LOCATION AULD CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Aridic Haploxererts
TYPICAL PEDON: Auld clay - cultivated. (Colors are for dry soil unless otherwise stated).
A1--0 to 3 inches reddish brown (5YR 4/3) clay, dark reddish brown (5YR 3/4) moist; strong medium granular structure; very hard, very firm, sticky, plastic; many very fine roots; common very fine interstitial pores; neutral (pH 7.0); clear smooth boundary. (3 to 12 inches thick)
A2--3 to 8 inches; dark reddish brown (5YR 3/3) clay, dark reddish brown (2.5YR 3/4) moist; strong medium angular blocky structure; very hard, very firm, sticky, very plastic; many very fine roots; common very fine interstitial pores; neutral (pH 7.0); clear wavy boundary. (5 to 11 inches thick)
A3--8 to 15 inches; dark reddish brown (5YR 3/3) clay, dark reddish brown (2.5YR 3/4) moist; strong coarse angular blocky structure; very hard, extremely firm, very sticky, very plastic; many very fine roots; common very fine tubular pores; prominent slickensides; mildly alkaline (pH 7.8); clear wavy boundary. (5 to 18 inches thick)
A13--15 to 23 inches; dark reddish brown (5YR 3/4) clay, dark reddish brown (2.5Y 3/4) moist; strong coarse angular blocky structure; very hard, very firm, sticky, plastic; many very fine exped roots (flattened); common very fine tubular pores; many prominent slickensides; strongly effervescent, lime segregated in many fine rounded soft masses; moderately alkaline (pH 8.0); gradual wavy boundary. (4 to 9 inches thick)
A14--23 to 28 inches; dark reddish brown (5YR 3/4) clay, dark reddish brown (2.5YR 3/4) moist; massive; very hard, very firm, sticky, plastic; few very fine exped roots; many very fine tubular pores; many prominent slickensides; strongly effervescent, lime segregated in many fine rounded soft masses; moderately alkaline (pH 8.0); clear irregular boundary. (0 to 24 inches thick)
C1---28 to 38 inches; reddish brown (5YR 5/3) heavy loam, reddish brown (5YR 4/3) moist; massive; hard, friable, slightly sticky, slightly plastic; few very fine tubular pores; strongly effervescent, lime segregated in many fine soft masses; moderately alkaline (pH 8.2); clear irregular boundary. (4 to 12 inches thick)
C2--38 to 44 inches; reddish brown (5YR 5/3) and light reddish brown (5YR 6/3) loam; massive; slightly hard, very friable, slightly sticky, slightly plastic; strongly effervescent, lime in many medium irregular soft masses; moderately alkaline (pH 8.2); abrupt wavy boundary. (4 to 12 inches thick)
C3--44 to 60 inches; light reddish brown (5YR 6/3) and white (10YR 8/1) weathered basic igneous rock; strongly effervescent containing large soft masses of lime in the upper part; moderately alkaline (pH 8.2).
TYPE LOCATION: Riverside County, California; about 11 miles northeast of Temecula, California; approximately 1,050 feet east and 1,180 feet south of W 1/4 corner section 29, T. 6 S., R. 2 W.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact of weathered rock is 40 to 60 inches. The soil between depths of 4 and 12 inches usually is moist in some parts from about December 1 until late May and is continuously dry the rest of the time. During the dry period soil cracks 1/2 to 1 1/2 inches wide at the surface and about 1/4 to 1/2 inch wide at the bottom extend to or partly through the upper part of the C horizon. Up to 10 percent of the soil volume is made up of rock fragments with most of the fragments near the surface and in the lower part of the soil material. In most pedons, most of the soil material in the C horizon and in a few pedons in the soil in the lower part of the A horizon is calcareous and has few to many lime segregations. Major soil cracks usually are closed all of the moist period and open all of the dry period. Mean annual soil temperature at a depth of 20 inches is about 65 degrees F.
The A horizon is reddish brown or dark reddish brown with hue of 5YR and value of 3 or more dry. The upper 10 to 30 inches of the A horizon is neutral or mildly alkaline. The upper part of the C horizon is reddish brown or yellow in hue of 5YR through 10YR.
COMPETING SERIES: These are the Alo, Altamont, Ayar, Bosanko, Capay, Centerville, Cibo, Porterville, and Seville series. Alo, Altamont, Ayar, and Cibo soils have hue of 7.5YR or yellower. Alo and Cibo soils have a lithic contact less than 40 inches below the surface. Bosanko soils have a chroma of less than 1.5 in the upper 20 to 30 inches of the profile. Centerville soils have a paralithic contact less than 40 inches below the surface. Porterville soils lack a paralithic contact within a depth of 60 inches. (See Remarks). Seville soils have a lime-silica hardpan at a depth of less than 40 inches.
GEOGRAPHIC SETTING: The Auld soils are gently sloping to steep in upland areas at elevations of 300 to 2,700 feet. They formed in residuum weathered from basic igneous rock. The climate is one of long dry summers and short mild winters with average annual precipitation of 10 to 16 inches. The average January temperature is 49 degrees F, average July temperature is 77 degrees F, and the average annual temperature is 62 degrees F. The frost-free season is 200 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Porterville soils and the Buren, Cajalco, Las Posas, and Wyman soils. Buren soils have fine textured argillic horizons and weak duripans. Cajalco, Las Posas, and Wyman soils have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for growing small grains or pasture and to a limited extent citrus fruits, flowers, and truck crops where irrigated. Naturalized vegetation is mainly annual grasses and forbs.
DISTRIBUTION AND EXTENT: The Auld soils occur in the foothills and interior valleys of southern California. They are inextensive, but rather widely distributed.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Riverside County, California 1973.
REMARKS: The auld soils were formerly classified as Grumusols. More study is needed to broaden differentia from the Porterville series.
Last revised by the state on 8/73.
Series reclassified on September, 1994. Competing series not reviewed at that time.