LOCATION ESTACADO TX+NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Aridic Paleustolls
TYPICAL PEDON: Estacado clay loam, on a level plain, 0.5 percent slope in cropland at an elevation of about 1,166 meters (3,825 feet). (Colors are for dry soil unless otherwise stated.)
Ap--0 to 15 cm (0 to 6 inches); dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, firm; many fine roots; many fine and medium tubular pores; slightly effervescent; moderately alkaline; clear smooth boundary. (13 to 25 cm thick)
Bt1--15 to 48 cm (6 to 19 inches); brown (10YR 4/3) clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; very hard, firm; many fine and medium roots between peds; many very fine and fine tubular pores; few distinct clay films on ped surfaces; few fine masses of calcium carbonate; strongly effervescent; moderately alkaline; clear wavy boundary. (13 to 51 cm thick)
Bt2--48 to 97 cm (19 to 38 inches); brown (7.5YR 4/4) clay loam, dark brown (7.5YR 3/4) moist; weak coarse prismatic structure parting to weak fine subangular blocky; hard, firm; common very fine and fine roots between peds; many very fine and fine tubular pores; few distinct clay films on ped surfaces; common fine nodules of calcium carbonate; strongly effervescent; moderately alkaline; gradual irregular boundary. (30 to 89 cm thick)
Btk1--97 to 127 cm (38 to 50 inches); reddish yellow (7.5YR 7/6) clay loam, reddish yellow (7.5YR 6/6) moist; weak coarse prismatic structure parting to weak fine subangular blocky; hard, firm; common very fine and fine roots between peds; many fine and medium tubular pores; few distinct clay films on ped surfaces; many masses and films of calcium carbonate; violently effervescent; moderately alkaline; gradual wavy boundary. (38 to 64 cm thick)
Btk2--127 to 203 cm (50 to 80 inches); pinkish white (7.5YR 8/2) clay loam; pinkish gray (7.5YR 7/2) moist; weak coarse prismatic structure parting to weak fine and medium subangular blocky; hard, firm; common very fine and fine roots between peds; many fine and medium tubular pores; few distinct clay films on ped surfaces; many masses and nodules of calcium carbonate; violently effervescent; moderately alkaline.
TYPE LOCATION: Deaf Smith County, Texas; from the intersection of U.S. Highway 385 and U.S. Highway 60 in Hereford, 11 kilometers (6.75 miles) north on U.S. Highway 385, 5 kilometers (3 miles) east on county road, 0.8 kilometer (0.5 mile) north on county road, 183 meters (600 feet) east in cropland; Latitude: 34 degrees, 25 minutes, 30 seconds N; Longitude: 102 degrees, 20 minutes, 10 seconds W; Hereford NE, Texas USGS quad; NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture control section is dry in some or all parts for more than 180 but less than 205 days, cumulative, in normal years. July through August and December through February are the driest months. These soils are intermittently moist in September through November and March through June.
Mean annual soil temperature: 15 to 18 degrees C (59 to 64 degrees F).
Depth to argillic horizon: 13 to 25 cm (5 to 10 inches).
Depth to secondary calcium carbonate: 13 to 61 cm (5 to 24 inches).
Depth to calcic horizon: 61 to 102 cm (24 to 40 inches).
Solum thickness: more than 203 (80 inches).
Particle-size control section: 20 to 35 percent silicate clay.
A horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5, 2 to 4 moist
Chroma: 2 or 3
Texture: loam, clay loam
Effervescence: slight to violent
Reaction: slightly alkaline or moderately alkaline
Bt horizons:
Hue: 7.5YR or 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 to 6
Texture: sandy clay loam, clay loam
Visible calcium carbonate: less than 5 percent as films, threads, or nodules
Effervescence: strong or violent
Reaction: slightly alkaline or moderately alkaline
Btk horizons:
Hue: 7.5YR or 10YR
Value: 4 to 8, 3 to 7 moist
Chroma: 3 to 6
Matrix color is redder than 7.5YR and chroma is 5 or more
Texture: sandy clay loam, clay loam
Visible calcium carbonate: 5 to 50 percent as films, threads, masses, and nodules
Effervescence: strong or violent
Reaction: moderately alkaline
COMPETING SERIES: This is the
Acuff series. Similar soils include the
Manson,
Mansker,
Olton,
Pep,
Portales,
Sunray, and
Texline series.
Acuff and Olton series: non-calcareous in the upper horizons and have a calcic horizon between 76 to 152 cm (30 and 60 inches), in addition the Olton soils have 35 to 45 percent clay in the particle-size control section.
Manson series: has a calcic horizon within 38 to 61 cm (15 and 24 inches) of the soil surface.
Mansker series: has a calcic horizon within 38 to 61 cm (15 and 24 inches) of the soil surface and has carbonatic mineralogy.
Pep and Portales series: do not have an argillic horizon.
Sunray and Texline series: have mean annual soil temperatures less than 15 degrees C (59 degrees F).
GEOGRAPHIC SETTING:
Parent material: calcareous, moderately fine textured alluvial and eolian sediments of the Blackwater Draw Formation of Pleistocene age.
Landform: on nearly level to gently sloping plains.
Slopes: 0 to 5 percent.
Mean annual air temperature: 14 to 17 degrees C (57 to 62 degrees F).
Mean annual precipitation: 432 to 533 millimeters (17 to 21 inches).
Frost-free period: 180 to 220 days.
Elevation: 763 to 1,402 meters (2,600 to 4,600 feet).
Thornthwaite annual P-E Index Values: 30 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the similar
Acuff and
Olton series, and the
Amarillo,
Pantex,
Pep,
Posey, and
Pullman series.
Acuff, Amarillo, Olton, Pantex, and Pullman soils: are on similar landscape positions and are non-calcareous in the surface and Bt horizons.
Pep soils: are on similar landscape positions and do not have an argillic horizon.
Posey soils: are on similar landscape positions and have a calcic horizon within 24 inches of the soil surface.
DRAINAGE AND PERMEABILITY: Well drained. Moderately slow permeability. Surface runoff is negligible on 0 to 1 percent slopes, very low on 1 to 3 percent slopes, and low on 3 to 5 percent slopes.
USE AND VEGETATION: Mainly used for crop production. Principal crops grown are cotton, grain sorghum, and wheat. Climax vegetation in rangeland is mainly mid and short grasses and includes blue grama, sideoats grama, and buffalograss, with lesser amounts of vine-mesquite, western wheatgrass, galleta or tobosa, silver bluestem, wild alfalfa, and prairieclover with a light to moderate overstory of mesquite. This soil has been correlated to the Deep Hardland (077CY022TX) range site in MLRA-77.
DISTRIBUTION AND EXTENT: The Southern High Plains, Southern Part (MLRA 77C in LRR H) of western Texas and eastern New Mexico. The soil is moderately extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hale County, Texas; 1969.
REMARKS: These soils were previously included with the Portales and Mansker series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 48 cm. (Ap, Bt1 horizons)
Argillic horizon: 15 to 203 cm. (Bt1, Bt2, Btk1, Btk2 horizons)
Calcic horizon: 97 to 203 cm. (Btk1, Btk2 horizons)
Pale feature: Clay content does not decrease within 152 cm (60 inches) of the surface by as much as 20 percent and argillic horizon has matrix colors redder than hue 7.5YR and chroma 5 or more.
ADDITIONAL DATA: ARS Bushland Experiment Station data from Deaf Smith County, TX (S91TX-117-001); NSSL data from Carson County, TX (S93TX-065-001) (69L007-69L010).
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006.