LOCATION OCEANO CAEstablished Series
TAXONOMIC CLASS: Mixed, thermic Lamellic Xeropsamments
TYPICAL PEDON: Oceano sand, annual grass and forbs, grazed. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1.5 inches; grayish brown (10YR 5/2) sand, dark grayish brown (10YR 4/2) moist; single grained; loose; many very fine roots; many very fine interstitial pores; slightly acid (pH 6.1); clear smooth boundary. (0 to 3 inches thick)
A2--1.5 to 4 inches; grayish brown (10YR 5/2) sand, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, common very fine roots; many very fine interstitial pores; moderately acid (pH 5.9); gradual smooth boundary. (0 to 6 inches thick)
A3--4 to 15 inches; light brownish gray (10YR 6/2) sand, brown (10YR 4/3) moist; massive; soft, very friable; few very fine roots; many very fine interstitial, few fine tubular pores; strongly acid (pH 5.5); gradual smooth boundary. (11 to 22 inches thick)
AC--15 to 20 inches; light brownish gray (10YR 6/2) sand, brown (10YR 4/3) moist; massive; soft, very friable; few very fine roots, many very fine interstitial and few fine tubular pores; strongly acid (pH 5.5); gradual smooth boundary. (15 to 25 inches thick)
C1--20 to 39 inches; pale brown (10YR 6/3) sand, yellowish brown (10YR 5/4) moist; massive; soft, very friable; few very fine roots; many very fine interstitial and few fine tubular pores; strongly acid (pH 5.3); gradual smooth boundary. (15 to 25 inches thick)
C2--39 to 55 inches; pale brown (10YR 6/3) sand, yellowish brown (10YR 5/4) moist; massive; soft, very friable; few very fine roots; many very fine interstitial pores; several weak 1/8 inch thick lamellae (7.5YR 4/4 moist, 5/4 dry); slightly hard, somewhat branched, upper lamellae bends up into C1 horizon; slightly more firm than C1; strongly acid (pH 5.1); gradual smooth boundary. (14 to 20 inches thick)
C3--55 to 75 inches; light yellowish brown (10YR 6/4) sand, yellowish brown (10YR 5/4) moist; massive; soft, very friable; many very fine interstitial pores; horizon of maximum lamellae, 1/4 inch thick, hard when dry, two continuous, several discontinuous, similar in color to lamellae above; black specks 1 to 5 mm in diameter about 1 percent of mass; strongly acid (pH 5.1); gradual smooth boundary. (15 to 25 inches thick)
C4--75 to 90 inches; light yellowish brown (10YR 6/4) sand, yellowish brown (10YR 5/4) moist; massive; soft, very friable; plastic; many very fine interstitial pores; weak lamellae 1/4 inch to 3/8 inch thick, discontinuous, slightly wavy, sand grains very thinly coated; slightly more coarse than C3; strongly acid (pH 5.5).
TYPE LOCATION: Santa Barbara County, California; 3.7 airline miles south-southeast of center of Santa Maria; central portion of the SE1/4 of NW1/4 section 36, T.10 N., R.34 W. 34 degrees North latitude, 53 minutes, 43 seconds, 120 degrees West longitude, 24 minutes, 40 seconds
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 59 degrees to 62 degrees F., and usually the temperature is not below 47 degrees F. at any time. Soil between the depths of about 12 and 35 inches usually is dry all of the time from late April or May until November and usually is moist in some or all parts all the rest of the year. The soil is sand or loamy sand throughout and rock fragments are lacking. It is mostly moderately acid but the range is slightly to strongly acid. There is no clear reaction trend with depth except that the uppermost and lowermost horizons commonly are less acid.
The A horizon is grayish brown, brown, light brownish gray, pale brown or light yellowish brown. In uncultivated soils the organic matter content ranges from 2 to 4 percent in the uppermost 2 to 4 inches, but decreases with depth and the average for the upper 10 inches is about 1/2 to 1 percent.
Lower horizons are either B or C horizon. They are light gray or light yellowish brown to brown with hue 10YR or 7.5YR, value of 5 through 7 and chroma of 3 or 4. A few weak and somewhat discontinuous lamellae 1/8 to 1/2 inch thick are present. The first lamellae occur at a depth of about 25 to 32 inches and continue to a depth of about 60 to 90 inches. They have stronger chroma, redder hue of lower value, or a combination of these features, compared to the matrix color. The matrix is soft or loose and the lamellae are slightly hard or hard, Some of the lamellae are slightly brittle. Lamellae have few to common very thin or thin clay bridges between mineral grains. In some pedons are lamellae 1/4 to 3/4 inches thick below 40 inches.
COMPETING SERIES: These are the Marina series in this family and the Arnold, Baywood, Corralitos, Delhi, Garey, Metz, Tangair, and Tujunga series. Arnold soils have a paralithic contact of soft sandstone and lack lamellae. Baywood soils have mollic epipedons. Corralitos and Tujunga soils are stratified and lack lamellae. Delhi soils are neutral and lack lamellae. Garey soils have argillic horizons made up of lamellae. Marina soils have B horizons with slightly hard matrix and hard lamellae. Metz soils are alkaline and are not sandy in all parts of the 10- to 40-inch section. Tangair soils are saturated within 40 inches of the surface part of the year.
GEOGRAPHIC SETTING: Oceano soils are on dune-like topography at elevations of 25 to 1,100 feet. Slopes are 0 to 50 percent. The soils formed in sandy eolian deposits near the Pacific Ocean. The climate is subhumid mesothermal with cool, rainless but foggy summers and cool moist winters. The mean annual subhumid mesothermal with cool, rainless but foggy summers and cool moist winters. THe mean annual precipitation is 10 to 20 inches. Average January temperature is 50 degrees F., average July temperature is 63 degrees F.; mean annual temperature is 57 degrees to 59 degrees F. The average freeze-free season is 200 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Arnold, Baywood, Garey and Marina soils and the Elkhorn and San Andreas soils. Elkhorn soils have argillic horizons with more than 18 percent clay. San Andreas soils are sandy loams with a paralithic contact at depths of 40 inches or less.
DRAINAGE AND PERMEABILITY: Excessively drained; very slow runoff; surface drainage pattern is very poorly developed; rapid permeability.
USE AND VEGETATION: Used mainly for range. Some areas have been planted to eucalyptus trees and localized areas are used for growing truck crops and fruit with irrigation. Areas closer to the coast tend to have a brush cover of bush lupine, ceanothus, chamise and scrub live oak whereas more inland or cleared areas have a cover of annual grasses and forbs.
DISTRIBUTION AND EXTENT: Oceano soils occur near the ocean in central and south-central California. They are of moderate extent in MLRA 14d.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Monterey County, California, 1972.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as mixed, thermic Argic Xeropsamments. Competing series were not checked at that time.
ADDITIONAL DATA: Two NSSL pedons in Santa Barbara County: S62CA-083-001 (type location) and S62CA-083-002 (range in characteristics).