LOCATION WEBILE CA

Established Series
Rev. LEW-GMK-LCL-WBS-ET
05/2016

WEBILE SERIES

The Webile series consists of very deep, very poorly drained soils formed in highly decomposed organic material underlain by fine textured alluvium from mixed sources. Webile soils are in fresh water marshes and river channels. Slope is less than two percent. The annual precipitation is about 30 centimeters (12 inches) and the annual temperature is about 16 degrees C (60 degrees F).

TAXONOMIC CLASS: Clayey, mixed, euic, thermic Terric Haplosaprists

TYPICAL PEDON: Webile muck-on an east facing slope of less than 1 percent in a cultivated field at 2.7 meters (9 feet) below sea level. (Colors are for moist soil unless otherwise stated. pH is by 0.01 M calcium chloride for organic layers)

Oap1 -- 0 to 23 centimeters (0 to 9 inches); sapric material, black (10YR 2/1) unrubbed or rubbed, muck; no fibers unrubbed or rubbed; weak very fine granular structure; slightly hard, slightly sticky and nonplastic; very strongly acid (pH 4.6); gradual smooth boundary. (15 to 25 centimeters thick)

Oap2--23 to 41 centimeters (9 to 16 inches); sapric material, very dark brown (10YR 2/2 unrubbed and rubbed) muck; less than 2 percent fibers unrubbed and none rubbed; weak very coarse subangular blocky structure; slightly hard, slightly sticky and nonplastic; cracks are 2.5 centimeters wide and about 25 to 35 centimeters apart; very strongly acid (pH 4.6); clear smooth boundary. (10 to 18 centimeters thick)

Oa1 -- 41 to 71 centimeters (16 to 28 inches); sapric material, dark yellowish brown (10YR 4/4) muck, very dark brown (10YR 2/2) rubbed; 40 percent fibers unrubbed and less than 5 percent rubbed; weak thin platy structure; thin discontinuous lens, 1 inch thick of gray (10YR 5/1) mineral material; cracks are 2.5 centimeters wide and 25 to 35 centimeters apart; very strongly acid (pH 4.6); gradual smooth boundary. (64 to 89 centimeters thick)

Oa2 -- 71 to 89 (28 to 35 inches); sapric material, dark yellowish brown (10YR 3/4) muck, very dark brown (10YR 2/2) rubbed; 40 percent fibers unrubbed, less than 10 percent rubbed; weak thick platy structure; very friable, slightly sticky and nonplastic; thin discontinuous lens, 2.5 centimeter thick of gray (10YR 5/1) mineral material; very strongly acid (pH 4.6); gradual smooth boundary. (13 to 25 centimeters thick)

Oa3--89 to 97 centimeters (35 to 38 inches); sapric material, dark yellowish brown (10YR 3/4) muck, very dark brown (10YR 2/2) rubbed; 40 percent fibers unrubbed, less than 10 percent rubbed; weak thick platy structure; very friable, slightly sticky and nonplastic; very strongly acid (pH 4.6), gradual smooth boundary. (5 to 10 centimeters thick)

Oa4-- 97 to 109 centimeters (38 to 43 inches); sapric material, dark yellowish brown (10YR 4/4) muck, very dark brown (10YR 2/2) rubbed; 20 percent fibers unrubbed, none rubbed; friable, slightly sticky and slightly plastic; very strongly acid (pH 5.0); clear smooth boundary. (10 to 15 centimeters thick)

2C--109 to 122 centimeters (43 to 48 inches); very dark gray (N 3/0) mucky clay, 10 percent yellow (2.5Y 7/6) fibers that darken when exposed to air; massive; firm, very sticky and plastic; slightly acid (pH 6.1); clear smooth boundary. (7 to 20 centimeters thick)

2C2-- 122 to 160 centimeters (48 to 63 inches); dark gray (N 4/0) clay; massive; firm, very sticky and plastic; neutral (pH 7.0)

TYPE LOCATION: Contra Costa County, California. Byron Tract, 850 meters east of main drain and 240 meters south of Indian Slough. 37 degrees, 54 minutes, 55 seconds N latitude and 121 degrees, 34 minutes, 28 seconds W longitude in an unsectionized area. USGS Woodward Island, California 7.5 minute topographic quadrangle.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 16.5 degrees C.
Depth to mineral layer: 90 to 130 centimeters.
Series control section thickness: 130 centimeters.
Organic matter: 25 to 70 percent.
Fiber content: 0 to 60 percent before rubbing and 0 to 10 percent after rubbing.

Some pedons have one or more layers of highly organic mineral soil 1 to 4 centimeters thick with an aggregate thickness of less than 10 centimeters. Some pedons have layers of moderately decomposed hemic material below a depth of 43 centimeters, with the total thickness of hemic material being less than 25 centimeters.

The Oap horizon:
Hue: 10YR or N
Value: 2, 3, 4 or 5 dry and moist
Chroma: 1 or 0 dry and moist
Organic matter: 25 to 55 percent, 0 to 2 percent fiber before rubbing and 0 percent after rubbing.
Structure: weak to strong
Reaction: very strongly to strongly acid.

The Oa horizon:
Hue: 10YR or N
Value: 2, 3, or 4 dry and moist, 2 rubbed
Chroma: 2, 3, or 4 dry and moist, 1 or 2 rubbed
Organic matter: 25 to 55 percent, 0 to 2 percent fiber before rubbing and 0 percent after rubbing
Structure: Weak to strong
Reaction: very strongly to strongly acid.

The 2C horizon:
Hue: 2.5 Y or 10YR dry, 10YR, 2.5Y, 5G or N moist
Value: 4 dry and 3 or 4 moist
Chroma: 1 or 2 dry, 0, 1 or 2 moist
Organic matter: 25 to 55 percent, 0 to 2 percent fiber before rubbing and 0 percent after rubbing
Texture of the fine earth: clay, silty clay, sandy clay or silty clay loam
Structure: weak to strong
Reaction: slightly acid to mildly alkaline
Redox concentrations: distinct or prominent, 5YR hues

COMPETING SERIES: These are the Kingile and Lanexa soils. Kingile soils have fine textured mineral horizons at depths of 43 to 91 centimeters (17 to 36 inches). Lanexa soils are formed in fresh to slightly brackish water marshes along rivers and creeks of the Atlantic Coastal Plain. They also have thin lenses and strata of mineral soil material in the control section, moderate permeability in the organic layer and a salinity of 4 to 8 dS/m in the upper part of the profile.

GEOGRAPHIC SETTING: The Webile soils are in fresh water marshes and river channels of the San Joaquin-Sacramento Delta. Slopes are less than 2 percent. The soils formed in hydrophytic plant remains over fine textured mixed mineral alluvium. The organic material is derived from tule and reed fibers. Elevations are at sea level to 4.5 meters (15 feet) below sea level on islands protected by levees and on nearly level river deltas. The climate is subhumid with hot dry summers and cool moist winters. The mean annual precipitation is 305 to 407 millimeters (12 to 16 inches). Mean January temperature is about 7 degrees C (45 degrees F); mean July temperature is about 24 degrees C (75 degrees F); mean annual temperature is about 16 degrees C (60 to 61 degrees F). Frost-free period ranges from 250 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Kingile and the Egbert, Peltier, Rindge, Ryde and Shinkee soils, on a similar topography. Egbert and Peltier soils are mineral soils that have a fine particle size control section. Rindge soils have continuous sapric organic material to a depth of 130 centimeters (51 inches) or more. Ryde soils are mineral soils that are fine-loamy. Shinkee soils are organic soils with loamy mineral material below 50 to 91 centimeters (20 to 35 inches).

DRAINAGE AND PERMEABILITY: Very poorly drained; very slow runoff; rapid permeability in the organic material and slow permeability in the underlying mineral material. The water table is lowered by artificial drainage with open drains and pumps. The water table is usually at a depth of 91 to 152 centimeters (3 to 5 feet) during the growing season and at or near the surface at some time during the winter. Areas that are used for annual crops are flooded during the winter months.

USE AND VEGETATION: The Webile soils are used for cropland to grow crops such as field corn, asparagus, irrigated pasture, tomatoes, milo, small grains and sugar beets. Vegetation in uncultivated areas is sedges and tules.

DISTRIBUTION AND EXTENT: Webile soils are in the islands of the Sacramento-San Joaquin Delta of California. The series is of small extent in MLRA-16.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Contra Costa County, California, 1973.

REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy and again in March 2016 using the Twelfth Edition to Soil Taxonomy. This series was formerly classified as clayey, mixed, euic, thermic Terric Medisaprists.

Diagnostic horizons and features recognized in this pedon are:

Histic epipedon - the zone from the surface to a depth of 109 centimeters (43 inches (Oap1, Oap1, Oa2, Oa3, Oa4)); sapric material.

ADDITIONAL DATA: This soil was laboratory sampled as 71C0094 (S1972CA013009) and 13N3987 S2012CA077001).

National Cooperative Soil Survey
U.S.A.