LOCATION TASAJAL TXEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, active, hyperthermic Petrocalcic Natrustalfs
TYPICAL PEDON: Tasajal loamy fine sand in rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 3 inches; pale brown (10YR 6/3) loamy fine sand, brown (10YR 4/3) moist; weak fine granular and subangular blocky structure; slightly hard, very friable; many very fine and fine roots; few fine pores; moderately acid; clear smooth boundary. (7 to 20 inches thick)
A2--3 to 12 inches; pale brown (10YR 6/3) loamy fine sand, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable; many very fine and fine roots; few fine pores; moderately acid; abrupt smooth boundary. (0 to 10 inches thick)
2Btnl--12 to 19 inches; brown (10YR 4/3) fine sandy loam, dark brown (10YR 3/3) moist; moderate coarse prismatic structure parting to moderate medium blocky; extremely hard, firm; few very fine and fine roots; few fine pores; few faint clay films on faces of peds; grayish brown (10YR 5/2) organic coating along the contact of the A and Btn horizons, EC is 3.2 dS/m; neutral; clear smooth boundary. (4 to 12 inches thick)
2Btn2--19 to 28 inches; light yellowish brown (10YR 6/4) fine sandy loam, yellowish brown (10YR 5/4) moist; weak medium prismatic structure parting to weak fine and medium blocky; very hard, firm; few very fine and fine roots; few fine pores; few faint clay films on faces of peds; EC is 9.3 dS/m; very slightly effervescent; moderately alkaline; clear smooth boundary. (5 to 20 inches thick)
2Btkn--28 to 34 inches; very pale brown (10YR 7/4) fine sandy loam, light yellowish brown (10YR 6/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, few very fine and fine roots; few faint clay films on faces of peds; EC is 10.8 dS/m; few fine and medium concretions of calcium carbonate; very slightly effervescent; moderately alkaline; abrupt wavy boundary. (5 to 20 inches thick)
3Bkm--34 to 36 inches; very pale brown (10YR 8/2) indurated caliche; platy and etched; hardness is more than 3 on the Moh's scale dry; clear smooth boundary. (1 to 4 inches thick)
3Bk--36 to 50 inches; very pale brown (10YR 8/2) weakly cemented caliche; massive but contains a few fractures.
TYPE LOCATION: Brooks County, Texas; from the intersection of U.S. Highway 281 and Farm Road 755, which is 3.2 miles south of Encino; 7.3 miles west of Rachal on Farm Road 755, 5.1 miles north and west on Farm Road 430, 1 mile south on paved road to ranch road; 6.3 miles west and 1.6 miles south on ranch road; 1300 feet west in rangeland. Santa Elena, Texas USGS topographic quadrangle; Latitude: 26 degrees, 52 minutes, 11 seconds N.; Longitude: 98 degrees, 24 minutes, 49 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS: Solum thickness and depth to the petrocalcic horizon ranges from 30 to 50 inches. Secondary calcium carbonates occur below a depth of 20 inches. Electrical conductivity of the saturation extract is less than 2 dS/m in the A horizon and ranges to as much as 6 dS/m in the 2B horizons. One or more lithologic discontinuties occur in most pedons.
The A horizons has hue of 10YR, value of 5 or 6, and chroma of 2 or 3. Texture is loamy fine sand or fine sand. Reaction is moderately acid to neutral.
The 2Btn horizon has hue of 10YR, value of 4 to 6, and chroma of 2 to 4. A few brownish concentrations occur in some pedons. Exchangeable sodium in the upper 16 inches is more than 15 percent and increases with depth. Reaction is neutral to strongly alkaline.
The 2Btkn horizon has hue of 10YR value of 6 to 8, and chroma of 3 or 4. A few brownish concentrations occur 1n some pedons. Calcium carbonate concretions and masses range from few to common. Reaction is moderately alkaline or strongly alkaline.
The 3Bk horizon is strongly cemented or indurated in the upper part and becomes less cemented with increasing depth.
COMPETING SERIES: There are no series in the same family. Similar soils are Quiteria, Sauz and Willamar series. These soils do not have a petrocalcic horizon. Quiteria soils have low chroma depletions due to wetness within 20 inches of the soil surface. Sauz and Willamar soils have an aquic moisture regime.
GEOGRAPHIC SETTING: Tasajal soils have plane slopes with gradients of 0 to 1 percent. They formed in sandy eolian sediments (sand sheet) overlying loamy sediments of Pleistocene or Pliocene age, mainly of the Goliad Formation. Climate is semiarid with mean annual precipitation ranging from 22 to 25 inches. Mean annual temperature range is 73 to 74 degrees F. Thornthwaite P-E index ranges from 26 to 30.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Quiteria, and the Nueces and Sarita series on similar landscape positions. Nueces soils have a sandy epipedon more than 20 inches thick. Sarita soils have a sandy epipedon more than 40 inches thick. In addition, the Nueces and Sarita soils have less than 15 percent exchangeable sodium.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Used primarily for rangeland and wildlife habitat. The native vegetation in excellent condition is composed of 90 percent grasses, 5 percent woody plants and 5 percent forbs.
DISTRIBUTION AND EXTENT: Central Rio Grande Plain and Sandsheet Prairie, Texas; LLR I, MLRA 83C and 83E. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Brooks County, Texas. The name is from a lake in Brooks County.
REMARKS: Tasajal soils were formerly included with the Hebbronville and Comitas series.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 12 inches
Natric horizon - the zone from approximately 12 to 34 inches
Petrocalcic horizon - 34 to 36 inches
ADDITIONAL DATA: None
TAXONOMIC VERSION: Keys to Soil Taxonomy, Ninth Edition, 2003.