LOCATION BASTSIL TX

Established Series
Rev. GLL-RM-JAW
08/2017

BASTSIL SERIES

The Bastsil series consist of very deep, well drained moderately permeable soils that formed in loamy alluvial sediments. These nearly level to gently sloping soils are on stream terraces on river valleys. Slopes range from 0 to 5 percent. Mean annual precipitation is about 828 mm (33 in) and the mean annual air temperature is about 19 degrees C (66 degrees F).

TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Udic Paleustalfs

TYPICAL PEDON: Bastsil loamy fine sand--cropland. (Colors are for dry soil unless otherwise stated.)

A--0 to 15 cm (0 to 6 in); light brown (7.5YR 6/4) loamy fine sand, brown (7.5YR 4/4) moist; single grained; loose, very friable; many very fine and fine roots; few siliceous pebbles; slightly acid; clear smooth boundary. (10 to 20 cm [4 to 8 in] thick)

E--15 to 41 cm (6 to 16 in); light brown (7.5YR 6/4) loamy fine sand, brown (7.5YR 5/4) moist; single grained; loose, very friable; many very fine and fine roots; few coarse roots; few siliceous pebbles; slightly acid; abrupt smooth boundary. (0 to 30 cm [0 to 12 in] thick)

Bt1--41 to 79 cm (16 to 31 in); red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; common medium faint to coarse yellowish red (5YR 4/6) mottles; weak coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, friable; common fine roots; many fine pores; few wormcasts; common thin patchy clay films on faces of peds and bridging sand grains; few siliceous pebbles; slightly acid; gradual wavy boundary. (30 to 64 cm [12 to 25 in] thick)

Bt2--79 to 109 cm (31 to 43 in); strong brown (7.5YR 5/6) sandy clay loam, strong brown (7.5YR 5/6) moist; common fine and medium faint yellowish red (5YR 5/6 ) mottles; moderate coarse prismatic structure parting to weak and moderate medium and coarse subangular blocky; very hard, friable; common fine roots; many fine and very fine pores; few wormcasts; common clay films on faces of peds and bridging sand grains; few siliceous pebbles; few black masses up to 1 cm in diameter; slightly acid; gradual wavy boundary. (25 to 66 cm [10 to 26 in] thick)

Bt3--109 to 132 cm (43 to 52 in); strong brown (7.5YR 5/6) sandy clay loam, strong brown (7.5YR 5/6) moist; common medium distinct dark red (2.5YR 3/6) mottles in interior of peds; moderate coarse prismatic structure parting to weak and moderate medium and coarse subangular blocky; extremely hard, friable; common fine roots and many fine and very fine pores in strong brown part; common thin patchy clay films on faces of prisms and bridging sand grains; few smooth, rounded siliceous pebbles; slightly acid; gradual irregular boundary. (0 to 38 cm [0 to 15 in] thick)

Bt/E--132 to 203 cm (52 to 80 in); red (2.5YR 4/6) sandy clay loam, red (2.5YR 4/6) moist (Bt part); common faint medium and coarse red (10R 4/6) and few medium distinct reddish yellow (7.5YR 6/6) mottles in interiors of peds; moderate and strong coarse prismatic structure parting to medium prismatic and coarse blocky; extremely hard, firm; coarse prisms coated with light gray (10YR 7/2) sand grains l mm thick (E part); medium prisms and coarse blocks coated with light gray (10YR 7/2) clay films; common fine roots in light gray areas; common very fine pores in light gray areas; few siliceous pebbles; slightly acid.

TYPE LOCATION: Hill County, Texas, about 17 miles west of Hillsboro in coastal bermudagrass field. North from Whitney on Farm R oad 933 for 5 miles, west on Farm Road 1713 for 5.5 miles into McCown Park, south on sand road for 0.5 mile, east 0.15 mile, south 0.25 mile, west 0.25 mile and south 0.15 mile. Site is 375 ft west of road and 75 ft south of wooded area.
USGS topographic quadrangle: Allen Bend, TX;
Latitude: 31 degrees, 55 minutes, 55.445 seconds N;
Longitude: 97 degrees 23 minutes, 33.362 seconds W.
Datum: WGS84.

RANGE IN CHARACTERISTICS:
Soil moisture: An ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than 90 but less than 150 cumulative days in normal years.
Soil depth: very deep, greater than 203 cm (80 in)
Thickness of ochric epipedon: 20 to 41cm (8 to 16 in)
Depth to argillic horizon: 20 to 41 cm (8 to 16 in)
Depth to secondary calcium carbonates (when present): 157 to 203cm (61 to 80 in)
Particle-size control section (weighted average)
Clay content: 20 to 30 percent
Rock fragments: 0 to 15 percent
Beds of siliceous gravel and sand are typically within a depth of 1.5 to 3.7 m (5 to 12 ft). The gravel are mainly smooth, rounded, and less than 8 cm (3 in) across.
Some pedons mentioned iron manganese concretions in the lower Bt horizons

A or Ap horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 4 to 6
Chroma: 2 to 6
Texture: loamy fine sand or fine sandy loam
Rock fragments: amount-0 to 6 percent; size-2 to 75 mm; kind- quartzite
Reaction: medium acid to neutral unless limed.

E horizon (when present):
Hue: 5YR, 7.5YR, or 10YR
Value: 5 to 8
Chroma: less than 4
Texture: loamy fine sand or fine sandy loam
Rock fragments: amount-0 to 6 percent; size-2 to 75 mm; kind- quartzite
Reaction: strongly acid to slightly acid unless limed.
The E horizon is absent in some pedons as a result of being mixed with the A horizon by cultivation.

Bt horizon:
Hue: 2.5YR, 5YR, 7.5YR, or 10YR
Value: 4 to 7
Chroma: 1 to 8.
Typically there are mottles of these colors or in other shades of red and yellow.
Texture: sandy clay loam, fine sandy loam, loam, and clay loam.
Clay films: location-on all faces of peds
Rock fragments: amount-0 to 9 percent; size-2 to 75 mm; kind- quartzite
Reaction:medium acid to mildly alkaline. In some pedons the reaction increases with depth.

Bt/E horizon (when present):
Hue: 2.5YR, 5YR, or 7.5YR
Value: 4 to 6
Chroma: 4 to 8
Grayish uncoated sand and silt particles are on the surface of peds and in streaks or pockets. These soil materials (E) range from a few coatings between peds to about 15 percent by volume.
Texture: sandy clay loam but ranges from sandy loam to clay loam.
Clay films (when present): location-on all faces of peds
Rock fragments: amount-0 to 9 percent; size-2 to 75 mm; kind- quartzite
Reaction: medium acid to mildly alkaline. However, parts or spots in this horizon of some pedons are strongly acid.

BCt horizon (when present):
Hue: 2.5YR, 5YR, or 10YR
Value: 4 to 6
Chroma: 6
Few mottles of 10YR7/2 can be present.
Texture: loamy fine sand, loamy sand or stratified beds of sand and gravel
Clay films (when present): location-on all faces of peds
Rock fragments: amount-0 to 9 percent; size-2 to 75 mm; kind- quartzite
Reaction: variable and ranges from medium acid to moderately alkaline.
Some pedons have a 2C horizon below a depth of 152 cm (60 in)
Some pedons are calcareous.

COMPETING SERIES: This includes the Duffau series. Other similar soils include Bastrop, Delwin, Gasil, Gholson Konawa, and Silawa series.
Duffau soils: are on uplands formed in the cretaceous Paluxy sand and does not have B/E horizons and does not have sandy or gravelly sediments below the solum.
Bastrop, Delwin, and Konawa soils: have mixed mineralogy.
Flynn soils: have fragments of weathered glaucontic materials in the lower argillic horizon.
Gasil soils: have control sections with hue of 7.5YR or 10YR and base saturation less than 75 percent throughout the argillic horizon.
Gholson soils: have a clay decrease of more than 20 percent of the maximum within 152 cm (60 in).
Silawa soils: are more acid throughout the argillic horizon and have less clay in the lower part.

GEOGRAPHIC SETTING:
Parent material: loamy, alluvial sediments
Landscape: on nearly level or gently sloping stream terraces
Slope: 0 to 5 percent, typically 1 to 3
Mean annual precipitation: 711 to 944 mm (28 to 37 in)
Mean annual air temperature: 17.8 to 20.2 degrees C (64 to 68 degrees F)
Frost-free period: 220 to 266 days
Elevation: 83.9 to 305 m (275 to 1000 ft)
Thornthwaite P-E Index: 44 to 62
The climate is subhumid. The average summer moisture deficit is 7 to 9 inches. .

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aquilla, Desan, Gasil, Minwells, and Silstid series.
Aquilla soils: have a sandy control section and are on similar terrace positions.
Desan soils: have sandy grossarenic surfaces.
Gasil and Silstid soils: are on higher lying upland positions.
Minwells soils: have a clayey control section.
Silstid soils: have sandy arenic surfaces. These soils are on similar or slightly higher terrace positions.

DRAINAGE AND PERMEABILITY:
Drainage class: Well;
Permeability class: Moderate;
Runoff: negligible on slopes less than 1 percent and low on slopes of 1 to 5 percent.
Wetness: There is a water table for short periods of less than 30 days below a depth of 122 cm (48 in) in most years.

USE AND VEGETATION: Used mainly for crops and improved pastures. Crops include peanuts, grain sorghum, small grain, and truck crops. Pastures of improved bermudagrass or kleingrass are common. Native vegetation is mainly little bluestem with other perennial grasses and grape, greenbriar, low shrubs, with post oak and blackjack oak trees.

DISTRIBUTION AND EXTENT: Central Texas, mainly along terraces of the Brazos and Trinity Rivers or other rivers that have watersheds primarily with soils of Cretaceous age. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas.

SERIES ESTABLISHED: Hill County, Texas, 1975.

REMARKS: The soils were formerly included with Bastrop series.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 41 cm (0 to 16 in) (A & E horizons)
Argillic horizon: 41 to 203 cm (16 to 80 in)
Paleustalf feature: clay content does not decrease by more than 20 percent of the maximum content within 152 cm (60 in) from the soil surface.

ADDITIONAL DATA: NSSL: S73TX-109-1; S74TX-113-1 & 2; S80TX-099-1 & 2; S80TX-099-6 & 7 & 8; S80TX-193-1 & 2. All are mineralogy determination or mineralogy and particle-size.

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

National Cooperative Soil Survey
U.S.A.