LOCATION WILCO                   TX

Established Series
Rev. MLG-CKH
11/2010

WILCO SERIES

The Wilco series consists of very deep, well drained, slowly permeable soils that formed in sandy alluvium and eolian deposits over clayey residuum weathered from sandstone and shale. These soils are on nearly level to sloping paleoterraces. Slopes range from 0 to 8 percent. Mean annual precipitation is about 736 mm (29 in) and the mean annual temperature is about 22 degrees C (72 degrees F).

TAXONOMIC CLASS: Fine, mixed, active, hyperthermic Typic Paleustalfs

TYPICAL PEDON: Wilco loamy fine sand, on a convex, 2 percent slopes in cultivated land; elevation is 149 meters (490feet). (Colors are for dry soil unless otherwise stated.)

Ap--0 to 15 cm (0 to 6 in); pale brown (10YR 6/3) loamy fine sand, brown (10YR 5/3) moist; single grain; loose, very friable; many fine roots; moderately acid; clear smooth boundary. (10 to 20 cm [4 to 8 in] thick)

A--15 to 41 cm (6 to 16 in); pale brown (10YR 6/3) loamy fine sand, brown (10YR 5/3) moist; single grain; soft, very friable; many fine roots; moderately acid; abrupt wavy boundary. (15 to 30 cm [6 to 12 in] thick)

Bt1--41 to 51 cm (16 to 20 in); brown (10YR 5/3) sandy clay, brown (10YR 4/3) moist; many medium and coarse distinct yellowish red (5YR 5/6) lithochromic mottles; moderate fine blocky structure; very hard, very firm; few fine roots; few fine pores; common clay films on faces of peds; slightly acid; gradual wavy boundary. (8 to 25 cm [3 to 10 in] thick)

Bt2--51 to 81 cm (20 to 32 in); brown (7.5YR 5/4) sandy clay, brown (7.5YR 4/4) moist; common fine and medium distinct yellowish red (5YR 5/6) and yellowish brown (10YR 5/4) lithochromic mottles; moderate fine blocky structure; very hard, very firm; few fine roots; common clay films on faces of peds; neutral; gradual wavy boundary. (20 to 46 cm [8 to 18 in] thick)

Bt3--81 to 97 cm (32 to 38 in); reddish yellow (7.5YR 6/6) sandy clay loam, strong brown (7.5YR 5/6) moist; many coarse distinct yellowish red (5YR 5/6) mottles; weak and moderate fine blocky structure; hard, firm; few fine roots; few clay films on faces of peds; neutral; gradual wavy boundary. (13 to 46 cm [5 to 18 in] thick)

BC1--97 to 114 cm (38 to 45 in); light yellowish brown (10YR 6/4) fine sandy loam, yellowish brown (10YR 5/4) moist; few fine faint strong brown (7.5YR 5/6) lithochromic mottles; weak medium blocky structure; hard, friable; moderately alkaline; clear smooth boundary. (13 to 38 cm [5 to 15 in] thick)

BCk--114 to 152 cm (45 to 60 in); very pale brown (10YR 7/3) fine sandy loam, pale brown (10YR 6/3) moist; weak very coarse subangular blocky structure; slightly hard, friable; estimated 30 percent by volume of small fragments of gray (10YR 6/1) clayey shale; few fine weakly cemented calcium carbonate concretions; very slightly effervescent; moderately alkaline.

TYPE LOCATION: Wilson County, Texas; 5.5 miles west of intersection of Highways 181 and 97 in Floresville at a point 1/4 mile north of Highway 97 and 35 yards west of unpaved county road. Dewees, Texas USGS topographic quadrangle; Latitude: 29 degrees, 4 minutes, 57.064 seconds, N.; Longitude: 98 degrees, 13 minutes, 32.262 W.; NAD 83.

RANGE IN CHARACTERISTICS:

Soil Moisture: A typic-ustic moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days but less than 180 cumulative days in normal years. June through August and December through February are the driest months. These soils are intermittently moist in September through November and March through May.
Mean annual soil temperature: 72 to 74 (22 to 23.5 degrees F).
Solum thickness: 150 to 200 cm (60 to 80 in)
Depth to abrupt textural change: 15 to 46 cm (6 to 18 in)
Depth to argillic: 20 to 64 cm (8 to 25 in)
Depth to secondary calcium carbonate: 102 to 178 cm (40 to 70 in)

Particle-size control section (weighted average)
Clay content: 35 to 45 percent

A horizon
Hue: 5YR to 10YR
Value: 4 to 7
Chroma: 3 to 6
Texture: loamy fine sand or fine sand
Clay content: 5 to 15 percent
Effervescence: none
Reaction: moderately acid to neutral

Bt Horizons

Hue: 2.5YR to 10YR
Value: 4 to 7
Chroma: 4 to 6
Texture: sandy clay, clay, sandy clay loam, or clay loam
Clay content: 35 to 48 percent
Mottles: common to many, medium and coarse, distinct and prominent, shades of red, yellow, brown or olive
Effervescence: none
Reaction: moderately acid to slightly alkaline

BC Horizon
Hue: 2.5YR to 10YR
Value: 4 to 7
Chroma: 4 to 6
Texture: fine sandy loam, sandy clay loam or clay loam
Clay content: 35 to 48 percent
Effervescence: none to slight
Reaction: slightly alkaline or moderately alkaline

BCk Horizon (where present)
Hue: 2.5YR to 10YR
Value: 4 to 7
Chroma: 4 to 6
Texture: fine sandy loam or sandy clay loam
Coarse fragments: 2 to 75 cm, channers, weakly cemented sandstone and claystone
Identifiable secondary carbonates: 1 to 5 percent, films and threadlike, weakly cemented, in the matrix
Effervescence: none to strong
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Floresville (TX) and Miguel (TX) series and the similar Devine (TX) and Webb (TX) series.

Floresville and Miguel soils: have fine sandy loam textures in the A horizon and have secondary forms of calcium carbonate between depths of 71 to 100 cm (28 and 40 in)
Devine soils: have more than 35 percent coarse fragments in the upper Bt horizon
Webb soils: lack an abrupt texture change between the A and Bt horizon and are dry in the moisture control section for longer periods
Papalote soils: have grayish colors in the upper Bt

GEOGRAPHIC SETTING:
Parent Material: sandy alluvium and eolian deposits over loamy and clayey residuum derived from sandstone and claystone bedrock
Landscape: inland dissected coastal plain
Landform: paleoterraces
Slope: 0 to 8 percent
Mean annual precipitation: (26 to 32 in)
Mean annual temperature: (70 to 74 degrees F.)
Frost free period: 270 to 305 days
Elevation: 65 to 168 m (215 to 550 ft)
Thornthwaite annual P-E indices: 36 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Floresville (TX), Miguel (TX), Nusil (TX) and Rhymes (TX) series.
Floresville and Miguel soils: are on a similar surface
Nueces and Sarita soils: have sandy surface layers thicker than 50 cm (20 in) and are on similar surfaces

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; slow permeability.

USE AND VEGETATION: Used for dry and irrigated cropland, pasture, and rangeland. Main crops are peanuts, grain sorghums, corn, cotton, and watermelons. Pastures are mainly improved bermudagrass. Present native vegetation includes bristlegrass, windmillgrass, threeawn, mesquite, huisache, whitebrush, cacti, and annuals.

DISTRIBUTION AND EXTENT: Northern Rio Grande Plain, Texas; LRR I; MLRA 83A. The series is of large extent.

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

SERIES ESTABLISHED: Wilson County, Texas; 1972.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 41 cm (0 to 16 in)

Argillic horizon: 41 to 97 cm (16 to 38 in)

ADDITIONAL DATA: Lab data was performed on 2 pedons from McMullen County at the local project office.

TAXONOMIC VERSION: Keys to Soil Taxonomy, Eleventh Edition, 2010

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National Cooperative Soil Survey
U.S.A.