LOCATION RYER CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Haploxeralfs
TYPICAL PEDON: Ryer silt loam; native pasture. (Colors are for dry soil unless otherwise noted.)
Al--O to 10 inches; pale brown (lOYR 6/3) silt loam, brown (lOYR 5/3) moist; massive, dry, very weak thin platy and weak fine granular structure moist; hard, friable, slightly sticky and nonplastic; many fine roots; many fine tubular and interstitial pores; medium acid (pH 5.7); clear smooth boundary. (6 to 12 inches thick)
Bl--10 to 20 inches; pale brown (lOYR 6/3) heavy silt loam, brown (1OYR 5/3) moist; weak medium angular blocky structure; hard, friable and firm, slightly sticky and slightly plastic; common fine roots; common fine interstitial and tubular pores; few thin clay films on faces of peds; medium acid (pH 5.7); clear smooth boundary. (6 to 10 inches thick)
B2t--20 to 44 inches; brown (lOYR 5/3) heavy clay loam, dark brown (lOYR 4/3) moist; moderate medium angular blocky structure; very hard, firm, sticky and plastic; few fine roots concentrated in seams; common moderately thick dark brown (7.5YR 4/4) clay films on faces of peds, dark brown (7.5YR 3/4) moist; slightly acid (pH 6.2) in the upper part, becoming neutral (pH 7.3) in the lower part; gradual smooth boundary. (18 to 28 inches thick)
B3--44 to 64 inches; brown (lOYR 5/3) light clay loam, dark brown (lOYR 4/3) moist; weak medium and fine angular blocky structure; very hard, firm, slightly sticky and plastic; few fine roots; few thin dark brown (7.5YR 4/4) clay films on faces of peds; mildly alkaline (pH 7.8); diffuse irregular boundary. (10 to 24 inches thick)
IIC--64 to 84 inches; pale brown (lOYR 6/3) stratified loam and very fine sandy loam, brown (lOYR 5/3) moist; massive; hard, friable, nonsticky and slightly plastic; neutral (ph 6.7).
TYPE LOCATION: Nerced County, California; 8 miles northeast of Ryer Station, in cut bank of Dry Creek in SW 1/4 SW 1/4 sec. 34, T.4S., R.13E.
RANGE IN CHARACTERISTICS: Thickness of the solum is more than 40 inches. The mean annual soil temperature is about 60 degrees to 65 degrees F. and the soil temperature is always above 47 degrees F. The soil between depths of 4 and 12 inches becomes moist in November or early December and remains moist until May or early June. Rock fragments make up to 15 percent of the soil.
The A horizon is brown light brownish gray, pale brown, light yellowish brown or light brown (lOYR 5/3, 6/2, 6/3, 6/4; 7.5YR 6/4). It is loam, silt loam, clay loam or silty clay loam. Reaction is medium acid to neutral. Either a transitional A3 horizon or a Bl horizon is present. In some pedons both horizons are present.
The B2t horizon is brown, yellowish brown or dark brown, pale brown, light yellowish brown or light brown (lOYR 5/3 5/4, 6/3, 6/4, 7.5YR 6/4, 5/4, 4/4). It is heavy clay loam or clay. Reaction is slightly acid to mildly alkaline. The B3 and C horizon is calcareous in some pedons.
The C horizon is brown, pale brown, yellowish brown, light yellowish brown, brownish yellow, or light brown (lOYR 5/3, 5/4, 6/3, 6/4, 6/6; 7.5YR 5/4, 6/4). It is stratified loam, sandy loam, and clay loam.
COMPETING SERIES: These are the Dibble, Los Banos, Phipps, and Stomar series. Dibble and Phipps soils are 20 to 40 inches deep to a paralithic contact. Phipps soils also have a B2t horizon in 5YR hue. Los Banos soils have a calcareous B2t horizon in 5YR hue. Stomar soils (see Remarks).
GEOGRAPHIC SETTING: Ryer soils are on fairly old terraces and have slope gradients of O to 9 percent. They formed from alluvium from mixed but dominantly basic igneous rocks. Elevations are 40 to 1500 feet. The climate is typified by hot, dry summers and cool, moist winters. Mean annual precipitation is 10 to 25 inches. Average January temperature is about 45 degrees F., average July temperature is about 78 degrees F., and mean annual temperature is 59 degrees to 63 degrees F. Frost-free season is 200 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Honcut, Wyman and Yokohl soils. Honcut soils have less than 18 percent clay and lack B2t horizons. Wyman soils have less than 35 percent clay. Yokohl soils have a duripan underlying the B2t horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: Used mainly for dryland grain and pasture. Vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Low terraces along the east side of the northern San Joaquin and southern Sacramento Valleys in California. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced Area, California, 1953.
REMARKS: Stomar soils appear to be Xeralfic Haplargids. More field investigations are needed to properly classify the Stomar series.
OSED scanned by SSQA. Last revised by state on 3/77.