LOCATION CALCROSS UTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Xeric Torriorthents
TYPICAL PEDON; Calcross loam--irrigated cropland. (Colors are for air-dry soil unless otherwise stated.)
Ap--0 to 9 inches; brown (7.5YR 5/4) loam, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; many fine, common very fine tubular pores; moderately calcareous (11 percent carbonates) carbonates are disseminated; moderately alkaline (pH 8.1); abrupt smooth boundary. (4 to 9 inches thick)
A--9 to 13 inches; brown (7.5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; weak medium and fine subangular blocky structure; hard, friable, sticky and plastic; common fine and very fine roots; many fine, common very fine tubular pores; moderately calcareous (13 percent carbonates) carbonates are disseminated; moderately alkaline (pH 8.2); abrupt smooth boundary. (0 to 10 inches thick)
C1--13 to 16 inches; reddish brown (5YR 5/4) loam, dark reddish brown (5YR 3/4) moist; weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; few fine, common very fine tubular pores; moderately calcareous (11 percent carbonates) carbonates are disseminated; moderately alkaline (pH 8.4); abrupt smooth boundary. (3 to 16 inches thick)
C2--16 to 44 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; weak coarse prismatic structure parting to moderate fine and very fine subangular blocky; very hard, firm, sticky and plastic; few fine and very fine roots; few medium, common fine, and many very fine tubular pores; strongly calcareous (16 percent carbonates) carbonates are disseminated; moderately alkaline (pH 8.4); gradual wavy boundary. (9 to 41 inches thick)
C3--44 to 60 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; weak coarse subangular blocky structure; hard, firm, sticky and plastic; few fine roots; common fine and very fine tubular pores; moderately calcareous (19 percent carbonates) carbonates are disseminated; strongly alkaline (pH 8.5).
TYPE LOCATION: Iron County, Utah; about 2 miles north of Kanarraville and 1/4 mile west of the old highway; 2,640 feet north and 2,640 feet west of the southeast corner of sec. 23., T. 37 S., R. 12 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 47 to 53 degrees F., and the mean summer soil temperature ranges from 65 to 71 degrees F. In 6 or more out of 10 years, the moisture control section is continually dry in all parts for 60 to 75 days during the summer, and continually moist in all parts for 60 to 75 days during the winter and early spring.
The particle-size control section ranges from 18 to 35 percent clay and less than 15 percent fine sand or coarser.
The A horizon has hue of 7.5YR or 5YR, value of 5 to 7 dry, 3 to 5 moist, and chroma of 3 or 4. It is loam, silt loam or silty clay loam. This horizon is moderately alkaline or strongly alkaline.
The C horizon has hue of 2.5YR or 5YR, value of 5 to 7 dry, 3 to 5 moist, and chroma of 3 to 6. Texture is dominantly silty clay loam or silt loam with strata of very fine sandy loam or loam. This horizon is moderately alkaline or strongly alkaline. Some pedons have gypsum in this horizon.
COMPETING SERIES: These are the Kudlac and Manassa series. Kudlac soils are formed in lacustrine sediments, have hue of 7.5YR to 2.5Y below the surface layer and have a Bk horizon. Manassa soils have an exchangeable sodium percentage of more than 15 percent above a depth of 20 inches and more than 40 percent below 20 inches.
GEOGRAPHIC SETTING: Calcross soils are on toeslopes of alluvial fans and alluvial plains at elevations of 5,000 to 6,000 feet. Slopes range from 0 to 5 percent. These soils formed in alluvium from sandstone, siltstone, shale, limestone and some igneous rocks. The mean annual temperature is 45 to 53 degrees F. The mean summer temperature is 67 to 72 degrees F. Average annual precipitation is 8 to 12 inches. The freeze-free period is 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashdown, Bandag, Wales and Woodrow soils. The Ashdown, Bandag and soils are on alluvial fans upslope of the Calcross soils. Ashdown and Bandag soils are fine-loamy. Wales and Woodrow soils are on flood plains downslope of the Calcross soils. They have an irregular decrease in organic matter with depth. In addition, Wales soils are fine-loamy. Woodrow soils have hue of 7.5YR or 10YR below the surface layer.
DRAINAGE AND PERMEABILITY: Well drained, low to medium runoff, moderately slow or slow permeability.
USE AND VEGETATION: These soils are used for rangeland, wildlife habitat, and irrigated cropland. Alfalfa and small grains are the principal crops. Native vegetation is mainly basin big sagebrush, bottlebrush squirreltail, green rabbitbrush, western wheatgrass and tall native bluegrass.
DISTRIBUTION AND EXTENT: Southern Utah. These soils are moderately extensive. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Iron-Washington Area, Iron County, Utah, 1997.
REMARKS: The diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to a depth of 13 inches (Ap and A horizons).
Calcareous feature - the fine earth fraction effervesces from 10 to 20 inches with cold dilute HCL.
Previously classified as Torrifluvent, but it did not have an irregular decrease in organic matter as required for that placement.
The classification is based on the "Keys to Soil Taxonomy, Eighth Edition, 1998". The cation exchange activity class is an estimate based on NASIS data.
ADDITIONAL DATA: Lab sample number S72UT-021-013.