LOCATION SILSTID                 TX

Established Series
Rev. GLL-CLN-RM
02/2018

SILSTID SERIES

The Silstid series consists of very deep, well drained, moderately permeable soils that formed in residuum weathered from beds of sandy or loamy materials and interbedded sandstones. These nearly level to sloping soils are on uplands. Slopes range from 0 to 8 percent.

TAXONOMIC CLASS: Loamy, siliceous, semiactive, thermic Arenic Paleustalfs

TYPICAL PEDON: Silstid fine sand in a Silstid fine sand, 1 to 5 percent slopes in rangeland at an elevation of 160.8 m (527.6 ft). (Colors are for dry soil unless otherwise stated.)

A--0 to 64 cm (0 to 25 in); pale brown (10YR 6/3) fine sand, brown (10YR 5/3) moist; single grain; loose; common fine roots; slightly acid; clear smooth boundary. (13 to 64 cm [5 to 25 in] thick)

E--64 to 94 cm (25 to 37 in); 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. (25 to 64 cm [10 to 25 in] thick)

Bt1--94 to 107 cm (37 to 42 in); 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. (10 to 51 cm [4 to 20 in] thick)

Bt2--107 to 132 cm (42 to 52 in); 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. (15 to 51 cm [6 to 20 in] thick)

Bt3--132 to 213 cm (52 to 84 in); 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 very pale brown (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; from the intersection of Highway 304 and a gravel road 3.1 miles south of Delhi, Texas; 0.5 mile south on gravel road to the intersection with another gravel road; 1.5 miles west on gravel road; 1.8 miles southeast adjacent to a petroleum pipeline in a wooded pasture. Delhi USGS topographic quadrangle; Latitude: 29 degrees 46 minutes 19.18 seconds N; Longitude: 97 degrees 46 minutes 19.18 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 days but less than 150 cumulative days in normal years.
Soil Depth: Very Deep, 152 to more than 203 cm (60 to more than 80 in).
Depth to abrupt textural change: 56 to 93 cm (22 to 36.6 in)
Depth to albic materials: 10 to 66 cm (4 to 26 in)
Depth to albic horizon: 10 to 66 cm (4 to 26 in)
Depth to argillic horizon: 56 to 93 cm (22 to 36.6 in)
Thickness of the Ochric epipedon: 10 to 66 cm (4 to 26 in)
Thickness of the A and E horizons: 51 to 102 cm (20 to 40 in).

Particle-size control section (weighted average)
Clay content: 35 to 50 percent in control section
Rock fragments: 0 to 15 percent

A horizon:
Hue: 7.5YR or 10YR
Value: 4 to 7
Chroma: 2 to 6
Texture: loamy fine sand or fine sand
Rock fragments: amount- 0 to 15 percent; size 2 to 250 mm; kind- quartzite or chert
Reaction: moderately acid to neutral

E horizon:
Hue: 7.5YR or 10YR
Value: 5 to 8
Chroma: 2 to 6
Texture: loamy fine sand or fine sand
Rock fragments: amount- 0 to 15 percent; size- 2 to 250 mm; kind- quartzite or ironstone nodules
Reaction: moderately acid to neutral

Bt Horizon (upper):
Hue: 5YR, 7.5YR or 10YR
Value: 5 to 7
Chroma: 6 to 8
Texture: Sandy clay loam, loam, or fine sandy loam
Clay content: 18 to 32 percent
Clay films: location- on all faces of peds, contrast- faint to distinct
Redox concentrations: amount- few to common, size- fine to medium, location- throughout
Rock fragments: amount- 0 to 15 percent; size- 2 to 250 mm; kind- quartzite or ironstone nodules
Reaction: strongly acid to slightly acid

Bt Horizon (lower):
Hue: 5YR, 7.5YR or 10YR
Value: 5 to 7
Chroma: 6 to 8
Texture: Sandy clay loam, loam, or fine sandy loam
Clay content: 18 to 32 percent
Clay films: location on all faces of peds, contrast- faint to distinct
Redox concentrations: amount- many, size- fine to medium, location- throughout
Rock fragments: amount- 0 to 15 percent; size- 2 to 250 mm; kind- quartzite or ironstone nodules
Reaction: strongly acid to slightly acid
Other features: Streaks or pockets of uncoated sand are in the lower part of most pedons.

C Horizon (when present below a depth of 152 cm [60 in]):
Hue: 2.5YR to 10YR
Value: 6 to 8
Chroma: 2 to 8
Texture: fine sandy loam, sandy clay loam or weakly cemented sandstone.
Rock fragments: amount- 0 to 15 percent; size- 2 to 250 mm; kind- quartzite
Reaction: strongly acid to slightly acid

COMPETING SERIES: This is the Heaton series in the same family. Similar soils are the Coving, Dougherty, Dutek, Heatly, Nimrod, Nobscot, Stidham, and Styx series.
Heaton soils: have redder colors, and do not have redoximorphic features in the upper Bt horizon. Coving and Nimrod soils have iron depletions with chroma of 2 or less within 76 cm (30 in) of soil surface.
Dougherty, Heatly, and Stidham soils: have mixed mineralogy.
Dutek soils: have a 20 percent decrease in clay from the maximum within a depth of 152 cm (60 in).
Nobscot soils: have less than 18 percent clay in the control section and mixed mineralogy.
Styx soils: have iron depletions with chroma of 2 or less in the lower Bt horizon with a perched water table.

GEOGRAPHIC SETTING:
Parent material: sandy or loamy residuum weathered from sandstone
Landscape: Inland dissected coastal plains
Landform: convex linear summit on interfluve on ridges, convex linear shoulder on interfluve on ridges, convex linear backslope on side slope on ridges
Slope: 0 to 8 percent
Mean annual precipitation: 711 to 1143 mm (28 to 45 in)
Mean annual air temperature: 17.8 to 20.6 degrees C (64 to 69 degrees F)
Frost-free period: 242 to 276 days
Elevation: 54.7 to 244 m (179 to 800 ft)
Thornthwaite P-E Index: 44 to 64

GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing soil and the Birome, Gasil, Konsil, Nimrod, Padina, Patilo, and Robco soils.
Birome soils: have a clayey argillic horizon and are above on low hills or ridges.
Nimrod soils: are slightly lower in the landscape.
Gasil and Konsil soils: have epipedons less than 51 cm (20 in) thick and are on similar positions.
Patilo and Padina soils: have sandy epipedons more than 102 cm (40 in) thick and are on slightly higher positions in the landscape.
Robco soils: are in drains and footslopes in poorer drained positions

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; Land Resource Region J - Southwestern Prairies Cotton and Forage Region; MLRA 87A - Texas Claypan Areas, Southern Part. The series is of large extent.

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

SERIES ESTABLISHED: Caldwell County, Texas; 1972.

REMARKS: Silstid soils were formerly included in the Stidham series.

Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 94 to 144 cm (37 to 57 in) (Bt1, Bt2, and Bt3 horizons)

Ochric epipedon: 0 to 94 cm (0 to 37 in) (A and E horizon)
Albic horizon: 64 to 94 cm (25 to 37 in) (E horizon)
Argillic horizon: 94 to 213 cm (37 to 84 in) (Bt1, Bt2 and Bt3 horizon)

Abrupt texture change: At the upper boundary of the Bt1 horizon

Additional Comments: Assigned semiactive cation exchange activity class 2/97.

ADDITIONAL DATA: S80TX-145-001, Falls County, TX; S86TX-287-001, Lee County, TX.

Soil Interpretation Record No.: TX0085

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

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National Cooperative Soil Survey
U.S.A.