LOCATION DECY               CA
Established Series
Rev. DWS/WDB/DJE
02/1999

DECY SERIES


The Decy series consists of moderately deep, well drained soils formed in material weathered from sedimentary and metasedimentary rock. Decy soils are on mountains and have slopes of 15 to 50 percent. The mean annual precipitation is about 55 inches and the mean annual temperature is about 52 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Humic Dystroxerepts

TYPICAL PEDON: Decy gravelly sandy loam--on a southeast facing convex slope of 25 percent under ponderosa pine at an elevation of 4,760 feet. (Colors are for dry soil unless otherwise stated. When described on July 10, 1980 the soil was dry in all parts).

01--1 inch to 0; decomposed and partially decomposed conifer litter consisting of needles, twigs, and cones.

A1--0 to 2 inches; brown (10YR 4/3) gravelly sandy loam, very dark brown (10YR 2/2) moist; moderate very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine interstitial pores; 15 percent pebbles 2 to 30 mm in diameter; very strongly acid (pH 4.6); abrupt smooth boundary. (1 to 3 inches thick)

A2--2 to 8 inches; brown (10YR 4/3) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; moderate very fine, fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine, fine and medium roots; many very fine and fine and common medium interstitial pores; 20 percent pebbles 2 to 40 mm in diameter; very strongly acid (pH 4.9); clear wavy boundary. (4 to 10 inches thick)

Bwl--8 to 15 inches; brown (10YR 5/3) gravelly sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine, many medium and common coarse roots; many very fine and fine interestitial pores; few thin silt coatings on peds; 30 percent pebbles 2 to 50 mm in diameter; very strongly acid (pH 4.9); clear wavy boundary. (5 to 12 inches thick)

Bw2--15 to 24 inches; yellowish brown (10YR 5/4) very gravelly sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and common medium and coarse roots; common very fine and fine interstitial pores; common thin silt coatings on peds and in pores; 35 percent pebbles 2 to 75 mm in diameter and 5 percent cobbles 75 to 125 mm in diameter; very strongly acid (pH 5.0); abrupt wavy boundary. (7 to 16 inches thick)

R--24 inches; hard fractured sandstone and interbedded shale; fractures are 0 to 1/4 inch wide and 1/4 to 1 inch apart; few fine roots in fractures.

TYPE LOCATION: Lake County, California; 0.2 miles north of the intersection with road 19N19 on road 1NO2 then upslope 60 yards, 350 feet south, 2,100 feet west of northeast corner of sec. 23, T. 19 M., R. 10 S., Mendocino National Forest.

RANGE IN CHARACTERISTICS: Thickness of the solum and the depth to a lithic contact is 20 to 40 inches. The mean annual soil temperature is 49 degrees to 55 degrees F. The soil temperature exceeds 41 degrees F from March 15 to December 15 and exceeds 47 degrees from April 15 to November 15. The soil is dry in all parts of the moisture control section (9 to 24 inches) from July 1 to October 15 and is moist in all parts of the moisture control section form January 1 to May 15. The particle-size control section (10 to 24 inches) ranges from 10 to 25 percent clay and has 35 to 55 percent rock fragments. Base saturation of the solum is 25 to 40 percent throughout by sum of cation. Reaction of the solum is medium through very strongly acid.

The A horizon has dry color of 10YR 4/4 or 4/3 and moist color of 10YR 3/3, 3/2, or 2/2. It is gravelly sandy loam or gravelly loam. Gravel ranges from 15 to 30 percent. Where the A horizon is not thick enough for an umbric epipedon the upper part of the B2 horizon is dark enough to qualify.

The Bw horizon has dry color of 10YR 5/4 or 5/3 and moist color of 10YR 4/4, 4/3, 3/4, or 3/3. It is very gravelly sandy clay loam, very gravelly sandy loam, or very gravelly loam. The upper part of the Bw horizon ranges from less than 35 to more then 35 percent fragments. The average of the control section is greater than 35 percent. Clay content usually increases by less than 1.2 times that of the overlying horizon and where it does increase by more than 1.2 times, the increase in clay is reached in more than 30 cm veritical distance. Total rock fragments range from 35 to 55 percent and consist of stones and cobbles that range from 0 to 10 percent, and gravel ranges from 30 to 45 percent.

COMPETING SERIES: These are the Coyata, Delphi, and Schneider series. The Coyata soils have hues of 7.5YR and 5YR and have 27 to 35 percent clay in the particle-size control section. Delphi and Schneider soils are deeper than 40 inches.

GEOGRAPHIC SETTINGS: Decy soils are on mountains. Slopes are 15 to 50 percent. The soils formed in material weathered from sedimentary and metasedimentary rock. Elevations are from 2,800 to 5,000 feet. The climate is subhumid with warm dry summers and cool moist winters. The annual precipitation is 40 to 60 inches. Snowfall is 15 to 30 inches. Mean January temperature is about 36 degrees F; mean July temperature is about 66 degrees F; mean annual temperature is about 52 degrees F. Frost-free season is about 110 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sanhedrin, Deadwood, Freezeout, Neuns, and Yollabolly soils. Sanhedrin soils have an argillic horizon. Deadwood soils are shallower than 20 inches to a lithic contact. Neuns soils lack an umbric epipedon. Freezeout and Yollabolly soils have a frigid soil temperature regime.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are used primarily for timber production, water supply and wildlife habitat. Native vegetation is ponderosa pine, Douglas-fir, black oak, and manzanita.

DISTRIBUTION AND EXTENT: Coast Range of Northern California. The series is not extensive.

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

SERIES ESTABLISHED: Lake County, California, 1980.

REMARKS: The presence of silans or grainy grey ped coatings was confirmed by microscopic examination of samples at the WNTC.

ADDITIONAL DATA: Samples from this pedon were sent to the SCS National Soil Survey Laboratory for analysis. Pedon number is S80-CA-033-05. Sample numbers 81-259 through 81-262.


National Cooperative Soil Survey
U.S.A.