LOCATION COPANO TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Vertic Albaqualfs
TYPICAL PEDON: Copano fine sandy loam in rangeland. (Colors are for moist soil unless otherwise stated.)
A--0 to 12 inches; dark grayish brown (10YR 4/2) fine sandy loam, grayish brown (10YR 5/2) dry; weak fine and very fine subangular blocky structure; very friable; slightly hard; nonsticky, nonplastic; common very fine and fine roots; common fine and very fine pores; few fine faint organic stains on peds; neutral; clear wavy boundary. (9 to 18 inches thick)
E--12 to 14 inches; light brownish gray (10YR 6/2) fine sandy loam, light gray (10YR 7/2) dry; weak very fine subangular blocky structure; very friable; slightly hard; nonsticky, nonplastic; common very fine and fine roots; common fine and very fine pores; neutral; abrupt wavy boundary. (0 to 3 inches thick)
Btg--14 to 23 inches; dark gray (10YR 4/1) clay, gray (10YR 5/1) dry; common fine and medium distinct dark yellowish brown (10YR 4/6) and few fine faint gray mottles; moderate medium prismatic structure parting to moderate fine and medium blocky; very firm, extremely hard; very sticky, very plastic; common fine roots; common fine pores; common very dark gray (10YR 3/1) vertical streaks along old filled cracks; thick continuous clay films on faces of peds; neutral; clear wavy boundary. (6 to 12 inches thick)
Btgc--23 to 42 inches; light brownish gray (10YR 6/2) sandy clay, light gray (10YR 7/2) dry; common medium prominent dark yellowish brown (10YR 4/6) and few fine faint mottles; moderate fine and medium blocky structure; very firm, very hard; sticky and plastic; few fine roots; few fine pores; few dark grayish brown (10YR 4/2) vertical streaks extending to horizon below; few thin discontinuous clay films on faces of peds; few fine and medium black concretions 1 to 5 mm in diameter; slightly alkaline; gradual wavy boundary. (6 to 19 inches thick)
BCc--42 to 56 inches; pale brown (10YR 6/3) sandy clay loam, very pale brown (10YR 7/3) dry; common fine faint brownish yellow mottles; moderate medium subangular blocky structure; very firm, very hard, sticky and plastic; few fine roots; common fine and medium black concretions 1 to 5 mm in diameter;; moderately alkaline; gradual wavy boundary. (6 to 17 inches thick)
Ckc--56 to 72 inches; light gray (10YR 7/2) sandy clay loam, very pale brown (10YR 8/2) dry; massive; very firm, very hard, sticky and plastic; few fine black concretions 1 or 2 mm in diameter; about 5 percent by volume calcium carbonate concretions and masses 2 to 8 mm in diameter; calcareous; moderately alkaline.
TYPE LOCATION: Refugio County, Texas; from the intersection of US 77 and Farm Road 774 in Refugio, 4.5 miles east on Farm Road 774, 3.1 miles north and northeast on paved oil lease road, 0.1 mile north on graveled road, 0.3 mile east on pipeline right-of-way and 20 feet south in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 38 to 60 inches. Depth to secondary forms of calcium carbonate ranges form 32 to more than 72 inches. Most pedons have few to common dark concretions below the A horizon that are assumed to be mostly iron and manganese. Clay content in the upper 20 inches of the Bt horizon ranges from 38 to 55 percent.
The A horizon is dark grayish brown to light gray with a hue of 10YR, values of 4 through 7 and chromas of 2 or 3. It is fine sandy loam or loamy fine sand. Reaction ranges from medium acid through neutral.
The E horizon is pale brown to light gray with a hue of 10YR, values of 6 or 7 and chroma of 2 or 3. It is fine sandy loam or loamy fine sand. Reaction ranges from medium acid through neutral. This horizon is absent in some pedons. Some pedons have a BE horizons 1 to 3 inches thick. It is sandy clay loam or fine sandy loam and has the same reaction as the E horizon. It is dark gray (10YR 4/1).
The Btg horizon is dark grayish brown to light gray with a hue of 10YR, values of 4 through 7 and chromas of 1 or 2. Yellowish, brownish, reddish, and grayish mottles range from few to many. It is clay or sandy clay. Evidence of cracking in the form of vertical streaks, 2 to 5 mm wide, of very dark gray fine sandy loam or sandy clay loam, range from few through common. Cracks at a depth of 20 inches are 0.4 to 1.2 inches wide when the soil is dry. They extend from the top of the Btg horizons into the upper part of the BC horizon. Cracks do not extend through the A horizon to the surface, except where rainfall or other agitation allows the A horizon to fall into cracks. Some pedons have dark gray coatings on ped faces. Reaction of the Btg horizon ranges from neutral through moderately alkaline. Dark concretions and weakly cemented masses, 1 to 5 mm in diameter, range from none to common. COLE ranges 0.09 to 0.11.
The BC horizon is light gray to very pale brown with a hue of 10YR, values of 6 through 8 and chromas of 1 through 4. Yellowish, brownish, reddish, and grayish mottles ranges from none through common. Texture is sandy clay loam, clay loam or sandy clay. Some pedons have vertical dark gray streaks in the upper 1 or 2 inches. Dark concretions and weakly cemented masses, 1 to 5 mm in diameter, range from none to common. Concretions and soft powdery forms of calcium carbonate comprise 0 to 15 percent by volume. Reaction is mildly alkaline or moderately alkaline. The matrix is noncalcareous or calcareous.
The C horizon is light gray to very pale brown with hues of 10YR or 2.5Y, values of 7 or 8 and chromas of 2 through 4. Some pedons have a few yellowish and brownish mottles. Texture is sandy clay loam, or sandy clay. Dark concretions and masses, 1 to 5 mm in diameter, range from none to few. Concretions and soft powdery forms of calcium carbonate comprise 0 to 15 percent by volume. Reaction is mildly alkaline or moderately alkaline. The matrix is calcareous or noncalcareous.
COMPETING SERIES: The proposed Vidauri is the only competing series. Similar series include Edna, Inez, Lufkin, Mabank, and Telferner series. Edna, Lufkin, and Mabank soils have average annual soils temperatures less than 72 degrees F. Inez and Telferner soils have COLE values less than 0.09. Vidauri soils are typically more acid and have sola more that 60 inches thick.
GEOGRAPHIC SETTING: Capono soils are in poorly defined drainageways or slight depressions on uplands in the southern part of the Gulf Coast Prairies and the eastern part of the Northern Rio Grande Plain Land Resource Areas. Slopes are generally less than 1 percent, but range up to 2 percent. Surfaces are plane to slightly concave and depressional. The soils formed in clayey and loamy fluviatile sediments of Pleistocene age, mostly of the Beaumont Formation and the upper part of the Lissie Formation. Mean annual temperature ranges from 71 to 74 degrees F, mean annual precipitation ranges from 30 to 40 inches. Thornthwaite P-E index ranges from 40 to 52.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Vidauri series and the Edroy, Fadin, Inez, Orelia, Papalote and Victoria series. Vidauri soils are typcially more acid and support a prairie type native plant community. These soils, as well as Inez and Orelia soils, occur on similar surfaces. Edroy soils have mollic epipedons that are more clayey. They occur in more distinct depressions. Faddin, Inez, Orelia, and Papalote lack vertic properties. Faddin and Papalote occur at slightly higher elevations. Victoria soils are clayey throughout and have intersecting slickensides. They occur at slightly higher elevations.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff or ponded; very slow permeability. A water table is perched for long periods in the A, E, and upper Btg horizons especially during the fall, winter, and spring months, most years. Following cyclonic storms, the soil may be saturated most of the year. The soil is at or near the wilting point during July and August in most years under native conditions.
USE AND VEGETATION: Used mainly for rangeland. A few areas are used for improved pasture and growing grain sorghum. Native vegetation is about 75 percent grasses, 20 percent woody species, 5 percent forbs and a trace of grasslikes. Grasses include little bluestem, bushy bluestem, brownseed paspalum, longtom, bristlegrasses, carpetgrass, dropseeds, windmillgrasses, and annuals. Woody species include live oak, hackberry, sesbania, mesquite, huisache, and mustang grape, and dewberry vines. Forbs include sensitivebriar, bundleflower, snotbean, and other perennial and annual species. Grasslikes include sedges, rushes, and other water tolerant species.
DISTRIBUTION AND EXTENT: Southern Gulf Coast Prairies and eastern Northern Rio Grande Plain Land Resource Areas. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Refugio County, Texas; 1984. The name is from Copano Bay, which lies partially in Refugio County.
REMARKS: These soils were formerly included in the Edna, Papagua, and Papalote series.