LOCATION STRABER TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Aquic Paleustalfs
TYPICAL PEDON: Straber loamy fine sand--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 8 inches; pale brown (10YR 6/3) loamy fine sand, brown (10YR 5/3) moist; weak fine granular structure; loose, very friable; common fine roots; few siliceous pebbles; moderately acid; clear smooth boundary. (2 to 9 inches thick)
E--8 to 14 inches; very pale brown (10YR 7/3) loamy fine sand, pale brown (10YR 6/3) moist; single grained; loose, very friable; few fine roots; few siliceous pebbles; moderately acid; abrupt wavy boundary. (4 to 12 inches thick)
Bt1--14 to 24 inches; brownish yellow (10YR 6/6) sandy clay, yellowish brown (10YR 5/6) moist; common medium distinct light gray (10YR 7/2) and yellowish red (10YR 6/6) mottles; moderate medium angular blocky structure parting to weak very fine subangular blocky; extremely hard, very firm, sticky and plastic; few fine roots; common clay films; few fine siliceous pebbles; strongly acid; gradual wavy boundary.
Bt2--24 to 42 inches; light gray (2.5Y 7/2) sandy clay, light brownish gray (2.5Y 6/2) moist; common medium distinct brownish yellow (10YR 6/6) and strong brown (7.5YR 5/6) mottles; weak coarse angular blocky structure; extremely hard, very firm, sticky and plastic; few fine roots; many light brownish gray (10YR 6/2) clay films; 10 percent of siliceous pebbles; strongly acid; gradual wavy boundary.
Bt3--42 to 59 inches; light gray (2.5Y 7/2) sandy clay, light brownish gray (2.5Y 6/2) moist; common coarse distinct yellowish brown (10YR 5/4) and few fine prominent red (2.5YR 4/6) mottles; moderate medium prismatic structure parting to weak coarse angular blocky; extremely hard, very firm, sticky and plastic; few fine roots; few thin clay films; neutral; clear wavy boundary. (combined thickness of the Bt horizon is 30 to 60 inches)
Bk--59 to 65 inches; light gray (2.5Y 7/2) clay loam; light brownish gray (2.5Y 6/2) moist; moderate medium angular blocky structure; very hard, firm; common soft masses of calcium carbonate; mildly alkaline; gradual wavy boundary. (0 to 30 inches thick)
BCk--65 to 80 inches; pale yellow (5YR 7/3) clay loam, pale olive (5Y 6/3) moist; weak medium subangular blocky structure; hard, firm; common masses of calcium carbonate; calcareous; moderately alkaline.
TYPE LOCATION: Fayette County, Texas; from intersection of U. S. Highway 90 and Farm Road 957 in Schulenburg, 3.5 miles south on Farm Road 957 and 80 feet west.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches thick. Base saturation is 40 to 75 percent by sum of cations in upper part of the argillic horizon. The boundary between the E and Bt horizon is abrupt over the subsoil crests and clear over the deeper subsoil troughs. The texture change is abrupt. Siliceous pebbles range from none to 15 percent by volume.
Combined the A and E horizons are 10 to 20 inches thick in more than 50 percent of the pedon, but is as thin as 7 inches over some subsoil crests. The A horizon has hue of 7.5YR or 10YR, value of 4 to 7, and chroma of 2 or 3. Where values are less than 3.5 moist, it is less than 6 inches thick. The E horizon is about l or 2 units of value higher than the A horizon. Texture is loamy fine sand, loamy sand, or gravelly loamy fine sand. Reaction is strongly acid to neutral.
The Bt1 horizon has hue of 7.5YR, 10YR or 2.5Y, value of 5 or 6 and chroma of 2 to 8. Redoximorphic features are in shades of red, brown, yellow and gray. Some pedons have a mixed color matrix of reds, yellows, browns, and grays. Texture is clay or sandy clay with a weighted average clay content of 35 to 50 percent in the upper 20 inches of the Bt horizons. Reaction is very strongly acid or strongly acid.
The Bt2 and Bt3 horizons have hue of 10YR, 2.5Y or 5Y, value of neutral to 7 and chroma of 1 to 6. Redoximorphic features in shades of red, yellow, brown, gray, and olive range from common to many. Texture is sandy clay, clay loam, or sandy clay loam. Reaction ranges from very strongly acid to moderately acid in the upper Bt2 horizon and moderately acid to slightly alkaline in the lower Bt3 horizon. Iron enriched red or dark red masses of iron accumulation range from 0 to about 5 percent.
The Bk, BCk and BC horizons have hue of 10YR or 2.5Y, value of 5 to 8 and chroma of 2 to 6. Mottles in shades of gray, brown, yellow or red occur in some pedons. They are clay loam, sand clay or sandy clay loam. Masses of calcium carbonate range from none to common. Reaction ranges from slightly acid to moderately alkaline.
COMPETING SERIES: This is the Chaney series. Similar soils are the Chazos, Demona, Delfina, Floresville, Miguel, Papalote, Shiro, Tabor, Tremona, and Wilco series. Chaney soils have redder hue and are less acid in the Bt1 horizons, and typically receive less precipitation. Chazos soils are moderately acid or slightly acid in the Bt1 horizon and commonly contain a higher percentage of higher chroma colors in the argillic horizon. Demona and Tremona soils have sandy A horizons 20 to 40 inches thick. Delfina soils have fine-loamy control sections and, in addition, have hyperthermic temperature regimes. Floresville, Miguel, and Wilco soils do not have iron depletions due to wetness and have a hyperthermic temperature regime. Papalote soils are neutral to moderately alkaline in the Bt2 horizons and are in a hyperthermic temperature regime. Shiro soils have a paralithic contact between 20 and 40 inches, and do not have iron depletions that are due to current day wetness. Tabor soils have fine sandy loam A horizons, have smectitic mineralogy and exhibit vertic properties.
GEOGRAPHIC SETTING: Straber soils are on uplands. Slope gradients range from 0 to 8 percent and surfaces are weakly convex. The soil formed in alkaline clayey and loamy materials mainly of the Willis or Citronelle geology of early Pleistocene Age. Mean annual temperature ranges from 68 to 72 degrees F. and mean annual precipitation ranges from 32 to 43 inches. Frost free days range from 260 to 280 days and elevation ranges from 220 to 450 feet. Thornthwaite P-E indices range from 44 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Catilla, Fordtran, Garcitas, and Tremona series. Catilla soils have sandy A horizons more than 40 inches thick and are on slightly higher smooth divides. Fordtran and Garcitas soils have sandy A horizons 20 to 40 inches thick and are on nearby areas. Tremona soils are on similar positions.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Permeability is very slow. Runoff is low on slopes less than 1 percent, medium on 1 to 3 percent slopes, high on 3 to 5 percent slopes, and very high on slopes greater than 5 percent. A perched water table exists for a few days to several weeks during September to May.
USE AND VEGETATION: Mainly used for rangeland. Native vegetation is little bluestem, paspalum, panicum, and threeawn grasses, and included woody species such as post oak, blackjack oak, and yaupon.
DISTRIBUTION AND EXTENT: South-central Texas, mainly in the southern part of the Texas Claypan. The soil is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: DeWitt County, Texas; l973.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 14 inches. (A and E horizons)
Albic horizon - 8 to 14 inches. (E horizons)
Abrupt texture change at 14 inches. E/Bt1 contact)
Argillic horizon - 14 to 54 inches. (Bt horizons)