LOCATION AQUILLA TXEstablished Series
TAXONOMIC CLASS: Sandy, siliceous, thermic Lamellic Paleustalfs
TYPICAL PEDON: Aquilla fine sand--cultivated field.
(Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; light brown (7.5YR 6/4) fine sand, brown (7.5YR 5/4) moist; single grained, loose, very friable; common fine roots; few, fine organic stains; slightly alkaline; clear smooth boundary. (3 to 12 inches thick)
A--7 to 14 inches; brown (7.5YR 5/4) fine sand, brown (7.5YR 4/4) moist; single grained; loose, very friable; many fine roots; slightly alkaline; gradual smooth boundary. (3 to 28 inches thick)
Bw--14 to 26 inches; reddish yellow (7.5YR 6/6) fine sand, strong brown (7.5YR 5/6) moist; weak, fine subangular blocky structure; loose, very friable; many fine roots; sand grains are coated; slightly alkaline; clear wavy boundary. (0 to 22 inches thick)
E and Bt1--26 to 49 inches; light reddish brown (5YR 6/4), reddish brown (5YR 5/4) moist loamy sand, with about 20 percent yellowish red (5YR 5/8), light reddish brown (5YR 6/4), reddish brown (5YR 5/4) moist, sandy loam lamellae 1/8 to 1/2 inch thick; single grained between the lamellae and weak fine subangular blocky structure in the lamellae; very friable; common fine roots; few medium, smooth pebbles; neutral; gradual smooth boundary. (15 to 40 inches thick)
E and Bt2--49 to 62 inches; light brown (7.5YR 6/4), brown (7.5YR 5/4) moist loamy sand with yellowish red (5YR 5/6) yellowish red (5YR 4/6) moist, sandy loam lamellae 1/8 to 3/4 inch thick; weak fine subangular blocky structure in the lamellae and single grained between the lamellae; very friable; few fine roots; few medium smooth pebbles; neutral; gradual smooth boundary. (12 to 30 inches thick)
2Bt--62 to 90 inches; red (2.5YR 5/6), red (2.5YR 4/6) moist, sandy clay loam, few fine faint concentrations of reddish brown; moderate medium subangular blocky structure; friable; few fine roots; few distinct clay films; small pockets of clean sand grains, about 10 percent medium smooth pebbles; slightly acid; gradual smooth boundary. (0 to 40 inches thick)
2C--90 to 110 inches; red (2.5YR 5/6), red (2.5YR 4/6) moist, gravelly sandy clay loam; massive; very friable; few fine roots; few fine black concretions; about 40 to 60 percent by volume of smooth pebbles; slightly acid.
TYPE LOCATION: Hill County, Texas; about 5 miles north of Whitney on Farm Road 933; 5.5 miles west on Farm Road l7l3 into McCowan Park; 0.75 mile south, 0.25 mile east, 0.75 mile south, and 1.25 miles west on dirt road. Site is on the north side of field road in the southwest corner of the field, near timbered area.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 70 to more than 90 inches. The soil ranges from moderately acid to slightly alkaline. The average content of clay, plus silt, plus very fine sand, ranges from 25 to 45 percent in the solum. Silt content averages less than 10 percent. There is a water table that ranges from 48 to 60 inches below the soil surface for several weeks during the wet season.
The A horizons have hue of 7.5YR or 10YR, value of 5 to 8, and chroma 2 to 6. Texture is fine sand or loamy fine sand.
The Bw horizon, present in most pedons, has hue of 5YR or 7.5YR, value 5 to 7, and chroma 4 to 8. Texture is fine sand or loamy fine sand.
The E part of the E and Bt horizons has hue of 2.5YR to 7.5YR, value of 5 to 7, and chroma of 4. Texture is fine sand, loamy sand, or loamy fine sand. The Bt part is thin lamellae comprising from 10 to 30 percent of the horizon that are generally discontinuous and less than 1 inch thick. Combined thickness of the lamellae is more than 6 inches within 80 inches of the surface. The lamellae have color in hue of 10R to 7.5YR, value 5 to 7 and chroma 6 to 8. Texture is loamy fine sand, fine sandy loam, or sandy loam. Most pedons contain a few pockets and streaks of clean sand grains and some pedons have a few depletions in chroma of 2 in the lower part.
The 2Bt horizon has about the same colors as found in the lamellae of the E and Bt horizons. Texture is mainly sandy clay loam but ranges to fine sandy loam with up to about 20 percent gravel. The 2C horizon commonly contains 30 to 60 percent by volume of rounded quartz gravel.
COMPETING SERIES: This is the Faula series in the same family and the Aline, Bienville, Eufaula, and Goltry series. Faula soils do not have a perched water table between 48 and 60 inches at some time during the year. Aline and Goltry soils occur in cooler and drier climates; in addition, Goltry soils have wetness depletions within 60 inches of the soil surface. Bienville soils are moist for longer periods of time. Eufaula soils have a lower percent of fines, do not have a seasonal water table within 60 inches of the surface and are in slightly cooler climates.
GEOGRAPHIC SETTING: Aquilla soils are on Pleistocene age terraces. The soils are nearly level to gently undulating. Slopes are mainly 0 to 5 percent. The soils formed in thick sandy sediments that have been reworked by wind. At the type location, the average annual temperature is 67 degrees F., the average annual precipitation is 35 inches, and the Thornthwaite P-E index is about 56.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bastrop, Konawa, and Stidham series. All of these soils have a continuous Bt horizon and fine-loamy textural control section.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very low runoff; moderately rapid permeability.
USE AND VEGETATION: Some areas are in peanuts, watermelons, and other truck crops. Some areas are in improved bermudagrass. Native vegetation includes post oak, ash, elm, cottonwood, and hickory. The under story is dense briars and shrubs. Grasses include big bluestem, Indiangrass, little bluestem, and switchgrass.
DISTRIBUTION AND EXTENT: Central Texas, generally along terraces of the Brazos River. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hill County, Texas; 1975.
REMARKS: The Aquilla soils were previously included in the Eufaula series.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 14 inches (Ap, A and Bw horizon).
Argillic horizon - 26 to 90 inches; combined thickness of the lamellae is more than 6 inches thick within 80 inches of the surface.
Pale feature - clay content does not decrease significantly from the maximum above 60 inches.
Lamellic feature - argillic horizon is made up of lamellae.
ADDITIONAL DATA: Lincoln Soil Survey Laboratory sample 73L676 confirms siliceous mineralogy.
TAXONOMIC VERSION: Soil Taxonomy, Second Edition, 1999.