LOCATION FOOTHILL           CA
Tentative Series
DZM/JFR/JJJ
02/97

FOOTHILL SERIES


The Foothill series consists of moderately deep, well drained soils on mountain and hill slopes. These soils formed from granitic rocks. Slopes range from 9 to 60 percent. The average annual precipitation is about 13 inches, and the average annual temperature is about 61 degrees F.

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

TYPICAL PEDON: Foothill sandy loam, on a mountain slope of 30 percent under annual grasses, and blue oaks at 2,440 feet elevation. (Colors are for dry soil unless otherwise stated. When described on February 14, 1994 the soil was moist throughout.)

A-- 0 to 4 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; many very fine roots; common very fine interstitial pores; 4 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (2 to 8 inches thick)

BAt-- 4 to 9 inches; grayish brown (10YR 5/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak medium and coarse subangular blocky structure; hard, friable, sticky and plastic; common very fine roots; common very fine interstitial and tubular pores; common thin clay films bridging mineral grains; 5 percent gravel; neutral (pH 7.0); clear smooth boundary. (4 to 12 inches thick)

Bt1-- 9 to 18 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; common very fine roots; common fine and medium tubular pores; few moderately thick and common thin clay films bridging mineral grains; 5 percent gravel; neutral (pH 7.2); gradual wavy boundary. (9 to 15 inches thick)

Bt2-- 18 to 24 inches; brown (10YR 5/3) sandy clay loam, dark yellowish brown (10YR 3/4) moist; weak coarse subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine, fine and medium roots; few fine and medium tubular pores; common thin clay films bridging mineral grains; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 10 inches thick)

BC-- 24 to 30 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 3/4) moist; massive; slightly hard, friable,slightly sticky and slightly plastic; few very fine and coarse roots; few fine and medium tubular pores; 7 percent gravel; neutral (pH 6.8).

Cr--30 inches; weathered granitic rock.

TYPE LOCATION: Kern County, California; 1.5 miles south of Sequoia National Forest boundary; about 400 feet east and 2,800 feet north of the southwestern corner of Sec. 11, T.29S., R.30E., MDB&M, Mt. Adelaide Quadrangle.

RANGE IN CHARACTERISTICS:

Depth to weathered rock: 20 to 40 inches.

Mollic epipedon thickness: 8 to 18 inches.

Soil Temperature - The mean annual soil temperature is 60 to
65 degrees F. The soil temperature is
greater than 41 degrees F. from about
Febuary 1 to December 15 (300 to 330
days) and is greater than 47 degrees F
from about March 1 to December 1 (250 to
290 days).

Soil Moisture - The soils are dry from about June 1 to
November 1 (140 to 160 days). The soil is
moist in some or all parts for 90 or more
days when the soil temperature is greater
than 47 degrees F.

Reaction: neutral to mildly alkaline

Control section:
Texture: sandy clay loam
Average percent clay: 20 to 30 percent
Rock fragements: 0 to 14 percent

A horizon
Hue: 10YR
Value: 4 or 5; 2 or 3 moist
Chroma: 2 or 3; moist or dry
Organic matter: 1.0 to 3.0
Texture: sandy loam, or loam.

Bt horizon
Hue: 10YR or 7.5YR
Value: 4,or 5; 3 or 4 moist
Chroma: 2, 3 or 4 moist or dry
Texture: sandy clay loam,
Average percent clay: 20 to 30 percent
Rock fragements: 0 to 14 percent

COMPETING SERIES: These are the Ballard, Bohna, Chualar, Chuloak, Francisican, Gilroy, Pinto, Sagaser, Shimmon, Soper, and Tehachapi soils. The Ballard, Chualar, Chuloak, Pinto and Tehachapi soils are greater than 40 inches deep and are on alluvial fans and terraces. Bohna soils are greater than 60 inches deep. The Franciscan and Gilroy soils have a lithic contact. Sagaser soils are greater than 40 inches deep over sandstone and shale. Shimmon soils are dry from 110 to 125 days. Soper soils have more than 15 percent rock fragments in the texture control section.

GEOGRAPHIC SETTING: Foothill soils are on mountain slopes of 9 to 60 percent slope. These soils formed in material weathered from granitic rocks. Elevations are 1,500 to 4,500 feet. The average annual precipitation is about 10 to 20 inches. The mean annual air temperature is about 58 to 64 degrees F. The mean January temperature is about 38 to 43 degrees F., mean July temperature is about 74 to 78 degrees F., and the frost-free season is about 175 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arujo, Sesame, Tweedy, Tunis and Walong soils. Arujo soils are deep. Sesame soils lack a mollic epipedon. Tweedy soils are mesic. Tunis soils are coarse-loamy and shallow. Walong soils lack an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderately slow permeability.

USE AND VEGETATION: This soil is used for watershed, livestock grazing, and wildlife habitat. Native vegetation is mostly blue oak, and annual grasses such as soft chess and slender oats with some gooseberry and California Buckeye.

DISTRIBUTION AND EXTENT: Southern Sierra Nevada Range in California. This series is not extensive in MLRA 18.

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

SERIES PROPOSED: Kern County; Kern County, Northeastern Part and Southeastern Part of Tulare County, California 1995.

REMARKS: Diagnostic horizons and features recognized in this pedon:

Mollic epipedon -- Zone from 0 to 18 inches (A, BAt, Bt1)

Argillic horizon -- Zone from 4 to 24 inches (Bt1, Bt2, Bt3)

Paralithic contact -- 30 inches (Cr)


National Cooperative Soil Survey
U.S.A.