LOCATION REIFF CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid, thermic Mollic Xerofluvents
TYPICAL PEDON: Reiff very fine sandy loam - on a E facing slope of 1 percent that is cultivated at 40 feet elevation. (Colors are for dry soil unless otherwise stated. When described the profile was moist below a depth of 2 feet.)
Ap--0 to 3 inches; grayish brown (10YR 5/2) very fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure parting to granular; hard, friable, slightly sticky and slightly plastic; few coarse and common very fine roots; many very fine interstitial and tubular pores; slightly acid (pH 6.5); abrupt smooth boundary. (3 to 10 inches thick)
A--3 to 16 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; massive; hard, friable, slightly sticky and slightly plastic; common medium and coarse and many very fine roots; many very fine interstitial and common very fine tubular pores; colloid stains on mineral grains; neutral (pH 7.0); clear wavy boundary. (8 to 15 inches thick)
AC--16 to 24 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common medium and many very fine roots; many very fine interstitial and common very fine tubular pores; colloid stains on mineral grains; mildly alkaline (pH 7.5); clear irregular boundary. (6 to 10 inches thick)
C1--24 to 43 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common medium and many very fine and fine roots; many very fine interstitial and tubular pores; colloid stains on mineral grains; moderately alkaline (pH 8.0); diffuse smooth boundary. (15 to 25 inches thick)
C2--43 to 60 inches; brown (10YR 5/3) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, slightly sticky and nonplastic; common medium and very fine roots; many very fine interstitial and tubular pores; colloid stains on mineral grains; moderately alkaline (pH 8.0).
TYPE LOCATION: Yolo County, California; about 2 miles southwest of Knights Landing; about 0.75 miles west of Road 102 and 100 feet north of Road 14 and 1,300 feet east of the SW corner of section 22 T. 11 N, R. 2 E, MDB&M. Knights Landing Quadrangle.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 62 to 68 degrees F and the soil temperature is above 47 degrees F at all times. The soil between the depths of 5 and 22 inches is dry in all parts from June to November and moist in some or all parts the rest of the time. Thin silt, sand and gravel lenses are common in the profile. Gravel content in some or all horizons range up to 30 percent, but most pedons have little if any gravel. Few faint mottles occur within the profile of some pedons. Organic matter content decreases irregularly with depth. Some pedons have fine stratification below 6 inches.
The A horizon is 10YR 5/3, 5/2, 4/2, 4/3; 7.5YR 5/4. Moist colors are 10YR 3/4, 3/3, 3/2, 2/2; 7.5YR 3/4. It is sandy loam, fine sandy loam, or loam. Reaction is slightly acid to moderately alkaline. Organic matter contant is more than one percent and some orall of the horizon is massive and hard when dry.
The C horizon is 10YR 6/4, 6/3, 5/4, 5/3, 5/2, 4/3, 4/2; 7.5YR 6/4, 5/4, 3/2. Moist colors are 10YR 4/4, 4/3, 4/2, 3/4, 3/3, 3/2; 7.5YR 4/4, 3/4, 3/2. It is stratified sand, loamy fine sand, loamy sand, sandy loam, fine sandy loam, very fine sandy loam, loam, silt loam or silty clay loam. It is neutral to moderately alkaline and may be calcareous.
COMPETING SERIES: These are the Arvin and Steuber series in the same family and the Maywood and San Emigdio soils in other families. Arvin and Steuber soils have an organic matter content of less than 1 percent in the A horizon. In addition, Arvin soils have more than 15 percent very coarse plus coarse sand. Steuber soils have soil temperatures less than 47 degrees F. in the winter months. Maywood soils have A horizons with moist values of 4 or more. San Emigdio soils are calcareous throughout the 10 to 20 inch zone.
GEOGRAPHIC SETTING: The Reiff soils are on flood plains, or alluvial fans and are nearly level to moderately sloping. The soils formed in material weathered from mixed sources. Elevations are 30 to 500 feet. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation varies from 10 to 20 inches. Mean January temperature is 46 degrees F; mean July temperature is 77 degrees F; mean annual temperature varies from 60 to 63 degrees F. Frost-free period ranges from 240 to 275 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anderson, Columbia, Visalia and Yolo soils. Anderson soils are loamy-skeletal. Columbia soils have a water table within 60 inches during part of the year. Visalia soils have more than 20 inches thick of mollic surface horizons. Yolo soils are fine-silty.
DRAINAGE AND PERMEABILITY: Well drained; very slow to slow runoff; moderately rapid permeability. Areas in Sacramento and San Joaquin Counties are subject to occasional periods of flooding in December to April.
USE AND VEGETATION: Used for row, field and orchard crops such as tomatoes, sugar beets, flowers, alfalfa, corn, beans, grapes, almonds, walnuts, avocados and citrus. Uncultivated areas have annual grasses and forbs, such as soft chess, filaree, wild oats, mustard and valley oak.
DISTRIBUTION AND EXTENT: Sacramento Valley and the northern part of San Joaquin Valley, California. The series is moderately extensive in MLRA- 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Yolo County, California, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 24 inches (Ap, A, AC)
The Reiff soils that were mapped in the 1974 Shasta County Area report are excluded from this revised concept. These soils will probably be reclassified as mollisols when re-mapped. Soils mapped in the San Diego Area report are now excluded from the range of the Reiff concept due to having more than 15 percent very coarse plus coarse sand.