LOCATION VENICE CAEstablished Series
TAXONOMIC CLASS: Euic, thermic Typic Haplohemists
TYPICAL PEDON: Venice muck - on a south facing slope of less than l percent slope that is cultivated at 9 feet below sea level. (Colors are for moist soil unless otherwise stated.)
Oap--0 to 12 inches; black (10YR 2/1) muck, very dark gray (10YR 3/1) dry; less than 5 percent tule and reed fibers before rubbing and none when rubbed; moderate medium and coarse granular structure; nonsticky and nonplastic; strongly acid (pH 5.5); abrupt wavy boundary. (10 to 16 inches thick)
Oe1--12 to 32 inches; very dark brown (10YR 2/2) mucky peat, dark brown (10YR 3/3) rubbed, black (N 2/0) dry; 60 percent tule and reed fibers before rubbing, 25 percent when rubbed; massive; nonsticky and nonplastic; very strongly acid (pH 5.0); abrupt wavy boundary. (10 to 22 inches thick)
Oe2--32 to 60 inches; very dark brown (10YR 2/2) mucky peat, very dark grayish brown (10YR 3/2) rubbed, black (N 2/0) dry; 40 percent tule and reed fibers before rubbing, 18 percent when rubbed; massive; nonsticky and nonplastic; very strongly acid (pH 5.0).
TYPE LOCATION: San Joaquin County, California, Northwest portions of Venice Island. 38 degrees, 4 minutes, 51 seconds N latitude and 121 degrees, 33 minutes, 15 seconds W longitude in an unsectionized area. Bouldin Island quad.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 63 degrees F. Thickness of the series control section is 51 inches. The electrical conductivity is less than 15 millimhos per centimeter. Organic matter in the control section ranges from 35 to 75 percent by weight with the combustion method and is more than 45 percent below the Oap layer. Fibers in the control section range from 30 to 65 percent before rubbing and 16 to 35 percent after rubbing. Individual fibers are mostly yellowish brown (10YR 5/4), very dark grayish brown (10YR 3/2) after rubbing.
The Oap is 10YR 2/1, N 2/0, 10YR 2/2 moist and 10YR 3/1, N 3/0, 10YR 3/2 dry. Values may decrease one unit on exposure to air. It is sapric, having 35 to 55 organic matter with the mineral part being clayey. It has 2 to 20 percent fibers before rubbing and less than 10 percent after rubbing. Textures are mucky sandy loam, mucky silt loam or muck. Reaction is very strongly acid to neutral (in calcium chloride).
The Oe is 10YR 2/2, N 2/0, 5YR 2.5/2 moist unrubbed, 2.5Y 3/2, 10YR 3/3, 3/2 N 3/0, 5YR 3/2 moist rubbed and 10YR 2/2, 2/1, N 2/0, 5YR 2.5/1 dry. Values may decrease one unit on exposure to air. It is hemic, having 45 to 75 percent organic matter with 35 to 70 percent fibers before rubbing and 15 to 35 percent fibers after rubbing. Reaction is very strongly or slightly acid (in calcium chloride).
COMPETING SERIES: These are the Kingsland and Suisun series. Kingsland soils formed from swampy vegetation dominated by tupelo cypress and related non-woody fibrous hydrophytic plants. Suisun soils have an electrical conductivity of 15 or more.
GEOGRAPHIC SETTING: The Venice soils are in fresh water marshes and river channels and have slopes of less than 2 percent. The soils formed from hydrophytic plant remains mostly from tules, reeds and mixed mineral alluvium. The soils are in islands protected by levees at elevations of 0 to 20 feet below sea level. The climate is subhumid with hot dry summers and cool moist winters. The mean annual precipitation is 14 to 16 inches. Mean January temperature is about 45 degrees F.; mean July temperature is about 75 degrees F.; mean annual temperature is about 60 degrees F. Frost-free season ranges from 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kingile, Rindge, Ryde and Valdez soils. Kingile and Rindge soils are on similar topography. Ryde soils are on flood plains and Valdez soils are on old river channels. Kingile soils have continuous mineral soil material at depths of less than 36 inches. Rindge soils have less than 16 percent rubbed fibers dominating the control section. Ryde and Valdez soils are mineral soils.
DRAINAGE AND PERMEABILITY: Very poorly drained; very slow runoff; rapid permeability. The water table is controlled by open drains and pumps. The water table is usually kept at a depth of 36 to 48 inches during the growing season (April through October) and at or near the surface at some time during the rest of the year.
USE AND VEGETATION: Used for cropland to grow specialty crops, vegetable, field crops and small grains. Native vegetation on uncultivated areas is sedges and tules.
DISTRIBUTION AND EXTENT: Islands of the Sacramento-San Joaquin Delta of California. The soils are of small extent in MLRA-16.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sacramento-San Joaquin Delta, 1935.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as Euic, thermic Typic Medihemists. Competing series were not checked at that time.
Diagnostic horizons and features recognized in this pedon are:
Histic epipedon - 0 to 12 inches (Oap) Sapric and Hemic material dominates the series control section (0 to 51 inches)