LOCATION DEV TX

Established Series
Rev. AJT-MLG-WJG
11/2013

DEV SERIES

The Dev series consists of very deep, well drained, moderately rapidly permeable soils that formed in gravelly loamy alluvium derived from limestone. These nearly level to very gently sloping soils occur on flood plains. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 508 mm (20 in) and the mean annual air temperature is about degrees 17.8 C (64 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic Cumulic Haplustolls

TYPICAL PEDON: Dev very gravely loam--rangeland.
(colors are for dry soil unless otherwise stated.)

A--0 to 56 cm (0 to 22 in); dark grayish brown (10YR 4/2) extremely gravelly loam; very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky and granular structure; hard, friable; few fine roots; 65 percent by volume of subrounded limestone gravel, and a few cobbles and stones; calcareous; moderately alkaline; diffuse wavy boundary. Thickness is 50 to 102 cm (20 to 40 in)

C--56 to 203 cm (22 to 80 in); light yellowish brown (10YR 6/4) extremely gravelly loam; yellowish brown (10YR 5/4) moist; weak fine subangular blocky and weak medium granular structure; hard, friable; 65 percent by volume of subrounded limestone gravel, mostly less than 25 mm (1 in) in diameter and a few cobbles and stones; contains several intermittent thin strata of gravel containing less than 5 percent fines; few threads of calcium carbonate and thin films on the coarse fragments; calcareous; moderately alkaline.

TYPE LOCATION: Southwest part of Sutton County, Texas; from the intersection of U.S. Highway 277 and Ranch Road 189, 17.8 miles west on Ranch Road 189 to the Devils River, 1.4 miles north on county road, about 250 feet west along stream bank channel.
USGS topographic quadrangle: Flat Rock Draw SW, TX; Latitude: 30 degrees, 18 minutes, 16 seconds N; Longitude: 100 degrees, 57 minutes, and 3 seconds W; Datum: WGS84. UTM Easting 312405.68 m, UTM Northing 3354133.00 m, UTM Zone 14.

RANGE IN CHARACTERISTICS:
Soil moisture: Aridic-ustic moisture regime
Organic matter: an irregular decrease with depth and some pedons have a buried A horizon
Some pedons have layers consisting of nearly all coarse fragments and discontinuous strata of loam or clay loam.

Particle-size control section (weighted average):
Clay content: 8 to 35 percent
Rock fragments: 35 to 90 percent; limestone or chert; gravel, cobbles, and stones
Calcium carbonate: 40 to 80 percent by weight in less than 20 mm fraction

A horizon
Hue: 10YR
Value: 3 to 5
Chroma: 2 or 3
Texture: loam, clay loam, sandy loam with fragment modifiers
Rock fragments: 0 to 90 percent total; 0 to 60 percent gravel; 0 to 25 percent cobbles; 0 to 5 percent stones; mostly limestone with some chert; nonflat; subrounded; indurated.
Calcium carbonate equivalent: 20 to 90 percent
Effervesence: strong or violent
Reaction: slightly alkaline or moderately alkaline

C horizon
Hue: 7.5 YR or 10YR
Value: 5 to 7
Chroma: 2 to 4
Texture: sand, sandy loam, loam, clay loam with fragment modifiers and may be stratified
Clay content: 1 to 35 percent
Rock fragments: 35 to 90 percent total; 30 to 75 percent gravel; 0 to 35 percent cobbles; 0 to 5 percent stones; mostly limestone with some chert; nonflat; subrounded; indurated.
Identifiable secondary carbonates: 0 to 5 percent; films, threads, or coatings in soil and on surface of fragments
Calcium carbonate equivalent: 40 to 90 percent
Effervesence: strong or violent
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: There are no competing series in the same family. Closely similar series are the Iraan, Oakalla, Rioconcho, Rio Diablo, and Vanderpool series.
Iraan: has a fine-silty particle-size control section
Oakalla and Vanderpool: have a fine-loamy particle-size control section and occur in the typic-ustic moisture regime
Rioconcho and Rio Diablo: have a fine particle-size control section

GEOGRAPHIC SETTING:
Parent Material: gravelly loamy alluvium derived from limestone
Landscape: river valleys or dissected plateaus
Landform: flood plains or draws of high velocity streams
Slope: 0 to 3 percent
Soil moisture: Aridic Ustic moisture regime
Mean annual precipitation: 356 to 762 mm (14 to 30 in)
Thornthwaite P.E. indices: 19 to 35
Mean annual air temperature: 16.7 to 21.1 degrees C (62 to 70 degrees F)
Frost-free period: 210 to 270 days
Elevation: 198.1 to 1303.0 m (650 to 4275 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Angelo, Ector, Mailtrail, Rioconcho, and Rio Diablo series.
Angelo soils: have a fine-silty particle-size control section and a calcic horizon.
Ector soils: are shallow to a lithic contact and occur higher in the landscape.
Mailtrail soils: are shallow to a petrocalcic and occur higher in the landscape.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately rapid. Runoff is negligible. Frequently or occasionally flooded for brief or very brief duration per year.

USE AND VEGETATION: Used for native range. The soil commonly has a moderate cover of red grama, sideoats grama, threeawns, and plains bristlegrass, and a thin to moderate overstory of mesquite, cedar, and catclaw. A few live oak, pecan, and other deciduous trees are adjacent to stream channels.

DISTRIBUTION AND EXTENT: Western and southwestern Texas, LRR I - Southwest Plateaus and Plains Range and Cotton Region, Edwards Plateau, MLRA 81A and 81B. The series is of moderate extent.

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

SERIES ESTABLISHED: Terrell County, Texas; 1966.

REMARKS: Periodic catastrophic floods deposit most of the coarse fragments which are mainly of limestone, and the smaller floods deposit a large part of the clay and silt size particles.

Edited 11/2013 (RFG-THW): Converted to tabular format and added metric measurements. Updated the competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this soil are:
Mollic epipedon - 0 to 56 cm (0 to 22 in) (A horizon)
Cambic horizon - 56 to 152 cm (22 to 60 in) (C horizon)

ADDITIONAL DATA: NSSL data is available from Sutton County S91TX435-001 and from TAMU Soil Characterization Lab for Real County S90TX385-002.

Taxonomic Version: Keys to Soil Taxonomy, Eleventh Edition, 2010

National Cooperative Soil Survey
U.S.A.