LOCATION PANTEX TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Torrertic Paleustolls
TYPICAL PEDON: Pantex silty clay loam, on a level plain, 0.3 percent slope in cultivated field at an elevation of about 3,447 feet. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; very dark grayish brown (10YR 3/2) silty clay loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; hard, firm; common fine roots; common very fine and fine pores; slightly alkaline; clear smooth boundary. (5 to 10 inches thick)
Bt1--7 to 20 inches; very dark grayish brown (10YR 3/2) silty clay, very dark brown (10YR 2/2) moist; strong medium angular blocky structure; few wedge shaped peds with long axes tilted 10 to 15 degrees from horizontal; very hard, very firm; few fine roots; common fine pores; few pressure faces; common distinct clay films on faces of peds; moderately alkaline; gradual smooth boundary. (6 to 20 inches thick)
Bt2--20 to 34 inches; brown (7.5YR 4/2) silty clay, dark brown (7.5YR 3/2) moist; strong medium angular blocky structure; common wedge shaped peds with long axes tilted 10 to 15 degrees from horizontal; very hard, very firm; few very fine roots; common fine pores; few pressure faces; common distinct clay films; moderately alkaline; gradual smooth boundary. (8 to 18 inches thick)
Bt3--34 to 49 inches; brown (7.5YR 4/3) silty clay loam, dark brown (7.5YR 3/3) moist; strong medium angular blocky structure; very hard, very firm; few fine roots; common very fine and fine pores; common distinct clay films; few threads of calcium carbonate in pores; strongly effervescent; moderately alkaline; gradual smooth boundary. (8 to 20 inches thick)
Bt4--49 to 60 inches; brown (7.5YR 4/4) silty clay loam, dark brown (7.5YR 3/4) moist; moderate medium blocky structure; very hard, very firm; few fine roots; common very fine and fine pores; common prominent clay films; few films and threads of calcium carbonate; slightly effervescent; moderately alkaline; gradual smooth boundary. (10 to 20 inches thick)
Bt5--60 to 71 inches; yellowish red (5YR 5/6) silty clay loam, yellowish red (5YR 4/6) moist; strong medium angular blocky structure; very hard, very firm; few fine roots; common very fine and fine pores; common prominent clay films; few threads of calcium carbonate in pores; slightly effervescent; moderately alkaline; gradual smooth boundary. (10 to 20 inches thick)
Btk--71 to 91 inches; reddish yellow (5YR 7/6) silty clay loam, reddish yellow (5YR 6/6) moist; moderate medium subangular blocky structure; very hard, firm; common very fine pores; few distince clay films; about 50 percent visible calcium carbonate in the form of masses, films, and threads; violently effervescent; moderately alkaline.
TYPE LOCATION: Carson County, Texas; 1.1 miles northeast of Panhandle on U. S. Highway 60 from its intersection with Texas Highway 15, 800 feet north of U. S. Highway 60 in cropland; Latitude: 35 degrees, 21 minutes, 30 seconds N; Longitude: 101 degrees, 22 minutes, 20 seconds W; Panhandle East, 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: 57 to 64 degrees F.
Depth to argillic horizon: 5 to 10 inches.
Depth to secondary calcium carbonate: 33 to 45 inches.
Depth to calcic horizon: 60 to 80 inches.
Solum thickness: more than 80 inches.
Particle-size control section: 35 to 55 percent silicate clay.
Ap horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 2 or 3
Texture: silty clay loam
Effervescence: none
Reaction: neutral to slightly alkaline
Bt horizons:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 6
Texture: silty clay, silty clay loam, clay
Calcium carbonate equivalent: 0 to 3 percent in the lower part of horizon.
Effervescence: very slight to slight
Reaction: slightly to moderately alkaline
Btk horizons:
Hue: 5YR or 7.5YR
Value: 5 to 8 dry, 4 to 7 moist
Chroma: 2 to 6
Texture: silty clay loam, silty clay, clay loam
Calcium carbonate equivalent: 20 to 60 percent as masses and concretions
Effervescence: strong to violent
Reaction: moderately alkaline
COMPETING SERIES:
Pullman is the only competing series in the same family. Similar soils are the
Darrouzett,
Lofton,
Olton, and
Sherm series.
Pullman series: has a calcic horizon within 60 inches of the soil surface.
Darrouzett and Sherm series: have average annual soil temperatures less than 59 degrees F.
Lofton and Olton series: have calcic horizons at depths less than 60 inches from the soil surface.
GEOGRAPHIC SETTING:
Parent material: fine, clayey eolian sediments derived from Blackwater Draw Formation of Pleistocene age.
Landform: plane to slightly convex broad plains.
Slopes: dominantly 0.2 to 0.8 percent, but ranges to 1 percent.
Mean annual air temperature: 55 to 62 degrees F.
Mean annual precipitation: 16 to 22 inches.
Frost-free period: 180 to 210 days.
Elevation: 2,500 to 4,500 feet.
Thornthwaite annual P-E Index Values: 30 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Pullman soils as well as the
Estacado,
Lazbuddie,
Lofton,
McLean,
Pep, and
Randall series.
Pullman soils occur on similar landscape positions and have a calcic horizon at less than 60 inches from the soil surface.
Estacado and Pep soils occupy similar, but more sloping positions near draws or playas and are calcareous to the surface with fine-loamy control sections.
Lazbuddie soils occur on benches above playa floors, and in slightly depressed areas.
Lofton soils occur on slightly lower positions in the landscape and do not have hues of 7.5YR or redder in the matrix.
McLean and Randall soils occur on playa floors and do not have hues of 7.5YR or redder in the matrix.
DRAINAGE AND PERMEABILITY: Well drained. Slow permeability. Surface runoff is low on 0 to 1 percent slopes.
USE AND VEGETATION: Mainly cultivated to corn, grain sorghum, and winter wheat. A considerable acreage is irrigated. Climax vegetation includes blue grama and buffalograss, with lesser amounts of vine-mesquite, western wheatgrass, galleta or tobosa, silver bluestem, wild alfalfa, and prairieclover. This soil has been correlated to the Deep Hardland (077CY022TX) range site in MLRA-77.
DISTRIBUTION AND EXTENT: Southern High Plains of west Texas and eastern New Mexico (sub-MLRA 77C). The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES PROPOSED: MLRA-77 Soil Survey; Carson County, Texas; 1991.
REMARKS: This series was formerly included in the Pullman series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 20 inches. (A and Bt1 horizons)
Argillic horizon: 7 to 91 inches. (Bt horizons)
Calcic horizon: 71 to 91 inches. (Btk horizon)
Vertic properties: Deep, wide cracks greater than 20 inches deep and wedge-shaped aggregates. COLE greater than 0.07.
ADDITIONAL DATA: NSSL Sample Nos. S93TX-065-002 (Carson Co. TX)
Soil interpretations record: TX1240
Taxonomic version: Keys to Soil Taxonomy, Eighth Edition, 1998.