LOCATION BLAKENEY TX+NM+AZEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Ustic Petrocalcids
TYPICAL PEDON: Blakeney fine sandy loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 7 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots and pores; 10 percent strongly cemented calcium carbonate fragments less than one inch in diameter; effervescent; moderately alkaline; gradual smooth boundary. (4 to 10 inches thick)
Bw--7 to 18 inches; pale brown (10YR 6/3) fine sandy loam, brown (10YR 5/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, friable, slightly sticky and nonplastic; common very fine roots; 10 percent medium hard calcium carbonate fragments; effervescent; moderately alkaline; abrupt wavy boundary. (0 to 14 inches thick)
Bkm--18 to 32 inches; white caliche, strongly calcium carbonate cemented, rounded plates, 2 to 4 inches in diameter; abrupt wavy boundary. (6 to 36 inches thick)
BCk--32 to 68 inches; pinkish white, weakly calcium carbonate cemented; massive; about 25 percent powdery masses of calcium carbonate; effervescent; moderately alkaline.
TYPE LOCATION: Andrews County, Texas; from Andrews, Texas, 15 miles west on Texas Highway 87, then 50 feet in rangeland. Latitude: 32 degrees, 21 minutes, 55 seconds N; Longitude: 102 minutes, 47 minutes, 48 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness and depth to the petrocalcic ranges from 6 to 20 inches. Textures throughout are sandy loam, loam, fine sandy loam or cobbly fine sandy loam. Clay content ranges from 8 to 18 percent clay. Content of coarse fragments above the petrocalcic ranges from about 0 to 25 percent. Soil temperature ranges from 64 to 70 degrees F. Weighted average of organic carbon in the upper 16 inches ranges from 0.15 to 0.60 percent where the sand to clay ratio ranges from 4.0 to 9.0. Ustic aridic soil moisture regime.
The A and Bw horizons have hue of 7.5YR or 10YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 6, dry or moist.
The Bkm horizon is usually laminar in the upper 0.5 inch to 2 inches. Plates are from 1 to 3 inches thick. In some pedons this horizon is divided into an upper part that is laminar and strongly cemented and a lower part that is massive and weakly cemented.
The underlying B horizons are loamy calcareous materials that are fine sandy loam, sandy loam, or loam and range from massive to subangular blocky to weakly cemented by calcium carbonate.
COMPETING SERIES: These are the Conger (TX), Kolar (NM) and Shumla (NM) series. Conger soils contain more than 18 percent clay in the control section. Kolar soils have soil temperatures of 59 to 63 degrees F. Shumla soils have a lithic contact between 20 and 40 inches that occurs immediately below the petrocalcic horizon.
GEOGRAPHIC SETTING: Blakeney soils occupy nearly level to gently sloping fan terraces, ridges, divides, and foot slopes. These soils developed in calcareous, loamy materials. The climate is semiarid. Mean annual precipitation ranges from 10 to 17 inches and the mean annual air temperature ranges from 62 to 68 degrees F. Frost-free days range from 180 to 240 days and elevation ranges from 2,000 to 4,600 feet. Thornthwaite P-E indices range from 18 to 25.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Conger and Kimbrough series, and Ratliff series. Ratliff soils have calcic horizons below 20 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to high. Permeability is moderately rapid above and below the petrocalcic horizon.
USE AND VEGETATION: Used mostly for livestock grazing but a few acres are cultivated. Vegetation consists of sideoats grama, blue grama, vine-mesquite, black grama, plains bristlegrass, hairy grama and small mesquite trees.
DISTRIBUTION AND EXTENT: Southern part of the High Plains and adjacent margins of the Edwards Plateau and Trans-Pecos areas of west Texas and in adjoining areas in New Mexico and Arizona. (MLRA 41, 42, 70, 77D) The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Andrews County, Texas; 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 7 inches (A horizon)
Cambic horizon - The zone from 7 to 18 inches (Bw horizon)
Petrocalcic horizon - The zone from 18 to 32 inches (Bkm horizon)