LOCATION AYCAB NV
Established Series
Rev. JFS-DD-RLB-JBF
02/2018
AYCAB SERIES
The Aycab series consists of moderately deep, well drained soils that formed in residuum derived from granitic rocks. Aycab soils are on predominantly north-facing mountain side slopes. Slopes are 15 to 75 percent. The mean annual precipitation is about 400 mm and the mean annual temperature is about 6 degrees C.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Pachic Haplocryolls
TYPICAL PEDON: Aycab gravelly coarse sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 cm; very dark grayish brown (10YR 3/2) gravelly coarse sandy loam, black (10YR 2/1) moist; weak fine subangular blocky parting to moderate fine granular; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; few fine tubular pores; 20 percent gravel; slightly acid (pH 6.1); clear wavy boundary. (3 to 8 cm thick)
A2--5 to 20 cm; dark grayish brown (10YR 4/2) gravelly coarse sandy loam, black (10YR 2/1) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine tubular pores; 20 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (8 to 18 cm thick)
A3--20 to 41 cm; dark grayish brown (10YR 4/2) gravelly coarse sandy loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, common medium roots; many very fine and fine and, medium tubular pores; 25 percent gravel; neutral (pH 6.6); clear wavy boundary. (15 to 23 cm thick)
A4--41 to 74 cm; brown (10YR 4/3) gravelly coarse sandy loam, very dark brown (10YR 2/2) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; common very fine and fine, few medium tubular pores; 30 percent gravel; neutral (pH 6.8); clear wavy boundary. (0 to 36 cm thick)
Bw--74 to 97 cm; dark yellowish brown (10YR 4/4) gravelly coarse sandy loam, dark brown (10YR 3/3) moist; common coarse brown (10YR 4/3) and very dark brown (10YR 2/2) moist organic stains; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine, few medium tubular pores; 30 percent gravel; neutral (pH 6.8); clear wavy boundary. (15 to 33 cm thick)
Cr--97 cm; highly fractured, semi-weathered granodiorite with more typical granitic grus below this. The fractured bedrock above granitic grus is about 8 to 10 cm thick, digs with spade easily and is broken in hands with minimal effort.
TYPE LOCATION: West Humboldt County, Nevada; in the Bilk Creek Mountains; about 1,400 feet east and 1,600 feet south of the northwest corner, section 12, T. 46 N., R. 31 E.; USGS Trident Peak 7.5 minute topographic quadrangle; latitude 41 degrees 52 minutes 50 seconds N and longitude 118 degrees 27 minutes 36 seconds W; WGS84 Decimal Degrees 41.8805556 latitude, -118.4600000 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, dry late July through early October; xeric soil moisture regime.
Mean annual soil temperature: 6 to 8 degrees C.
Mean summer soil temperature: 13 to 15 degrees C.
Mollic epipedon thickness: 50 to 100 cm (may or may not include Bw horizon)
Reaction of profile: Neutral or slightly acid.
Depth to paralithic contact: 60 to 100 cm.
Particle-size control section - Texture: Typically coarse sandy loam, but strata of sandy loam or loam are allowable. Clay content: 8 to 18 percent.
Rock fragments: 15 to 35 percent, predominantly 2 to 5 mm size gravel.
A horizon
Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 1 through 3 with chroma of 1 occurring predominantly in the A1 or A2 horizons and chroma of 3 occurring in the A3 horizon and below.
Bw horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 through 4.
Structure: Subangular blocky or is massive.
Consistence: Soft or slightly hard dry.
Other Features: Mixed colors are common in this horizon due to root and rodent activity. The Bw horizon may or may not meet the requirements of a cambic horizon.
COMPETING SERIES: These are the
Brownsgulch,
Coffepot,
Coutis,
Earcree,
Fleecer,
Foxvire,
Gardners Fork,
Grayhead,
Hailman,
Moonlight,
Naz,
Razorba,
Shook,
Skyway,
Taral and
Tosp series.
Brownsgulch,
Coutis,
Earcree,
Fleecer,
Foxvire,
Gardners Fork,
Hailman,
Moonlight,
Naz,
Razorba,
Taral and
Tosp soils lack a paralithic contact within 100 cm.
Coffepot soils lack a Bw horizon.
Grayhead soils has an ustic soil moisture regime.
Shook soils have a lithic contact at 76 to 127 cm and have more than 35 percent rock fragments in the lower part of the series control section.
Skyway soils have a lithic contact within 100 cm and have textures of fine sandy loam or loam in their particle-size control sections.
GEOGRAPHIC SETTING: Aycab soils are on concave mountain side slopes, on predominantly north aspects. These soils formed in residuum derived from granitic rocks. Slopes are 15 to 75 percent. Elevations are 1,800 to 3,100 meters. The climate is cold, continental with cold, moist winters and cool, dry summers. The mean annual precipitation is 360 to 510 mm that comes largely from winter snowfall. Mean annual temperature is 6 to 8 degrees C., and the frost-free season is less than 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the tentative
Tosp and Woodcabin soils. Tosp soils lack a paralithic contact within 102 cm. Woodcabin soils have a paralithic contact within 51 cm.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to very rapid runoff; high saturated hydraulic conductivity.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly mountain big sagebrush, snowberry, mountain brome and Columbia needlegrass.
DISTRIBUTION AND EXTENT: Northwest Nevada. These soils are not extensive. MLRA 24.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County, Nevada, west part, 1987.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon and Pachic feature - The zone from the surface to 74 cm (A1, A2, A3, and A4 horizons).
Paralithic contact - The boundary at 97 cm (Cr layer).
Particle-size control section - The zone from 25 to 97 cm (A3, A4, Bw and part of A2 horizons.
National Cooperative Soil Survey
U.S.A.