LOCATION LUCERNE CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Xeric Haplargids
TYPICAL PEDON: Lucerne sandy loam, on a slope of 1 percent under Joshua tree, Morman-tea, buckwheat, cholla, annual grasses and forbs at 3,180 feet elevation. (Colors are for dry soil unless otherwise stated. When described the soil was moist below 76 inches.)
A1--0 to 2 inches; pale brown (10YR 6/3) sandy loam, dark brown (10YR 3/3) moist; weak very fine and fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; about 3 percent fine (2 to 5 mm) pebbles; neutral (pH 6.8); abrupt smooth boundary. (2 to 4 inches thick)
Bt1--2 to 7 inches; light yellowish brown (10YR 6/4) sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial, few very fine tubular pores; many thin clay films as bridges between mineral grains; about 3 percent fine (2 to 5 mm) pebbles; neutral (pH 6.7); clear smooth boundary. (4 to 10 inches thick)
Bt2--7 to 22 inches; light yellowish brown (10YR 6/4) sandy loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, few fine and coarse roots; many very fine interstitial, few very fine tubular pores; common thin few moderately thick clay films as bridges between mineral grains, few thin clay films in pores; about 3 percent fine (2 to 5 mm) pebbles; neutral (pH 7.0); gradual smooth boundary. (8 to 21 inches thick)
Bt3--22 to 35 inches; brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, few fine roots; many very fine interstitial, common very fine tubular pores; common thin and moderately thick clay films as bridges between mineral grains, few thin clay films in pores; about 3 percent fine (2 to 5 mm) pebbles; neutral (pH 6.8); gradual smooth boundary. (13 to 24 inches thick)
Bt4--35 to 62 inches; light yellowish brown (10YR 6/4) sandy loam, brown (7.5YR 4/4) moist; weak fine and medium angular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine interstitial, common very fine tubular pores; clay films as in above horizon; about 3 percent fine (2 to 5 mm) pebbles; neutral (pH 6.7); clear wavy boundary. (13 to 30 inches thick)
Btb--62 to 76 inches; reddish yellow (7.5YR 6/6) heavy sandy loam, strong brown (7.5YR 5/6) moist; moderate medium and coarse angular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine interstitial, common very fine tubular pores; continuous moderately thick clay films in bridges between mineral grains, common moderately thick clay films in pores; about 5 percent (2 to 10 mm) pebbles; neutral (pH 7.0).
TYPE LOCATION: San Bernardino County, California; southeast of Hesperia, approximately 100 feet north and 50 feet east of intersection of Seaforth Street and Windsor Avenue in NE1/4 SE1/4 NW1/4 section 35, R.4N., R.4W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 59 to 64 degrees F. and the soil temperature usually is not below 47 degrees F. at any time. The soil from about 8 to 24 inches is usually moist in some part from early December to mid-March and is continuously dry the rest of the year. Solum thickness is 40 to 80 inches.
The A horizon is 10YR 6/2, 6/3 or 6/4. Moist color is 10YR 3/3, 4/3 or 4/4. This horizon is neutral or slightly acid. Rock fragments range from 2 to 25 percent.
The B2t horizon is 10YR 6/3, 6/4, 6/6, 7/3; 7.5YR 5/4, 5/6). Moist color is 10YR 4/3, 4/4, 5/3, 5/6; 7.5YR 3/4, 4/4, 4/6). This horizon is sandy loam with 8 to 18 percent clay and has at least 3 percent more clay than the A horizon and has 2 to 30 percent rock fragments. It is neutral or slightly alkaline and is noncalcareous or slightly effervescent.
Older buried horizons occur frequently in these soils with depth to the upper boundary about 60 inches and lower boundaries below depths of 72 to 78 inches. These horizons are heavy sandy loam, sandy clay loam or gravelly sandy loam and have about 5 to 20 percent by volume gravel. Weathered granitic cobbles make up to 5 percent by volume. Some pedons lack the buried B horizon and have a gravelly sandy loam, sandy loam, or loamy sand C horizon.
COMPETING SERIES: This is the Adelanto series. Adelanto soils have A and B1 horizons 12 to 40 inches thick.
GEOGRAPHIC SETTING: Lucerne soils are on alluvial fans, fan terraces and terraces at elevations of 2,900 to 4,800 feet. Slopes range from 0 to 5 percent. The soil formed in alluvium from mixed but dominantly granitic sources. The climate is arid with hot, dry summers and cool somewhat moist winters. The mean annual precipitation is 4 to 9 inches, most of which occurs as rain in late autumn and winter. Some moisture falls occasionally as snow. The mean annual temperature is 57 to 63 degrees F.; the average January temperature is about 42 to 44 degrees F.; and the average July temperature is 82 to 84 degrees F. The frost free season is 140 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hesperia soils. Hesperia soils lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately rapid permeability. Some areas have rapid permeability in the substratum.
USE AND VEGETATION: Used mainly for homesites and recreation. Vegetation is Utah juniper, scattered Joshua, annual grasses and forbs, and perennial grasses.
DISTRIBUTION AND EXTENT: Alluvial fans and terraces of the Mojave Desert of California in MLRA 30. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Bernardino County, California, Mojave River Area, 1978.
REMARKS: Series reclassified on September, 1994. Competing series not reviewed at that time. The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET