LOCATION OCCIDENTAL CA

Established Series
Rev: DWH/ET/SAA
03/2017

OCCIDENTAL SERIES

The Occidental series consists of very deep, very poorly drained soils on reclaimed salt marshes and tidal marshes on alluvial plains. These soils formed in mixed alluvium. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 1015 millimeters. Mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine, mixed, superactive, nonacid, isomesic Fluvaquentic Endoaquepts

TYPICAL PEDON: Occidental peat on a less than 1 percent slope under pasture grasses, salt grass, plantain, trefoil and cinquefoil at an elevation of 2 meters. (Colors are for moist soil unless otherwise stated. When described on June 26, 1990 the soil was moist throughout with a water table at 74 centimeters.)

Oi--0 to 8 centimeters; very dark grayish brown (10YR 3/2) peat, very dark grayish brown (10YR 3/2) rubbed; 90 percent fibers, 50 percent rubbed; neutral (pH 7.0); abrupt wavy boundary. (0 to 13 centimeters thick)

Az--8 to 30 centimeters; dark grayish brown (2.5Y 4/2) silty clay loam, light brownish gray (2.5Y 6/2) dry; weak medium and coarse subangular blocky structure; hard, firm, moderately sticky, moderately plastic; many fine and very fine roots; common very fine interstitial and tubular pores; thin stratification observable; many medium prominent dark yellowish brown (10YR 4/6) iron manganese masses in the matrix; EC 7 dS/m, neutral (pH 7.0); gradual wavy boundary. (10 to 33 centimeters thick)

Bzg1--30 to 43 centimeters; dark gray (5Y 4/1) silty clay loam, gray (5Y 6/1) dry; weak fine subangular blocky structure; hard, firm, moderately sticky, moderately plastic; many fine and very fine roots; common very fine tubular pores; many medium prominent strong brown (7.5YR 4/6) iron manganese masses in the matrix; EC 10 dS/m; slightly alkaline (pH 7.5); gradual wavy boundary. (13 to 64 centimeters thick)

Bzg2--43 to 160 centimeters; dark gray (5Y 4/1) silty clay loam, gray (5Y 6/1) dry; weak fine subangular blocky structure; hard, firm, moderately sticky, moderately plastic; common very fine roots; common very fine tubular pores; many prominent yellowish red (5YR 4/6) discontinuous iron stains lining root channels and/or pores; many medium prominent strong brown (7.5YR 4/6) iron manganese masses in the matrix; EC 20 dS/m; moderately alkaline (pH 8.0). (23 to 117 centimeters thick)

TYPE LOCATION: Humboldt County, California; about 4.8 kilometers west of Loleta on Cannibal Road, north at Eel River School, north 500 meters to farm site. Pedon is 1100 meters north northeast of the north side of the barn; nonsectionized area, T.3N. R.2W. HB&M, Cannibal Island Quadrangle; WGS84 Decimal degrees 40.657500040 degrees, 39 minutes, 27 seconds north latitude, -124.2783333 124 degrees, 16 minutes, 42 seconds west longitude, UTM Zone 10 391929mE, 4501537mN, NAD 83.

RANGE IN CHARACTERISTICS:

Soil Moisture: The soil is usually moist in all parts in the soil moisture control section (between the depths 13 and 40 centimeters) in most years, and is saturated in some part during the months of December through April. Soils have an aquic moisture regime.

Soil Temperature: The mean annual soil temperature at 50 centimeters is 12 to 14 degrees C. The average summer soil temperature is about 16 degrees C and the average winter soil temperature is about 10 degrees C. The difference between average summer and winter soil temperatures is 6 or less degrees C.

Particle Size Control Section (weighted average):
Clay content: 35 to 40 percent

Depth to redoximorphic features: 0 to 10 centimeters

Endosaturation: The water table is at a depth of 0 to 10 centimeters from December to April, between 15 to 90 centimeters in May, between 30 to 90 centimeters June through July, and 90 to greater than 183 centimeters from August through November.

Electrical conductivity: moderate to strong (8 to 25 dS/m).

O horizon
Hue: 10YR
Value: 3, 4 dry
Texture of fine earth: peat

Reaction: neutral

Az horizon
Hue: 10YR, 2.5Y, 5Y
Value: 4 or 5, moist or dry
Chroma: 1 or 2, moist or dry.
Texture of fine earth: silty clay loam
Clay content: 30 to 40 percent
Reaction: slightly acid to neutral

Redoximorphic features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 7.5YR, 10YR
Value: 3 to 6
Chroma: 4 to 6

Bzg horizon
Hue: 2.5Y, 5Y, N
Value: 4 or 5 moist, 4 to 7 dry
Chroma: 0 to 2, moist or dry
Texture of fine earth: silty clay loam, silty clay
Clay content: 35 to 43 percent
Reaction: moderately acid to moderately alkaline

Redoximorphic features: iron-manganese masses in the matrix and iron stains lining root channels and/or pores
Quantity: common to many
Hue: 5YR, 7.5YR, 10YR
Value: 3 to 6
Chroma: 4 to 6

COMPETING SERIES: This is the Swainslough. Swainslough has an electrical conductivity of less than 8 dS/m.

GEOGRAPHIC SETTING: Occidental soils are on reclaimed salt marshes and tidal marshes on alluvial plains near the Pacific Ocean and are influenced by its tidal fluctuations. Slopes are 0 to 2 percent. These soils formed in mixed alluvium. Elevation is 0 to 5 meters. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 890 to 2030 millimeters. The mean January temperature is about 9 degrees C. The mean July temperature is about 14 degrees C. The mean annual air temperature is 10 to 13 degrees C. Frost free season is about 275 to 330 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arlynda, Swainslough, Weott, and Wigi soils. Swainslough, Weott, and Arlynda soils are in backswamps, depressions, and low floodplain steps on alluvial plains above the influence of tidal fluctuations. Weott and Arlynda soils also have less than 35 percent clay in the particle size control section. Wigi soils are on salt marshes within the influence of tidal fluctuations close to the Pacific Ocean and have a salic horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained; very high runoff; slow permeability, moderately low saturated hydraulic conductivity. The soils are occasionally flooded for brief periods December through February. The soils are frequently ponded 1 to 15 centimeters deep for long periods December through March.

USE AND VEGETATION: These soils are used for pasture, hay, and wetland wildlife habitat. Nearly all areas of this soil have been cleared. Natural vegetation is assumed to have been perennial grasses, rushes, and sedges and salt tolerant varieties of same.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt. MLRA 4B. The series is not extensive.

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

SERIES ESTABLISHED: Humboldt County, California, 2013. Proposed 1994. Name is from region near Ferndale, California.

REMARKS: Occidental soils were classified as fine, mixed superactive, nonacid, mesic Fluvaquentic Endoaquepts in 2001 based on changes in Keys to Soil Taxonomy, Ninth edition. HOBO temperature data recorded 2001 to 2004 indicates moisture in the very poorly drained areas moderates the soil temperatures so that mean summer and mean winter temperatures differ by 6 degrees C or less. These soils are reclassified as fine, mixed, superactive, nonacid, isomesic Fluvaquentic Endoaquepts.

Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon - the zone from 0 to 30 centimeters. (Oi and Az horizons)
2. Cambic horizon - the zone from 30 to 160 centimeters. (Bzg1, Bzg2 horizons)
3. Particle-size control section - the zone between 25 and 100 centimeters (Bng1, Bng2) averages 36 percent clay.
4. Aquept suborder - In the layer directly beneath the epipedon, there is chroma of 2 and redox concentrations from 8 to 160 centimeters.
5. Fluvaquentic subgroup - An irregular decrease in organic-carbon content between a depth of 25 and 125 centimeters below the mineral soil surface.

ADDITIONAL DATA: NASIS User Pedon ID: 90CA600614
Original location was re-described 4/5/2001 for Field Review May 2001. Electrical Conductivity values are from Typical pedon location samples analyzed at Humboldt State University Soil Lab by Soil Survey staff on 5/15/2001. Original location was re-described 4/5/2001 for Field Review May 2001.
Soil-Vegetation Survey sample number s64-CA12-008 Bayside silty clay is supporting data collected in this area, from a description for the Soils of Western Humboldt County, California.

Soil classified using Keys to Soil Taxonomy, 12th edition.

National Cooperative Soil Survey
U.S.A.