LOCATION VILLA CAEstablished Series
TAXONOMIC CLASS: Sandy, mixed, thermic Typic Torrifluvents
TYPICAL PEDON: Villa loamy sand, on a 1 percent slope in an alfalfa field at 2,500 feet elevation. (Colors are for dry soil unless otherwise stated. When described the soil profile was moist was moist throughout.)
Ap--0 to 7 inches; light brownish gray (10YR 6/2) loamy sand, dark grayish brown (10YR 4/2) moist; moderate medium angular blocky structure; slightly hard, very friable; common very fine roots; few very fine interstitial and tubular pores; mildly alkaline (pH 7.8); abrupt smooth boundary. (0 to 12 inches thick)
C1--7 to 22 inches; light brownish gray (10YR 6/2) loamy sand, grayish brown (10YR 5/2) moist; moderate medium platy structure soft, loose; common very fine roots; 2 or 3 thin (1/2 inch) lenses of sand with 2 to 4 mm plates of dark brown (10YR 4/3) moist, sandy loam between plates in the lower part; slightly effervescent with disseminated lime; mildly alkaline (pH 7.8); abrupt smooth boundary. (0 to 20 inches thick)
C2--22 to 44 inches; pale brown (10YR 6/3) loamy sand, brown (10YR 5/3) moist; moderate medium platy structure; soft, loose; few very fine roots; few very fine tubular pores; 2 or 3 (1/2 to 1 1/2 inch) lenses of dark brown (10YR 3/3) moist, sandy loam in the upper part; common to many lenses (2 to 4 inches) of dark brown (10YR 3/3) moist, sandy loam in the lower part; slightly effervescent with disseminated lime; mildly alkaline (pH 7.6); abrupt smooth boundary. (10 to 30 inches thick)
C3--44 to 56 inches; light brownish gray (10YR 6/2) loamy fine sand, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable; few very fine roots; few very fine tubular pores; 3 or 4 2 to 5 mm) lenses of dark brown (10YR 3/3) moist, sandy loam with organic carbon material between lenses that stain fingers; about 3 to 5 percent pebbles (1/4 to 3/8 inch); strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); gradual smooth boundary. (0 to 14 inches thick)
C4--56 to 60 inches; dark grayish brown (10YR 4/2) loamy sand; light brownish gray (10YR 6/2) moist; massive; slightly hard, very friable; few very fine tubular pores; mildly alkaline (pH 7.6).
TYPE LOCATION: San Bernardino County, California; northwest of Helendale on Starbuck Ranch; 100 feet east of the old corral fence in NW1/4 SE1/4 section 15, T.8N., R.4W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 63 to 65 degrees F. and the soil temperature is never below 47 degrees F. The soil between depths of 12 and 36 inches is usually dry and is not moist for as long as 60 consecutive days.
The Ap horizon, or upper 10 inches of the C1 horizon where present, is pale brown, light brownish gray, very pale brown or light yellowish brown (10YR 6/2, 6/3, 6/4, 7/3, 7/4). Overblown areas have weak platy structure. This horizon is slightly effervescent to strongly effervescent with disseminated lime. It is noncalcareous in some pedons.
The C horizon to a depth of 40 inches is similar in color to the surface. It is loamy sand or sand. Thin strata of dark brown (10YR 4/3) moist, sandy loam with (1 to 2 mm) bands of organic carbon between plates commonly occur at depths of 20 to 40 inches. Structure is moderate medium or thick platy or is massive. Reaction is mildly alkaline or moderately alkaline and disseminated lime is slightly effervescent or strongly effervescent. Fine gravel content is 0 to 10 percent. The lower part of the C horizon below a depth of 40 inches, is sandy loam, loamy fine sand, loamy sand or sand. It is slightly calcareous with disseminated lime; some strata are noncalcareous. Thin strata (1/4 to 3/8 inch) of dark brown sandy loam are common. Fine gravel content of 0 to 10 percent may be present below 50 inches. A few pedons have few to common, fine to medium, faint to distinct dark yellowish brown, or reddish yellow mottles that are deeper than 36 inches.
COMPETING SERIES: These are the Cowan and Vinton series in the same family. Cowan soils have hue of 2.5YR or 5YR. Vinton soils are intermittently moist in the moisture control section for 30 to 40 days during the summer and are well drained.
GEOGRAPHIC SETTING: Villa soils are on river flood plains with slopes of 0 to 2 percent at elevations of 2,100 to 2,800 feet. They formed in alluvium from mixed sources but mainly granitic rock. The average annual precipitation is 4 to 6 inches, coming mainly as rain in late autumn and winter, though some occasionally fall as snow. The mean annual temperature is about 61 to 65 degrees F.; the mean the mean January temperature is about 44 degrees F.; and the mean July temperature is about 83 degrees F. The frost free season is about 200 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cajon and Victorville soils. Cajon soils lack stratification and are somewhat excessively drained. Victorville soils have a coarse loamy control section.
DRAINAGE AND PERMEABILITY: Moderately well drained with an intermittent water table occurring at a depth of 36 inches to 6 feet for brief intervals during the winter and late spring. Slow runoff; moderately rapid permeability.
USE AND VEGETATION: Most areas are used for irrigated crops such as alfalfa. The native vegetation is saltbush, mesquite, creosotebush, annual grasses and forbs.
DISTRIBUTION AND EXTENT: Flood plains along the Mojave Desert of California. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Bernardino County, California (Mojave River Area), 1978.