LOCATION PANTEX TX

Established Series
Rev. FBP-RM-TCB
09/2022

PANTEX SERIES

The Pantex series consists of very deep, well drained, slowly permeable soils that formed in clayey eolian sediments of Pleistocene age. These soils are on nearly level plains. Slope ranges from 0 to 1 percent. Mean annual precipitation is 483 mm (19 in) and mean annual temperature is 15 degrees C (59 F).

TAXONOMIC CLASS: Fine, mixed, superactive, thermic Torrertic Paleustolls

TYPICAL PEDON: Pantex silty clay loam, on a level plain, 0.3 percent slopes in cultivated field at an elevation of about 1,051 meters (3,447 ft). (Colors are for dry soil unless otherwise stated.)

Ap--0 to 18 cm (0 to 7 in); 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. (13 to 25 cm [5 to 10 in] thick)

Bt1--18 to 51 cm (7 to 20 in); 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 shiny pressure faces; common distinct clay films on ped surfaces; moderately alkaline; gradual smooth boundary.

Bt2--51 to 86 cm (20 to 34 in); 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 shiny pressure faces; common distinct clay films on ped surfaces; moderately alkaline; gradual smooth boundary.

Bt3--86 to 124 cm (34 to 49 in); 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 on ped surfaces; few fine threads of calcium carbonate in pores; strongly effervescent; moderately alkaline; gradual smooth boundary.

Bt4--124 to 152 cm (49 to 60 in); 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 on ped surfaces; few fine films and threads of calcium carbonate; slightly effervescent; moderately alkaline; gradual smooth boundary.

Bt5--152 to 180 cm (60 to 71 in); 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 on ped surfaces; few fine threads of calcium carbonate in pores; slightly effervescent; moderately alkaline; gradual smooth boundary. (the combined thickness of Bt horizons is 127 to 190 cm [50 to 75 in] thick)

Btkk--180 to 230 cm (71 to 91 in); 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 distinct clay films on ped surfaces; about 50 percent calcium carbonate by volume in the form of masses, films, and threads; violently effervescent; moderately alkaline.

TYPE LOCATION: Carson County, Texas; 1.77 kilometers (1.1 mile) northeast of Panhandle on U. S. Highway 60 from its intersection with Texas Highway 15, 244 meters (800 ft) 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 83.

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: degrees C (57 to 64 degrees F).
Depth to argillic horizon: 15 to 25 cm (6 to 10 in).
Depth to secondary calcium carbonate: 76 to 150 cm (30 to 60 in).
Depth to calcic horizon: 152 to 203 cm (60 to 80 in).
Solum thickness: more than 203 cm (80 in).
Particle-size control section: 35 to 50 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 or 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
Visible secondary calcium carbonate: 0 to 3 percent in the lower Bt horizons.
Effervescence: very slight or slight
Reaction: slightly or moderately alkaline

Btk horizons:
Hue: 5YR or 7.5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6
Texture: silty clay loam, silty clay, clay loam
Percent calcium carbonate by volume: 5 to 50 percent as masses, nodules, and finely disseminated carbonates.
Calcium carbonate by weight (CCE): 3 to 35 percent.
Effervescence: strong or violent
Reaction: moderately alkaline

Btkk horizon:
Hue: 5YR or 7.5YR
Value: 7 or 8 dry, 6 or 7 moist
Chroma: 1 to 6
Texture: silty clay loam, silty clay, clay loam
Percent calcium carbonate by volume: 50 to 70 percent as masses, nodules, and finely disseminated carbonates.
Calcium carbonate by weight (CCE): 35 to 50 percent.
Effervescence: strong or violent
Reaction: moderately alkaline

COMPETING SERIES: Pullman is the only competing series in the same family. Similar soils include the Acuff, Estacado, Lofton, and Olton series.
Pullman series: have a calcic horizon within 152 cm (60 in) of the soil surface.
Acuff series: have a fine-loamy particle-size class.
Estacado series: have a fine-loamy particle-size class and a calcic horizon between 63 and 100 cm (25 to 40 in).
Lofton series: have a calcic horizon between 51 and 102 cm (20 to 40 in).
Olton series: have a COLE in the upper 100 cm (40 in) of less than 0.06 and a calcic horizon between 76 and 152 cm (30 to 60 in).

GEOGRAPHIC SETTING:
Parent material: 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: 13 to 17 degrees C (55 to 62 F).
Mean annual precipitation: 432 to 533 mm (17 to 21 in).
Frost-free period: 180 to 210 days.
Elevation: 914 to 1372 m (2,998 to 4,500 ft).
PZ Index Values: 16 to 21.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Pullman and the Estacado, Lofton, and Olton series. Also included are the Lazbuddie, McLean, Pep, and Randall series.
Pullman, Estacado, and Olton soils are on similar landscape positions.
Lofton and Lazbuddie soils are on playa benches or shallow depressions.
McLean and Randall soils are on playa floors and pond.
Pep soils are on similar landscape positions but have a fine-loamy particle-size class and do not have an argillic horizon.

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. Native vegetation includes blue grama and buffalograss, with lesser amounts of vine-mesquite, western wheatgrass, galleta or tobosa, sideoats grama, silver bluestem, wild alfalfa, and prairie clover. This soil has been correlated to the Deep Hardland (R077CY022TX) range site in MLRA-77.

DISTRIBUTION AND EXTENT: Southern High Plains of Texas (MLRA 77C). The series is extensive.

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

SERIES ESTABLISHED: MLRA-77 Soil Survey; Carson County, Texas; 1991.

REMARKS: These soils were formerly included in the Pullman series.

Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: 0 to 51 cm (0 to 20 in) A and Bt1 horizons.
Argillic horizon: 18 to 231 cm (7 to 91 in) Bt horizons.
Calcic horizon: 180 to 231 cm (71 to 91 in) Btkk horizon.
Vertic properties: Deep, wide cracks greater than 51 cm (20 in) deep and wedge-shaped aggregates.
COLE in the upper 100 cm (40 in) is greater than 0.06.

ADDITIONAL DATA: KSSL Sample Nos. S93TX-065-002 (Carson Co. TX)

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

National Cooperative Soil Survey
U.S.A.