LOCATION ELINDIO TXEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, hyperthermic Aridic Calciustolls
TYPICAL PEDON: Elindio silty clay loam - rangeland.
(Colors are for dry soil unless otherwise stated.)
A--0 to 15 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky and granular structure; hard, friable; many fine roots, common fine pores and root channels; few worm casts; few small fragments of shell; calcareous; moderately alkaline; gradual smooth boundary. (9 to 20 inches thick)
Bw--15 to 26 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; moderate fine subangular blocky structure; very hard, firm; common fine roots; few fine pores and root channels; few worm casts; few fragments of snail shell; few films and threads of calcium carbonate; calcareous; moderately alkaline; gradual wavy boundary. (9 to 22 inches thick)
Bk1--26 to 39 inches; very pale brown (10YR 7/3) clay loam, pale brown (10YR 6/3) moist; moderate fine and medium subangular blocky structure; very hard, firm; few fine roots; few fine pores and root channels; few worm casts; contains about 5 percent by volume of soft masses and films and threads of secondary calcium carbonate; calcareous; moderately alkaline; gradual wavy boundary. (7 to 18 inches thick)
Bk2--39 to 72 inches; very pale brown (10YR 7/4) clay loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; very hard, firm; many fine and medium pores; few krotovina, contains about 25 percent by volume of soft masses of secondary calcium carbonate; calcareous; moderately alkaline.
TYPE LOCATION: Maverick County, Texas; 9.9 miles northwest of High School in Eagle Pass on U.S. Highway 277 (this point is 1.1 miles southeast of junction of U.S. Highway 277 and Texas Highway 131); 0.4 mile east on old airport road; 100 feet north in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness is 40 to more than 60 inches. Calcium carbonate equivalent ranges from about 10 to 25 percent in the A horizon and from about 20 to 40 percent in the B and C horizons. Salinity is typically less than 2.0 mmho/cm, but in irrigated areas salinity ranges from 4 to 16 mmho/cm due to poor water management.
The A horizon is very dark grayish brown and has hue of 10YR, value of 4 and 5, and chroma of 2 or 3. Texture is silty clay loam or clay loam. The 10 to 40 inch control section is clay loam or clay with a clay content of 30 to 45 percent. An estimated 10 to 20 percent of the clay is carbonate clay.
The Bw horizon has hue of 2.5Y or 10YR, value of 5 or 6 and chroma of 2 through 4. Texture is clay loam or clay.
The Bk horizon has hue of 2.5y or 10YR, value of 5 through 8 , and chroma of 2 through 4. Visible secondary calcium carbonate in the form of soft masses and concretions ranges from about 2 to 35 percent by volume in the lower part of the Bk horizon. Some pedons have Ck horizons below 40 inches with colors the same as the Bk horizons.
COMPETING SERIES: These are the Uvalde series of the same family and the similar Acuna, Angelo, Castroville, Dant, Knippa, Lewisville, Nuvalde, and Quanah series. Uvalde soils are dry in the moisture control section for shorter periods. Acuna soils have carbonatic mineralogy. Angelo and Knippa soils crack when dry and have mean annual soil temperatures less than 72 degrees F. Castroville, Lewisville, Nuvalde and Quanah soils are moist in the control section for longer periods of time. Dant soils lack a calcic horizon within a depth of 40 inches and have a fine-loamy control section.
GEOGRAPHIC SETTING: Elindio soils occur on nearly level to gently sloping stream terraces and uplands. Slope gradients range from 0 to 3 percent but are mainly less than 1.5 percent. The soil formed in alluvium that is high in calcium carbonate and is derived from limestone areas. The climate is hot and semiarid. Average annual precipitation is 18 to 22 inches and the annual temperature is 70 to 74 degrees F. Frost free period is 275 to 290 days and elevation ranges from 550 to 700 feet. The Thornthwaite P-E indices are about 21 to 27.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dant, Darl, Mavco, and Zapata series. Dant soils have a COLE greater than 0.07 and lack calcic horizons at depths of less than 40 inches. The Darl and Zapata soils have petrocalcic horizons and, in addition, Darl, Mavco and Zapata soils ochric epipedons; Mavco soils also have Bt horizons. These soils occur on similar surfaces.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used almost exclusively as rangeland. Native grasses are mainly red grama, threeawn, bristlegrass, pink pappusgrass, Hall's panicum, fall witchgrass, tobosa, and curlymesquitegrass. Woody plants are mesquite, guayacan, spiny hackberry, condalias, whitebrush, guajillo, and pricklypear cactus.
DISTRIBUTION AND EXTENT: The northwestern Rio Grande Plain of Texas and probably Mexico. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Maverick County, Texas; 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 15 inches. (A-horizon)
Cambic horizon - 15 to 26 inches. (Bw horizon)
Calcic horizon - 26 to 72 inches. (Bk horizon)
Soft powdery lime - 26 to 72 inches. (Bk horizon)