LOCATION WEIGANG                 TX

Established Series
JWS-JDN-CKH
11/2010

WEIGANG SERIES

The Weigang series consists of shallow, well drained, moderately permeable soils that formed in residuum that weathered from sandstone bedrock and claystone. These soils are on gently sloping to steep uplands. Slopes range from 1 to 25 percent. Mean annual precipitation is about 635 mm (25 in) and the mean annual air temperature is about 21.7 degrees C (71 degrees F).

TAXONOMIC CLASS: Loamy, mixed, active, hyperthermic, shallow Typic Argiustolls

TYPICAL PEDON: Weigang loam, in rangeland; elevation is 75 meters (246 feet). (Colors are for dry soil unless otherwise stated.)

A1--0 to 15 cm (O to 6 in); dark grayish brown (10YR 4/2), sandy clay loam, very darkgrayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable; common fine and medium roots; common fine and medium pores; few fine fragments of sandstone to 1/4 inch across; neutral; clear smooth boundary. (10 to 25 cm (4 to 10 in thick))

Bt--15 to 41 cm (6 to 16 in); dark grayish brown (10YR 4/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure parting to moderate medium blocky; hard, friable; 15 percent clay films on surfaces of peds; common fine roots; few fine pores; few fine fragments of sandstone to 1/2 inch across; neutral; abrupt wavy boundary. (15 to 36 cm (6 to 14 in thick))

Cr--41 to 56 cm (16 to 22 in); white (2.5Y 8/1) weakly cemented sandstone bedrock, moderately hard and brittle; contains streaks that are yellow, yellowish brown, and brown; noncalcareous matrix; moderately alkaline.

TYPE LOCATION: Atascosa County, Texas; from the intersection of U.S. Highway
281 and farm market road 791 in Campbellton; 6.5 miles south on U.S. Highway 281; then 50 feet west in rangeland; (Arrow S Ranch) Whitsett, Texas USGS topographic quadrangle; Latitude: 28 degrees, 39 minutes, 18.62 seconds N; Longitude: 98 degrees, 17 minutes, 9.68 seconds 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: 22.2 to 23.9 degrees C (72 to 75 degrees F).
Solum thickness: 20 to 50 cm (8 to 20 in, and the range in thickness is common within horizontal distances of less than 6.1 meters (20 feet).
Depth to argillic: 0 to 25 cm (0 to 10 in)
Depth to paralithic contact: to the top of the contact 41 cm (16 in)

A horizon
Hue: 7.5YR or 10YR
Value: 3 to 5
Chroma: 1 to 3
Texture: fine sandy loam, loam, clay loam, or sandy clay loam
Reaction: slightly acid to slightly alkaline.
Coarse fragments: sandstone

Bt horizon or Btk (where present)
Hue: 7.5YR or 10YR
Value: 2 to 5
Chroma: 1 to 3
Texture: sandy clay loam, loam or clay loam
Coarse fragments: sandstone 0 to 55 percent stones, 0 to 20 percent cobbles and 0 to 15 percent channers
Reaction: slightly acid to slightly alkaline

BCk horizon (where present)
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 3 to 6
Texture: sandy clay loam, loam or clay loam
Coarse fragments: sandstone 0 to 55 percent stones, 0 to 20 percent cobbles and 0 to 15 percent channers
Reaction: slightly alkaline to strongly alkaline

Cr layer
Sandstone interbedded with claystone bedrock with thin layers of calcium carbonate.
Reaction: slightly acid to moderately alkaline

COMPETING SERIES: There are no competing series in the same family. Similar series are the Cuero, Ecleto, Runge, Tela, and Zavco series.
Cuero soils: are more than 50 cm (20 in) thick and have a mollic epipedon more than 50 cm (20 in) thick.
Ecleto soils: are clayey and smectitic
Runge and Tela soils: are more than 50 cm (20 in)
Zavco soils: are more than 50 cm (20 in) and are dry in the moisture control section for longer periods.

GEOGRAPHIC SETTING:
Parent material: loamy materials over thick beds of sandstone or interbedded sandstone and claystone bedrock of the Jackson Formation.
Landform: Ridges
Slope: 1 to 25 percent
Mean annual air temperature: 21 to 23 degrees C (70 to 74 degrees F)
Mean annual precipitation: 559 to 660 cm (22 to 26 in)
Frost-free period: 270 to 320 days
Elevation: 64.5-144.5 m
Thornthwait annual P-E indices: 30 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Coy, Laparita, Monteola,
Picosa, and Tordia series.
Coy, Laparita, Monteola, and Tordia soils: are in lower, less sloping positions; very deep and more clayey throughout. In addition, Coy and Monteola soils are calcareous throughout.
Picosa soils: are on a similar position; and do not have an argillic horizon.

DRAINAGE AND PERMEABILITY: The soil is well drained. Permeability is moderate. The sandstone bedrock layer is slowly to very slowly permeable. Runoff is very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, medium on 5 to 20 percent slopes, high on 20 to 25 percent slopes.

USE AND VEGETATION: Mainly used as native rangeland and wildlife habitat. A few areas are cultivated or they are used as improved pasture. The native plant community is mainly red grama, threeawn, red lovegrass, Hall's panicum, bristlegrass, and pink pappusgrass. Woody vegetation is mainly blackbrush, spiny hackberry, and agarita.

DISTRIBUTION AND EXTENT: In the north-central part of the Rio Grande Plain of
Texas (LRR I, MLRA 83A). This soil is of moderate extent.

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

SERIES ESTABLISHED: Atascosa County, Texas; 1977.

REMARKS:
Diagnostic horizons associated with this pedon are:

Particle size control section: 6 to 16 in (Bt horizon)
Mollic epipedon: 0 to 41 cm (0 to 16 in). (A horizon)
Argillic horizon: 15 to 41 cm (6 to 16 in). (Bt Horizon)
Paralithic contact: 41 to 56 cm (16 to 22 in). (Cr Layer)

ADDITIONAL DATA: Particle size analysis, sieve analysis, sodium absorption ratio, electrical conductivity, pH were all performed at the local project office from McMullen County.

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

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National Cooperative Soil Survey
U.S.A.