LOCATION ELOSO                   TX

Established Series
Rev. RM-MLG-JKW
11/2010

ELOSO SERIES

The Eloso series consists of moderately deep to siltstone, well drained, soils that formed in clayey alluvial sediments over the Catahoula siltstone. These nearly level to gently sloping soils are on broad interfluves. Slopes range from 0 to 5 percent. Mean annual precipitation is about 813 mm (32 in)and the mean annual air temperature is about 21.1 degrees C (70 degrees F).

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Pachic Vertic Haplustolls

TYPICAL PEDON: Eloso clay, in pastureland; elevation is 143 meters (470 feet). (Colors are for dry soil unless otherwise stated)

Ap--0 to 13 cm (0 to 5 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; weak medium prismatic structure parting to weak medium subangular blocky; very hard, extremely firm, very sticky, very plastic; common fine roots; common fine tubular pores; few fine concretions of calcium carbonate; slightly alkaline; clear smooth boundary.

A--13 to 30 cm (5 to 12 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate medium prismatic structure parting to moderate medium and coarse subangular blocky; very hard, extremely firm, very sticky, very plastic; common fine roots; few fine and medium tubular pores; few faint pressure faces; few fine and medium concretions of calcium carbonate; slightly effervescent; slightly alkaline; gradual wavy boundary. (combined thickness of the A horizon is 20 to 51 cm [8 to 20 in])

Bk--30 to 71 cm (12 to 28 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, extremely firm, very sticky, very plastic; common fine roots concentrated along vertical surfaces of peds; few fine and medium tubular pores; common rounded and platy fragments and few fine masses of calcium carbonate; common black and very dark gray worm casts; common prominent pressure faces; few small slickensides; strongly effervescent; slightly alkaline; gradual wavy boundary. (10 to 46 cm [4 to 18 in] thick)

BCk--71 to 94 cm [28 to 37 in]; gray (10YR 6/1) silty clay, gray (10YR 5/1) moist; weak medium and coarse prismatic structure parting to moderate fine subangular blocky; hard, very firm, sticky, plastic; common fine roots; few fine tubular pores; common fine very dark gray worm casts; few fine threads and coats of calcium carbonate on vertical surfaces of peds; common fine and medium concretions of calcium carbonate; common prominent pressure faces; strongly effervescent; slightly alkaline; gradual wavy boundary. (0 to 28 cm [0 to 11 in] thick)

2Cr--94 to 203 cm (37 to 80 in); very pale brown (10YR 8/2) noncalcareous weakly cemented siltstone with texture of silt loam, light gray (10YR 7/2) moist; massive; few fine roots; common thick continuous coats of calcium carbonate along vertical cracks in upper part; distinct bedding planes; slightly alkaline.

TYPE LOCATION: Karnes County, Texas; from the intersection of U.S. Highway 181 and Farm Road 99 in Karnes City; 8.2 miles west on Farm Road 99 to county road in Coy City; 2.0 miles north on county road; 0.4 mile east in pastureland. Coy City, Texas USGS topographic quadrangle; Latitude: 28 degrees, 51 minutes, 20 seconds N; Longitude: 98 degrees, 02 minutes, 45 seconds W.NAD 83.

RANGE IN CHARACTERISTICS:

Soil Moisture: A typic-ustic moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days but less than 180 cumulative days in normal years. June through August and December through February are the driest months. These soils are intermittently moist in September through November and March through May.
Depth to paralithic contact: 50 to 100 cm (20 to 40 in).
Particle-size control section (weighted average)
Clay content: 40 to 55 percent

Linear extensibility ranges from 6 to 13 cm (2.5 to 5 in). When dry, cracks up to 1 inch wide extend to a depth of more than 50 cm (20 in).

A Horizon
Hue: 10YR
Value: 2 or 3
Chroma: 1 or 2
Texture: clay loam or clay
Identifiable secondary carbonate: amount-0 to 5 percent, kind-concretions
Effervescence: none or slight
Reaction: neutral or slightly alkaline
Clay content: 35 to 55 percent

Bk (Bw where present) Horizon (upper part)
Hue: 10YR
Value: 2 or 4
Chroma: 1 or 2
Texture: clay or silty clay
Identifiable secondary carbonate: amount-0 to 10 percent, kind-concretions, films, masses or threads
Effervescence: none or slight
Reaction: slight or moderately alkaline
Clay content: 40 to 55 percent


Bk Horizon (lower part)
Hue: 10YR
Value: 5 to 7
Chroma: 1 to 3
Texture: clay loam, silty clay loam, clay, or silty clay
Identifiable secondary carbonate: amount-0 to 10 percent, kind-concretions, films, masses or threads
Effervescence: none to strong
Reaction: slight or moderately alkaline
Clay content: 35 to 45 percent

BCk Horizon
Hue: 10YR or 2.5Y
Value: 3 to 7
Chroma: 1 to 4
Texture: clay loam, silty clay loam, silty clay or clay
Identifiable secondary carbonate: amount-0 to 10 percent, kind-concretions, films, masses or threads
Effervescence: slight to strong
Reaction: slight or moderately alkaline
Clay content: 35 to 45 percent


2Cr (2Crk where present) Horizon
Hue: 7.5YR to 2.5Y
Value: 6 to 8
Chroma: 1 to 4
Texture: noncalcareous weakly cemented siltstone bedrock of loam or silt loam texture interbedded with thin layers of calcium carbonate. This material slakes in water.
Identifiable secondary carbonate: amount-0 to 5 percent, kind-concretions or masses and are mostly in the upper part, size-fine
Effervescence: matrix is noncalcareous; slight to strong in vicinity of carbonates
Reaction: slight or moderately alkaline
Clay content: 18 to 27 percent

COMPETING SERIES: This includes the Divot series in the same familySimilar soils include the Condido (TX), Dosrios (T) (TX) Greenvine (TX), Roenbrock (TX) and Tordia (TX) series.
Condido soils: are shallow over a petrocalcic horizon
Divot soils: formed in clayey alluvium on nearly level flood plains; very deep
Dosrios soils: are Vertisols; have exchangeable sodium percentage more than 15 within 50 cm (20 in) of the surface
Greenvine: are in an udic moisture regime; are Vertisols
Tordia soils: 100 to 150 cm (40 to 60 in) thick over a paralithic contact.
Rosenbrock soils: have thicker sola; are Vertisols.

GEOGRAPHIC SETTING:
Parent material: clayey sediments over noncalcareous weakly consolidated siltstone interbedded with thin layers of soft calcium carbonate of the Catahoula formation
Landform: broad interfluves on inland dissected coastal plains
Slope: 0 to 5 percent
Mean annual air temperature range: 21.1 to 23.4 cm (70 to 74 degrees F).
Mean annual precipitation range: 711 to 813 mm (28 to 32 in)
Precipitation Pattern: Precipitation occurs mostly during the months of April through June and September through October.
Frost-free period: 275 to 300 days
Elevation: 107 to 168 m (350 to 550 ft)
Thornthwaite annual P-E indices: 31 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Condido (TX), Choke (TX), Pavelek (TX), Fashing (TX), Rosenbrock (TX), Monteola (TX), and Tordia (TX) soils.
Condido, Pavelek, and Fashing soils: on a slightly higher position on a similar landform;have sola less than 50 cm (20 in) thick;Condido and Pavelek soils have petrocalcic horizons.
Rosenbrock, Monteola, and Tordia soils: on a similar to slightly lower position on a similar landform; sola more than 100 (cm) 40 in) thick. Choke soils: on a similar landform; have a fine-silty particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is very slow. Runoff is low on 0 to 1 percent slopes, medium on 1 to 3 percent slopes, and high on 3 to 5 percent slopes.

USE AND VEGETATION: Used mainly as rangeland and wildlife habitat. Some areas are cultivated with small grains and grain sorghum. Also, some areas are used as bermudagrass pasture and hayland. Native grasses include Texas wintergrass, sideoats grama, bristlegrasses, Hall's panicum, Texas grama, threeawns, and red grama. Woody vegetation is mainly agarito, prickly pear, lotebush, mesquite, spiny hackberry, persimmon, blackbrush, and live oak. Rolling Blackland 25 to 35 inch PZ ecological site; R083AY399TX.

DISTRIBUTION AND EXTENT: Northern and Central Rio Grande Plain, Texas; LRR I; MLRA 83A, 83C. The series is of moderate extent.

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

SERIES ESTABLISHED: Karnes County, Texas 1989. The name is from a small community in southwest Karnes County.

REMARKS: These soils were formerly included in the Monteola and Coy series. The series was updated during the correlation of the initial soil survey of McMullen County.

Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - 0 to 71 cm (0 to 28 in). (Organic carbon is rounded from laboratory data from 0.55 to 0.6 to include the Bk horizon).

Vertic feature - the soil cracks when dry and has PLE of more than 7 cm (2.5 in) and few to common wedge-shaped aggregates.

Paralithic contact at 94 cm (37 in to the top of the 2Cr).

ADDITIONAL DATA: Karnes County, Texas; TAMU Characterization lab numbers S88TX-255-007.

TAXONOMIC VERSION: Keys to Soil Taxonomy, Eleventh Edition, 2010.

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National Cooperative Soil Survey
U.S.A.