LOCATION WALKERWELLS             TX

Established Series
LEL, JAC, ALS
07/2012

WALKERWELLS SERIES

The Walkerwells series consists of very deep well drained soils that formed in alluvium derived from sandstone. Walkerwells soils are on flood plains and in drainageways. Slopes range from 0 to 3 percent. Mean annual air temperature is about 65 degrees F. (18 degrees C) and the mean annual precipitation is about 13 inches (330 mm).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Ustifluventic Haplocambids

TYPICAL PEDON: Walkerwells silty clay loam - rangeland. (Colors are for dry soil unless otherwise stated.)

A1--0 to 6 inches, (0 to 15 cm); 70 percent light brownish gray (10YR 6/2), silty clay loam, very dark grayish brown (10YR 3/2) moist; 32 percent clay; 30 percent very pale brown (10YR 7/3), loam, light yellowish brown (10YR 6/4) moist; 27 percent clay; weak fine and medium subangular blocky structure; soft, friable, slightly sticky and nonplastic; common fine and medium roots; common fine and medium pores; 19 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary.

A2--6 to 9 inches, (15 to 23 cm); 70 percent light brownish gray (10YR 6/2), silty clay loam, dark grayish brown (10YR 4/2) moist; 32 percent clay; 30 percent light brownish gray (10YR 6/2), silt loam, dark grayish brown (10YR 4/2) moist; 26 percent clay; moderate fine and medium granular and strong fine granular structure; soft, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine and medium pores; 20 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary.

Ab1--9 to 15 inches, (23 to 38 cm); light brownish gray (10YR 6/2), silty clay loam, dark grayish brown (10YR 4/2) moist; 33 percent clay; moderate medium and coarse subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine and medium pores; 19 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary.

Ab2--15 to 20 inches, (38 to 50 cm); light brownish gray (10YR 6/2), silty clay loam, very dark grayish brown (10YR 3/2) moist; 31 percent clay; strong medium subangular blocky structure; moderately hard, friable, moderately sticky and slightly plastic; common fine and medium roots; common fine and medium pores; 16 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.2); gradual smooth boundary.

Ab3--20 to 26 inches, (50 to 66 cm); grayish brown (10YR 5/2), silty clay loam, very dark grayish brown (10YR 3/2) moist; 38 percent clay; strong coarse subangular blocky structure; hard, firm, moderately sticky and slightly plastic; common fine and medium roots; common fine and medium pores; 17 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (Combined thickness of A horizons is 5 to 30 inches [13 to 76 cm])

Bwb1--26 to 39 inches, (66 to 99 cm); grayish brown (10YR 5/2), silty clay loam, very dark grayish brown (10YR 3/2) moist; 37 percent clay; strong fine prismatic parting to moderate medium and coarse subangular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; common fine and medium roots; common fine and medium pores; 19 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary.

Bwb2--39 to 50 inches, (99 to 127 cm); light yellowish brown (10YR 6/4), silty clay, dark yellowish brown (10YR 4/4) moist; 41 percent clay; moderate fine prismatic parting to strong fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine and medium roots; common fine and medium pores; 5 percent faint pressure faces; 3 percent fine carbonate masses; 25 percent calcium carbonate equivalent; violently effervescent; 1 percent gypsum; moderately alkaline (pH 7.9); clear smooth boundary. (Combined thickness of Bwb horizons is 20 to 55 inches [50 to 140 cm])

Bkyb--50 to 62 inches, (127 to 157 cm); yellowish brown (10YR 5/4), silty clay, dark yellowish brown (10YR 4/4) moist; 50 percent clay; moderate fine prismatic parting to strong fine subangular blocky structure; hard, firm, moderately sticky and very plastic; common fine, medium and coarse roots; common fine and medium pores; 15 percent faint pressure faces; 2 percent fine carbonate masses; 8 percent fine threadlike gypsum masses; 35 percent calcium carbonate equivalent; violently effervescent; 4 percent gypsum; moderately alkaline (pH 8.0); clear smooth boundary.

Byb--62 to 80 inches, (157 to 203 cm); dark yellowish brown (10YR 4/4), silty clay, dark yellowish brown (10YR 3/4) moist; 45 percent clay; strong extremely coarse prismatic parting to weak fine and medium subangular blocky structure; moderately hard, friable, nonsticky and slightly plastic; common fine, medium and coarse roots; common fine and medium pores; 40 percent fine gypsum masses; 10 percent fine gypsum masses on vertical ped faces; 22 percent calcium carbonate equivalent; strongly effervescent; 31 percent gypsum; strongly alkaline (pH 8.6).

TYPE LOCATION: Culberson County, Texas; from the intersection of U.S. Highway 80 and Texas Highway 54 in Van Horn; 0.65 mile north on Texas Highway 54 to intersection with FM 2185; 48.7 miles east and north on FM 2158 to end of pavement; 11.8 miles north on Smileys Road to intersection with KC Road; 12.7 miles east on Nevill Road to intersection with ranch road; 0.3 mile west on ranch road to intersection; 0.3 mile south on ranch road to intersection; 1.3 miles south on ranch road to intersection; 0.2 mile south on ranch road to intersection; 0.2 mile south on ranch road to dirt tank; and 1,200 feet west of tank dam in range. (Two Mill Draw East USGS 7.5 minute topographic quadrangle; Latitude: 31 degrees, 31 minutes, 57.35 seconds North; Longitude: 104 degrees, 14 minutes, 30.75 seconds West, NAD27; UTM coordinates: 571971 m E, 3488878 m N, NAD83, UTM Zone 13.

RANGE IN CHARACTERISTICS:

Soil Moisture: The soil is intermittently moist in some part of the soil moisture control section during July to September. It is driest during November to March. Most precipitation occurs as high intensity rain during afternoon convective thunderstorms from June to September. Ustic aridic soil moisture regime

Soil temperature: 62 to 65 degrees F. (17 to 18 degrees C)

Particle-size control section (weighted average)
Clay content: 25 to 35 percent. Clay content of individual strata may vary from 15 to 50 percent.
Content coarser than very fine sand: less than 15 percent
Rock fragment content: less than 1 percent, but individual strata may contain up to 5 percent

A and Ab horizons
Hue: 10YR
Value: 5 through 7 dry, 3 through 6 moist
Chroma: 2 through 4, dry or moist
Texture: very fine sandy loam, loam, silt loam, silty clay loam, clay loam
Clay content: 15 to 38 percent
Effervescence: strong or violent
Reaction: moderately alkaline

Bwb and Bw horizons (where present)
Hue: 10YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 2 through 4, dry or moist
Texture: loam, silt loam, silty clay loam, silty clay, clay loam
Clay content: 20 to 41 percent
Coarser than fine sand content: less than 15 percent
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline

Bkb horizon (where present)
Hue: 10YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: loam, silt loam, silty clay loam, clay loam
Clay content: 20 to 35 percent
Calcium carbonate equivalent: 10 to 35 percent
Coarser than fine sand content: less than 15 percent
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline

Bkyb and Byb horizons
Hue: 10YR
Value: 4 through 8, dry, 3 through 7 moist
Chroma: 2 through 4, dry or moist
Texture: silty clay, silty clay loam, clay loam
Calcium carbonate equivalent: 10 to 35 percent
Gypsum content: 1 to 40 percent
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline

COMPETING SERIES: There are no competeing series.
GEOGRAPHIC SETTING: Walkerwells soils are on floodplains and in drainageways in karst. They formed in alluvium derived from sandstone with influence from rock gypsum. Slope gradient ranges from 0 to 3 percent. Elevation ranges from 4,000 to 5,500 feet (1,219 to 1,676 m). The mean annual precipitation is 12 to 16 inches (305 to 406 mm). The mean annual air temperature is 62 to 67 degrees F. (17 to 19 degrees C). The frost-free period is about 210 to 250 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dellahunt (T) (TX), Elcor (T) (TX), Hollebeke (T) (TX), Hollomex (NM), Joberanch (T) (TX), Neimahr (T) (TX), and Pokorny (T) (TX) soils. Dellahunt soils have a gypsic horizon within 40 inches (100 cm) of the surface and occur higher in the landscape. Elcor, Hollebeke, and Neimahr soils have a lithic contact within 20 inches (50 cm) of the surface and occur higher in the landscape. Hollomex soils have hypergypsic mineralogy and occur higher in the landscape. Hollebeke, Joberanch, and Pokorny soils have a petrogypsic horizon and occur higher in the landscape.

DRAINAGE AND PERMEABILITY: Well drained; low runoff; slow permeability; occasionally flooded for brief periods from June through September.

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation physiognomy is tall grassland. Giant sacaton normally forms a dense vegetative cover, with scattered western honey mesquite and hackberry trees.

DISTRIBUTION AND EXTENT: LRR-D, MLRA 42, Southern Desertic Basins, Plains, and Mountains, Desert Grassland LRU. Trans-Pecos Texas and southeastern New Mexico in areas of Permian-age Castile formation gyprock. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES PROPOSED: Culberson County, Texas; Soil Survey of Culberson County, Texas, Main Part 2010. Name is from a local ranch.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from 0 to 6 inches (0 to 15 cm) (A1 horizon)

Cambic horizon - the zone from 26 to 50 inches (66 to 127 cm) (Bwb1, Bwb2 horizons)

Gypsic horizon - the zone from 50 to 80 inches (127 to 203 cm) (Bkyb and Byb horizons)

Ustifluventic subgroup - irregular decrease of organic carbon with depth

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010

ADDITIONAL DATA: Characterization data from National Soil Survey Laboratory are available for the typical pedon, S08-TX109-009.

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National Cooperative Soil Survey
U.S.A.