cm): 0 to 8
Gypsum: 0 to 2 percent
Sodium Adsorption Ratio 0 to 12
Effervescence: strongly effervescent to violently effervescent
Reaction: moderately alkaline (7.9 to 8.4)

BCk or 2BCk horizons:
Hue: 2.5YR or 5YR
Value: 3 to 5, 2.5 to 4 moist
Chroma: 4 to 6
Texture: clay loam, silty clay loam, silty clay, or clay
Calcium carbonate equivalent: 2 to 20 percent
Identifiable secondary carbonate: few to many, fine to coarse, concretions, films or masses
Electrical Conductivity (mmhos/cm): 0 to 8
Gypsum: 0 to 2 percent
Sodium Adsorption Ratio 0 to 12
Effervescence: slight or violent
Reaction: slightly alkaline or moderately alkaline (7.4 to 8.4)

C or 2C horizons:
Color: in shades of red, brown, gray, or green
Texture: clay loam, silty clay loam, silty clay, clay, or weakly consolidated claystone
Calcium carbonate equivalent: 1 to 10 percent
Electrical Conductivity (mmhos/cm): 0 to 8
Gypsum: 0 to 2 percent
Sodium Adsorption Ratio 0 to 12
Effervescence: very slight to strong
Reaction: slightly alkaline or moderately alkaline (7.4 to 8.4)

COMPETING SERIES: There are no competing series in the same family. Similar soils are the Agra (OK), Deandale (TX), Hollister (OK), Renfrow (OK), Sagerton (TX), Westill (OK), and Wichita (TX) series.
Agra and Renfrow soils: have secondary carbonates below a depth of 60 cm (24 in) and are moist for longer periods of time
Deandale and Hollister soils: have a mollic epipedon more than 50 cm (20 in) thick and have smectitic mineralogy
Sagerton soils: have a distinct calcic horizon and do not have vertic properties
Westill soils: have sola less than 152 cm (60 in) thick and have developed mainly in the Blaine Formation of Permian age
Wichita soils: have an ochric epipedon

GEOGRAPHIC SETTING:
Parent material: formed in alluvium from redbed clay and claystone, mainly of the Clear Fork Group of Permian age
Landscape: alluvial plains
Landform: paleoterraces
Slope: 0 to 3
Mean annual precipitation: 584 to 710 mm (23 to 28 in)
Mean annual air temperature: 13.9 to 17.8 degrees C (57 to 64 degrees F)
Frost-free period: 180 to 230 days
Elevation: 305 to 670 m (1,000 to 2,200 ft)
Thornthwaite annual P-E indices: 33 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Deandale, Hollister, Tilvern, Vernon, and Wichita series which are on slightly lower landscape positions.
Tilvern and Vernon soils: are higher on positons, have an ochric epipedon, and have sola less than 152 cm (60 in) thick

DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is medium on slopes less than 1 percent and high on 1 to 5 percent slopes.

USE AND VEGETATION: Mainly in cropland with small grains, cotton, and sorghums grown. Native vegetation is mainly buffalograss, grama grasses, vine mesquite, Texas wintergrass, prickly pear and mesquite.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

DISTRIBUTION AND EXTENT: LRR-H; Rolling Limestone Prairie (MLRA 78D) and Eastern Part of the Central Rolling Red Plains (MLRA 78C) of northwest Texas and western Oklahoma. The series extent is large.

SERIES ESTABLISHED: Tillman County, Oklahoma; 1932.

REMARKS:
Classification is changed from Typic Paleustolls to Vertic Paleustolls 4/2000 based on data from several pedons. Also the series is being restricted to soils that are very deep to redbed claystone. Soils formerly mapped in the Tillman series on the Blaine Formation will be included mostly with the Westill series, which is deep to redbed claystone.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 45 cm (0 to 18 in) (A, Bt1, and Bt2 horizons).
Argillic horizon: 10 to 188 cm (4 to 74 in) (Bt and Btk horizons).
Pale feature: Clay content does not decrease by as much as 20 percent from the maximum within 152 cm (60 in) with chroma of 5 or more in some part of the argillic horizon.

The assignment of the cation-exchange activity class is based on lab data from several pedons.

ADDITIONAL DATA: KSSL data, Lab. Nos. 67L538 - 67L543; 67L772, February 1968, and S96OK-065-003.

Taxonomic version: Keys to Soil Taxonomy, Twelfth Edition, 2014

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National Cooperative Soil Survey
U.S.A.