LOCATION GENCEY CA

Established Series
IRD: BAL/JPS/ET
04/2015

GENCEY SERIES

The Gencey series consists of very deep, somewhat excessively drained soils on floodplains. These soils formed in alluvium derived from mixed sources. Slope ranges from 0 to 2 percent. The mean annual precipitation is about 1524 millimeters (59 inches) and the mean annual temperature is about 16 degrees C (60 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, active, nonacid, thermic Typic Xerofluvents

TYPICAL PEDON: Gencey loam - under a stand of annual and perennial grasses. When described on June 13, 2002, the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 centimeters (0 to 2 inches); light olive brown (2.5Y 5/3) loam, dark olive brown (2.5Y 3/3) moist; moderate fine and very fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine roots throughout; many fine and medium tubular, and many very fine interstitial pores; 10 percent gravel; slightly acid (pH 6.4); abrupt smooth boundary.

A2--5 to 10 centimeters (2 to 4 inches); light olive brown (2.5Y 5/3) loam, dark olive brown (2.5Y 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, and fine roots throughout; common fine and medium tubular pores; 10 percent gravel; slightly acid (pH 6.3); abrupt smooth boundary. (Combined thickness of the A horizons is 10 to 20 centimeters)

AC--10 to 46 centimeters (4 to 18 inches); light olive brown (2.5Y 5/3) silt loam, dark olive brown (2.5Y 3/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine roots throughout; common fine and medium tubular pores; 10 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (0 to 50 centimeters thick)

C1--46 to 94 centimeters (18 to 37 inches); light yellowish brown (2.5Y 6/4) very stony loam, olive brown (2.5Y 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots throughout; common fine and medium tubular pores; 10 percent gravel, 20 percent cobbles, 25 percent stones; slightly acid (pH 6.3); gradual wavy boundary.

C2--94 to 178 centimeters (37 to 70 inches); light olive brown (2.5Y 5/4) extremely stony sandy loam, olive brown (2.5Y 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine, common fine through coarse roots throughout; common fine and medium tubular pores; 30 percent gravel, 10 percent cobbles, 30 percent stones; slightly acid (pH 6.3). (Combined thickness of the C horizons is 100 to 150 centimeters)

TYPE LOCATION: Humboldt County, California; Hoopa Valley; USGS Hoopa topographic quadrangle; UTM Zone 10 443906mE, 4543206mN, NAD83; WGS84 41.0380556, -123.6672222.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil moisture control section is dry from July 1st to October 15th and moist in all parts from November 15 to June 1st. This soil has a xeric soil moisture regime.

Soil temperature: The mean annual soil temperature is 15 to 20 degrees C (59 to 68 degrees F). The difference between the mean summer and mean winter temperature is greater than 6 degrees C. This soil has a thermic soil temperature regime.

Soil reaction: slightly acid throughout the soil profile.

Organic carbon irregularly decrease with depth from 25 to 125 centimeters.

Surface fragments: 5 to 15 percent gravel

Particle Size Control Section (weighted average):

Clay content: 10 to 18 percent
Rock fragments: 35 to 85 percent, mostly gravel, cobbles and stones.

A horizons

Hue: 10YR or 2.5Y
Value: 3 through 5, dry or moist
Chroma: 2 through 5, dry or moist

Texture of the fine earth fraction: loam
Clay content: 7 to 18 percent
Rock fragments: 10 to 15 percent gravel

C horizons

Hue: 10YR or 2.5Y
Value: 4 through 7 dry; 3 through 5 moist
Chroma: 2 through 4 dry or moist

Texture of the fine earth fraction: sandy loam, loam or silt loam
Clay content: 10 to 18 percent
Rock fragments: 5 to 35 percent gravel, 15 to 20 percent cobbles and 20 to 35 percent stones

COMPETING SERIES: This is the Anderson series. Anderson soils are 7.5YR or redder throughout the profile.

GEOGRAPHIC SETTING: The Gencey soils are on nearly level floodplain-steps with slopes of 0 to 2 percent at elevations of 74 to 195 meters (243 to 640 feet). They formed in recent gravelly and cobbly alluvium derived from mixed sources. The climate is subhumid with warm dry summers and cool moist winters. The mean annual precipitation is 1250 to 2032 millimeters (49 to 80 inches). Mean annual air temperature is 15 to 20 degrees C (59 to 68 degrees F). The frost free period is about 240 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Floaters and Soctish series. The Floaters soils are frequently flooded on lower level floodplains and Soctish are non-flooded on higher level stream terraces.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; low runoff; moderately rapid saturated hydrologic conductivity, occasionally flooded for very brief durations.

USE AND VEGETATION: Used for livestock grazing, orchards and urban development. Vegetation on uncultivated areas is bristly dogtail, soft brome, blue wildrye and orchardgrass.

DISTRIBUTION AND EXTENT: Siskyou-Trinity Area, MLRA 5. These soils are of small extent.

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

SERIES ESTABLISHED: Humboldt County, California, 2012. Proposed 2006.

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

1. Ochric epipedon - the zone from the surface to a depth of 10 centimeters (A1 and A2 horizons)
2. Particle size control section - The zone from 25 to 100 centimeters, averaging (by weight) 15 percent clay and 40 percent rock fragments.

ADDITIONAL DATA

This soil was mapped as a Haploxeroll by the Department of Land, Air, and Water Resources, University of California, Davis, in 1975 for the Soil Survey of Hoopa Valley, California. It was determined that the colors were lithochromic.

Soil analysis performed by the Soil Morphology Laboratory, University of California, Davis. Sample ID: 12-75-1

NASIS User Pedon ID: 02CA023605012

Soils classified using Keys to Soil Taxonomy, 11th edition.

National Cooperative Soil Survey
U.S.A.