LOCATION WASHOE NV+NMEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Xeric Haplargids
TYPICAL PEDON: Washoe cobbly coarse sand--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; brown (10YR 5/3) cobbly coarse sand, very dark grayish brown (10YR 3/2) moist; single grain; loose, nonsticky and nonplastic; few fine, and common very fine roots; many very fine and fine interstitial pores; 15 percent gravel and 15 percent cobbles; slightly acid (pH 6.1); abrupt smooth boundary. (0 to 2 inches thick)
A2--2 to 5 inches; pale brown (10YR 6/3) cobbly light sandy loam, dark brown (10YR 3/3) moist; weak medium and fine granular structure; soft, very friable, nonsticky and nonplastic; common fine, and many very fine roots; common fine and very fine vesicular pores; 15 percent gravel and 15 percent cobbles; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 4 inches thick)
A3--5 to 8 inches; brown (10YR 5/3) gravelly coarse sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine granular structure; soft, friable, nonsticky and nonplastic; common fine, and many very fine roots; common fine and very fine interstitial, and few very fine tubular pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); abrupt smooth boundary. (3 to 4 inches thick)
Bt1--8 to 11 inches; brown (10YR 5/3) gravelly coarse sandy loam, dark brown (10YR 3/3) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, and many very fine roots; common very fine, and few fine tubular pores; common faint clay films on faces of peds and lining pores; 20 percent gravel and 5 percent cobbles; neutral (pH 6.7); abrupt wavy boundary. (3 to 6 inches thick)
Bt2--11 to 20 inches; brown (7.5YR 4/4) very gravelly sandy clay loam, dark brown (10YR 3/3) moist; massive; very hard, friable, sticky and plastic; very few fine, and common very fine roots; few fine and very fine interstitial, and few fine tubular pores; common faint clay films bridging mineral grains, lining pores, and coating rock fragments; 30 percent gravel and 10 percent cobbles; slightly acid (pH 6.5); clear wavy boundary. (8 to 12 inches thick)
Bt3--20 to 28 inches; brown (7.5YR 4/4) very gravelly coarse sandy loam, brown (7.5YR 4/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; few fine and very fine interstitial pores; common faint clay films bridging mineral grains and lining pores; 30 percent gravel and 5 percent cobbles; most rock fragments show visible signs of weathering; slightly acid (pH 6.5); gradual wavy boundary. (7 to 20 inches thick)
Bt4--28 to 42 inches; brown (7.5YR 4/4) extremely gravelly coarse sandy loam, dark brown (7.5YR 3/2) moist; massive; hard, friable, slightly sticky and slightly plastic; very few very fine roots; many very fine and fine interstitial pores; clay films bridging mineral grains and on rock fragments; 50 percent gravel and 20 percent cobbles; shows visible signs of weathering; slightly acid (pH 6.5); gradual wavy boundary. (0 to 15 inches thick)
C--42 to 60 inches; light yellowish brown (10YR 6/4) very gravelly loamy coarse sand, yellowish brown (10YR 5/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine interstitial pores; 40 percent gravel and 15 percent cobbles; neutral (pH 6.9).
TYPE LOCATION: Douglas County, Nevada; about 300 feet east and 75 feet south of the center of section 28, T. 12 N., R. 20 E.
RANGE IN CHARACTERISTICS: The solum is 32 to 45 inches thick. The mean annual soil temperature is 51 to 53 degrees F. These soils are usually dry but are moist in the winter and spring. The soil is slightly acid or neutral. The argillic horizon is 24 to 40 inches thick. The upper 20 inches of the argillic horizon has average texture of gravelly coarse sandy loam or gravelly sandy clay loam with l8 to 27 percent clay, more than 35 percent medium sand and coarser, and 35 to 50 percent rock fragments.
The A horizons have value of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3. This horizon is commonly cobbly with l5 to 20 percent cobbles and 15 to 20 percent gravel. The cobbles have been removed from some area.
The Bt horizons have hue of 10YR or 7.5YR, value of 4 to 6 dry, 3 or 4 moist, and chroma of 3 or 4.
The C horizon has value of 5 or 6 dry, 4 or 5 moist, and chroma of 3 or 4. This horizon is loamy sand or loamy coarse sand modified with 45 to 80 percent rock fragments ranging in size from gravel to boulders. Rock fragments are mostly weathered granitic rocks.
COMPETING SERIES: This is the Lithgow series. Lithgow soils have bedrock at a depth of 20 to 40 inches.
GEOGRAPHIC SETTING: Washoe soils are on terraces at elevations of about 4,400 to 5,200 feet. Slopes are 0 to 15 percent. They formed in alluvium derived from ixed igneous rocks such as granite and andesite. The climate is semiarid. Mean annual precipitation is 8 to 12 inches; mean annual temperature is 48 to 50 degrees F.; mean January temperature is 30 to 32 degrees F.; mean July temperature is 68 to 70 degrees F.; and the frost-free season is about 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dressler, Glenbrook, and Leviathan soils. Dressler soils are somewhat poorly drained. Glenbrook soils have granitic bedrock within 20 inches. Leviathan soils have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Used primarily for rangeland and urban development. The vegetation is principally Wyoming big sagebrush, Nevada ephedra, rabbitbrush, Anderson's peachbrush, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Western Nevada. These soils are moderately extensive. The series concept is in MLRA 26 in Nevada. Other acreage occurs in MLRA 70C in central New Mexico in the out-of-date soil survey of Torrance County Area (NM674).
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Douglas County (Carson Valley), Nevada 1940.
REMARKS: The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data.
ADDITIONAL DATA: SSIR No. 23.