LOCATION LOFTON TX+NM

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

LOFTON SERIES

The Lofton series consists of very deep, moderately well drained, very slowly permeable soils that formed in clayey lacustrine deposits from the Blackwater Draw Formation of Pleistocene age. These nearly level soils are on playa steps or shallow depressions. Slope ranges from 0 to 1 percent. Mean annual precipitation is 483 mm (19 in), and mean annual temperature is 16 degrees C (61 degrees F).

TAXONOMIC CLASS: Fine, mixed, superactive, thermic Vertic Argiustolls

TYPICAL PEDON: Lofton clay loam, on north-facing, nearly level, 0.5 percent slope within playa basin in cropland at an elevation of about 1,032 m (3,385 ft). (Colors are for dry soil unless otherwise stated.)

Ap--0 to 23 cm (0 to 9 in); dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; weak fine granular structure; hard, friable; common fine roots; common fine pores; slightly alkaline; abrupt smooth boundary. (10 to 25 cm [4 to 10 in] thick)

Bt1--23 to 61 cm (9 to 24 in); dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; moderate medium angular blocky structure; extremely hard, firm; common fine roots; many fine pores; common prominent clay films on faces of peds; slightly alkaline; gradual smooth boundary.

Bt2--61 to 97 cm (24 to 38 in); grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; strong medium angular blocky structure; extremely hard, very firm; common fine roots; common fine pores; common prominent clay films on faces of peds; some peds are wedge-shaped and have pressure faces tilted 10 degrees to 15 degrees from horizontal; few films and filaments of calcium carbonate in lower part; matrix is noneffervescent; moderately alkaline; gradual wavy boundary. (20 to 51 cm [8 to 20 in] thick)

Btk--97 to 132 cm (38 to 52 in); grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate medium angular blocky structure; very hard, firm; few very fine roots; common distinct clay films on faces of peds; about 3 percent visible calcium carbonate in the form of filaments and films; strongly effervescent; moderately alkaline; clear smooth boundary. (25 to 76 cm [10 to 30 in] thick)

Bk--132 to 203 cm (52 to 80 in); grayish brown (10YR 5/2) silty clay, dark grayish brown (10YR 4/2) moist; weak medium angular blocky structure; hard, friable; common distinct clay films on faces of peds; about 25 percent calcium carbonate by volume in the form of filaments, masses, and nodules; violently effervescent; moderately alkaline.

TYPE LOCATION: Armstrong County, Texas; from the intersection of U.S. Highway 287 and Texas State Highway 207 in Claude, 1.5 miles south on Texas State Highway 207, 0.5 mile west on county road, and 100 ft north of road in cropland; Latitude: 35 degrees, 05 minutes, 30 seconds N; Longitude: 101 degrees, 22 minutes, 25 seconds W; Claude, Texas USGS quad; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: A typic-ustic moisture regime. The soil moisture control section is dry in some or all parts more than 90 but less than 180 cumulative days in normal years. July through August and November through March are the driest months. These soils are intermittently moist in September through October and April through June. The soil receives runoff from surrounding soils and the soil moisture control section is moist for longer periods than that of the surrounding soils.
Mean annual soil temperature: 15 to 18 degrees C (59 to 64 degrees F).
Depth to argillic horizon: 15 to 25 cm (6 to 10 in).
Depth to secondary calcium carbonate: 50 to 100 cm (20 to 40 in).
Depth to calcic horizon: 100 to 150 cm (40 to 60 in).
Vertic properties: COLE is more than 0.06 within 100 cm (40 in) of the soil surface.
Solum thickness: more than 203 cm (80 in).
Particle-size control section: 35 to 50 percent silicate clay.

Ap horizon
Hue: 10YR or 2.5Y
Value: 3 or 4, 2 or 3 moist
Chroma: 1 or 2
Texture: silty clay loam, clay loam
Reaction: neutral to moderately alkaline
Effervescence: none

Bt horizons
Hue: 10YR or 2.5Y
Value: 3 to 5, 2 to 4 moist
Chroma: 1 to 3
Texture: silty clay, clay
Reaction: slightly alkaline to moderately alkaline
Effervescence: none or slight

Btk horizon
Hue: 10YR or 2.5Y
Value: 5 to 8, 4 to 7 moist
Chroma: 1 to 6
Texture: clay loam, silty clay, clay
Calcium carbonate equivalent: 5 to 30 percent
Visible secondary calcium carbonate: 3 to 40 percent by volume in the form of films, filaments, masses, or nodules
Reaction: moderately alkaline
Effervescence: violent

Bk horizon
Hue: 10YR or 2.5Y
Value: 5 to 8, 4 to 7 moist
Chroma: 1 to 6
Texture: clay loam, silty clay, clay
Calcium carbonate equivalent: 5 to 40 percent
Visible secondary calcium carbonate: 15 to 50 percent by volume in the form of films, filaments, masses, or nodules
Reaction: moderately alkaline
Effervescence: violent

COMPETING SERIES: This is the Culp series in the same family. Similar soils include Lazbuddie, Lockney, McLean, Olton, Pantex, Pullman, and Westill series.
Culp soils: are moist in the soil moisture control section for longer periods and have mean annual soil temperatures of more than 20 degrees C (68 degrees F).
Lazbuddie soils: have an ochric epipedon.
Lockney and McLean soils: do not have an argillic horizon.
Olton, Pantex, and Pullman soils: have hues of 7.5YR or redder in matrix.
Westill soils: have an active cation-exchange activity class.

GEOGRAPHIC SETTING:
Parent material: clayey lacustrine deposits from the Blackwater Draw Formation of Pleistocene age.
Landform: nearly level playa steps or shallow depressions.
Slopes: 0 to 1 percent.
Mean annual air temperature: 14 to 17 degrees C (57 to 62 degrees F).
Mean annual precipitation: 432 to 533 mm (17 to 21 in).
Frost-free period: 185 to 220 days.
Elevation: 884 to 1,402 m (2,900 to 4,600 ft).
Thornthwaite annual P-E Index Values: 25 to 36.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Lazbuddie, Lockney, and McLean, Olton, Pantex, and Pullman series and the Portales, Randall, and Zita series.
Lazbuddie and Lockney soils: are on similar landscape positions, do not have an argillic horizon, and have 50 to 60 percent clay in the particle-size control section.
McLean and Randall soils: are on slightly lower landscape positions and have 50 to 60 percent clay in the particle-size control section.
Olton, Pantex, and Pullman soils: are on slightly higher landscape positions on surrounding nearly level plains.
Portales and Zita soils: have a cambic horizon and have less than 35 percent clay in the particle-size control section.

DRAINAGE AND PERMEABILITY: Moderately well drained and very slow permeability.
Surface runoff is low on less than one percent slopes. These soils are occasionally ponded for very brief periods.

USE AND VEGETATION: Mainly cultivated to cotton, grain sorghum, corn, and winter wheat. Native vegetation varies according to amount of water available. It includes western wheatgrass, vine-mesquite, buffalograss, blue grama, knotgrass, and bur ragweed. Sedges, spike rushes, and curly dock occur in wetter areas.
This soil has been correlated to the Deep Hardland 16-21"PZ (R077CY022TX) ecological site in MLRA-77C.

DISTRIBUTION AND EXTENT: Southern High Plains, Southern Part (MLRA 77C in LRR H) of western Texas and eastern New Mexico. The series is moderately extensive.

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

SERIES ESTABLISHED: Harding County, New Mexico; 1940.

REMARKS: Series revised MLRA-77 Soil Survey update of Carson County, Texas; 1998 with minor revision in 2007.

Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: 0 to 61 cm (0 to 24 in). (A and Bt1 horizons)
Argillic horizon: 23 to 132 cm (9 to 52 in). (Bt1, Bt2, and Btk horizons)
Calcic horizon: 132 to 203 cm (52 to 80 in). (Bk horizon)
Vertic feature: COLE is more than 0.06 within 100 cm (40 in) of the soil surface.

ADDITIONAL DATA: KSSL data from Hale County, TX (S01TX-189-004).

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

National Cooperative Soil Survey
U.S.A.