LOCATION VALERA                  TX

Established Series
Rev. OLB-BJW-MLG-WJG
12/2013

VALERA SERIES

The Valera series consists of soils that are moderately deep to a petrocalcic horizon underlain by indurated limestone bedrock. These well drained, moderately slowly pearmeable soils formed in clayey slope alluvium derived from limestone of Cretaceous age. These nearly level to moderately sloping soils occur on footslopes of hillslopes on dissected plateaus. Slope ranges from 0 to 6 percent. Mean annual precipitation is about 610 mm (24 in) and the mean annual air temperature is about 18 degrees C (65 degrees F).

TAXONOMIC CLASS: Fine, smectitic, thermic Petrocalcic Calciustolls

TYPICAL PEDON: Valera silty clay--rangeland.
(Colors are for dry soil unless otherwise stated.)

A1--0 to 36 cm (0 to 14 in); dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate very fine subangular blocky and weak very fine blocky structure parting to granular structure; very hard, very firm; few fine roots; strongly effervescent; moderately alkaline; gradual wavy boundary.

A2--36 to 61 cm (14 to 24 in); brown (7.5YR 4/3) silty clay, dark brown (7.5YR 3/3) moist; moderate very fine and fine blocky structure; very hard, very firm; 1 percent fine carbonate concretions; 5 percent limestone gravel; strongly effervescent; moderately alkaline; gradual wavy boundary. Combined thickness of the A horizon is 50 to 112 cm (20 to 44 in)

Bw--61 to 76 cm (24 to 30 in); brown (7.5YR 5/4) silty clay, brown (7.5YR 4/4) moist; moderate very fine and fine blocky structure; very hard, very firm; 1 percent fine carbonate concretions; 5 percent limestone gravel; strongly effervescent; moderately alkaline; abrupt irregular boundary. Thickness of the Bw horizon is 0 to 64 cm (0 to 25 in)

Bkm--76 to 91 cm (30 to 36 in); pink (7.5YR 7/4) strongly cemented calcium carbonate; many imbedded fragments of limestone; 1 percent fine carbonate masses; violently effervescent; moderately alkaline; abrupt irregular boundary. Thickness of the Bkm horizon is 3 to 30 cm (1 to 12 in)

R--91 to 116 cm (36 to 46 in); fractured indurated limestone bedrock, cracks are filled with reprecipitated calcium carbonate.

TYPE LOCATION: Menard County, Texas; From the intersection of U.S. Highway 83 and Texas Highway 29, 19.2 miles west on U.S. Highway 83, 2.6 miles east on county road, 4.9 miles north on county road, 0.5 mile northeast of county road in pastureland.
USGS topographic quadrangle: Fort McKavett NE, TX; Latitude: 30 degrees, 57 minutes, 14.8 seconds N; Longitude: 100 degrees, 3 minutes, 31.1 seconds W; Datum: NAD83

RANGE IN CHARACTERISTICS:
Soil moisture: Typic-ustic moisture regime
Depth to petrocalcic horizon: 50 to 102 cm (20 to 40 in)
Depth to lithic contact: 53 to 102 cm (21 to 40 in)
Cracks: when dry, 1 to 2 cm (less than 1 in) wide that extend from the surface to a depth of 25 to 50 cm (10 to 20 in) or more
Coefficient of linear extensibility: Less than 0.07 in all horizons.
Effervescence: Strong to violent
Reaction: Slightly alkaline or moderately alkaline

Particle-size control section (weighted average):
Total clay content: 35 to 55 percent
Carbonate clay content: 3 to 20 percent
Coarse fragments: 0 to 14 percent by volume, 2 to 75 mm, limestone

A horizon
Hue: 5YR to 10YR
Value: 3 to 7 dry, 3 to 6 moist
Chroma: 1 to 4 dry, 1 to 3 moist
Texture: Silty clay loam, clay loam, silty clay, or clay
Total clay content: 35 to 55 percent
Carbonate clay content: 0 to 15 percent
Calcium carbonate equivalent: 3 to 40 percent
Electrial conductivity (mmhos/cm): 0 to 2

Bw or Bk horizon
Hue: 7.5YR or 10YR
Value: 4 to 7 dry, 3 to 5 moist
Chroma: 2 to 4, dry and moist
Texture: Silty clay loam, clay loam, silty clay, or clay
Total clay content: 35 to 55 percent
Carbonate clay content: 10 to 20 percent
Calcium carbonate equivalent: 40 to 90 percent
Electrial conductivity (mmhos/cm): 0 to 2

Bkm horizon
Hue: 7.5YR or 10YR
Value: 7 or 8, dry and moist
Chroma: 1 to 4, dry and moist
Cementation: Weakly cemented to strongly cemented, with a laminar cap
Other features: The boundary between the A and the Bkm horizon is clear to abrupt, and wavy to irregular.

R layer
Texture: limestone bedrock with interbedded caliche, marl, and limestone fragments, and secondary carbonates in fractures
Cementation: strongly cemented to indurated

COMPETING SERIES: This is the Pratley series in the same family. Similar soils are the Cho, Eola, Kavett, Mailtrail, Mereta, Ozona, and Prade series.
Cho, Kavett, Mereta, and Ozona soils: are less than 50 cm (20 in) deep to a petrocalcic horizon
Eola, Mailtrail, and Prade soils: are less than 50 cm (20 in) deep to a petrocalcic horizon and have more than 35 percent coarse fragments in the particle-size control section
Pratley soils: have paralithic material below the petrocalcic horizon

GEOGRAPHIC SETTING:
Parent material: Clayey slope alluvium derived from limestone of Cretaceous age.
Landscape: Dissected plateau
Landform: Footslopes on hillslopes
Slope: dominantly 0 to 3 percent, but ranges up to 6 percent
Precipitation Pattern: The majority of the yearly rainfall occurs during the spring and fall months. The winter and summer months are normally drier.
Mean annual precipitation: 508 to 787 mm (20 to 31 in)
Thornthwaite P.E. indices: 29 to 42
Mean annual air temperature: 16.7 to 18.9 degrees C (62 to 66 degrees F)
Frost-free period: 215 to 240 days
Elevation: 403.9 to 792.5 m (1325 to 2600 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Angelo, Dev, Kavett, Mereta, Nuvalde, and Tarrant series.
Angelo and Nuvalde soils: are very deep alluvial soils and occur on similar or lower positions
Dev soils: have more than 35 percent coarse fragments in the particle-size control section and occur on lower flood plains
Mereta soils: occur on knolls and similar landform positions
Kavett and Tarrant soils: occur on higher summit, shoulder, and backslope positions

DRAINAGE AND PERMEABILITY: Well drained. Permeability in the soil is moderately slow. Permeability in the petrocalcic horizon is slow to very slow. Runoff is low on 0 to 1 percent slopes, medium on 1 to 5 percent slopes, and high on 5 to 6 percent slopes.

USE AND VEGETATION: Mostly in rangeland. The remainder is used for cropland or wildlife. The major crops are forage sorghums and small grains. The climax plant community is a tall grass prairie. The dominant grass is little bluestem. Other plants include sideoats grama, vine mesquite, yellow Indiangrass, big bluestem, Canada wildrye, live oak, silver bluestem, Texas wintergrass, cane bluestem, hairy wedelia, Texas cupgrass, tall dropseed, and plains lovegrass. The dominant forbs include Maximilian sunflower, Engelmann daisy, and bushsunflower. The woody plants include elm, live oak, hackberry, bumelia, green briar and elbowbush. With heavy stocking rates, the site could potentially deteriorate to a plant population of tumblegrass, hairy tridens, Texas grama, red threeawn, western ragweed, broomweed, prairie coneflower, and Ashe juniper.

DISTRIBUTION AND EXTENT: West-Central Texas; LLR-I: Southwest Plateaus and Plains Range and Cotton Region; MLRA 81B - Edwards Plateau, Central Part. The series is extensive with about 250,000 acres.

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

SERIES ESTABLISHED: Coleman County, Texas; l922.

REMARKS: Soils formerly classified as shallow phases of the Valera series are now placed in the Kavett series.

Edited 12/2013 (RFG-THW): Added metric, carbonate clay, CCE, and EC values. Updated the competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 61 cm (0 to 24 in) (A1 and A2 horizons)
Cambic horizon: 61 to 76 cm (24 to 30 in) (Bw horizon)
Petrocalcic horizon: 76 to 91 cm (30 to 36 in) (Bkm horizon)
Lithic contact: 91 cm (36 in) (top of R layer)

ADDITIONAL DATA: KSSL data is available from Menard County 63TX327001 and 63TX327002 and Sutton County 87TX435001. It should be noted that each of these pedons should be classified as fine-silty once carbonate clay is subtracted from total clay.

Taxonomic Version: Keys to Soil Taxonomy, Eleventh Edition, 2010.

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National Cooperative Soil Survey
U.S.A.