LOCATION SUNDOWN NV
Established Series
Rev. EWB/WED/JVC/JBF
05/2016
SUNDOWN SERIES
The Sundown series consists of very deep, somewhat excessively drained soils that formed in eolian deposits with a strong pyroclastic influence of volcanic glass over alluvium derived from mixed rocks. Sundown soils are on sand sheets superimposed over fan remnants and fan skirts. Slopes are 0 to 8 percent. The mean annual precipitation is about 150 mm and the mean annual temperature is about 12 degrees C.
TAXONOMIC CLASS: Mixed, mesic Typic Torripsamments
TYPICAL PEDON: Sundown loamy fine sand--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 cm; light gray (10YR 7/2) loamy fine sand, brown (10YR 5/3) moist; weak thin platy structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine vesicular and many very fine and fine interstitial pores; 10 percent fine gravel; strongly effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (3 to 18 cm thick)
C1--8 to 25 cm; light gray (10YR 7/2) loamy sand, brown (10YR 5/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine tubular pores; 5 percent fine gravel; strongly effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (13 to 34 cm thick)
C2--25 to 48 cm; light gray (10YR 7/2) loamy fine sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; 10 percent fine gravel; strongly effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (0 to 34 cm thick)
C3--48 to 119 cm; light gray (10YR 7/2) loamy fine sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; common very fine tubular and many very fine and fine interstitial pores; 10 percent fine gravel; violently effervescent; very strongly alkaline (pH 9.2); abrupt smooth boundary. (60 to 120 cm thick)
2C4--119 to 132 cm; very pale brown (10YR 7/3) sandy clay loam, yellowish brown (10YR 5/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine vesicular pores and few fine tubular pores; 10 percent fine gravel; violently effervescent; strongly alkaline (pH 9.0).
TYPE LOCATION: Lincoln County, Nevada; approximately 1,950 feet north and 2,510 feet east of the southwest corner of section 5, T. 3 S., R. 56 E.; USGS Tempiute Mountain North 7.5 minute topographic quadrangle; latitude 37 degrees 42 minutes 48 seconds N and longitude 115 degrees 42 minutes 21 seconds W; WGS84 Decimal Degrees 37.7133333 latitude, -115.7058333 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in some part for short periods during winter and early spring months, and intermittently moist in some part for 10 to 20 days cumulative between July and October due to convection storms; Typic torric moisture regime.
Mean annual soil temperature: 12 to 15 degrees C.
Reaction: Moderately alkaline through very strongly alkaline.
Effervescence: Slightly effervescent through violently effervescent throughout.
A horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
C horizons
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Dominantly loamy fine sand, with thin strata of sand, fine sand, or loamy sand in some pedons.
Rock fragments: Up to 15 percent, mainly gravel.
Structure: Subangular blocky or is massive or single grain.
Other features: Buried horizons may be present at depths of 100 to 150 cm in some pedons with texture of sandy clay loam predominating.
COMPETING SERIES: These are the
Als,
Ecklund,
Hawsley,
Isolde,
Kawich,
Razito,
Sheppard,
Stumble,
Tipper,
Tipperary,
Tricera, and
Yenrab series.
Als soils are not effervescent throughout.
Ecklund and
Tipper soils have bedrock at depths of 50 to 100 cm.
Razito soils are not influenced by volcanic glass.
Kawich and
Isolde soils are dominated by fine sand in the particle-size control section.
Sheppard soils have hue of 5YR and are not influenced by volcanic glass.
Stumble soils have noncalcareous A horizons.
Hawsley soils have a Ck horizon.
Tipperary soils are dominated by sand in the particle-size control section and are not influenced by volcanic glass.
Tricera soils are free of carbonates to depths of 100 cm or more and are not influenced by volcanic glass.
Yenrab soils have greater than 15 percent exchangeable sodium.
GEOGRAPHIC SETTING: Sundown soils are on sand sheets superimposed over fan remnants and fan skirts. These soils formed in eolian deposits with a strong pyroclastic influence of volcanic glass over alluvium derived from mixed rocks. Slopes are 0 to 8 percent. Elevations range from 1,250 to 1,740 meters. The climate is arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 100 to 175 mm, the mean annual temperature is 12 to 14 degrees C, and the frost-free period is 130 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Cliffdown,
Fang,
Koyen,
Monte Cristo, and
Oricto soils. Cliffdown soils have more than 15 percent gravel in the particle-size control section and are not sandy. Fang and Koyen soils are coarse-loamy. Monte Cristo and Oricto soils have argillic horizons.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; very low or low surface runoff; high saturated hydraulic conductivity.
USE AND VEGETATION: Sundown soils are used for livestock grazing and wildlife habitat. The vegetation is mainly Indian ricegrass, fourwing saltbush, littleleaf horsebrush, and shadscale.
DISTRIBUTION AND EXTENT: West-central to east-central Nevada. These soils are moderately extensive. MLRA 29.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Nye County (Big Smoky Valley Area), Nevada, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and part of the C1 horizons).
Particle-size control section - The zone from 25 to 100 cm (C2 and part of the C3 horizons).
Sundown soils need field and lab studies to quantify the content of volcanic glass present.
National Cooperative Soil Survey
U.S.A.