LOCATION AGUEDA             CA
Established Series
Rev. GES-LCL-LAB
01/2003

AGUEDA SERIES


The Agueda series have dark gray, calcareous silty clay loam A horizons, dark gray calcareous silty clay loam AC horizons, and grayish brown and gray sandy loam and silty clay loam calcareous C horizons.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Pachic Haploxerolls

TYPICAL PEDON: Agueda silty clay loam - cultivated field in pasture (Colors are for dry soil unless otherwise noted.)

Ap--0 to 6 inches; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; strong medium and coarse granular structure; hard, firm, sticky, plastic; many very fine, fine, and medium roots; many fine and very fine interstitial and many fine and very fine tubular pores; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 10 inches thick)

A12--6 to 42 inches; dark gray (10YR 4/1) silty clay loam, black (10YR 2/1) moist; weak coarse prismatic parting to strong fine granular structure; hard, friable, sticky, plastic; many very fine, fine, and medium roots; many very fine interstitial and many very fine and fine tubular pores; strongly effervescent with filaments, threads, and disseminated lime; moderately alkaline (pH 8.0); vertical cracks 1/4 to 1/2 inches wide; diffuse irregular boundary. (26 to 40 inches thick)

AC--42 to 55 inches; dark gray (10YR 4/1) silty clay loam, with few medium distinct grayish brown and pale brown (10YR 5/2, 6/3) mottles; mottled very dark gray, dark grayish brown and grayish brown (10YR 3/1, 4/2, 5/2) moist; few fine prominent dark reddish brown (5YR 3/3) mottles in lower half of horizon; weak medium subangular blocky parting to strong fine and medium granular structure; hard, firm, sticky, plastic; common very fine and fine roots; many very fine interstitial and many fine and medium tubular pores; few iron concretions; strongly effervescent with filaments, threads, soft masses and disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 14 inches thick)

IIC1--55 to 63 inches; grayish brown (10YR 5/2) sandy loam, very dark gray (10YR 3/1) moist; few medium distinct dark grayish brown (10YR 4/2) mottles; massive; hard, very friable, slightly sticky, slightly plastic; common very fine and fine roots; many very fine interstitial and many very fine, fine, and medium pores; few iron concretions; slightly effervescent with filaments, threads, and disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 12 inches thick)

IIIC2--63 to 72 inches; gray (10YR 5/1) light silty clay loam, very dark gray (10YR 3/1) moist; few reddish brown (5YR 4/4) mottles; weak medium subangular blocky parting to moderate fine and medium granular structure; hard, firm, sticky, plastic; common very fine and fine roots; many very fine, fine and medium tubular pores; few iron concretions; strongly effervescent with filaments, threads, and disseminated lime; moderately alkaline (pH 8.0).

TYPE LOCATION: Santa Barbara County, California; about 6 miles west of Highway 101 on State Highway 1; approximately 350 feet north of Highway 1 on road into Rancho de Los Llantos and 900 feet west along El Jaro Creek, a part of Yridisis Ranch.

RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 59 to 62 F. The mean summer and mean winter soil temperatures are about 67 and 54 F. respectively. Soil between depths of about 4 to 12 inches usually is moist in some part shortly after the first of November and stays moist until sometime in May and is dry all the rest of the year. The soil is slightly to strongly effervescent throughout, but the lime is less than 15 percent.

The A horizon is gray, dark gray, or very dark gray in 10YR hue. It is loam, clay loam, silt loam, or silty clay loam and has 18 to 35 percent clay. The same textural limits apply to the 10 to 40 inches section. Organic matter ranges from 1 to 4 percent to a depth of more than 20 inches and decreases regularly with increasing depth.

The C horizon is pale brown, brown, grayish brown, dark grayish brown, gray or light gray in 10YR hue. Distinct or prominent mottles are present in some pedons. This horizon is sandy loam, loam, clay loam, or silty clay loam and has common stratification.

COMPETING SERIES: These are the Conejo, Fontana, Gazos, Linne, Salinas, and San Benito series. Conejo soils have a chroma of 2 to 3 and have no secondary lime. Fontana, Linne, and San Benito soils have a paralithic contact at depths of 20 to 40 inches. Gazos soils have a lithic contact at depths of 20 to 40 inches. Salinas soils are noncalcareous in the upper part.

GEOGRAPHIC SETTING: Agueda soils are on nearly level to moderately steep slopes and are at elevations of 50 to 1000 feet. They formed in alluvium from calcareous sedimentary rocks. The climate is subhumid mesothermal with cool to warm rainless summers with some fog, and cool moist winters. Mean annual precipitation is 14 to 20 inches. The average January temperature is about 50 F; average July temperature is 62 to 64 F; mean annual temperature is 57 to 60 F. the average frost-free season is 230 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing linne and Salinas soils and the Botella, Elder, and Santa Lucia soils. Botella soils have argillic horizons and are noncalcareous. Elder soils are coarse-loamy and noncalcareous. Santa Lucia soils have 35 percent rock fragments and have a lithic contact at depths of 20 to 40 inches.

DRAINAGE AND PERMEABILITY: Well and moderately well drained; medium runoff; moderate permeability.

USE AND VEGETATION: Used for growing small grain, pasture, range, and irrigated field and truck crops. Noncultivated areas have annual grass and forbs with scattered live oak.

DISTRIBUTION AND EXTENT: Agueda soils are of moderate extent in valleys of the Coast Range, south of San Francisco.

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

SERIES ESTABLISHED: Santa Barbara County (Santa Ynes Area), California, 1927.

REMARKS: These soils were formerly classified as Brunizems.

The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET

Last revised by the state on 9/74.


National Cooperative Soil Survey
U.S.A.