LOCATION BAKERSFIELD CATentative Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Torrifluventic Haploxerolls
TYPICAL PEDON: Bakersfield fine sandy loam, in a plowed field, at an elevation of 300 feet. (When described on September 6, 1988, the soil was dry from 0 to 3 inches and slightly moist below; Colors are for dry soil unless otherwise stated).
Ap1--0 to 3 inches; grayish brown (2.5Y 5/2) fine sandy loam, very dark grayish brown (2.5Y 3/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine and fine tubular and interstitial pores; slightly acid (pH 6.2); clear smooth boundary. (3 to 10 inches thick)
Ap2--3 to 10 inches; dark grayish brown (10YR 4/2) fine sandy loam, very dark gray (10YR 3/1) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few very fine and fine tubular pores; slightly acid (pH 6.2); abrupt smooth boundary. (0 to 9 inches thick)
A--10 to 16 inches; dark grayish brown (10YR 4/2) fine sandy loam, brown (10YR 3/1) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine and few fine tubular pores; neutral (pH 7.0); abrupt wavy boundary. (0 to 10 inches thick)
C1--16 to 29 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist, with thin strata of brown (10YR 5/3) sand and loamy fine sand, dark brown (10YR 3/3) moist; massive; hard, friable, slightly sticky and slightly plastic; sandy strata are soft to slightly hard, very friable, nonsticky and nonplastic; few very fine roots; few very fine and fine tubular pores in loam, common very fine interstitial pores in sandy strata; slightly effervescent in some strata; moderately alkaline (pH 8.0); abrupt smooth boundary. (10 to 18 inches thick)
C2--29 to 45 inches; light brownish gray (2.5Y 6/2) sandy loam, dark grayish brown (2.5Y 4/2) moist; many yellowish brown (10YR 5/8) medium and large prominent mottles, strong brown (7.5YR 4/6) moist; massive; hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine and few fine tubular pores; moderately alkaline (pH 8.0); abrupt smooth boundary. (8 to 20 inches thick)
Ck--45 to 51 inches; light brownish gray (10YR 6/2) and pale brown (10YR 6/3) loam, black (10YR 2/1) and dark brown (10YR 3/3) moist; few brown (7.5YR 4/2) fine prominent mottles, dark brown (7.5YR 3/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, friable, sticky and plastic; few very fine roots; many very fine, common fine, and few medium tubular pores; slightly effervescent, carbonates segregated as common fine soft masses, filaments and threads; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 12 inches thick)
C'1--51 to 58 inches; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; few brown (7.5YR 4/2) fine and medium prominent mottles, dark brown (7.5YR 3/2) moist; weak medium prismatic structure parting to weak medium subangular blocky; hard, friable, sticky and plastic; few very fine roots; many very fine and few fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 12 inches thick)
C'2--58 to 66 inches; light gray (2.5Y 7/2) fine sand, grayish brown (2.5Y 5/2) moist; common strong brown (7.5YR 5/6) fine and medium prominent mottles, strong brown (7.5YR 4/6) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine tubular pores; moderately alkaline (pH 8.0).
TYPE LOCATION: Kern County, California; about 13 miles south of downtown Bakersfield; 0.8 mile east of Wible Road and 160 feet south of dirt road through middle of section; 2,255 feet east and 2,480 feet north of the southwest corner of Sec. 36, T. 31 S., R. 27 E., MDB&M; 35 degrees, 11 minutes, 10 seconds north latitude and 119 degrees, 0 minutes, 10 seconds west longitude; Conner quadrangle.
RANGE IN CHARACTERISTICS:
Soil temperature - Average annual: 62 to 67 degrees F and the soil temperature is never below 47 degrees F.
Soil moisture - the soil moisture control section is dry throughout from mid April to late December and is never moist more than 90 consecutive days.
Particle size control section:
Rock fragments: 0 to 3 percent
Clay content: ranges from 0 to 27 percent but averages 5 to 18 percent.
A horizons
Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry, 1, 2, or 3 moist
Texture: fine sandy loam or sandy loam
Organic matter: 1 to 2 percent
Effervescence: noneffervescent or slightly
Electrical conductivity: 0 to 4 in non saline-sodic phases and 2 to 16 in saline-sodic phases
Sodium absorption ratio: 2 to 15
Reaction: slightly acid to mildly alkaline in non saline-sodic phases and moderately alkaline or strongly alkaline in saline-sodic phases.
C horizon
Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry, 2, 3, or 4 moist
Chroma: 1, 2, or 3 dry and moist
Texture: stratified, ranging from sand to silt loam
Organic matter: decreases irregularly with depth
Effervescence: noneffervescent to strongly with finer strata being more effervescent
Electrical conductivity: 0 to 4 in non saline-sodic phases and 8 to 30 in saline-sodic phases
Sodium absorption ratio: 2 to 8 in non saline-sodic phases and 13 to 50 in saline-sodic phases
Reaction: moderately alkaline in non saline-sodic phases and strongly alkaline in saline-sodic phases.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Bakersfield soils are on floodplains. Slopes are 0 to 2 percent. The soils formed in stream alluvium derived dominantly from granitic rock. Elevations are 280 to 680 feet. The climate is arid with hot dry summers and cool, somewhat moist winters. The mean annual precipitation is 5 to 8 inches. The mean annual temperature is 62 to 67 degrees F. Mean July temperature is about 85 degrees F., and mean January temperature is about 47 degrees F. The frost-free season is 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cajon, Kimberlina, Milagro (T), Panoche, Vineland (T), Wasco, and Weedpatch (T) soils. Cajon and Vineland soils are on similar landforms and are sandy. Kimberlina and Wasco soils are on adjacent low alluvial fans and have a regular decrease in organic matter. Milagro soils are on similar landforms and have an ochric epipedon. Panoche soils are on adjacent low alluvial fans, are fine-loamy, and have a regular decrease in organic matter. Weedpatch soils are on adjacent relic basin floors and have a calcic horizon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderately slow or slow permeability. Bakersfield soils have been artificially drained and protected from flooding in most areas by dams, levees, and diversions. The saline-sodic phase of this soil still has a water table at a depth of 4 to 6 feet from June through August and below 6 feet during the rest of the year.
USE AND VEGETATION: Used primarily for irrigated crops such as cotton, alfalfa, dry beans, onions, carrots, lettuce, and wheat. Some areas are used for homesites and pasture. Native vegetation is dominantly annual grasses and forbs with scattered willow and sycamore trees.
DISTRIBUTION AND EXTENT: Southern San Joaquin Valley of California. The series is moderately extensive. MLRA is 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Kern County, California, 1988. The name is from the city of Bakersfield.
REMARKS: The acidity in the Ap horizons at the type location and in many other areas of the Bakersfield series may be due to the use of fertilizers or soil amendments.
Diagnostic horizons and features recognized in the profile are:
Mollic epipedon -- the zone from the soil surface to 16 inches (Ap1, Ap2, A)
Torrifluventic subgroup -- Has a well defined irregular decrease in organic carbon with depth based on modified Walkley-Black method and visual observation. The moisture regime is aridic bordering on xeric.
Particle size control section -- The zone from 10 to 40 inches.