LOCATION DRYFIELD CA

Established Series
JWH/JME/KP
07/2016

DRYFIELD SERIES

The Dryfield series consists of very deep, well drained soils formed in colluvium and residuum derived from sandstone. Dryfield soils are on mountains and ridges. Slopes range from 2 to 50 percent. Mean annual precipitation is about 2160 millimeters and the mean annual temperature is about 14 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, active, thermic Typic Dystroxerepts

TYPICAL PEDON: Dryfield fine sandy loam, on a east facing 14 percent slope under grass at an elevation of 710 meters. (Colors are for dry soil unless otherwise noted. When described on 6/6/03, the soil was slightly moist throughout.)

A--0 to 11 centimeters; brown (10YR 5/3) fine sandy loam, dark grayish brown (10YR 4/2) moist; 17 percent clay; moderate medium granular structure; very friable, slightly hard, nonsticky and nonplastic; common very fine roots throughout; strongly acid, pH 5.3; abrupt wavy boundary.

Bt1--11 to 49 centimeters; brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; very friable, slightly hard, slightly sticky and slightly plastic; common very fine roots throughout; common very fine tubular pores; 50 percent patchy distinct clay films on all faces of peds; strongly acid, pH 5.3; clear smooth boundary.

Bt2--49 to 70 centimeters; pale brown (10YR 6/3) fine sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; friable, moderately hard, slightly sticky and slightly plastic; common very fine roots throughout; common very fine tubular pores; 50 percent patchy distinct clay films on all faces of peds; strongly acid, pH 5.5; clear wavy boundary.

Bt3--70 to 105 centimeters; light yellowish brown (10YR 6/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; friable, moderately hard, slightly sticky and slightly plastic; common fine roots throughout; common very fine tubular pores; 25 percent patchy prominent clay films on all faces of peds; moderately acid, pH 5.8; gradual wavy boundary.

Bt4--105 to 130 centimeters; light yellowish brown (10YR 6/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; friable, hard, slightly sticky and slightly plastic; few very fine roots throughout; few very fine tubular pores; 20 percent patchy prominent clay films on all faces of peds; moderately acid, pH 5.9; gradual wavy boundary.

Bt5--130 to 150 centimeters; light yellowish brown (10YR 6/4) fine sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; friable, hard, slightly sticky and slightly plastic; few very fine tubular pores; 10 percent patchy faint clay films on all faces of peds; slightly acid, pH 6.1; gradual wavy boundary.

BCt--150 to 190 centimeters; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; massive; friable, hard, slightly sticky and slightly plastic; few very fine tubular pores; 5 percent patchy faint clay films on all faces of peds; moderately acid, pH 5.7.

TYPE LOCATION: Humboldt County, California; about 6.5 kilometers east of Garberville, CA. USGS 7.5 minute topographic quadrangle Harris, California; WGS84 Decimal degrees 40.0975000 latitude and -123.7188889 longitude; UTM zone 10 0438613mE, 4438812mN; NAD 83.

RANGE IN CHARACTERISTICS:

Soil Temperature: The mean annual soil temperature at 50 centimeters is 15 to 19 degrees C and the difference between mean summer and mean winter soil temperatures is 6 degrees C or greater. The soil has a thermic temperature regime.

Soil Moisture: The soil moisture control section, in normal years, is dry in all parts for 45 or more consecutive days in the 4 months following the summer solstice and moist in all parts for 45 or more consecutive days in the 4 months following the winter solstice. The soil has a xeric moisture regime.

Particle-size control section (weighted average):
Clay content: 15 to 17 percent clay
Depth to bedrock: more than 150 cm
Rock fragments: 0 to 10 percent

A horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6, 3 or 4 moist
Chroma: 2 through 4 dry or moist
Texture: fine sandy loam or loam
Clay content: 10 to 15 percent
Rock fragments: 0 to 10 percent
Reaction: strongly to moderately acid

Upper B horizons:
Hue: 7.5YR or 10YR
Value: 5 through 7, 4 or 5 moist
Chroma: 3 through 6 dry or moist
Texture: fine sandy loam or loam
Clay content: 15 to 17 percent
Rock fragments: 0 to 10 percent strongly cemented sandstone
Reaction: strongly to moderately acid

Lower B horizons:
Hue: 7.5YR or 10YR
Value: 5 through 7, 4 or 5 moist
Chroma: 3 through 6 dry or moist
Texture: fine sandy loam, loam, or sandy clay loam
Clay content: 16 to 27 percent
Rock fragments: 0 to 15 percent
Reaction: moderately to slightly acid

C horizon (when present):
Hue: 7.5YR through 2.5Y
Value: 5 through 7, 4 or 5 moist
Chroma: 3 through 6 dry or moist
Texture: fine sandy loam, loam, or sandy clay loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 20 percent strongly cemented sandstone
Pararock fragments: 0 to 59 percent weakly cemented sandstone
Reaction: moderately to slightly acid

COMPETING SERIES: This is the Kanaka series from Shasta County (1965). Kanaka soils are moderately deep over granodiorite.

GEOGRAPHIC SETTING: Dryfield soils are on mountains and ridges. Slopes range from 2 to 50 percent. Elevations are 100 to 760 meters. The soils formed in colluvium and residuum derived from sandstone of the Franciscan Complex. The climate is subhumid with warm, dry summers and cool, wet winters. Mean annual precipitation is 1500 to 3050 millimeters. Mean annual temperature is 13 to 15 degrees C. Frost free season is about 240 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Yorknorth, and Witherell soils. Yorknorth soils contain more than 35 percent clay in the particle size control section. Witherell soils have lithic materials with cracks spaced less than 10 centimeters apart between 25 and 50 centimeters. Yorknorth soils are on concave to linear positions and Witherell soils are on convex positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to high runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used mainly for livestock grazing. The vegetation includes slender oat, wild oat, soft brome, ripgut brome, , bristly dogstail grass, medusa head, silver hairgrass, hairy catsear, common sheep sorrel, and other annual and perennial grasses and forbs.

DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area, MLRA 5. The series is not extensive.

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

SERIES ESTABLISHED: Humboldt County, Southern Part, California, 2011. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 11 centimeters (A horizon).
Cambic horizon: The zone from 11 to 190 centimeters (Bt1, Bt2, Bt3, B4, Bt5, BCt horizons)
Particle size control section - The zone from 25 to 100 centimeters averages 16 percent clay, 51 percent fine sand or coarser, by weight, and 4 percent gravel, by volume (Bt1, Bt2, Bt3 horizons).

ADDITIONAL DATA: NSSL Pedon 03N0876. NASIS User Pedon ID 03CA601152.
Keys to Soil Taxonomy, 12th edition.

National Cooperative Soil Survey
U.S.A.