LOCATION EELRIVER CA
Established Series
REV: JWH/JTB/ET
07/2016
EELRIVER SERIES
The Eelriver series consists of very deep, somewhat poorly drained soils formed in alluvium derived from mixed sedimentary sources. Eelriver soils are on flood-plain steps in mountain river valleys. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 1500 mm and the mean annual temperature is about 11 degrees C.
TAXONOMIC CLASS: Fine-silty, isotic, nonacid, isomesic Aquic Udifluvents
TYPICAL PEDON: Eelriver silt loam on a northeast facing 1 percent slope under a canopy of redwood with California laurel, Pacific swordfern, and redwood sorrel in the understory, at an elevation of 54 meters. (Colors are for moist soil unless otherwise stated) When described on November 13, 2008 the soil was moist throughout.
Oi--0 to 3 cm; slightly decomposed plant material, brown (7.5YR 4/4) rubbed moist; about 100 percent fiber, 90 percent rubbed; slightly acid (pH 6.3) abrupt smooth boundary.
A1--3 to 10 cm; light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; moderately hard, friable, slightly sticky and moderately plastic; common very fine, fine, medium, and coarse roots throughout; slightly acid (pH 6.3); clear smooth boundary.
A2--10 to 26 cm; light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; moderately hard, friable, slightly sticky and moderately plastic; common very fine, fine, medium, and coarse roots throughout; common very fine tubular pores; slightly acid (pH 6.3); clear smooth boundary.
C--26 to 40 cm; pale brown (10YR 6/3) silt loam, dark grayish brown (10YR 4/2) moist; massive; moderately hard, friable, slightly sticky and moderately plastic; common fine, medium, coarse, and very coarse roots throughout; common very fine tubular pores; slightly acid (pH 6.3); gradual smooth boundary.
2Ab--40 to 68 cm; yellowish brown (10YR 5/4) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; moderately hard, friable, slightly sticky and moderately plastic; common fine, medium, and coarse roots throughout; common very fine tubular pores; 1 percent fine faint irregular dark grayish brown (10YR 4/2) iron depletions in matrix and 2 percent fine distinct irregular dark yellowish brown (10YR 4/6) iron-manganese masses in matrix; slightly acid (pH 6.2); gradual smooth boundary.
2C1--68 to 90 cm; yellowish brown (10YR 5/4) silt loam, brown (10YR 4/3) moist; massive; moderately hard, friable, slightly sticky and moderately plastic; common medium and coarse roots throughout; common very fine tubular pores; 1 percent fine faint irregular dark grayish brown (10YR 4/2) iron depletions in matrix and 2 percent fine distinct irregular brownish yellow (10YR 6/6) moist, iron- manganese masses with clear boundaries throughout; slightly acid (pH 6.2); gradual smooth boundary.
2C2--90 to 125 cm; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; massive; moderately hard, friable, slightly sticky, moderately plastic; common medium, coarse, and very coarse roots throughout; common very fine tubular pores; slightly acid (pH 6.2); clear smooth boundary.
2C3--125 to 160 cm; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; massive; hard, friable, slightly sticky and moderately plastic; common medium, coarse, and very coarse roots throughout; common very fine tubular pores; 1 percent fine distinct irregular brownish yellow (10YR 6/6) moist, iron-manganese masses with clear boundaries throughout; slightly acid (pH 6.1); gradual smooth boundary.
2C4--160 to 200 cm; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; massive; hard, friable, slightly sticky and moderately plastic; common fine, medium, and coarse roots throughout; common very fine tubular pores; 1 percent fine distinct irregular brownish yellow (10YR 6/6) moist, iron-manganese masses with clear boundaries throughout; slightly acid (pH 6.1).
TYPE LOCATION: Humboldt County, California; about 3.5 kilometers north of the town of Weott; USGS Quadrangle Redcrest, CA; WGS84 Decimal degrees latitude and -123.9246194 longitude UTM Zone 10 421477mE, 4467247mN; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Temperature: The mean annual soil temperature at 50 centimeters is 10 to 12 degrees C and the difference between mean summer and mean winter soil temperatures is less than 6 degrees C. The soil has an isomesic soil temperature regime.
Soil Moisture: The soil moisture control section is not dry in any part for as long as 90 cumulative days in normal years and is dry in all parts for less than 45 consecutive days in the 4 months following the summer solstice. The soil has a udic soil moisture regime.
Depth to Redoximorphic Features: 25 to 50 centimeters
Particle size control section (weighted average):
Rock fragments: 0 to 2 percent gravel
Clay content: 18 to 25 percent
Particles 0.1 millimeters or coarser: less than 15 percent
A horizons:
Hue: 10YR or 2.5Y
Value: 3 or 4, 5 to 6 dry
Chroma: 2 to 3, moist or dry
Clay content: 15 to 25 percent
Reaction: moderately acid to slightly acid
Redoximorphic Features: fine and medium iron-manganese masses
Quantity: none to many
Hue: 10YR or 2.5Y
Value: 4 through 6
Chroma: 3 through 8
Ab horizons (not present in all pedons):
Hue: 10YR or 2.5Y
Value: 2 or 3, 4 or 5 dry
Chroma: 1 to 3, moist or dry
Texture: silt loam
Clay content: 15 to 25 percent
Rock fragments: 0 to 2 percent gravel
Reaction: slightly acid to neutral
Redoximorphic Features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 7.5YR, 10YR or 2.5Y
Value: 4 through 6
Chroma: 3 through 6
Redoximorphic features: fine and medium iron depletions
Quantity: few to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
C horizons:
Hue: 10YR or 2.5Y
Value: 3 or 4, 5 to 6, dry
Chroma: 2 or 3, moist or dry
Texture: silt loam, very fine sandy loam, fine sandy loam
Clay content: 15 to 25 percent
Rock fragments: 0 to 2 percent gravel
Reaction: slightly acid to neutral
Redoximorphic Features: fine and medium iron-manganese masses
Quantity: none to many
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 3 to 8
Redoximorphic features: fine and medium iron depletions
Quantity: none to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Eelriver soils are on linear to slightly concave positions on flood-plain steps in mountain river valleys. Slopes are 0 to 2 percent. Elevations are 30 to 170 meters. These soils formed in alluvium from mixed sedimentary sources. The climate is humid with cool, foggy summers and cool, wet winters. Mean annual precipitation is 1250 to 2500 millimeters. The mean annual temperature is 10 to 12 degrees C. Frost free season is about 330 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Cottoneva (CA),
Pepperwood (CA), and
Shivelyflat (CA) soils. Cottoneva and Pepperwood soils have greater than 15 percent particles 0.1 mm or coarser. Pepperwood and Shivelyflat soils occur under cultivated or cleared conditions where the difference between mean winter and mean summer soil temperature is 6 degrees C or greater. Cottoneva and Pepperwood soils occur on linear to slightly convex positions on floodplain steps and natural levees. Shivelyflat soils occur on the same positions as Eelriver soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained; low runoff; moderately low saturated hydraulic conductivity. The soils are rarely flooded for very brief periods December through February. The soils frequently have 1 to 3 cm of ponding for very brief periods December through March.
USE AND VEGETATION: This soil is used mainly for timber, wildlife, recreation, and watershed. Natural vegetation is redwood, California bay, Pacific swordfern, redwood-sorrel, sedges, and other forbs.
DISTRIBUTION AND EXTENT: Coastal Redwood Belt, MLRA 4B. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County, South Part, California, 2010. The name is from the Eel River.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon: The zone from 0 to 26 centimeters. (Oi, A1, A2) horizons)
2. Particle size control section: The zone from 28 to 103 centimeters averages 18 percent clay, and 5 percent fine sand or coarser (C1, 2Ab, 2C1 and 2C2 horizons)
3. Aquic feature: The zone from 40 to 200 centimeters with redox depletions with chroma of 2 and also aquic conditions for some time in normal years(C1, 2Ab, 2C1, 2C2, 2C3, and 2C4 horizons)
4. Isotic feature: 15 bar water/clay is 0.6 or more and the NaF pH is greater than 8.8 in more than one half of the horizons in the control secion.
ADDITIONAL DATA: NSSL Pedon 09N0169 NASIS User Pedon ID: 08CA6011077
Soil classified using Keys to Soil Taxonomy, 12th edition.
National Cooperative Soil Survey
U.S.A.