LOCATION HOBAN TXEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Ustic Haplocalcids
TYPICAL PEDON: Hoban silty clay loam--cropland (colors are for dry soil unless otherwise stated).
Ap--0 to 8 inches; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; weak, fine granular and subangular blocky structure; hard, friable; few very fine roots; strongly effervescent, moderately alkaline; abrupt smooth boundary (6 to 12 inches thick).
A--8 to 18 inches; brown (7.5YR 5/4) silty clay loam, brown (7.5YR 4/4) moist; weak, medium subangular blocky structure; hard, friable; few very fine roots; common fine pores; strongly effervescent; moderately alkaline, gradual boundary (4 to 12 inches thick).
Bk--18 to 46 inches; pink (7.5YR 7/4) silty clay loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; hard, friable; few very fine roots; common fine pores; films and threads of calcium carbonate comprising 2 or 3 percent by volume; 23 percent calcium carbonate equivalent; few medium pebbles; strongly effervescent, moderately alkaline; clear wavy boundary (16 to 35 inches thick).
Cky1--46 to 60 inches; pink (7.5YR 7/4) silty clay loam, light brown (7.5YR 6/4) moist; massive; hard, friable; 40 to 50 percent by volume bodies of calcium sulfate and calcium carbonate; strongly effervescent, moderately alkaline; diffuse wavy boundary (10 to 20 inches thick).
Cky2--60 to 72 inches; pink (7.5YR 7/4) silty clay loam, light brown (7.5YR 6/4) moist; massive; hard, friable; 10 percent by volume bodies calcium sulfate and calcium carbonate; strongly effervescent, moderately alkaline.
TYPE LOCATION: Reeves County, Texas; in the edge of a cultivated field, 300 feet north of the Pecos Experiment Station, TAES, 6.5 miles south of Interstate Highway 20 on Farm Road 869.
RANGE IN CHARACTERISTICS:
Depth to gypsic horizon: 40 to 60 inches
Depth to the calcic horizon: 12 to 40 inches
Soil moisture: The soil is dry more than 3/4 of the time in the moisture control section. Ustic aridic moisture regime.
Texture of the control section: clay loam, silty clay loam, silty clay, clay
Total clay content: 28 to 55 percent
Silicate clay content: less than 35 percent
A horizon
Hue: 10YR, 7.5YR
Value: 5 to 7(in cultivated areas values are 5 and 6, and in rangeland areas values are 7)
Chroma: 2 to 4, dry or moist
Texture: clay loam, loam, silty clay loam, silty clay
Bk horizon
Hue: 10YR, 7.5YR
Value: 5 to 7, dry or moist
Chroma: 2 to 4, dry or moist
Texture: clay loam, silty clay loam, or silty clay
Calcium carbonate: 3 to about 10 percent by volume
Cky horizon
Hue: 10YR, 7.5YR
Value: 5 to 8, dry or moist
Chroma: 2 to 6, dry or moist
Texture: clay loam, silty clay loam, silty clay, clay
Calcium sulfate: 5 to 50 percent by volume
Calcium carbonate: 5 to 50 percent by volume
COMPETING SERIES: These are the Conchas (NM), Poquita (NM), Quay (NM), Reagan (TX), and Stovall (TX) series. Conchas soils have a lithic contact between 20 and 40 inches. Poquita soils lack gypsum accumulations between 40 and 60 inches and have hue of 5YR or 2.5YR in the particle-size control section. Quay, Reagan, and Stovall soils lack accumulations of gypsum in the lower part of the calcic horizon. In addition, Conchas, Poquita, and Quay soils are in the Pecos-Canadian Plains and are more moist in May and June. Reagan soils are in the Edwards Plateau (MLRA 81) and are more moist in May and June.
GEOGRAPHIC SETTING: These soils are in broad nearly level to very gently sloping valleys, outwash plains, or basins mainly near salt lakes. Slopes are plane and gradients are generally less than 1 percent but range up to 3 percent. The soil formed in calcareous loamy or clayey materials mostly of alluvial origin. The climate is arid to semiarid. Mean annual rainfall ranges from 8 to 12 inches and mean annual temperature ranges from 60 degrees to 67 degrees F. Frost-free days range from 210 to 240 and elevation ranges from 2,000 to 4,000 feet. Thornthwaite P-E indices are less than 25.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Delnorte, McCarran, Mimbres, Monahans, Pajarito, Reakor, Reeves, and Upton series. Delnorte and Upton soils have a petrocalcic horizon at a depth of less than 20 inches. McCarran soils have a gypsiferous horizon at depth less than 20 inches. Mimbres and Pajarito soils lack a calcic horizon within 40 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow. Permeability is moderate.
USE AND VEGETATION: Irrigated cropland and rangeland. Crops grown are cotton, alfalfa, grain sorghum, barley, and some vegetables. Native vegetation consists of burrograss, tobosa, blue grama, black grama, mesquite, and creosotebush.
DISTRIBUTION AND EXTENT: Arid and semiarid areas of western Texas and southern New Mexico and possibly Arizona and Nevada. The series is of moderate extent. MLRA 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Reeves County, Texas; 1976
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon the zone from 0 to 18 inches (Ap and A horizons)
Calcic horizon the zone from 18 to 72 inches (Bk and Cky horizons)
Gypsic horizon the zone from 46 to 72 inches (Cky1 and Cky2 horizons)
Classified according to Soil Taxonomy Second Edition, 1999
ADDITIONAL DATA: Laboratory data is available as follows: Lincoln Lab. Nos. 16520-16526; 16527-16534. Texas Agricultural Extension Service Sample Nos. K810-816 and K829-835 dated June 10, 1958.
Updated competing series section 4/11/08, CEM