LOCATION SABENYO TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, carbonatic, hyperthermic Aridic Calciustepts
TYPICAL PEDON: Sabenyo loam--cropland. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 5 inches; brown (10YR 5/3) loam, dark brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable; few fine roots; few fine pores and old root channels; few strongly cemented calcium carbonate concretions up to 1/4 inch diameter; 40 percent calcium carbonate equivalent; few fragments of snail shells on surface; 1/4 inch platy surface crust of slightly lighter color; violently effervescent; moderately alkaline; abrupt smooth boundary. (0 to 6 inches thick)
A--5 to 11 inches; brown (10YR 5/3) loam, dark brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; hard, friable; few fine roots; few fine pores and old root channels; few weakly cemented calcium carbonate concretions up to 1/4 inch diameter; about 40 percent calcium carbonate equivalent; few fragments of snail shell; violently effervescent; moderately alkaline; abrupt smooth boundary. (4 to 8 inches thick)
Bk2--11 to 17 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 5/4) moist; moderate fine and medium subangular blocky structure; hard, friable; many fine pores and old root channels; many threads of calcium carbonate; common concretions of calcium carbonate up to 1/2 inch diameter; 40 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; clear smooth boundary. (4 to 11 inches thick)
Bk3--17 to 34 inches; reddish yellow (7.5YR 7/6) clay loam, reddish yellow (7.5YR 7/6) moist; weak fine and medium subangular blocky structure; hard, friable; few fine and medium pores; 30 percent weakly cemented concretions of calcium carbonate up to 1.0 inch diameter; 50 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; gradual smooth boundary. (6 to 24 inches thick)
Bk4--34 to 55 inches; reddish yellow (7.5YR 7/6) clay loam, reddish yellow (7.5YR 7/6) moist; weak fine subangular blocky structure; hard, friable; 25 percent pinkish white (7.5YR 8/2) strongly cemented concretions of calcium carbonate up to 2 inches in diameter; 50 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; gradual wavy boundary. (10 to 25 inches thick)
BCk--55 to 85 inches; pink (7.5YR 8/4) sandy loam, pink (7.5YR 7/4) moist; massive; slightly hard, 50 percent calcium carbonate equivalent; violently effervescent; moderately alkaline.
TYPE LOCATION: Uvalde County, Texas; 7.3 miles south on Farm Market Road 187 from its intersection with U. S. Highway 90 in Sabinal; east 200 feet from right-of-way in cultivated field; 100 feet north of cross-fence.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 70 inches. An estimated 1/4 to 1/2 of the clay fraction is carbonates. The 10- to 40-inch particle size control section ranges from loam to clay loam, averaging 18 to 30 percent silicate clay. The control section ranges from 40 to 80 percent by weight of calcium carbonate equivalent with 15 to 34 percent in the form of cemented concretions.
The Ap and A horizons have hue of 10YR, value of 5 to 7, and chroma of 2 or 3. Texture is loam or clay loam. It contains 30 to 70 percent by weight of calcium carbonate equivalent.
The Bk and Ck horizons have hue of 7.5YR or 10YR, value of 5 to 8, and chroma of 3 to 6. The Bk horizon is loam or clay loam and the BCk horizon is loam, sandy loam, or clay loam.
COMPETING SERIES: There are no other series in the same family. Similar soils are the Atco, Colibro, Conalb, McAllen, and Saspamco series. Atco and Saspamco soils are in the coarse-loamy family. Colibro soils are moist for longer periods. Conalb soils have an irregular distribution of organic matter due to stratification. McAllen soils, as well as Colibro and Saspamco soils, have less than 40 percent calcium carbonate in their control sections.
GEOGRAPHIC SETTING: Sabenyo soils are on stream terraces and footslopes in narrow valleys. They mainly occur on beveled slopes between broad level old terraces and lower terraces or flood plains. Slope gradients are 1 to 5 percent. The soil formed in loamy sediments derived from soils formed from limestone. Mean annual precipitation ranges from about 20 to 30 inches, mean annual temperature from 70 degrees to 72 degrees F., and mean annual Thornthwaite P-E indices from about 26 to 38.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Atco series and the Frio, Knippa, and Uvalde series, which have a mollic epipedon. Atco soils occur on younger terraces than Sabenyo soils.
DRAINAGE AND PERMEABILITY: Well drained; Permeability is moderate. Runoff is low.
USE AND VEGETATION: Used for cropland and range. Cultivated crops are small grain and grain sorghums. Native vegetation is mainly sparse stands of short and midgrasses and an overstory of thorny brush such as mesquite.
DISTRIBUTION AND EXTENT: In the northern part of the Rio Grande Plain. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Uvalde County, Texas; 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 11 inches. (A horizon)
Calcic horizon: 11 to 55 inches. (Bk horizons)