LOCATION DELMITA                 TX

Established Series
HCD-CMT-CLG-RM
08/2018

DELMITA SERIES

The Delmita series consists of moderately deep to a petrocalcic horizon, well drained, moderately permeable soils. These soils formed in non-calcareous loamy alluvium over calcareous loamy residuum and petrocalcics of the Goliad Formation. These nearly level to very gently sloping soils occur on broad, low ridges on inland, dissected coastal plains. Slope ranges from 0 to 3 percent. Mean annual air temperature is about 22 degrees C (72 degrees F) and mean annual precipitation is about 584 mm (23 in).

TAXONOMIC CLASS: Fine-loamy, mixed, active, hyperthermic Petrocalcic Paleustalfs

TYPICAL PEDON: Delmita fine sandy loam, on a northeast facing, 1.0 percent slope in rangeland; elevation is 85 m (280 ft). (Colors are for dry soil unless otherwise stated.)

A--0 to 36 cm (0 to 14 in); reddish brown (5YR 5/4) fine sandy loam; reddish brown (5YR 4/4) moist; weak fine subangular blocky structure; hard; friable, slightly sticky and slightly plastic; common fine roots and pores; noneffervescent; neutral; clear smooth boundary. (23 to 51 cm [9 to 20 in] thick)

Bt--36 to 76 cm (14 to 30 in); red (2.5YR 4/6) sandy clay loam; dark red (2.5YR 3/6) moist; moderate coarse prismatic structure parting to weak fine subangular blocky; very hard, friable, sticky and slightly plastic; few fine roots; few very fine and fine pores; few faint clay films on surfaces of peds and lining pores; noneffervescent; neutral; abrupt wavy boundary. (28 to 71 cm [11 to 28 in] thick)

Bkkm--76 to 203 (30 to 80 in); very pale brown (10YR 8/2) strongly cemented calcium carbonate, becoming less cemented and massive with depth; thick, platy, indurated, finely laminated cap in the upper part; violently effervescent; moderately alkaline.

TYPE LOCATION: Starr County, Texas; 5.5 miles east of LaGloria on Farm Road 1017; 1800 feet south on Farm Road 2294, 150 feet west in rangeland.
USGS topographic quadrangle: San Isidro, Texas.
Latitude: 26 degrees, 42 minutes, 26 seconds N;
Longitude: 98 degrees 26 minutes, 6 seconds W.;
Datum: NAD 83.

RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic moisture regime bordering on aridic. The soil moisture control section remains moist in some or all parts for less than 90 consecutive days in normal years.
Mean annual soil temperature: 22.2 to 24.4 degrees C (72 to 76 degrees F).
Depth to argillic horizon: 23 to 51 cm (9 to 20 in).
Depth to petrocalcic horizon: 51 to 102 cm (20 to 40 in).

Particle-size control section (weighted average).
Clay content: 18 to 30 percent.
Coarse Fragments: 0 to 5 percent.
CEC/clay ratio: 0.40 to 0.60.

A Horizon
Hue: 2.5YR to 7.5YR
Value: 4 to 6
Chroma: 4 to 6
Texture: loamy fine sand or fine sandy loam
Clay content: 5 to 18 percent
Base saturation: 75 to 100 percent
Calcium carbonate equivalent: 0 to 2 percent
Effervescence: none
Reaction (pH): neutral or slightly alkaline (6.6 - 7.8)

Bt Horizon
Hue: 2.5YR to7.5YR
Value: 4 to 6
Chroma: 3 to 6
Texture: fine sandy loam or sandy clay loam
Clay content: 18 to 30 percent
Clay films: few or common, faint or distinct, on surfaces of peds and lining pores.
Redox accumulations: A few redox features that are reddish and brownish occur in the lower depths of some pedons.
Base saturation: 100 percent.
Calcium carbonate equivalent: 0 to 2 percent.
Effervescence: none to slight
Reaction (pH): neutral or slightly alkaline (6.6 - 7.8)

Bkkm Horizon
Hue: 10YR
Value: 8 to 9.5
Chroma: 1 or 2
Cementation: strongly cemented calcium carbonate (petrocalcic), becomes less cemented with depth.
Calcium carbonate equivalent: 40 to 80 percent
Effervescence: violent
Reaction (pH): slightly alkaline or moderately alkaline (7.4-8.4)

COMPETING SERIES: There are no competing series in the same family. Similar soils are the Goliad, Lacoste, and Randado series.
Goliad soils: have a fine textured particle-size control section and a mollic epipedon.
Lacoste and Randado soils: are shallow to the petrocalcic horizon.

GEOGRAPHIC SETTING:
Parent material: noncalcareous loamy alluvium and/or eolian deposits over calcareous loamy residuum and petrocalcics of the Goliad Formation.
Landscape: inland, dissected coastal plains
Landform: interfluves and side slopes of broad, low hills and ridges.
Slope: 0 to 3 percent.
Precipitation pattern: The soil is driest during the months of June through August and December through February. These soils are intermittently moist in September through November and March through May.
Mean annual precipitation: 508 to 635 mm (20 to 25 in)
Thornthwaite annual P-E indices: 21 to 34
Mean annual air temperature: 21.7 to 23.3 degrees C (71 to 74 degrees F).
Frost-free period: 280 to 340 days.
Elevation: 30.5 to 274.3 m (100 to 900 ft).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brennan, Cuevitas, Randado, and Zapata series.
Brennan soils: are very deep, do not have a petrocalcic horizon, and occur on similar positions.
Cuevitas, Randado, and Zapata soils: are shallow to a petrocalcic horizon and occur on higher positions.

DRAINAGE AND PERMEABILITY:
Drainage class: Well.
Permeability class: Moderate.
Runoff: negligible on slopes less than 1 percent and low on slopes of 1 to 3 percent.

USE AND VEGETATION: Used predominantly for wildlife habitat and livestock grazing. About 20 percent is for dry-land crop production of cotton, grain sorghum, watermelon, and forage production. A few areas are irrigated and produce such crops as citrus, cotton, sorghums, and winter vegetables. Principal grasses of uncultivated areas include Arizona cottontop, lovegrass tridens, plains bristlegrass and pink pappusgrass. Woody vegetation includes mesquite, catclaw, lime pricklyash, desert yaupon, and pricklypear.

DISTRIBUTION AND EXTENT: South Texas; LRR I; MLRA 83C - Central Rio Grande Plain and 83E - Sandsheet Prairie; the series is of large extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Jim Hogg County, Texas, 1970.

REMARKS: This is a Benchmark Series.
Those areas with loamy fine sand surface texture are generally more associated with the MLRA 83E - Sandsheet Prairie.

Edited 11/2016 (RFG-GWH): Updated competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 36 to 76 cm (14 to 30 in) (Bt horizon).
Ochric epipedon: 0 to 36 cm (0 to 14 in) (A horizon).
Argillic horizon: 36 to 76 cm (14 to 30 in) (Bt horizon).
Petrocalcic horizon: 76 to 152 cm (30 to 60 in) (Bkkm horizon).
The petrocalcic becomes less cemented with increasing depth.

ADDITIONAL DATA: Particle-size analysis was performed at the local project office on eight (8) pedons. The assignment of the cation-exchange activity class is inferred from lab data from surrounding counties in the region.

TAXONOMIC VERSION: Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.