LOCATION EDGE TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Udic Paleustalfs
TYPICAL PEDON: Edge fine sandy loam, on a 3 percent slope in an old field being used for rangeland. (Colors are for moist soil unless otherwise stated).
A--0 to 8 inches; dark brown (10YR 4/3) fine sandy loam, pale brown (10YR 6/3) dry; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine and medium roots; few fine and medium pores; few fine ironstone pebbles; moderately acid; clear smooth boundary. (3 to 9 inches thick)
E--8 to 11 inches; brown (10YR 5/3) fine sandy loam, very pale brown (10YR 7/3) dry; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine and medium roots; few fine and medium pores; few fine ironstone pebbles; few fine fragments of red Bt material; slightly acid; abrupt smooth boundary. (0 to 10 inches thick)
Bt1--11 to 19 inches; dark red (2.5YR 3/6) clay, red (2.5YR 4/6) dry; moderate medium angular blocky structure parting to moderate fine angular blocky; extremely hard, firm, very sticky and very plastic; few fine and very fine roots; few fine pores; common distinct clay films on surfaces of peds; few fine distinct pale brown (10YR 6/3) mottles; very strongly acid; gradual smooth boundary. (6 to 12 inches thick)
Bt2--19 to 29 inches; red (2.5YR 4/6) clay; red (2.5YR 5/6) dry; weak medium and coarse prismatic structure parting to moderate fine angular blocky; extremely hard, firm, sticky and plastic; few fine and very fine roots; few fine pores; common distinct clay films on surfaces of peds; common medium distinct pale brown (10YR 6/3) iron depletions, and few fine distinct yellowish brown (10YR 5/4) masses of iron accumulation; very strongly acid; gradual smooth boundary. (8 to 20 inches thick)
Bt3--29 to 37 inches; red (2.5 YR 4/6) clay loam, red (2.5YR 5/6) dry; weak medium and coarse prismatic structure parting to moderate fine angular blocky; very hard, firm, sticky and plastic; few fine and very fine roots; few fine pores; few very dark gray (10YR 3/1) organic stains along root channels; common distinct reddish brown (5YR 5/4) clay films on surfaces of peds; common fine distinct light yellowish brown (10YR 6/4) masses of iron accumulation, and common fine distinct grayish brown (10YR 5/2) iron depletions; very strongly acid; gradual smooth boundary. (0 to 15 inches thick)
Bt4--37 to 43 inches; yellowish red (5YR 5/6) clay loam; reddish yellow (5YR 4/6) dry; weak medium prismatic structure parting to moderate fine subangular blocky; very hard, firm, sticky and plastic; few fine and very fine roots; few medium continuous pores; common distinct brown (7.5YR 4/4) clay films on vertical surfaces of peds; few medium very dark gray (10YR 3/1) organic stains; few fine light brownish gray (10YR 6/2) seams along old shale seams; few fine distinct yellowish brown (10YR 5/4) masses of iron accumulation; slightly acid; gradual smooth boundary. (0 to 12 inches thick)
BCt--43 to 48 inches; strong brown (7.5YR 5/6) sandy clay loam; reddish yellow (5YR 6/6) dry; weak very coarse prismatic structure parting to weak coarse subangular blocky; very hard, firm, sticky and plastic; few fine and very fine roots; common distinct brown (7.5YR 4/4) clay films on vertical surfaces of peds; few fine light brownish gray (10YR 6/2) seams along old shale bedding planes, in places, platy, inherited structure dominates; few fine faint light yellowish brown (10YR 6/4) masses of iron accumulation, and few fine distinct light brownish gray (10YR 6/2) iron depletions; neutral; gradual smooth boundary. (0 to 18 inches thick)
C/B1--48 to 58 inches; strong brown (7.5YR 5/6) weakly consolidated siltstone that has a loam texture; few medium distinct red (2.5YR 5/6) mottles; weak very coarse prismatic structure; very hard, friable, slightly sticky and sightly plastic; few very fine roots; few brown (7.5YR 5/4) clay films on vertical surfaces of peds; few medium masses of barite; horizon becomes stratified with depth in colors of strong brown (7.5YR 5/6), yellowish brown (10YR 5/6) and thin discontinuous gray (5YR 6/) seams of shale; slightly alkaline; gradual smooth boundary.
C/B2--58 to 75 inches; light yellowish brown (10YR 6/4) weakly consolidated siltstone that has a loam texture; massive; very hard, friable, slightly sticky and slightly plastic; few very fine roots; few horizontal, thin streaks of strong brown (7.5YR 5/6); slightly alkaline; gradual smooth boundary. (CB horizons range from 0 to 36 inches thick)
C--75 to 80 inches; light brownish gray (10YR 6/2) weakly consolidated siltstone that has a silt loam texture; very hard, friable; slightly alkaline.
TYPE LOCATION: Milam County, Texas; from U. S. Highway 79 in Milano; 2.5 miles west on Highway 36; 1.0 miles northeast on county road; 75 feet east of road in an old field being used for rangeland. Latitude 30 degrees, 44 minutes, 36 seconds N, Longitude 96 degrees 53 minutes 14 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 60 inches. Clay content of the 10- to 40- inch particle size control section ranges from 35 to 55 percent. Typically, it averages about 40 to 45 percent. The base saturation of the argillic horizon ranges from about 45 to 90 percent but is 75 percent or more in some part and the CEC per 100g clay ranges from 35 to 55. The shrink-swell is high in the upper part of the control section with a COLE of about 0.06 to 0.09. However, the PLE is less than 2.4 inches in the upper 50 inches of the soil. Some pedons have a few calcium carbonate concretions below a depth of 30 inches.
The A horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 2 to 4. The texture is fine sandy loam, very fine sandy loam, gravelly fine sandy loam or loam. Ironstone pebbles range from 0 to 35 percent. Reaction ranges from strongly acid to neutral.
The E horizon where present has hue of 7.5YR or 10YR, value of 5 to 7, and chroma of 2 to 4. The texture is fine sandy loam, very fine sandy loam or loam. Ironstone pebbles range from 0 to 10 percent by volume. Reaction ranges from very strongly acid to slightly acid. The combined thickness of the A and E horizons ranges from 6 to 19 inches, unless eroded.
The Bt horizon has hue of 2.5YR or 5YR, value of 3 to 5, and chroma of 4 to 8. However, some Bt1 horizons and typically lower Bt horizons are mottled with yellowish or brownish colors or have a mottled matrix in shades of red, brown and yellow. The Bt horizons contain colors with chroma of 2 or less in some pedons. However, they are considered to be inherited from parent material, or they are relict redoximorphic features. Texture is clay loam, sandy clay or clay with clay content ranging from 27 to 55 percent.
The Bt1 and Bt2 horizons are commonly clay or sandy clay. Lower Bt horizons are clay loam or sandy clay. Ironstone fragments mainly less than 6 inches across range from 0 to 10 percent. Reaction of the Bt1 horizon ranges from very strongly acid to moderately acid. Reaction of the lower Bt horizons ranges from very strongly acid to neutral.
The BCt horizon has matrix colors mainly in shades of brown with yellowish, reddish, or grayish mottles, fragments or strata. Thin strata or fragments of sandstone and ironstone make up less than 15 percent. The texture is sandy clay loam, clay loam, fine sandy loam, or is stratified with these and other clayey or sandy materials. Grayish shale fragments or strata make up about 5 to 15 percent of some pedons. Reaction ranges from very strongly acid to slightly alkaline.
The CB and C horizons have colors mainly in shades of gray or brown, typically with yellowish or reddish iron accumulations or strata. Texture is loam, silt loam, fine sandy loam, sandy clay loam, or stratified siltstone with these textures. Some pedons contain sandy strata. Barite ranges from none to a few fine or very fine masses. The reaction ranges from strongly acid to moderately alkaline.
COMPETING SERIES: These are the Callisburg, Chigley (OK), Cona, Margie, Minwells, Shiro, Truce, and Windthorst series. Similar soils are the Axtell, Gredge, and Rosanky series. Callisburg soils have sola thicker than 60 inches. Chigley soils have a lithic contact with conglomerate below 60 inches. Cona and Shiro soils have sola 20 to 40 inches thick. Margie soils have a BA horizon of sandy clay loam, formed in marine sediments high in glauconite, and have sola between 60 and 80 inches. Minwells soils formed in old alluvial deposits and are underlain by beds of gravel. Truce soils are underlain by shale. Axtell soils have vertic properties and sola thicker than 60 inches. Gredge soils have montmorillonitic mineralogy, and have sola greater than 60 inches. Rosanky soils are members of the Ultic subgroup, and do not have redoximorphic features in the upper part of the argillic horizon.
GEOGRAPHIC SETTING: Edge soils are on gently sloping to strongly sloping uplands. Slopes are mainly 3 to 8 percent but range from 1 to 12 percent. These soils formed in loamy and clayey residuum, mainly of the Wilcox Group. Mean annual temperature ranges from 64 to 68 degrees F., and mean annual precipitation ranges from 32 to 40 inches. Frost free days range from 240 to 270 days, and elevation ranges from 300 to 500 feet. Thornthwaite P-E indices range from 52 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Axtell, Crockett, Gasil, Gredge, Lufkin, Rosanky, and Silawa series. Axtell soils are typically on lower terrace positions. Gredge, Rosanky and Crockett soils are on positions similar to the Edge series. Crockett soils have a clayey argillic horizon with vertic properties. Gasil and Silawa soils have fine-loamy control sections and Gasil soils are on similar stream divide positions. Silawa soils are on slightly lower terrace positions. Lufkin soils are on lower flats or depressions and have grayish colors throughout.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is very slow. Runoff is medium on 1 to 3 percent slopes, high on 3 to 5 percent slopes, and very high on slopes greater than 5 percent.
USE AND VEGETATION: Used mainly for rangeland or improved pasture with a few cultivated areas. Native vegetation is a savannah with scattered post oak, blackjack oak, and elm trees with ground cover of medium and tall native grasses. Present vegetation is a fairly dense cover of oak trees, yaupon, American beautyberry and hawthorn with shade tolerant grasses such as longleaf uniola. Many areas have been cultivated in the past. These old cropland fields are being used for rangeland or have been established to bermudagrass, bahiagrass or other improved pasture grasses. A few small areas have been planted to loblolly pine. Old fields being used for rangeland are typically producing low quality perennial grasses, annuals grasses, forbs and some fields are being invaded by mesquite.
DISTRIBUTION AND EXTENT: Mainly in East Central Texas (MLRA 87A). The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Freestone County, Texas; 1986. The Edge series was originally established in Brazos County, Texas in 1955. In May, 1963 the series was placed on the inactive list and the soils were included with the similar Axtell series. The Axtell soils are members of a fine, montmorillonitic, thermic family of Udertic Paleustalfs. Axtell soils are typically on terraces or in valley fill positions and have a solum thicker than 60 inches and with vertic properties. The redefined Edge series has a concept similar to the original series established in Brazos County.
REMARKS: This pedon is within an area of Edge fine sandy loam, eroded. It is on a small area that is not eroded. There soils are not saturated in any part of the solum for more than 30 consecutive days during most years. Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 11 inches. (A and E horizons)
Argillic horizon - 11 to 48 inches. T(Bt and Bct horizons). The clay content decreases with depth. The upper part of the argillic horizon has high shrink-swell potential but the lower horizons have moderate or low potential. The clay mineralogy is mixed borderline to montmorillonitic.
Pale feature - Abrupt texture change at 11 inches.
ADDITIONAL DATA: NSSL Data: Milam County, S83TX-331-1 (832755-832761), TAMU Data: Bastrop County, S82TX-021-1-4, 84TX-021-1-5; Freestone County, S84TX-161-1-2, S84TX-161-2- 2; Milam County, S84TX-331-8-2, S84TX-331-9-2, S84TX-331-10- 2, S86TX-331-01-10; Lee County, S81TX-287-2 (1198-1207).
Soil Interpretation Records: TX1084; GRAVELLY TX1192