LAKE HODGES SOILS

LOCATION TUJUNGA            CA

Established Series
Rev. RCH-ARW-SBS-CAF
09/1999

TUJUNGA SERIES

The Tujunga series consists of very deep, somewhat excessively drained soils formed in alluvium weathered mostly from granitic sources. Tujunga soils are on alluvial fans and flood plains and have slopes of 0 to 9 percent. The mean annual precipitation is about 16 inches and the mean annual air temperature is about 62 degrees F.

TAXONOMIC CLASS: Mixed, thermic Typic Xeropsamments

TYPICAL PEDON: Tujunga sand on a 1 percent slope at about 700 feet elevation under native shrubs. (Colors are for dry soil unless otherwise noted.)

C1--0 to 12 inches; pale brown (10YR 6/3) sand, brown (10YR 5/3) moist; single grained; loose; mica flakes evident; very low in organic matter; very porous; slightly acid; diffuse boundary. (6 to 14 inches thick)

C2--12 to 48 inches; similar to surface soil but of more variable color due largely to mineral grains themselves; diffuse boundary. (30 to 50 inches thick)

C3--48 to 60 inches; stratified sand, coarse sand and gravel; single grained; loose; neutral. (Many feet thick)

TYPE LOCATION: Los Angeles County, California; Tujunga Wash southeast of San Fernando in R. 14 W., T. 1 N.; Sunland Quadrangle.

RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 60 to 66 degrees F. The soil temperature usually does not go below 47 degrees F. or is below 47 degrees F. for only a few days in January. The soil becomes moist below a depth of about 12 inches some time from October to December and remains moist in some part between depths of about 12 to 35 inches until April or May. Textures in the particle-size control section are sands or loamy sands, with more than 35 percent combined coarse and very coarse sand. Thin strata with silt sized particles or similar finer textures are lacking, though considerable stratification of coarse material is present. Rock fragments make up 2 to 35 percent by volume. Clay content ranges from 0 to 5 percent. The soils are slightly acid to neutral in the upper part and are slightly acid to slightly alkaline in the lower part.

The A horizon have dry colors of 10YR 7/2, 7/1, 6/4, 6/3, 6/2, 5/3 or 5/2 and moist colors of 10YR 5/4, 5/3, 5/2, 4/4, 4/3, 4/2, or 3/3.

The C horizon has dry colors of 10YR 8/1, 8/3, 8/4, 7/4, 7/3, 7/2, 7/1, 6/4, 6/3, 6/2, 5/8, 5/6, 5/4, 5/3, 5/2, or 5/1 and moist color of 10YR 6/3, 6/4, 6/2, 6/1, 5/3, 5/1, 4/4, 4/3, 4/2, 4/1 or 3/1.

COMPETING SERIES: These are the Arnold, Briones, Calhi, Corralitos, Delhi, Monoridge (T), and Monvero (T) series. Arnold soils are residual soils with 9 to 60 percent slopes and have less than 35 percent coarse and very coarse sand. Briones soils have a paralithic contact at a depth of 20 to 40 inches. Calhi soils are calcareous in the 10 to 40 inch control section. Corralitos soils are moderately acid. Delhi soils lack stratification and have less than 35 percent coarse and very coarse sand.

GEOGRAPHIC SETTING: Tujunga soils occur at elevations of 5 to 4,300 feet on alluvial fans and flood plains and have slopes of 0 to 9 percent. The soils formed in sandy alluvium derived mostly from granitic sources. The climate is subhumid mesothermal with cool moist winters and hot dry summers. Mean annual precipitation is 10 to 25 inches. Mean annual temperature is 58 to 65 degrees F.; mean January temperature is 45 to 50 degrees F.; mean July temperature is 75 to 80 degrees F. Frost-free season is 225 to 350 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Delhi soils and the Hanford, Soboba and Grangeville soils. Hanford soils have sandy loam texture in the control section. Grangeville soils are saturated with water part of each year to within 40 inches of the surface. Soboba sols have more than 35 percent rock fragments.

DRAINAGE AND PERMEABILITY: Somewhat excessively or excessively drained; negligible or very low runoff; rapid permeability. Flooding is none to frequent.

USE AND VEGETATION: Used mainly for grazing. Some areas used for growing citrus, grapes and other fruits. Uncultivated areas have a cover of shrubs, annual grasses and forbs.

DISTRIBUTION AND EXTENT: Central and southern California and in the northern San Joaquin Valley and southern Sacramento Valley. The series is of moderate extent in MLRA-14,17,18,19,29, and 30..

MLRA OFFICE RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Los Angeles County (Riverside Area), California, 1915.

REMARKS: Map units of Tujunga soil which occur at elevations above 1500 feet should probably be set up as a new series during MLRA updates. There are no taxonomic or series criteria to separate the high elevation soils. Tujunga soils mapped in the San Bernardino Co., S.W.part, Western Riverside Area, Tulare Co., Central part, occur above 1,500 feet in places and all of the Tujunga soil map units in the Kern Co., N. E. and S.E. parts are above 1,500 feet. Presently used in too many MLRAs: 14, 17, 18, 19, 29, 30.

Diagnostic horizons and features recognized in this pedon:

There are no diagnostic horizons recognized.

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National Cooperative Soil Survey
U.S.A.