LOCATION BALLARD CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Typic Argixerolls
TYPICAL PEDON: Ballard gravelly fine sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A11--0 to 10 inches; grayish brown (10YR 5/2) gravelly fine sandy loam, very dark brown (10YR 2/2) moist; moderate medium and coarse granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; 25 percent gravel; moderately acid (pH 6.0); gradual wavy boundary. (8 to 12 inches thick)
A12--10 to 18 inches; grayish brown (10YR 5/2) gravelly fine sandy loam, very dark brown (10R 2/2) moist; weak find and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine interstitial and many fine and medium tubular pores; 15 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (6 to 10 inches thick)
B1--18 to 34 inches; light yellowish brown (10YR 6/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, slightly sticky and slightly plastic; common very fine roots; many fine interstitial and common very fine and fine tubular pores; few thin clay films line pores, few thin colloidal stains on mineral grains; 15 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (6 to 16 inches thick)
B2t--34 to 44 inches; yellowish brown (10YR 5/4) gravelly heavy loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; many fine interstitial and common very fine and fine tubular pores; common moderately thick clay films line pores, few thin colloidal stains on mineral grains; 30 percent gravel; slightly acid (pH 6.5); gradual irregular boundary. (10 to 15 inches thick)
B3t--44 to 59 inches; very pale brown (10YR 7/3) extremely gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine interstitial pores; few thin clay films bridging mineral grains, very few thick clay films line pores; 70 percent gravel; slightly acid (pH 6.5); gradual boundary. (6 to 14 inches thick)
C--59 to 72 inches; very pale brown (10YR 7/4) extremely gravelly loamy sand, yellowish brown (10YR 5/6) moist; massive; slightly hard, very friable; nonsticky and nonplastic; many very fine interstitial pores; few moderately thick clay bridges between mineral grains and common thin films on pebbles; 90 percent gravel; slightly acid (pH 6.5).
TYPE LOCATION: Santa Barbara County, California; approximately 8 miles north of Buellton, 2.5 miles north of Zaca cutoff road from Highway 101, 1/4 mile west on oil well road, and 750 feet south on farm road; equivalent NE1/4 SE1/4 sec. 4, T.7N., R.31W., extended.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 59 degrees to 62 degrees F. Soil between depths of 12 to 24 inches is usually moist in some part shortly after the first of November and stays moist until sometime in May and is dry all through the year. Coarse and very coarse rounded sand particles make up less than 20 percent of the soil. The soil is slightly to moderately acid, usually near pH 6.0. Organic matter is 1 to 3 percent to a depth of about 12 inches and decreases regularly to less than 1 percent throughout the rest of the profile.
The A horizon has color of 10YR 5/2, 5/3 or 4/2). It is fine sandy loam or light loam with or without siliceous shale fragments. It has weak to strong granular structure.
The B2t horizon has color of 10YR 5/3, 6/3, 7/3, 5/4, 6/4, 7/4; 7.5YR 5/4 or 6/4. It is loam or heavy loam and has 18 to 25 percent clay and 10 to 35 percent siliceous shale fragments. The clay increase from the A horizon to the B horizon is small but distinct, well over 3 percent. This horizon has weak blocky structure or it is massive.
The C horizon has color of (10YR 7/3, 6/3 or 5/4. It is sandy loam or loamy sand and has 25 to 90 percent siliceous shale fragments.
COMPETING SERIES: These are the Chualar, Gilroy, Pinto, Shimmon, Soper and Tehachapi series. Chualar soils have a moderately developed B2t horizon with more than 20 percent coarse and very coarse angular sand particles. Gilroy and Soper soils are underlain by bedrock at a depth of about 20 to 40 inches. Pinto soils have an abrupt A/B horizon boundary and lack a transitional horizon between the A horizon and the B2t horizon. Shimmon soils have a paralithic contact at a depth of 20 to 40 inches. Tehechapi soils have a B2t horizon with 25 to 35 percent clay and siliceous shale fragments.
GEOGRAPHIC SETTING: Ballard soils are on stream terraces, and have slopes of 0 to 15 percent. Elevations are 500 to 1,200 feet. The soils formed in gravelly alluvium from sedimentary rocks. The climate is subhumid mesothermal with warm dry summers and cool moist winters. Mean annual precipitation is 15 to 20 inches. The average January temperature is about 50 degrees F., average July temperature is about 65 degrees F., and the annual temperature is about 58 degrees F. The average freeze-free season is 230 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chamise, Elder, and Santa Ynez soils. Chamise soils have more than 35 percent clay and more than 35 percent rock fragments in the B2t horizon. Elder soils lack a B2t horizon and have less than 18 percent clay in the 10- to 40-inch control section. Santa Ynez soils have a B2t horizon with more than 35 percent clay.
DRAINAGE AND PERMEABILITY: Well-drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used mainly for rangeland and production of dryland grain. Where irrigation water is available, they are used for production of orchards, alfalfa, and pasture. Native vegetation is annual grasses, forbs, and live oak trees.
DISTRIBUTION AND EXTENT: Coastal counties of south-central California. Ballard soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Santa Barbara County (Santa Ynez Area), California, 1927.
REMARKS: The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET