LOCATION TEHACHAPI          CA
Established Series
Rev. NLH/RWK/ET
03/2003

TEHACHAPI SERIES


The Tehachapi series consists of deep, well drained soils that formed in mixed alluvium on old alluvial fans and terraces. Tehachapi soils have slopes of 2 to 30 percent. The mean annual precipitation is about 10 inches and the mean annual air temperature is about 61 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Typic Argixerolls

TYPICAL PEDON: Tehachapi sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)

All--O to 2 inches; dark grayish brown (10YR 4/2) heavy sandy loam, very dark grayish brown (10YR 3/2) moist; strong medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common fine tubular pores; neutral (pH 7.0); clear smooth boundary. (2 to 4 inches thick)

A12--2 to 5 inches; dark grayish brown (10YR 4/2) heavy sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common fine tubular pores; neutral (pH 7.0), clear smooth boundary. (3 to 6 inches thick)

A13--5 to 11 inches; dark grayish brown (10YR 4/2) heavy sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common fine tubular pores; neutral (pH 7.0); clear smooth boundary. (6 to 10 inches thick)

Blt--11 to 19 inches; dark grayish brown (10YR 4/2), with equal amounts of dark reddish gray (5YR 4/2) sandy clay loam, dark grayish brown (10YR 3/2) and dark reddish brown (5YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and plastic; few medium roots; few fine and medium tubular pores; many moderately thick clay films on faces of peds and as bridges between mineral grains; neutral (pH 7.0); gradual smooth boundary. (6 to 9 inches thick)

B2t--19 to 32 inches; yellowish red (5YR 4/6) clay loam, reddish brown (5YR 4/3) moist; strong coarse angular blocky structure; very hard, firm, slightly sticky and plastic; few medium and coarse roots; few fine and medium tubular pores; common thick clay films on faces of peds and as bridges between mineral grains; slightly acid (pH 6.5); abrupt wavy boundary. (13 to 20 inches thick)

B31t--32 to 38 inches; yellowish red (5YR 5/6) sandy clay loam, reddish brown (5YR 4/4) moist; massive; very hard, friable, slightly sticky and slightly plastic; some pieces of this horizon when broken exhibit thick clay films; approximately 15 percent by volume of mixed gravel, 2mm to 3cm; neutral (pH 7.0); clear wavy boundary. (6 to 20 inches thick)

B32t--38 to 44 inches; brown (7.5YR 4/4) sandy clay loam, reddish brown (5YR 4/4) moist; massive; very hard, very firm, sticky and plastic; few very fine roots; many moderately thick clay films coating mineral grains and as colloidal stains; approximately 10 percent by volume of mixed gravel, 2mm to 3cm; slightly alkaline (pH 7.8); clear smooth boundary. (5 to 20 inches thick)

Cca--44 to 60 inches; reddish yellow (5YR 6/6) light sandy loam, reddish brown (5YR 4/4) moist; massive; very hard, few thin lime-silica cemented lamellae; some lamellae have some thin clay films bridging mineral grains; moderately alkaline (pH 8.0).

TYPE LOCATION: Kern County, California; in the Tehachapi Valley, 200 yards west of the center of section 24, T.32S., R.32E., MDB&M.

RANGE IN CHARACTERISTICS: The soil between the depths of 10 and 16 inches is moist in some or all parts from November until late May. Mean annual soil temperature is 60 degrees to 66 degrees F. The solum contains 0 to 35 percent by volume rock fragments, 2mm to 24 inches in size, with up to 20 percent of those as cobbles and stones in some pedons. Reaction is slightly acid through moderately alkaline throughout.

The A horizon is very dark grayish brown, dark brown, dark gray, dark grayish brown or brown (10YR 3/2 3/3, 4/1, 4/2, 4/3); brown (7.5YR 4/2, 5/2, 5/4); or reddish brown (5YR 4/3). It is sandy loam, loam or cobbly sandy clay loam. Organic matter content is more than 1 percent to a depth of 10 to 19 inches. Where cultivated, the surface has been mixed to form an Ap horizon about 9 inches thick. Colors are dark grayish brown or brown (10YR 4/2, 4/3).

A transitional A3 horizon or B1 is present in most pedons, or the horizon boundary is clear or irregular.

The B2t horizon is reddish yellow, light brown or brown (7.5YR 6/6, 6/4, 5/2); yellowish red, light reddish brown or reddish brown (5YR 5/6, 6/4, 5/4, 4/4, 4/6). It is clay loam, sandy clay loam, gravelly sandy clay loam or cobbly sandy clay, and averages 25 to 35 percent clay. Few fine filaments of lime occur in the lower part in some pedons.

The C horizon is yellow, brownish yellow, yellowish brown, reddish yellow light brown, brown, yellowish red, reddish brown or reddish gray (10YR 7/6, 6/6, 5/6; 7.5YR 6/6, 6/4, 5/4, 4/4; 5YR 6/6, 5/6, 5/4, 5/2). It is loamy sand, sandy loam, sandy clay loam or sandy clay, or gravelly or cobbly equivalents of each. Gravel and cobble content ranges from 0 to 50 percent. Thin lime-silica lamellae occur in some pedons but are below depth of 40 inches. These lamellae are weakly cemented and not continuous.

COMPETING SERIES: These are the Ballard, Chualar, Gilroy, Havala, Pinto and Soper series. Ballard soils have a weakly developed Bt horizon with is to 25 percent clay and less than 20 percent coarse and very coarse sand. Chualar soils have a moderately developed B2t horizon with 18 to 25 percent clay. Havala soils have dark A horizons more than 20 inches thick and have B2t horizons with dominantly 10YR and 2.5YR colors. Gilroy and Soper soils are underlain by bedrock at depths of 20 to 40 inches. Pinto soils have a strongly developed B2t horizon with an abrupt A/B horizon boundary.

GEOGRAPHIC SETTING: Tehachapi soils are formed on old stream terraces and alluvial fans from mixed alluvium. Gradients are 2 to 30 percent. Elevations are 1,000 to 4,300 feet. The climate is subhumid mesothermal with cool, moist winters and warm, dry summers. Mean annual precipitation is 9 to 12 inches some as snow. Average January temperature is 39 degrees to 47 degrees F., average July temperature is 72 degrees to 82 degrees F., and the mean annual temperature is 58 degrees to 64 degrees F. Freeze-free season is about 150 to 275 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Havala soils and the Arvin, Chanac, Pleito and Warong soils. Arvin, Chanac and Pleito soils lack an argillic horizon. Also, Arvin soils are coarse-loamy and Pleito soils have a mollic epipedon thicker than 20 inches. Walong soils are 20 to 40 inches deep to a paralithic contact, lack an argillic horizon and are coarse-loamy. They occur on the adjacent uplands.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.

USE AND VEGETATION: Used mainly for range, wildlife and watershed. Some areas grow apples, pears, dryland grain with citrus at the lower elevations where there is good air drainage. Vegetation is annual grasses, scattered oak trees and a few perennial grasses.

DISTRIBUTION AND EXTENT: Alluvial fans and stream terraces at the southeastern edge of the San Joaquin Valley and in the Tehachapi Mountain Valleys. Series is inextensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Kern County, California 1976.

REMARKS: Series was misclassified in earlier drafts as Aridic Argixerolls, fine, montmorillonitic, mesic.

The activity class was added to the classification in March of 2003. Competing series were not checked at that time. - ET

OSED scanned by SSQA. Last revised by state on 12/76.


National Cooperative Soil Survey
U.S.A.