LOCATION DUNGAN CA

Established Series
Rev: DWH/SAA/ET
07/2016

DUNGAN SERIES

The Dungan series consists of very deep, well drained soils on high floodplain steps, alluvial fans, and fan remnants of alluvial plains. These soils formed in mixed alluvium. Slopes range from 0 to 2 percent. Mean annual precipitation is about 1015 millimeters. Mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Fluventic Hapludolls

TYPICAL PEDON: Dungan silt loam on a 1 percent slope under pasture grasses and clover at an elevation of 7 meters. (Colors are for moist soil unless otherwise stated. When described on December 7, 1988 the soil was moist throughout.)

Ap1--0 to 8 centimeters; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common medium and many very fine and fine roots throughout; common very fine to medium tubular pores; neutral (pH 7.0); clear wavy boundary. (8 to 38 centimeters thick)

Ap2--8 to 33 centimeters; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium and coarse subangular blocky structure parting to strong very fine and fine subangular blocky; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots and few medium roots throughout; few fine and medium and common very fine tubular pores; neutral (pH 7.0); gradual wavy boundary. (0 to 31 centimeters thick)

Bw--33 to 74 centimeters; dark grayish brown (2.5Y 4/2) silt loam; grayish brown (2.5Y 5/2) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots and few medium roots; few fine, medium, and common very fine tubular pores; neutral (pH 7.0); clear wavy boundary. (0 to 51 centimeters thick)

C1--74 to 94 centimeters; dark grayish brown (2.5Y 4/2) fine sandy loam; dark grayish brown (2.5Y 4/2), and grayish brown (2.5Y 5/2) dry; single grain; loose, slightly sticky, non plastic; few very fine and fine roots; common very fine interstitial pores; neutral (pH 7.0); clear wavy boundary. (15 to 64 centimeters inches thick)

C2--94 to 155 centimeters; dark grayish brown (2.5Y 4/2) silty clay loam; light brownish gray (2.5Y 6/2) dry; weak fine subangular blocky structure; hard, firm, very sticky, very plastic; few very fine and fine roots; common very fine and fine tubular pores; slightly alkaline (pH 7.5). (15 to 114 centimeters thick)

TYPE LOCATION: Humboldt County, California; about 2.4 kilometers northeast of Ferndale, California, 225 meters west of Fulmor Road on Bertleson/Pedrotti Road, 50 meters south; 230 meters east and 760 meters north of the southwest corner Section 36, T.3N., R.2W. HB&M; Ferndale Quadrangle (7.5 minutes series); WGS84 Decimal degrees 40.5988889 latitude, -124.2522222 longitude, UTM Zone 10 394054mE, 4494971mN; NAD 83.

RANGE IN CHARACTERISTICS:

Soil Moisture: The soil moisture control section (15 to 43 centimeters) is not dry in all parts for as long as 90 cumulative days in normal years. The soils have a udic moisture regime.

Depth to redoximorphic features: greater than 100 centimeters

Soil Temperature: The mean annual soil temperature at 50 centimeters is 12 to 15 degrees C. The average summer soil temperature is about 18 degrees C and the average winter soil temperature is about 9 degrees C. The difference between average summer and winter soil temperatures is about 6 to 9 degrees C.

Particle-size control section (weighted average):
Clay content: 18 to 27 percent.

A horizon
Hue: 10YR or 2.5Y
Value: 2 or 3, moist
Clay: 18 to 27 percent
Reaction: Slightly acid to slightly alkaline.

Bw horizon
Texture of fine earth: very fine sandy loam or silt loam
Clay: 18 to 27 percent
Reaction: Neutral to slightly alkaline

Upper C horizon
Hue: 10YR, 2.5Y, or 5Y
Value: 3 or 4, 5 or 6 dry
Texture of fine earth: fine sandy loam, very fine sandy loam, loam, or silt loam
Clay: 10 to 27 percent
Reaction: Neutral to slightly alkaline.

Lower C horizon
Hue: 10YR, 2.5Y, or 5Y
Value: 3 or 4, 5 or 6 dry
Texture of fine earth: fine sandy loam, very fine sandy loam, loam, silt loam, or silty clay loam
Clay: 10 to 35 percent
Reaction: Neutral to slightly alkaline.

Redoximorphic features: fine and medium iron-manganese masses below 100 centimeters
Quantity: none to common

COMPETING SERIES: These are the Armiesburg, Battleground, Bismarckgrove, Dozaville, and Omadi series. These soils have a difference between average winter and summer soil temperature of more than 9 degrees C and have a mean January soil temperature below 8 degrees C.

GEOGRAPHIC SETTING: The Dungan soils are on high floodplain steps, alluvial fans, and fan remnants of alluvial plains near the Pacific Ocean. Slopes are 0 to 2 percent. These soils formed in mixed alluvium. Elevation is 3 to 50 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 8 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, Ferndale, Russ, and Weott soils. Arlynda soils are on meander scars and depressions and have redoximorphic features at 0 to 10 centimeters. Ferndale, Russ, and Weott soils lack a mollic epipedon. Ferndale soils have redoximorphic features at a depth greater than 100 centimeters, and are on high flood-plain steps. Russ soils are on natural levees, have redoximorphic features at a depth greater than 100 centimeters, and are coarse-loamy. Weott soils are fine-silty, on low flood-plain steps, and have redoximorphic features at 0 to 10 centimeters.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low runoff; moderately slow permeability, moderately high saturated hydraulic conductivity. The soils are rarely flooded for brief periods December through February.

USE AND VEGETATION: These soils are used for pasture, hay, and occasionally truck garden produce. Nearly all areas of this soil have had the native vegetation removed. The native vegetation is estimated to be a variable canopy of red alder, Sitka spruce, and black cottonwood with scattered willow and redwood, with an understory of blackberry, ferns, and grasses.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt and southern Oregon; MLRA 4. The series is not extensive.

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

SERIES ETABLISHED: Humboldt County, California, 2016; proposed 1994. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

1. Mollic epipedon - 0 to 33 centimeters (Ap1, Ap2 horizons)
2. Cambic horizon - 33 to 74 centimeters (Bw horizons)
3. Particle-size control section - 25 to 100 centimeters averages 19 percent clay, and 17 percent fine sand or coarser (Ap2, Bw, C1, C2 horizons)
4. Fluventic feature - an irregular decrease in organic-carbon content between 25 and 125 centimeters (Ap2, Bw, C1, and C2 horizons).

ADDITIONAL DATA: NSSL Lab Pedon No: 02N0784

NASIS User Pedon ID: 88CA600244

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

National Cooperative Soil Survey
U.S.A.