LOCATION SUP NV
Established Series
Rev. DMC/GJS/JBF
01/2023
SUP SERIES
The Sup series consists of very deep, well drained soils formed in colluvium derived from granitic and andesitic rocks. These soils are on concave mountain side slopes. Slopes are l5 to 50 percent. Mean annual precipitation is about 400 mm and mean annual temperature is about 6 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryolls
TYPICAL PEDON: Sup gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The surface is covered with 2 percent stones, 5 percent cobbles, and 20 percent gravel.
A1--0 to 5 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine tubular pores; 2 percent stones, 5 percent cobbles and 20 percent gravel; slightly acid (pH 6.2); abrupt smooth boundary. (5 to 10 cm thick)
A2--5 to 15 cm; grayish brown (10YR 5/2) very gravelly fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine tubular pores; 30 percent gravel and 15 percent cobbles; slightly acid (pH 6.2); abrupt smooth boundary. (5 to 15 cm thick)
A3--15 to 30 cm; brown (10YR 5/3) very gravelly sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine, common fine and medium, and few coarse roots; many very fine and few medium and coarse tubular pores; 30 percent gravel and 15 percent cobbles; slightly acid (pH 6.2); abrupt irregular boundary. (10 to 20 cm thick)
C1--30 to 56 cm; pinkish gray (7.5YR 6/2) extremely gravelly sandy loam, dark brown (7.5YR 3/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine through coarse roots; few very fine, fine and medium tubular pores; 50 percent gravel and 20 percent cobbles; moderately acid (pH 6.0); clear wavy boundary. (15 to 30 cm thick)
C2--56 to 79 cm; pale brown (10YR 6/3); extremely gravelly fine sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; 50 percent gravel and 25 percent cobbles; moderately acid (pH 6.0); abrupt wavy boundary. (18 to 30 cm thick)
C3--79 to 99 cm; pale brown (10YR 6/3); extremely gravelly fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; 50 percent gravel and 25 percent cobbles; moderately acid(pH 6.0); clear wavy boundary. (15 to 25 cm thick)
C4--99 to 152 cm; light brownish gray (10YR 6/2) very cobbly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; 20 percent gravel and 20 percent cobbles; moderately acid (pH 5.6).
TYPE LOCATION: Douglas County, Nevada; about 3/4 mile north of Mount Como; approximately 1,500 feet north and 750 feet west of southeast corner of section 35, T. 14 N., R. 22 E.; USGS Mount Como 7.5 minute topographic quadrangle; latitude 39 degrees 1 minutes 55 seconds N and longitude 119 degrees 28 minutes 30 seconds W; WGS84 Decimal Degrees 39.0319444 latitude, -119.4750000 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring and continuously dry in all parts for significant periods in summer and fall; xeric soil moisture regime.
Mean annual soil temperature: 7 to 8 degrees C.
Average summer soil temperature: 12 to 14 degrees.
Mollic epipedon thickness: 20 to 40 cm.
Depth to bedrock: 100 to over 150 cm.
Reaction: Moderately acid or slightly acid.
Base saturation: 50 to 75 percent.
Other features: Some pedons have a very thin surface organic layer.
Particle-size control section - Percent clay: 5 to l5.
Rock fragments: 45 to 75 percent of which 30 to 50 percent are gravel, 15 to 25 percent are cobbles.
A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
C horizons
Hue: l0YR or 7.5YR.
Value: 5 through 7 dry, 3 or 4 moist.
Chroma: 2 through 4.
Texture: Stratified very gravelly or extremely gravelly coarse sandy loam, sandy loam, fine sandy loan, and loam.
COMPETING SERIES: These are the
Basinpeak,
Berrycreek,
Decram,
Fairydell,
Foxmount,
Gaia,
Jackmill,
Klug,
Krackle,
Lag,
Middlehill,
Rockabin,
Steepshrub,
Timmercrek, and
Wareagle series.
Basinpeak,
Berrycreek,
Decram, and
Fairydell soils have more than 18 percent clay in the particle-size control section.
Foxmount,
Krackle,
Middlehill, and
Rockabin soils are moderately deep.
Gaia and
Timmercrek soils are intermittently moist in the upper part for 10 to 20 days cumulative due to convection storms between July and September.
Jackmill,
Klug,
Steepshrub and
Wareagle soils have cambic horizons.
Lag soils have a mean annual soil temperature of 2 to 4 degrees C.
GEOGRAPHIC SETTING: Sup soils are on concave mountain side slopes. Slopes are 15 to 50 percent. Elevations range from 2,135 to 2,750 meters. The soils formed in colluvium from granitic and andesitic rock. The climate is cold with most precipitation occurring during late fall, winter and spring. Mean annual precipitation is 400 to 500 mm; mean annual temperature is 4 to 7 degrees C; frost-free season is 50 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Genoa and
Glean soils. Genoa soils have an argillic horizon and a lithic contact at less than 50 cm. Glean soils have a mollic epipedon more than 50 cm thick.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium or rapid runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Livestock grazing and wildlife habitat. The vegetation is mainly curlleaf mountain mahogany, mountain big sagebrush, Nevada bluegrass, basin wildrye, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Western Nevada. The soil is of moderate extent. MLRA 26.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Douglas County, Nevada, 1981.
REMARKS: Diagnostic horizon and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 30 cm (A1, A2 and A3 horizons).
Particle size control section - The zone from 25 to 100 cm (C1, C2, C3 and part of A3 and C4 horizons).
National Cooperative Soil Survey
U.S.A.