LOCATION RAMONA CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Haploxeralfs
TYPICAL PEDON: Ramona fine sandy loam - cultivated (Colors are for dry soil unless otherwise noted.)
Ap--0 to 14 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; massive; hard, very friable, nonsticky, nonplastic; few fine roots: many very fine interstitial and tubular pores; moderately acid (pH 6.0); clear smooth boundary. (8 to 15 inches thick)
A12--14 to 23 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; massive; hard, very friable, slightly sticky, slightly plastic; few fine roots; common fine tubular pores; slightly acid (pH 6.5); clear smooth boundary. (5 to 10 inches thick)
B1--23 to 29 inches; brown (7.5YR 5/4) loam, dark reddish brown (5YR 3/4) moist; moderate coarse angular blocky structure; hard, friable, slightly sticky, slightly plastic; few fine roots; many fine tubular pores; few thin clay films on faces of peds and lining pores; slightly acid (pH 6.5); clear smooth boundary. (3 to 8 inches thick)
B21t--29 to 37 inches; reddish brown (5YR 4/4) sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate coarse prismatic structure; very hard, firm, sticky, plastic; few fine roots; common fine tubular pores; common thin clay films on faces of peds and lining pores; slightly acid (pH 6.5); gradual smooth boundary. (6 to 10 inches thick)
B22t--37 to 46 inches; yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic structure; very hard, firm, sticky, plastic; very few fine roots; few fine tubular pores; many moderately thick clay films on faces of peds and lining pores; slightly acid (pH 6.5); gradual smooth boundary. (6 to 12 inches thick)
B23t--46 to 58 inches; yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic structure; very hard, firm, sticky, plastic; few fine tubular pores; many moderately thick clay films on faces of peds and lining pores; slightly acid (pH 6.5); gradual smooth boundary. (8 to 14 inches thick)
B3--58 to 68 inches; yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate coarse angular blocky structure; very hard, firm, sticky, plastic; few fine tubular pores; many moderately thick clay films on faces of peds and lining pores; neutral (pH 6.8); clear irregular boundary. (6 to 12 inches thick)
C--68 to 74 inches; strong brown (7.5YR 5/6) fine sandy loam, dark brown (7.5YR 4/4) moist; massive; hard, firm, slightly sticky, slightly plastic; few fine pores; neutral (pH 7.0).
TYPE LOCATION: Riverside County, California; about 3 miles northwest of Beaumont, California; approximately 1,100 feet north and 500 feet west of the S1/4 corner of sec. 31, T.2S., R.1W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 59 degrees to 65 degrees F. and the soil temperature usually is not below 47 degrees F. or is below 47 degrees F. for only a few days in January. Soil between the depth of about 5 and 15 inches usually is moist in some or all parts from November or early December until late April or May and is dry all the rest of the year. The A and B horizons have more than 15 percent combined coarse and very coarse sand and 5 to 35 percent fine rock fragments of 2 to 5mm size. Rock fragments larger than 5mm are less than 5 percent. The C horizons are variable as to coarse sand, fine gravel, and rock fragments larger than 5mm but in general are more coarse than the A and B horizons.
The A horizon is light brownish gray to dark grayish brown or yellowish brown (10YR 6/2, 5/2, 4/2, 6/3, 5/3, 4/3, 5/4; 7.5YR 5/2, 5/4) when dry. It is course sandy loam, sandy loam, fine sandy loam or light loam and has less than 1 percent organic matter. After considerable cultivation or cattle trampling some or all of the A horizon is hard or very hard and massive when dry. It is neutral to moderately acid. The lower boundary is gradual or there is an A3 horizon or a B1 horizon or both horizons are present.
The B2t horizon is dark brown, strong brown, brown or light brown in 7.5YR hue or reddish brown or yellowish red in 5YR hue in yellowish in 10YR hue in the lower part. It is heavy sandy loam, sandy clay loam or loam with 18 to 27 percent clay. Total clay content is 3 to 12 percent more in the B2t horizon than in the A horizon. The B2t horizon is slightly acid or neutral in all parts or in some pedons it is slightly alkaline in the lower part. It has weak or moderate angular blocky or prismatic structure. In pedons having a B3 or B3t horizon, color of the transitional horizon is similar to the B2t horizon or it has a hue 1/4 letter interval less red. It is slightly acid to moderately alkaline.
The C horizon is coarse sandy loam, fine sandy loam or loam and is neutral to moderately alkaline. In some pedons it is calcareous in some part with a small amount of segregated or disseminated lime.
COMPETING SERIES: These are the Arbuckle, Blasingame, Borden, Esparto, Fallbrook, Montpellier, Sesame, Snalling, Tivy, Wasioja, and Wyman series. Arbuckle soils are gravelly with more than 15 percent gravel larger than 5mm in the argillic horizon. Blasingame and Tivy soils have a paralithic contact less than 40 inches below the surface. Borden soils have an argillic horizon that is moderately alkaline and is calcareous in some or all parts. Esparto soils are marginal to the silty family with less than 20 percent fine gravel, coarse and very coarse sand. Fallbrook soils have 27 to 35 percent clay in the argillic horizon. The difference in total clay content between A and B2t horizon is more than 10 percent absolute. Sesame soils have a lithic contact between A and B2t horizon is more than 10 percent absolute. Sesame soils have a lithic contact at a depth of 20 to 40 inches. Snalling soils are medium acid in the B2t horizon. (See Remarks). Wasioja soils have an aridic moisture regime marginal to xeric. Wyman soils have less than 15 percent coarse and very coarse sand, less than 10 percent absolute clay difference between A and B horizon and about 27 to 35 percent clay in the B2t horizon.
GEOGRAPHIC SETTING: The Ramona soils are nearly level to moderately steep. They are on terraces and fans at elevations of 250 to 3,500 feet. They formed in alluvium derived mostly from granitic and related rock sources. The climate is dry subhumid mesothermal with warm dry summers and cool moist winters. Mean annual precipitation is 10 to 20 inches. Average January temperature is 50 degrees F., average July temperature is about 70 degrees F., average annual temperature is 60 degrees to 66 degrees F. The frost-free season is 230 to 320 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Fallbrook and Montpellier soils and the Arlingtonk, Greenfield, Hanford, and Placentia soils. Arlington soils have a duripan. Greenfield soils have less than 18 percent clay in the argillic horizon. Hanford soils lack an argillic horizon. Placentia soils have a natric horizon with more than 35 percent clay.
DRAINAGE AND PERMEABILITY: Well-drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used mostly for production of grain, grain-hay, pasture, irrigated citrus, olives, truck crops, and deciduous fruits. Uncultivated areas have a cover of annual grasses, forbs, chamise or chaparral.
DISTRIBUTION AND EXTENT: The Ramona soils are in the interior valleys of central and the western part of southern California. The soils are extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Los Angeles County (Pasadena Area), California, 1915.
REMARKS: The Ramona soils are formerly classified as Noncalcic Brown soils. The Snalling soils are differentiated from Ramona soils on soil reaction in the B2t horizon. Some differentiae used to separate series within this family are difficult to apply consistently.
The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET
OSED scanned by SSQA. Last revised by state on 10/72.