LOCATION AUSTWELL TX

Established Series
ICM-ALN-KBH-AKS
07/2019

AUSTWELL SERIES

The Austwell series consists of very deep, poorly drained, very slowly permeable soils that formed in saline, calcareous, alluvial sediments high in smectitic clays . These nearly level soils occur on flood plains on low coastal plains. Slopes are less than 1 percent. Mean annual precipitation is about 889 mm (35 in) and the mean annual air temperature is about 22 degrees C (71 degrees F).

TAXONOMIC CLASS: Fine, smectitic, calcareous, hyperthermic Vertic Endoaquepts

TYPICAL PEDON: Austwell clay--rangeland. (Colors are for moist soil unless otherwise stated.)

A--0 to 20 cm (0 to 8 in); dark gray (10YR 4/1) clay, dark gray (10YR 4/1) dry; moderate coarsesubangular blocky structure; extremely hard, very firm, very sticky and plastic; common fine roots; electrical conductivity of the saturation extract is 9.0 dS/m; strongly effervescent; moderately alkaline; gradual wavy boundary. (Thickness is 10 to 66 cm [4 to 26 in] )

Bnzg1--20 to 66 cm (8 to 26 in); dark gray (10YR 4/1) clay, dark gray (N 4/) dry; moderate medium subangular and angular blocky structure; extremely hard, very firm, very sticky and plastic; few fine roots; many fine crystals of salt; electrical conductivity of the saturation extract is 9.0 dS/m; strongly effervescent; moderately alkaline; gradual smooth boundary. (Combined thickness is 40 to 106 cm [16 to 42 in] )

Bnzg2--66 to 107 cm (26 to 42 in); dark gray (10YR 4/1) clay, gray (10YR 5/1) dry; moderate coarse angular blocky structure; extremely hard, very firm, very sticky and plastic; few fine roots; few fine faint brown (10YR 4/3) iron concentrations; few fragments of shells; common crystals of salt; electrical conductivity of the saturation extract is 10.0 dS/m; strongly effervescent; moderately alkaline; gradual smooth boundary.

Czg--107 to 218 cm (42 to 86 in); gray (10YR 5/1) silty clay loam, gray (10YR 6/1) dry; massive; hard, firm, sticky and plastic; common fine and medium distinct yellowish brown (10YR 5/4) iron concentrations; ; electrical conductivity of the saturation extract is 10.0 dS/m strongly effervescent; moderately alkaline. (Thickness is 87 to 153 cm [34 to 60 in] )

TYPE LOCATION:
Calhoun County, Texas; about 15 miles southwest of Port Lavaca in flood plain of Guadalupe River; 4 miles west of intersection of Texas Highways 35 and 185; 85 feet south of Texas Highway 35 right-of-way; 1,200 feet west of Hog Bayou in rangeland.

USGS topographic quadrangle: Austwell, TX
Latitude: 28 degrees, 29 minutes, 35.209 seconds N
Longitude: 96 degrees, 50 minutes, 44.117 seconds W
Datum: WGS 84
UTM Easting 710882.30 m
UTM Northing 3153721.13 m
UTM Zone: 14

RANGE IN CHARACTERISTICS:
Soil Moisture: A peraquic soil moisture regime.
Mean annual soil temperature: 21.7 to 22.2 degrees C (71 to 72 degrees F)

Particle-size control section (weighted average):
Clay content: 40 to 60 percent

A horizon:
Hue: 10YR, 2.5Y, N/
Value: 4 or 5
Chroma: 1 or less
Texture: clay
Fragments: amount-0 to 3 percent; size-2 to 5 mm-; kind-shell
Electrical conductivity: 2 to 16 dS/M
Sodium adsorption ratio (SAR): 4 to 16
Effervescence: strong
Reaction (pH): moderately alkaline (7.9 to 8.4)

Bnzg horizon:
Hue: 10YR, 2.5Y, 5Y, or N/
Value: 4 to 7
Chroma: 2 or less. .
Texture: clay or silty clay
Redox concentrations: 1 to 20 percent; shades of brown, yellow, or red
Fragments: amount-0 to 3 percent; size-2 to 5 mm-; kind-shell
Electrical conductivity: 2 to 16 dS/m
Sodium adsorption ratio (SAR): 4 to 16
Effervescence: strong
Reaction (pH): moderately alkaline (7.9 to 8.4)

Czg horizon:
Hue: 10YR, 2.5Y, 5Y, or N/
Value: 4 to 7
Chroma: 2 or less. .
Texture: silty clay loam, clay, or silty clay
Some pedons are stratified with clayey and loamy layers
Redox concentrations: 1 to 20 percent; shades of brown, yellow, or red
Fragments: amount-0 to 3 percent; size-2 to 5 mm-; kind-shell
Sodium adsorption ratio (SAR): 4 to 16
Effervescence: strong
Reaction (pH): moderately alkaline (7.9 to 8.4)

COMPETING SERIES: There are no other series in this family. Similar soils are the Grulla, and Placedo series.
Grulla soils: do not have a cambic horizon; mixed mineralogy; cracks when dry
Placedo soils: do not have a cambic horizon; not calcareous; more acidic
GEOGRAPHIC SETTING:
Parent material: saline, calcareous, alluvial sediments high in smectitic clays
Landscape: low coastal plains
Landform: flood plains
Slope: less than 1 percent
Mean annual precipitation: 762 to 1016 mm (30 to 40 in)
Thornthwaite P-E Index: 40 to 64
Mean annual air temperature: 21.1 to 22.8 degrees C (70 degrees to 73 degrees F)
Frost-free period: 290 to 310 days
Elevation: 0 to 4.9 m (0 to 16 ft)

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Aransas, Laewest, and Victoria series.
Aransas soils: have a mollic epipedon;on similar landform.
Laewest and Victoria soils: are better drained; on a higher non-flooded landform
DRAINAGE AND PERMEABILITY:
Drainage class: Poorly
Permeability class: very slow
Runoff: high on slopes less than 1 percent
Flooding: floods from the rivers and streams occur 1 to 3 times a year for 1 to 3 weeks. Flooding occurs occasionally from storm tides from the Gulf of Mexico . The soils are saturated for long periods and are seldom dry below 30 cm (12 in).

USE AND VEGETATION:
Major uses: rangeland and wildlife.
Native vegetation: Gulf cordgrass, bushy sea-oxeye, spiny aster, marshhay cordgrass, and sedges.

Ecological sites assigned to phases and components of this series are listed below. Current ecological site assignments are in Web Soil Survey. Components of this series include the following ecological sites: Salty Bottomland
DISTRIBUTION AND EXTENT:
General area: Flood plains near sea level in the central part of the Gulf Coast of Texas
Land Resource Region: T (Atlantic and Gulf Coast Lowland Forest and Crop Region)
Major Land Resource Area: (150B)- Gulf Coast Saline Prairies
Extent: moderate

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

SERIES ESTABLISHED: Calhoun County, Texas; 1972.

REMARKS: Classification changed from Typic Haplaquepts to Vertic Endoaquepts 11/2000 based on typifying pedon description. Some limited data indicate these soils may be Vertisols. Further study and characterization data of the series is needed to verify hydrology and classification.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 20 cm (0 to 8 in) (A horizon).
Cambic horizon: 20 to 107 cm (8 to 42 in) (Bnzg1 and Bnzg2)

ADDITIONAL DATA: none

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

National Cooperative Soil Survey
U.S.A.