LOCATION DOCAS CA
Established Series
Rev. TDC/CJW/LCL
01/2023
DOCAS SERIES
The Docas series is a member of the fine-silty, mixed (calcareous), thermic family of Typic Xerofluvents. Typically, Docas soils have gray, slightly and strong effervescent, silty clay loam A horizons and light gray, violently effervescent C horizons.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, thermic Typic Xerofluvents
TYPIFYING PEDON: Docas silty clay loam - abandoned grain field (Colors are for dry soil unless otherwise stated.)
Ap1--0 to 3 inches; gray (10YR 6/1) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; strong medium and thick platy structure; slightly hard, friable, sticky, plastic; few very fine roots; many very fine tubular and common fine interstitial pores; slightly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear wavy boundary. (2 to 4 inches thick)
Ap2--3 to 9 inches; gray (10YR 6/1) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, sticky, plastic; few very fine roots; many very fine and few fine tubular pores; slightly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (6 to 12 inches thick)
A13--9 to 23 inches; gray (10YR 6/1) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate coarse subangular blocky structure; slightly hard, friable, sticky, plastic; common very fine roots; many very fine and common fine tubular pores; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); gradual wavy boundary. (10 to 16 inches thick)
C1--23 to 42 inches; light gray (2.5Y 7/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure; slightly hard, friable, sticky, plastic; common very fine roots; many very fine and common fine tubular pores; violently effervescent with segregated lime in filaments; moderately alkaline (pH 8.0); diffuse wavy boundary. (18 to 20 inches thick)
C2--42 to 62 inches; light gray (2.5Y 7/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, friable, sticky, plastic; few very fine roots; many very fine and few coarse tubular pores; violently effervescent with segregated lime in filaments; moderately alkaline (pH 8.0).
TYPE LOCATION: Monterey County, California; east of San Lucas; 6.4 miles east of Southern Pacific Railroad-State Highway 198 crossing and 100 feet south into field; NE1/4, SW1/4, NE1/4, sec. 31, T.21S., R.10E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 60 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 is usually dry all of the time from April or May until November or early December and is moist in some or all parts all the rest of the year. The soil is weakly to violently effervescent in all parts after plowing. The amount of lime increases somewhat from the surface downward. Most pedons have some fine lime segregations in the lower part. The 10 to 40 inch control section is silt loam or silty clay loam with 20 to 35 percent clay and less than 15 percent very fine sand or coarser. The soil has some fine stratification.
The A horizon is gray to light olive gray (10YR 6/1, 7/1, 6/2; 2.5Y 6/2; 5Y 6/1, 7/1, 7/2, 6/2). Organic matter ranges from less than 1 percent to 3 percent and decreases irregularly with depth.
The C horizon has about the same colors as the A horizon but its value usually is one-half to one unit higher or the chroma is one-half to one unit stronger than that of the A horizon.
COMPETING SERIES: These are the
Garretson,
Maywood,
Panoche, Ramada,
Reiff,
Salado,
Shedd, and
Wunjey series. Garretson soils have more than 15 percent sand and gravel and are noncalcareous. Maywood, Ramada, and Reiff soils have less than 18 percent clay and are noncalcareous in the upper part of the profile. Panoche soils have an aridic moisture regime. Shedd soils have a paralithic contact at depths of less than 40 inches. Salado and Wunjey soils have less than 18 percent clay.
GEOGRAPHIC SETTING: The Docas soils are nearly level to moderately sloping on fans and in small valleys at elevations of 300 to 2,000 feet. They formed in silty alluvium from shale formations. The climate is dry subhumid mesothermal with warm dry summers and cool moist winters. Mean annual precipitation is 10 to 14 inches . Average July temperature is about 75 degrees F.; average January temperature is about 48 degrees F.; mean annual temperature is 58 degrees to 62 degrees F. The freeze-free season is 200 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Shedd soils and the
Cropley,
Linne,
Rincon, and
Salinas soils. Cropley soils are clays with intersecting slickensides. Linne and Salinas soils have more than 15 percent rock fragments and sand coarser than very fine sand. Rincon soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well-drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: Used mostly for growing non-irrigated grain and pasture. Some areas used for growing irrigated row crops and forage crops. Vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Valleys of the Coast Range in central and south-central California. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Monterey County (King City Area), California, 1924.
REMARKS: The Docas soils were formerly classified as Alluvial soils.
OSED scanned by SSQA. Last revised by state on 8/72.
National Cooperative Soil Survey
U.S.A.