LOCATION COLIBRO TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, carbonatic, hyperthermic Typic Calciustepts
TYPICAL PEDON: Colibro sandy clay loam, on an east-facing, convex, 5 percent slope in rangeland at an elevation of 107 m (350 ft) (Colors are for dry soil unless otherwise stated.)
A--0 to 15 cm (0 to 6 in); grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; weak fine granular and very fine subangular blocky structure; hard, friable; many fine roots; few fragments of snail shells; few films and threads of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (13 to 25 cm [5 to 10 in] thick)
Bk1--15 to 41 cm (6 to 16 in); grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, friable; many fine roots; few fragments of snail shells; few films, threads and concretions of calcium carbonate; violently effervescent; moderately alkaline; gradual smooth boundary. (10 to 30 cm [4 to 12 in] thick)
Bk2--41 81 cm (16 to 32 in); pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; moderate fine subangular blocky structure; hard, friable; few fragments of snail shells; 5 percent films, threads, and concretions of calcium carbonate; violently effervescent; moderately alkaline; gradual smooth boundary. (20 to 51 cm [8 to 20 in] thick)
Bk3--81 to 122 cm (32 to 48 in); very pale brown (10YR 8/4) fine sandy loam, very pale brown (10YR 7/4) moist; weak fine subangular blocky structure; slightly hard, very friable; 5 percent faint films and threads of calcium carbonate in upper part; violently effervescent; moderately alkaline; gradual smooth boundary. (15 to 61 cm [6 to 24 in] thick)
2C--122 to 152 cm (48 to 60 in); very pale brown (10YR 8/3) loamy fine sand, very pale brown (10YR 7/3) moist; massive; slightly hard, very friable; violently effervescent; moderately alkaline.
TYPE LOCATION: Wilson County, Texas. About 4.25 miles west of Poth, Texas on Farm Road 541 to intersection with unpaved county road; south on county road 0.3 mile; site is 200 feet east of county road. Dewees USGS quad; Latitude is about 28 degrees 59 minutes 21 seconds N; Longitude is 98 degrees 6 minutes 8.5 seconds W. NAD 83
RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic soil moisture regime. The soil moisture control section is dry in some or all parts for 90 or more cumulative days in normal years. The summer months of June through August are the driest while the Fall through Spring months are the wettest.
Mean annual soil temperature: 22 to 23.5 degrees C (72 to 74 degrees F).
Solum thickness ranges from 40 to 60 inches over
sandy material.
Reaction is moderately alkaline throughout.
Particle-size control section (weighted average)
Clay content: 18 to 30 percent
Carbonate clay content: 1 to 10 percent
A Horizon
Hue: 10YR
Value: 4 to 6
Chroma: 2 to 4
Texture: loam, sandy clay loam or clay loam
Calcium carbonate equivalent: 30 to 50 percent
Identifiable secondary carbonate: amount-few to common, kind-threads, masses, films or nodules
Effervescence: strong or violent
Bk Horizon
Hue: 10YR
Value: 4 to 7
Chroma: 2 to 4
Texture: sandy clay loam, loam, or fine sandy loam
Calcium carbonate equivalent: 30 to 70 percent
Identifiable secondary carbonate: amount-few to common, kind-threads, masses, films or nodules
Effervescence: strong or violent
2C or C Horizon
Hue: 10YR
Value: 6 to 8
Chroma: 3 or 4
Texture: loam, sandy loam, fine sandy loam, loamy fine sand, or loamy sand
Calcium carbonate equivalent: 40 to 70 percent
Identifiable secondary carbonate: amount-few to common, kind-threads, masses, films or nodules
Effervescence: strong or violent
COMPETING SERIES: There are no series in the same family. Similar soils are the
Botero (WY),
Karnes (TX),
Kerrville (TX),
Rio Frio (TX) and the
Whitecow (MT) series.
Botero soils: less than 18 percent clay on particle-size control section; frigid soil temperature regime
Karnes soils: less than 18 percent clay on particle-size control section; thermic soil temperature regime
Kerrville soils: more than 35 percent pebble-size or larger fragments in the particle-size control section; limestone rock at 61 cm (24 in); thermic soil temperature regime
Rio Frio soils: have a clay loam surface texture; thermic soil temperature regime
Whitecow soils: more than 15 percent pebble-size or larger fragments in the particle-size control section; frigid soil temperature control section
GEOGRAPHIC SETTING:
Parent material: erosional calcareous loamy material of Quaternerary age
Landscape: Coastal plains
Landform: ancient alluvial terrace
Slope: dominantly about 4 percent but range from 0 to 12 percent
Mean annual air temperature range: 21 to 23.5 degrees C (70 to 74 degrees F).
Mean annual precipitation range: 660 to 864 mm (26 to 34 in)
Precipitation Pattern: November through March and July through August are the driest months, while April through June and September through October are the wettest.
Frost-free period: 240 to 270 days
Elevation: 76 to 152 m (250 to 500 ft)
Thornthwaite annual P-E indices: 36 to 44
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Saspamco (TX),
Coy (TX), and
Runge(TX) series.
Saspamco soils: have less than 18 percent clay in the particle-size control section and are on a similar landform
Coy soils: have a mollic epipedon; more than 35 percent clay in the particle-size control section; on a hillslope landform
Runge soils: have a mollic epipedon; on a hillslope landform
DRAINAGE AND PERMEABILITY: Well drained; runoff is negligible on 0 to 3 percent slopes, very low on 3 to 5 percent slopes, low on 5 to 10 percent slopes, medium on 10 to 12 percent slopes; moderately rapid permeability.
USE AND VEGETATION: Used for cropland and range. Cultivated crops are small grain, flax, corn, cotton, and grain sorghums. Present range vegetation consists of Arizona cottontop, feathery bluestems, plains bristlegrass, white tridens, hooded windmillgrass, Texas bristlegreas, pink pappusgrass,slim tridens, mesquite, whitebrush, lote, spiny hackberry, and pricklypear. (Ecological site name: Gray Sandy Loam 25-35" Pz; Ecological site number: R083AY389TX)
DISTRIBUTION AND EXTENT: Rio Grande Plain of south Texas; LRR I; MLRA 83; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Wilson County, Texas; 1972.
REMARKS: The series was formerly included with the Karnes soils.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon 0 to 41 cm (0 to 16 in)
Calcic horizon - 41 to 122 cm (16 to 48 in)
ADDITIONAL DATA: Laboratory data performed by the MLRA 150 Soil Survey Office are available on pedons from Goliad County, Texas.
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006