LOCATION CONQUISTA TX

Established Series
Rev. MLG-CKH-GWH
11/2010

CONQUISTA SERIES

The Conquista series consists of very deep, well drained, very slowly permeable soils on gently sloping to steep uplands. These soils are formed from loamy materials excavated during mining operations. The original clayey topsoil surface layer was removed, stockpiled and replaced during the reclamation process. Slopes range from 1 to 40 percent. Mean annual temperature range is about 22 degrees C (72 degrees F). Mean annual precipitation range is about 762 mm (30 in).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, hyperthermic Entic Haplustolls

TYPICAL PEDON: Conquista clay, in pastureland; elevation is 111 meters (365 feet). (Colors are for dry soil unless otherwise stated)

Ap--0 to 12 inches; black (10YR 2/1) clay, black (10YR 2/1) moist; weak fine and medium subangular blocky structure; many medium and coarse faint dark gray (10YR 4/1) and very dark gray (10YR 3/1) and few medium distinct grayish brown (10YR 5/2) spots; extremely hard, extremely firm; very sticky; very plastic; common medium and many very fine and fine roots; common very fine tubular pores; few pressure faces; strongly effervescent; moderately alkaline; abrupt smooth boundary. (10 to 17 inches thick)

2C--12 to 80 inches; pinkish white (5YR 8/2) gravelly loam, pink (7.5YR 7/4) moist; massive; slightly hard; very friable; slightly sticky; plastic; few very fine roots; common fine and coarse masses of calcium carbonate; 30 percent hard siltstone fragments from 1/4 to 3 inches across; strongly effervescent; moderately alkaline.

TYPE LOCATION: Karnes County, Texas; from the intersection of Farm Road 81 and Texas Highway 80 in Helena; 0.7 mile north on Texas Highway 80 to intersection with county road; 0.85 mile west, north and west on county road; 240 feet southwest in pasture. Helena, Texas USGS topographic quadrangle; Latitude: 28 degrees, 58 minutes, 20 seconds N; Longitude: 97 degrees, 49 minutes, 45 seconds W.; NAD 83.

RANGE IN CHARACTERISTICS: Rooting depth ranges from 60 to more than 80 inches. The clay content of the particle-size control section ranges from 18 to 35 percent silicate clay.

Soil moisture: An 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.
Solum thickness: 60 to more than 80 inches
Particle-size control section
Clay content: 18 to 35

A horizon

Hue: 10YR
Value: 2 to 4
Chroma: 1 or 2
Texture: Clay loam or clay
Clay content: 30 to 55 percent
Identifiable secondary carbonate: 2 percent, fine, masses
Coarse fragments: soft shale, siltstone, or siliceous para-channers and para-gravel range up to 5 percent
Effervescence: none to violent
Reaction: slightly alkaline or moderately alkaline.

2C horizon
Hue: 5YR to 2.5Y
Value: 6 to 8
Chroma: 2 to 4
Texture: loam, very fine sandy loam, sandy clay loam, clay loam or their gravelly counterparts
Most of this material slakes in water
Coarse fragments: consisting of weakly to strongly cemented siltstone and sandstone, from 1/4 inch to 3 inches across, range from 5 to 35 percent by volume. The interior of some coarse fragments is noncalcareous.
Effervescence: strong to violent
SAR: 0 to 8
Reaction: moderately alkaline or strongly alkaline
Other features: 2C soil materials are from the Cathoula Formation, Frio Formation, Jackson Group and Claiborne Group

COMPETING SERIES: There are no competing series. Similar soils are the Barge, Bigbrown, Bragg, Grayrock, and Kanima series.
All of these soils are forming in reclaimed mine spoil materials that have been mechanically reworked.
Barge soils: have a thermic temperature regime have fragments of diagnostic horizons within the control section
Kanima soils: have a thermic temperature regime and have fragments of diagnostic horizons within the control section
Bigbrown soils: have a thermic temperature regime and are not calcareous and have a fine-silty particle-size control section
Grayrock soils: have a thermic temperature regime and are not calcareous and have a fine-silty particle-size control section
Bragg soils: have a thermic temperature regime and are acid with siliceous mineralogy

GEOGRAPHIC SETTING:
Parent material: reclaimed mine spoil materials;
Landscape: inland, dissected coastal plain
Anthropogenic feature: reclaimed land
Slope: 1 to 40 percent
Other features: These soil areas are prominent in the landscape
Associated features: These areas are typically associated with partially filled mine pits that impound water; water areas are about 1 to 40 acres in size. The pits range in depth from 15.2 to 550 m (50 to 100 ft) deep to the permanent water level.
Mean annual temperature range: 21 to 23 degrees C (70 to 74 degrees F)
Mean annual precipitation range: 711 to 813 mm (28 to 32 in)
Frost-free period: 275 to 290 days
Elevation ranges from 68.6 to 167.6 m (225 to 550 ft); about 15.2 to 30.5 m5 (0 to 100 ft) higher than the natural surface elevation
Thornthwaite P-E indices: 31 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Ecleto (TX), Eloso (TX), Gillett (TX), Monteola (TX), Pavelek (TX), and Tordia (TX) soils. These soils: are on nearby undisturbed areas.
Ecleto soils: are on nearby undisturbed areas and have argillic horizons
Gillett soils: soils: are on nearby undisturbed areas and have argillic horizons
Pavelek, Eloso, Monteola, Tordia soils: are on nearby undisturbed areas and have greater than 35 percent clay in the particle-size control section

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: Most areas have been established to improved pastures of bermudagrass or bunchgrasses such as kleingrass or introduced bluestems.

DISTRIBUTION AND EXTENT: Northern Rio Grande Plain, Texas; LRR I; MLRA 83A; minor extent.

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

SERIES ESTABLISHED: Karnes County, Texas; 1989. The name is from a small creek in northwestern Karnes County.

REMARKS: These soils were formerly included with pits and dumps.

The diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: 0 to 30 cm (0 to 12 in) (Ap horizon)

Other features: The epipedon is calcareous throughout the control section.

Additional Comments: The ecological site for this unit needs further investigation and has not been correlated in MLRA 83.

ADDITIONAL DATA: Local lab analysis was performed on one pedon from McMullen County at the Robstown MLRA Project Office.

SOIL INTERPRETATION RECORD NUMBER: TX1185

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

National Cooperative Soil Survey
U.S.A.