LOCATION AUSTONIO TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Typic Hapludalfs
TYPICAL PEDON: Austonio fine sandy loam--pastureland. (Colors are for moist soil unless otherwise stated)
A1--0 to 8 cm (0 to 3 in); brown (10YR 4/3) fine sandy loam; weak very fine subangular blocky structure; slightly hard, very friable; many fine and few medium roots; few fine pores; slightly acid; clear smooth boundary.
A2--8 to 30 cm (3 to 12 in); brown (10YR 5/3) fine sandy loam; weak fine subangular blocky structure; slightly hard, very friable; many fine and few medium roots; few fine pores; moderately acid; clear smooth boundary. (combined thickness of the A horizons is 10 to 36 cm [4 to 14 in])
E--30 to 48 cm (12 to 19 in); light yellowish brown (10YR 6/4) fine sandy loam; weak fine subangular blocky structure; slightly hard, very friable; common fine and few medium roots; few fine pores; moderately acid; clear smooth boundary. (0 to 38 cm [0 to 15 in] thick)
Bt1--48 to 71 cm (19 to 28 in); yellowish brown (10YR 5/8) sandy clay loam; weak coarse prismatic structure parting to moderate fine subangular blocky; very hard, friable; common fine and few medium roots; few fine pores; thin clay films on surfaces of prisms and patchy clay films throughout; few fine prominent red (2.5YR 5/8) masses of iron accumulation; slightly acid; gradual smooth boundary.
Bt2--71 to 107 cm (28 to 42 in); yellowish brown (10YR 5/8) sandy clay loam; weak coarse prismatic structure parting to moderate fine subangular blocky; very hard, friable; few fine roots; common fine pores; thin clay films on surfaces of prisms and patchy clay fims throughout; common fine prominent red (2.5YR 5/8) masses of iron accumulation; slightly acid; gradual smooth boundary. (combined thickness of the Bt horizons is 41 to 71 cm [16 to 28 in])
BCt1--107 to 150 cm (42 to 59 in); brownish yellow (10YR 6/8) fine sandy loam; weak coarse prismatic structure parting to moderate fine subangular blocky; very hard, friable; few fine roots; few fine pores; thin clay films on surface of prisms, and few patchy clay films throughout; few fine faint light yellowish brown (10YR 6/4) iron depletions; strongly acid; gradual smooth boundary.
BCt2--150 to 173 cm (59 to 68 in); brownish yellow (10YR 6/6) fine sandy loam; weak coarse prismatic structure parting to weak fine subangular blocky; very hard, friable; few fine roots; few fine pores; thin clay films on surface of prisms and few patchy clay films throughout; few iron-manganese concretions and stains; strongly acid; clear smooth boundary. (combined thickness of the BCt horizons is (36 to 91 cm [14 to 36 in])
2C--173 to 203 cm (68 to 80 in); light yellowish brown (10YR 6/4) loamy fine sand; single grained; soft, very friable; few fine roots; few fine distinct brownish yellow (10YR 6/6) masses of iron accumulation; moderately acid.
TYPE LOCATION: Houston County, Texas; 6.3 miles southwest of Austonio on Texas Highway 21 to a gate on south side of 7-J Stock Farm Headquarters; 1.7 miles west along private road; 0.3 mile northwest to site in pasture. Sand Ridge USGS quad; Lattitude, 31 degrees, 06 minutes, 30 seconds N; Longitude, 95 degrees, 43 minutes, 03 seconds W. NAD 83.
RANGE IN CHARACTERISTICS:
Soil Moisture: An udic soil moisture regime. The soil moisture control section is not dry in any part for more than 90 days in normal years.
Mean annual soil temperature: 19 to 21 degrees C (67 to 70 degrees F)
Depth to argillic horizon: 10 to 74 cm (4 to 29 in)
Thickness of solum: 127 to about 203 cm (50 to about 80 in)
Particle-size control section (weighted average)
Clay content: 18 to 30 percent, the clay content decreases by 20 percent or more from the maximum within a depth of 100 to 150 cm (40 to 60 in)
Rock fragments: rounded quartzite or ironstone pebbles range from none to few
CEC/clay ratio: 0.40 to 0.60
Base Saturation: 60 to 90 percent in the lower part of the argillic horizon
A horizon
Hue: 7.5YR or 10YR
Value: 3 to 5, where value is 3, thickness is less than 18 cm (7 in)
Chroma: 2 to 4
Texture: fine sandy loam
Reaction: extremely acid to slightly acid (3.6 to 6.5) unless limed
E horizon
Hue: 7.5YR or 10YR
Value: 5 or 6
Chroma: 2 to 4, some pedons have an EB horizon with chroma of 6 or 8
Texture: fine sandy loam
Reaction: extremely acid to slightly acid (3.6 to 6.5)
Upper Bt horizon
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 6 or 8
Redox concentrations: amount-few to many, size-fine to medium, contrast-distinct to prominent, boundary-clear, shades-red, brown or yellow range
Texture: loam or sandy clay loam
Reaction: extremely acid to moderately acid (3.6 to 6.0)
Lower Bt horizons
Hue: 5YR to 10YR
Value: 4 to 6
Chroma: 6 or 8
Redox concentrations: amount-few to many, size-fine to medium, contrast-distinct to prominent, boundary-clear, shades-red, brown or yellow range
Or the horizon is variegated with these colors.
Lithochromic mottles: amount-none to many, size-fine to medium, contrast-distinct to prominent, boundary-clear, shades-gray
Texture: loam or sandy clay loam
Reaction: extremely acid to moderately acid (3.6 to 6.0)
BC or BCt horizon
Color: shades of red, yellow, or brown
Texture: fine sandy loam, loam or sandy clay loam
Albic materials: few streaks or spots of albic materials or uncoated sand
Reaction: extremely acid to strongly acid (3.6 to 5.5)
2C horizon
Color: shades of yellow, brown or gray
Texture: fine sandy loam or loamy fine sand
Albic materials: few streaks or spots of albic materials or uncoated sand
Reaction: extremely acid to slightly acid (3.6 to 6.5)
COMPETING SERIES: These are the
Alto and
Fulshear series in the same family, and
Attoyac,
Bernaldo,
Bowie, and
Kenefick soils in closely related families.
Alto soils: have ironstone pebbles throughout the profile and are underlain by weathered glauconitic material.
Fulshear soils: have neutral to moderately alkaline reaction and 2 to 10 percent calcium carbonate concretions in the lower part of the argillic horizons.
Attoyac soils: have a reddish Bt1 horizon and do not decrease in clay within a depth of 150 cm (60 in).
Bernaldo soils: have interfingerings of albic materials in the argillic horizon.
Bowie soils: contain more than 5 percent plinthite and have base saturation less than 35 percent in the lower part of the solum.
Kenefick soils: have base saturation that is 35 to 60 percent in the lower part of the solum.
GEOGRAPHIC SETTING:
Parent material: Pleistocene terraced derived from alluvium
Landscape: Coastal Plain
Landform: Small drainageways, escarpments or on side slopes above drainageways
Slope: Slope gradients are dominantly less than 3 percent, but range up to 15 percent along escarpments or on side slopes above drainageways.
Mean annual air temperature range: 18 to 20 degrees C (65 to 68 degrees F)
Frost-free period: 230 to 240 days
Elevation: 38 to 76 m (125 to 250 ft)
Thornthwaite P-E index: 64 to 68
GEOGRAPHICALLY ASSOCIATED SOILS: These are the closely related
Bernaldo soils, and the
Annona,
Besner,
Freestone, and
Mollville series. Bernaldo soils are on similar landscapes.
Annona soils: have a clayey subsoil and are on similar positions.
Besner soils: have a coarse-loamy control section and are on slightly higher positions.
Freestone soils: have glossic materials and are on similar or slightly lower positions.
Mollville soils: have grayish subsoil and are on slightly lower, more concave positions.
DRAINAGE AND PERMEABILITY: Austonio soils are well drained and are moderately permeable. Runoff is very low on slopes of 1 to 3 percent, low on slopes of 3 to 5 percent, and medium on slopes greater than 5 percent.
USE AND VEGETATION: Used mainly for pastureland. Some areas are cropped to corn, small grain or truck crops. Pastures are mainly improved bermudagrass, bahiagrass or common bermudagrass. Pastures are commonly overseeded with arrowleaf clover, crimson clover, or vetch.
DISTRIBUTION AND EXTENT: East Texas. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Houston County, Texas; 1991.
REMARKS: These soils were formerly included with the Stidham or Dougherty series. The series was assigned to an active activity class in March, 1999. The series was revised in 2002 to allow extremely acid reaction throughout the solum.
Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon------ 0 to 48 cm (0 to 19 in) (A1, A2, and E horizons).
Argillic horizon----- 48 to 173 cm (19 to 68 in) (Bt1, Bt2, BCt1 and BCt2 horizons).
ADDITIONAL DATA: TAMU data S89TX-225-001 (lab nos. 3849-3856)
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