LOCATION SANTA YNEZ CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Ultic Palexerolls
TYPICAL PEDON: Santa Ynez fine sandy loam, annual grass rangeland. (Colors are for dry soil unless otherwise noted.)
A11--0 to 3 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky and moderate fine and medium structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial, common very fine and few fine tubular pores; medium acid (pH 5.7); clear wavy boundary. (3 to 4 inches thick)
A12--3 to 16 inches; gray (10YR 5/1, grayish brown 5/2 rubbed) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and medium, few fine roots; common very fine and fine, few medium tubular pores; medium acid (pH 5.8); clear wavy boundary. (9 to 18 inches thick)
A2--16 to 18 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many medium roots mostly horizontal and matted on top of the B2t horizon; medium acid (pH 6.0); abrupt wavy boundary. (1/4 to 8 inches thick)
B21t--18 to 26 inches; grayish brown (10YR 5/2 exterior) clay, gray (10YR 5/1 inped), very dark grayish brown (10YR 3/2) moist; strong coarse columnar structure parting to strong medium prismatic; very hard, firm, very sticky and very plastic; common very fine and medium, few fine roots, mostly along faces of peds; few very fine tubular pores; continuous thin clay films on faces of peds and lining pores; medium acid (pH 6.0); clear wavy boundary. (5 to 10 inches thick)
B22t--26 to 36 inches; gray (10YR 5/1) clay loam (near sandy clay), very dark grayish brown (10YR 3/2 rubbed) moist; moderate coarse prismatic structure parting to strong coarse angular blocky; very hard, firm, sticky and plastic; common very fine and few fine and medium roots mostly along faces of peds; few fine tubular pores; continuous thick clay films line pores, many thin and moderately thick clay films on faces of peds; slightly acid (pH 6.4) in upper part, neutral (pH 7.3) in lower part; clear wavy boundary. (7 to 12 inches thick)
B3t--36 to 43 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2 rubbed) moist; many large distinct pale brown (10YR 6/3) mottles; weak coarse subangular blocky structure; very hard, firm, sticky and plastic; few very fine roots mostly along faces of peds; few very fine tubular pores; many thin clay films line pores and common thin clay films on faces of peds; mildly alkaline (pH 7.6); clear wavy boundary. (6 to 30 inches thick)
C--43 to 61 inches; light gray (2.5Y 7.2) sandy clay loam, grayish brown (2.5Y 5/2 rubbed) mixed grayish brown and light yellowish brown broken (2.5Y 5/2 and 6/4) moist; few fine prominent black (10YR 2/1) mottles that appear to be charcoal; massive; slightly hard, friable, slightly sticky and slightly plastic; moderately alkaline (pH 8.0).
TYPE LOCATION: Monterey County, California; near Corral de Tierra Valley about 0.5 mile south on Underwood Road from intersection with Corral de Tierra Road, NW corner SW 1/4 NW 1/4 NW 1/4 SW 1/4 sec. 20, T.16S., R.3E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 59 degrees to 63 degrees F. and the soil temperature usually is not below 47 degrees F. at any time. The soil between depths of about 5 and 15 inches usually is dry all of the time from late April or May until November or early December and is moist in some or all parts all the rest of the year. Rock fragments usually are in the form of shale fragments and they make up about 1 to 35 percent of the A and B horizons.
The A1 horizon is gray, dark gray, grayish brown or dark grayish brown in 10YR hue. It is fine sandy loam, sandy loam, loam or clay loam. This horizon is massive and slightly hard or it has granular or subangular blocky structure. It ranges from medium acid to neutral and has 50 to 75 percent base saturation in some or all parts. It has 2 to 5 percent organic matter.
The A2 horizon is light gray, light brownish gray, pale brown or white dry and grayish brown, light brownish gray, grayish brown or dark grayish brown moist. The upper boundary of the B2t horizon is abrupt and it has 15 to 25 percent more clay, absolute, than the A2 or A1 horizon.
The B2t horizon is gray to brown to olive gray (10YR 5/1, 5/2, 5/3, 4/2, 6/2, 6/3; 2.5Y 5/2, 5/4; 5Y 5/2, 5/3). It is clay, sandy clay or heavy clay loam and has 35 to 50 percent clay, and has columnar or prismatic structure and usually the primary structure parts to angular blocky structure or is angular blocky in the lower part. It ranges from medium acid to mildly alkaline and usually becomes more alkaline with increasing depth. Base saturation is 50 to 90 percent in the upper part and over 75 percent in the lower part. The lower boundary is gradual or diffuse or a B3 horizon is present.
The C horizon is light brownish gray to white (10YR 6/2, 7/2, 8/2, 6/3; 2.5Y 6/2, 7/2). It is fine sandy loam to clay loam, and is medium acid to moderately alkaline but the soil material is not effervescent.
COMPETING SERIES: These are the Malibu series in this family and the Los Osos, Sespe, Sween, Tierra and Watsonville series in other families. Los Osos, Sespe and Sween soils are underlain by bedrock at depths of 24 to 40 inches and have a base saturation of more than 75 percent and lack abrupt A/B horizon boundaries. Malibu soils have a lithic contact at depths of 22 to 40 inches. Tierra soils have hard or very hard and massive A horizons. Watsonville soils have an albic horizon, and are somewhat poorly drained.
GEOGRAPHIC SETTING: The Santa Ynez soils are on coastal terraces and footslopes and have slopes of 0 to 50 percent. Elevations are 20 to 1,200 feet. The soils formed in old alluvium from shale, sandstone, and granite. The climate is subhumid mesothermal with warm dry somewhat foggy summers and cool moist winters. Mean annual precipitation is 15 to 35 inches. Average January temperature is about 50 degrees F., average July temperature is about 65 degrees F.; mean annual temperature is 57 degrees to 60 degrees F. The freeze-free season is about 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Antioch, Arnold, Ballard, Chamise, Diablo, Elkhorn, Positas, San Andreas, and Santa Lucia soils. Antioch and Positas soils have massive and hard A horizons. Arnold, San Andreas, and Santa Lucia soils lack argillic horizons. Ballard and Elkhorn soils have less than 35 percent rock fragments and lack an abrupt A/B horizon boundary. Diablo soils are clay throughout and have cracks and slickensides that intersect.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to rapid runoff; very slow permeability.
USE AND VEGETATION: Used for range and few areas for growing field and forage crops mostly with irrigation. Uncultivated areas have a cover of annual grasses, forbs, scattered live oak, and a small amount of brush.
DISTRIBUTION AND EXTENT: Central and south-central coast counties of California. The 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 A2 horizon is not considered an albic horizon. More field study is needed on this soil. In the past, some soils now identified as being in the Santa Ynez series were grouped in the Tierra series. Tierra soils are now defined as having a dark colored epipedon that is hard or very hard and massive when dry.
OSED scanned by SSQA. Last revised by state on 6/76.