LOCATION SILSTID TXEstablished Series
TAXONOMIC CLASS: Loamy, siliceous, semiactive, thermic Arenic Paleustalfs
TYPICAL PEDON: Silstid fine sand--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 25 inches; pale brown (10YR 6/3) fine sand, brown (10YR 5/3) moist; single grain; loose; common fine roots; slightly acid; clear smooth boundary. (5 to 25 inches thick)
E--25 to 37 inches; very pale brown (10YR 7/4) fine sand, light yellowish brown (10YR 6/4) moist; single grain; loose; common fine roots; slightly acid; clear smooth boundary. (10 to 25 inches thick)
Bt1--37 to 42 inches; brownish yellow (10YR 6/6) sandy clay loam, yellowish brown (10YR 5/6) moist; moderate fine and medium subangular blocky structure; very hard, friable, sticky and plastic; few fine roots; few fine pores; thin patchy clay films on vertical surfaces of peds; few fine distinct red (2.5YR 4/8) masses of iron accumulation; moderately acid; clear smooth boundary. (4 to 20 inches thick)
Bt2--42 to 52 inches; reddish yellow (5YR 6/8) sandy clay loam, yellowish red (5YR 5/8) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; few fine roots; few fine pores; thin patchy clay films on surfaces of peds; many coarse distinct red (2.5YR 4/8) masses of iron accumulation; moderately acid; gradual wavy boundary. (6 to 20 inches thick)
Bt3--52 to 84 inches; reddish yellow (5YR 6/8) sandy clay loam, yellowish red (5YR 5/8) moist; moderate medium granular and moderate fine subangular blocky structure; hard, friable, sticky and plastic; few fine roots; few fine pores; thick patchy grayish brown (10YR 5/2) clay films; common medium white (10YR 8/2) pockets of uncoated sand in lower part; few fine roots; many medium distinct brown (10YR 5/3) and a few fine distinct red (2.5YR 4/6) masses of iron accumulation; moderately acid.
TYPE LOCATION: Caldwell County, Texas; 3.1 miles south of Delhi on Texas Highway 304 to the intersection with a gravel road; 0.5 mile south on gravel road to intersection with another gravel road; 1.5 miles in a westerly direction; 1.8 miles southeast in wooded pasture adjacent to a petroleum pipeline.
RANGE IN CHARACTERISTICS: Solum thickness is 60 to more than 80 inches. There are a few ironstone or sandstone pebbles throughout the solum in some pedons; pebbles comprise less than 15 percent by volume.
The A horizon has hue of 7.5YR or 10YR, value of 4 to 7 and chroma of 2 to 4. The E horizon is usually 1 to 3 units of value greater than the A1 horizon. Texture of the A and E horizons is loamy fine sand or fine sand and the combined thickness is 20 to 40 inches. Reaction ranges from moderately acid to neutral.
The Bt horizon has hue of 5YR, 7.5YR or 10YR, value of 5 to 7, and chroma of 6 to 8. Redoximorphic features of these colors and reddish masses of iron accumulation are throughout the horizon. The lower Bt horizons has a matrix that is dominated by redoximorphic features in some pedons. Texture is sandy clay loam, loam or fine sandy loam with clay content of 18 to 32 percent. Streaks or pockets of uncoated sand are in the lower part of most pedons. Reaction ranges from strongly acid to slightly acid.
Some pedons have a C horizon below a depth of 60 inches with brownish, reddish or yellowish colors. Texture is fine sandy loam, sandy clay loam or weakly cemented sandstone. Reaction ranges from strongly acid through slightly acid.
COMPETING SERIES: These are the Heaton, Loneoak, and Styx series. Similar soils are the Coving, Dougherty, Dutek, Heatly, Nimrod, Nobscot, and Stidham series. Heaton series typically have redder colors, and do not have redoximorphic features in the upper Bt horizon. Styx soils have iron depletions with chroma of 2 or less in the lower Bt horizon with a perched water table. Coving and Nimrod soils have iron depletions with chroma of 2 or less within 30 inches of soil surface. Dougherty, Heatly, and Stidham have mixed mineralogy. Dutek soils have a 20 percent decrease in clay from the maximum within a depth of 60 inches. Nobscot soils have less than 18 percent clay in the control section and mixed mineralogy.
GEOGRAPHIC SETTING: Silstid soils occur on uplands. Slope gradients range from 0 to 8 percent. The soil formed in beds of sandy or loamy materials and interbedded sandstones. Mean annual temperature ranges from 64 to 69 degrees F., and mean annual precipitation ranges from 28 to 38 inches. Frost free days range from 225 to 270 days, and elevation ranges from 300 to 800 feet. The Thornthwaite P-E indices are 44 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Nimrod soil and the Birome, Gasil, Konsil, Padina and Patilo soils. Nimrod soils are slightly lower in the landscape. Birome soils have a clayey argillic horizon and are above on low hills or ridges. Gasil and Konsil soils have epipedons less than 20 inches thick and are on similar positions. Patilo and Padina soils have sandy epipedons more than 40 inches thick and are on slightly higher positions in the landscape.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 3 percent, very low on 3 to 5 percent slopes, and low on 5 to 8 percent slopes.
USE AND VEGETATION: Largely in rangeland. Small areas are cropped to peanuts or grain sorghum, or they are used as improved pasture. Native vegetation is blackjack oak, post oak, and yaupon with an understory of mid and tall grasses.
DISTRIBUTION AND EXTENT: Central and north central Texas. The series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Caldwell County, Texas; 1972.
REMARKS: Silstid soils were formerly included in the Stidham series.
Semiactive cation exchange activity class. Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 37 inches. (A and E horizon)
Arenic feature - fine sand texture to 37 inches.
Argillic horizon - 37 to 84 inches. (Bt1, Bt2 and Bt3 horizon)
ADDITIONAL DATA: S80TX-145-001, Falls County, TX; S86TX-287-001, Lee County, TX.
Soil Interpretation Record No.: TX0085