LOCATION BASTROP                 TX+OK

Established Series
Rev. EHT-HCD-CLG-GLL
12/2016

BASTROP SERIES

The Bastrop series consists of very deep, well drained, moderately permeable soils formed in loamy alluvium. These soils occurs on nearly level to moderately sloping stream terraces. Slope ranges from 0 to 8 percent. Mean annual precipitation is about 813 mm (32 in), and mean annual air temperature is about 18.3 degrees C (65 degrees F).

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

TYPICAL PEDON: Bastrop fine sandy loam--in pastureland.
(Colors are for dry soil unless otherwise stated).

A1--0 to 25 cm (0 to 10 in); brown (7.5YR 5/4) fine sandy loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable; many fine and common medium roots; common very fine pores; few medium rounded siliceous pebbles; slightly acid; abrupt smooth boundary. (Thickness is 10 to 46 cm [4 to 18 in])

A2--25 to 33 cm (10 to 13 in); reddish brown (5YR 5/4) fine sandy loam, reddish brown (5YR 4/4) moist; weak medium and fine subangular blocky structure; slightly hard, friable; many fine and few medium roots; common very fine pores; few mole burrows up to 2-1/2 inches in diameter; few fine wormcasts; few medium rounded siliceous pebbles; slightly acid; clear wavy boundary. (Thickness is 0 to 15 cm [0 to 6 in])

Bt1--33 to 51 cm (13 to 20 in); reddish brown (5YR 4/4) sandy clay loam, reddish brown (5YR 4/4) moist; strong coarse prismatic and moderate medium subangular blocky structure; hard, friable; many fine and few medium roots; many very fine pores; common thin patchy clay films on surfaces of peds; many fine wormcasts; few worm nests and holes filled with slightly darker soil; few medium rounded siliceous pebbles; neutral; gradual wavy boundary. (Thickness is 10 to 51 cm [4 to 20 in])

Bt2--51 to 76 cm (20 to 30 in); yellowish red (5YR 4/6) sandy clay loam, yellowish red (5YR 4/6) moist; strong coarse prismatic and moderate medium subangular blocky structure; hard, firm; many fine roots; few medium roots; many very fine and fine pores; common thin dark reddish brown (5YR 3/4) clay films on surfaces of prisms; many fine wormcasts; few krotovinas as much as 0.5 inch in diameter; few medium rounded siliceous pebbles; neutral; gradual wavy boundary. (Thickness is 20 to 76 cm [8 to 30 in])

Bt3--76 to 127 cm (30 to 50 in); yellowish red (5YR 4/6) sandy clay loam, yellowish red (5YR 4/6) moist; strong coarse prismatic and moderate medium subangular blocky structure; hard, firm; common fine and few medium roots; many very fine and fine pores; common thin reddish brown (5YR 4/4) clay films on surfaces of prisms; many fine and very fine wormcasts; few medium rounded siliceous pebbles; neutral; gradual wavy boundary. (Thickness is 25 to 76 cm [10 to 30 in])

Bt4--127 to 183 cm (50 to 72 in); yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic and moderate medium and coarse subangular blocky structure; hard, firm; few fine roots; many very fine and few fine pores; common thin clay films on surfaces of prisms; common fine wormcasts; few medium rounded and angular siliceous pebbles; neutral; clear wavy boundary. (Thickness is 0 to 76 cm [0 to 30 in])

BCtk--183 to 203 cm (72 to 80 in); yellowish red (5YR 5/8) sandy clay loam, yellowish red (5YR 4/6) moist; weak coarse prismatic and moderate medium and coarse subangular blocky structure; hard, friable; few fine roots; common very fine and fine pores; few very fine wormcasts; few patchy clay films on surfaces of prisms; few medium rounded siliceous pebbles and few fragments of calcareous sandstone; few films and threads of calcium carbonate on surfaces of prisms; strongly effervescent; slightly alkaline.

TYPE LOCATION: Palo Pinto County, Texas south of Mineral Wells; from the intersection of Interstate Highway 20 and U.S. Highway 281, north on U.S. Highway 281 to the east end of the Brazos River bridge, and 0.8 mile north-northeast on U.S. Highway 281; site is west of the highway and 60 feet from a fence.
USGS topographic quadrangle: Brazos East, TX;
Latitude: 32 degrees, 39 minutes, 9.5 seconds, N;
Longitude: 98 degrees, 5 minutes, 51.5 seconds, W.
Datum: WGS84;
UTM Easting 584626 m, UTM Northing 3613139 m; UTM Zone 14.

RANGE IN CHARACTERISTICS:
Soil Moisture: Udic ustic soil moisture regime.
Solum thickness: 152 to 203 cm (60 to 80 in)
Rock fragments: 0 to 3 percent by volume siliceous gravel throughout

Particle-size control section (weighted average)
Clay content: 20 to 35 percent

A horizon:
Hue: 5YR to 10YR
Value: 4 to 6 dry, 4 moist
Chroma: 2 to 6
Texture: loamy fine sand, fine sandy loam, very fine sandy loam, or loam
Reaction (pH): moderately acid to slightly alkaline (5.6-7.8)

Bt horizons:
Hue: 2.5YR to 7.5YR
Value: 4 to 6
Chroma: 4 to 8
Texture: loam, sandy clay loam, or clay loam
Clay content: 20 to 35 percent
Effervescence: Most pedons are calcareous below 152 cm (60 in).
Reaction (pH): moderately acid to moderately alkaline (5.6-8.4)

BC, Btk, or Ck horizon: (where present)
Hue: 5YR to 7.5YR
Value: 5 to 7
Chroma: 4 to 8
Texture: sandy clay loam, loam, or clay loam with or without strata of fine sandy loam or loamy sand; Some pedons have gravelly or very gravelly layers below 152 cm (60 in) and most pedons have gravelly layers within a depth of 3.7 m (12 ft).
Identifiable secondary carbonate: Some pedons have films, threads, and/or concretions below 152 cm (60 in)
Reaction (pH): slightly acid to moderately alkaline (6.1-8.4)

COMPETING SERIES: There are no competing series in the same family. Similar soils are the Bastsil, Duffau, Galey, Konawa, Konsil, and May series.
Bastsil soils: have siliceous mineralogy
Duffau soils: have siliceous mineralogy and developed in material weathered from sandstone on higher positions
Galey soils: are moderately acid or strongly acid throughout the Bt horizon
Konawa and May soils: have argillic horizons with a significant decrease in clay from the maximum within 152 cm (60 in) of the surface
Konsil soils: have siliceous mineralogy, have a base saturation percentage in the Bt horizon of less than 75 percent, and have sandstone in the lower part of the solum.

GEOGRAPHIC SETTING:
Parent material: loamy alluvium
Landscape: river valleys
Landform: treads on terraces
Slope: 0 to 8 percent, but are dominantly less than 3 percent
Mean annual precipitation: 711 to 1092 mm (28 to 40 in)
Thornthwaite P-E indices range from 40 to 56.
Mean annual air temperature: 17.2 to 20.0 degrees C (63 to 68 degrees F)
Frost free period: 215 to 265 days
Elevation: 121.9 to 487.7 m (400 to 1,600 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Apalo, Axtell, Decordova, Minwells, Pedernales, and Travis series.
Apalo soils: occur on lower terrace positions, have a coarse-silty particle-size control section, and do not have an argillic horizon
Axtell soils: have a fine particle-size control section and are on higher terrace remnants
Decordova soils: have coarse-loamy particle-size control section and occur on lower terrace positions
Minwells soils: have a fine particle-size control section and are underlain by thick beds of gravelly material
Pedernales and Travis soils: have a fine particle-size control section

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent, low on 1 to 5 percent slopes, and medium on 5 to 8 percent slopes.

USE AND VEGETATION: About half of Bastrop soils are cultivated to cotton, corn, grain sorghums, tree fruits, peanuts, and vegetables. The remainder is planted in johnsongrass, sudan, bermudagrass, and oats, and is used as pastureland and hayland.

DISTRIBUTION AND EXTENT: Central and north central Texas mainly along the Colorado and Brazos Rivers; MLRAs 80B, 84B, and 85; Series is of large extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Bastrop County, Texas; 1907.

REMARKS:
Edited 12/2016 (RFG-TRD): Updated competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Particle-size control section - 33 to 83 cm (13 to 33 in) (Bt1, Bt2 and upper Bt3 horizons)
Ochric epipedon - 0 to 33 cm (0 to 13 in) (A horizons)
Argillic horizon - 33 to 203 cm (13 to 80 in) (Bt horizons)
Cation exchange activity class - Active
Pale feature - Soil does not have a 20 percent decrease in clay content within a depth of 152 cm (60 in), and has a chroma of 6 at 152 cm (60 in).

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

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National Cooperative Soil Survey
U.S.A.