LOCATION OAK GLEN CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Pachic Haploxerolls
TYPICAL PEDON: Oak Glen gravelly sandy loam, annual grass pasture. (Colors are for dry soil unless otherwise noted.)
A11--0 to 10 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark brown (10YR 2/2) moist; moderate very fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots; slightly acid (pH 6.3); diffuse smooth boundary. (8 to 14 inches thick)
A12--10 to 20 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; moderate very fine granular structure; soft, very friable, nonsticky and nonplastic; common fine roots; slightly acid (pH 6.3); diffuse smooth boundary. (8 to 14 inches thick)
C--20 to 60 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; few fine roots; slightly acid (pH 6.5).
TYPE LOCATION: San Bernardino County, California; 7 miles north of Beaumont, north side of Oak Glen Road; NW1/4 section 36, T.1S.M R.1W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is about 54 to 59 degrees F. The soil temperature is above 47 degrees F. all the time or is above 47 degrees F. after the middle of February (95 to 120 days) in some soils. Soil between depths of about 8 and 24 inches usually is continuously dry in all parts from late May or early June until late November or early December, and usually is moist in some or all parts all the rest of the year. Rock fragments, in all parts, are less than 35 percent and usually consist of less than 20 percent mineral grains 2 to 5 mm in diameter. Texture throughout the profile is relatively uniform and is fine sandy loam, sandy loam or coarse sandy loam. The soil profine is neutral to moderately acid but is usually slightly acid or near slightly acid. Base saturation is 75 to 95 percent. Organic matter decreases regularly with depth and is more than 1 percent to a depth of 20 to 30 inches or more.
The A horizon is brown, gray, grayish brown, dark grayish brown, dark gray or dark brown (10YR 5/3, 5/1, 5/2 4/2, 4/1 4/3). Moist colors are very dark brown, very dark grayish brown, dark brown or very dark gray (10YR 2/2, 3/2, 3/3, 3/1). This horizon has weak or moderate granular or subangular blocky structure. It contains 1.5 to 4 percent organic matter.
The C horizon is dark grayish brown, grayish brown, dark brown, brown yellowish brown, light yellowish brown or reddish brown (10YR 4/2, 4/3, 5/2, 3/3, 5/3, 5/4, 6/4; 7.5YR 4/2, 5/2, 5/4; 5YR 4/3, 4/4). It has weak granular or subangular blocky structure or is massive, and it is soft or slightly hard.
COMPETING SERIES: These are the Central Point (T), Edmunston, Imbler (T), Ritter (T), Stevens and Uhlig series. Central Point soils have a hard or very hard B horizon. Edmundston soils have a B horizon, have rock fragments that range from 2 to 10 mm and have a mean summer and winter difference of about 41 degrees F. Imbler soils have a mean annual soil temperature of 47 to 53 degrees F. Ritter soils are dominantly loam in the 10 to 40 inch control section, have a B horizon and are mildly alkaline in the lower part of the B horizon. Stevens soils are calcareous below a depth of 25 to 40 inches and are loam or silt loam in the particle size control section. Uhlig soils have a loam B horizon with the upper part containing a high component of loess and ash.
GEOGRAPHIC SETTING: Oak Glen soils are on fans and have slopes of 2 to 25 percent. Elevations are 3,400 to 6,000 feet. The soils formed in alluvium from a variety of rock but dominantly from granitic rock sources. The climate is subhumid mesothermal with warm, dry summers and cool, moist winters with some snow. The mean annual precipitation is 15 to 25 inches. The mean annual temperature is 52 to 57 degrees F.; the mean annual January temperature is about 42 degrees F.; and the mean July temperature is about 72 degrees F. The frost free season is 150 to 225 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Calpine, Crafton, Crouch and Mottsville soils. Calpine soils are moist in the 8 to 24 inch control section for less than 90 days when the soil temperature is above 47 degrees F. Crafton soils have a paralithic contact at a depth of less than 20 inches. Crouch soils have base saturation of less than 75 percent and have a mollic epipedon less than 20 inches thick. Mottsville soils are sandy in the control section.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are used for growing pasture or deciduous orchards and forested areas are used for recreation. Principal native plants are shrubs, mixed hardwoods, and pine trees. Naturalized plants are annual grasses and forbs.
DISTRIBUTION AND EXTENT: The Oak Glen soils occur in mountain valleys in southern California. They are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Bernardino County (Southwestern Part), California, 1972.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET