LOCATION CUYAMA CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Xeric Haplargids
TYPICAL PEDON: Cuyama loam, on a slope of 2 percent under annual grasses and forbs at 840 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 6/1/81 th soil was dry throughout.)
A1--0 to 3 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate coarse subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial and common fine tubular pores; violently effervescent, lime disseminated; 10 percent pebbles; moderately alkaline (pH 8.0); abrupt wavy boundary. (3 to 8 inches thick)
A2--3 to 8 inches; light yellowish brown (10YR 6/4) loam, brown (10YR 4/3) moist; weak moderate subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial and common fine tubular pores; violently effervescent, lime disseminated; 10 percent pebbles; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 6 inches thick)
Btk1--8 to 18 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few very fine roots; many very fine tubular and few very fine interstitial pores; few thin clay films on ped faces, in pores, and bridging sand grains; violently effervescent, lime disseminated and segregated in many large filaments and soft masses; 10 percent pebbles; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 12 inches thick)
Btk2--18 to 36 inches; reddish yellow (7.5YR 6/6) gravelly clay loam, strong brown (7.5YR 5/6) moist; weak fine prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; many thin clay films, bridging sand grains, on ped faces, and in pores, violently effervescent, lime disseminated and segregated in common fine filaments and soft masses; 20 percent pebbles and 5 percent cobbles; moderately alkaline (pH 8.2); clear wavy boundary. (15 to 20 inches thick)
2C1--36 to 56 inches; yellow (10YR 7/6) very cobbly sandy clay loam, dark yellowish brown (10YR 4/6) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few very fine disseminated and segregated in few fine soft masses; 20 percent cobbles and 20 percent pebbles; moderately alkaline (pH 8.2); clear wavy boundary. (15 to 25 inches thick)
2C2--56 to 65 inches; yellow (10YR 7/6) light sandy clay loam, dark yellowish brown (10YR 4/6) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine roots; common very fine tubular and many very fine interstitial pores; violently effervescent, lime disseminated and segregated in few fine soft masses; 10 percent pebbles moderately alkaline (pH 8.0).
TYPE LOCATION: Kern County, California; about 1.25 miles east of Bakersfield County Club; in the SW1/4 SE1/4, NW1/4 of Section 19, T.29S., R.29E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 26 to 46 inches, but averages 39 inches. The soil between a depth of 10 to 36 inches is usually moist in some part of the moisture control section from December 15 until April 30 and dry th remainder of the year. These soils have an Aridic moisture regime bordering on Xeric. Mean annual temperature is 60 to 64 degrees F.
The A horizon has dry color of 10YR 4/3, 5/3, 5/4, 5/6 or 6/4 and moist color of 10YR 3/4, 4/3 or 4/4. It is coarse sandy loam, sandy loam, or loam. Clay percentage ranges from 5 to 20. Gravel content ranges from 0 to 10 percent. Organic carbon is less than 0.5 percent and decreases regularly with depth. Reaction is mildly or moderately alkaline.
The B2tca horizon has dry color of 10YR 6/6, 5/6, 4/6; 7.5YR 5/6 or 5/4 and moist color of 10YR 4/6, 3/6; 7.5YR 6/6, 5/6 or 4/6. It is sandy clay loam, heavy loam or clay loam. Clay content is 20 to 35 percent. Gravel content ranges from 0 to 20 percent and cobble content ranges from 0 to 10 percent. It is strongly or violently effervescent in the lower part. In many places segregated lime is present in some part of the horizon. Reaction is mildly or moderately alkaline. SAR is 2 to 10.
The C horizon has dry color or 10YR 7/6, 6/6 or 6/4; 7.5YR 5/6 and moist color of 5/6, 4/6, 4/4; 7.5YR 5/6, 4/6. It is sandy clay loam, silt loam, loam, sandy loam, or loamy sand with 5 to 20 percent cobbles and 5 to 10 percent gravel. Some pedons are stratified. Lime is usually present throughout the horizon. SAR is 10 to 25.
COMPETING SERIES: This is the Delano series. The Delano soils have a solum averaging about 50 inches, lack cobbles, have less than 5 percent gravel throughout the profile, and the SAR is less than 5 in the substratum.
GEOGRAPHIC SETTING: Cuyama soils occur on dissected alluvial fans and stream terraces with stratified extremely gravelly and cobbly alluvium. Slopes are 2 to 30 percent. Elevation is 425 to 1,000 feet. The climate is arid with hot, dry summers and mild somewhat moist winters. The mean annual precipitation is 7 to 10 inches. Mean January temperature is 42 degrees F.; mean July temperature is 80 degrees F.; mean annual temperature is about 64 to 67 degrees F. Frost-free season is 275 to 325 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Delano soils and Premier and Chanac soils. Premier soils are coarse-loamy and Chanac soils have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils have limited use as rangeland, some areas are being used as homesites. Vegetation is annual grasses and forbs such as oats and red brome.
DISTRIBUTION AND EXTENT: Southeast edge of the San Joaquin Valley. These soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Upper San Joaquin Valley, California Reconnaissance, 1918.
REMARKS: The Cuyama is an established series but has not been used since the Bakersfield Soil Survey Report (1937) and the Wasco Soil Survey Report (1936). It is being reactivated.
Series reclassified on September, 1994. Competing series not reviewed at that time.