LOCATION KNOSS                   NV

Established Series
Rev. MTZ/GJS/JVC/JBF
05/2016

KNOSS SERIES

The Knoss series consists of shallow to a duripan, well drained soils that formed in alluvium derived from mixed rocks, loess, and volcanic ash. Knoss soils are on fan remnants. Slopes are 2 to 8 percent. The mean annual precipitation is about 150 mm and the mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Typic Natridurids

TYPICAL PEDON: Knoss cobbly very fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 5 percent gravel, 15 percent cobbles and less than 1 percent stones.

A1--0 to 5 cm; light gray (10YR 7/2) cobbly very fine sandy loam, grayish brown (10YR 5/2) moist; strong thin platy structure; slightly hard, very friable, nonsticky and slightly plastic; few very fine roots; many fine and medium vesicular pores; 10 percent gravel and 8 percent cobbles; strongly effervescent; strongly alkaline (pH 8.8); clear smooth boundary. (3 to 8 cm thick)

A2--5 to 18 cm; pale brown (10YR 6/3) very fine sandy loam, brown (10YR 5/3) moist; weak thin platy structure; slightly hard, very friable, nonsticky and slightly plastic; common very fine roots; many fine tubular pores; 10 percent gravel; strongly effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (0 to 15 cm thick)

Btnk--18 to 38 cm; brown (10YR 5/3) clay, brown (10YR 4/3) moist; strong fine prismatic structure; hard, firm, very sticky and very plastic; common very fine roots; few very fine tubular pores; many faint clay films on faces of peds; 5 percent gravel; common fine irregularly shaped coats of lime in seams; strongly effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (13 to 38 cm thick)

Bqkm--38 to 132 cm; very pale brown (10YR 8/3) indurated silica and lime cemented duripan, continuous thin laminar cap; very pale brown (10YR 7/4) moist; strong coarse platy structure; extremely hard, extremely firm; 40 percent gravel, 3 percent cobbles, and 3 percent stones; violently effervescent; very strongly alkaline (pH 9.4); abrupt smooth boundary. (25 to 100 cm thick)

Bk--132 to 152 cm; pale brown (10YR 6/3) extremely gravelly loamy sand, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; many fine interstitial pores; 65 percent gravel and 5 percent cobbles, very thin lime coats on rock fragments; violently effervescent; strongly alkaline (pH 9.0).

TYPE LOCATION: Pershing County, Nevada; about 40 miles southeast of Mill City in Buena Vista Valley; about 1,250 feet east and 1,300 feet north of the southwest corner of section 27, T. 26 N., R. 36 E.; USGS Logan Peak, NV 7.5 minute topographic quadrangle; latitude 40 degrees 05 minutes 21 seconds N and longitude 117 degrees 55 minutes 25 seconds W; WGS84 Decimal Degrees 40.0891667 latitude, -117.923611 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist for short periods in winter through early spring, dry from late May through November; typic aridic soil moisture regime.
Mean annual soil temperature: 11 to 13 degrees C.
Depth to identifiable secondary carbonates: 5 to 20 cm.
Depth to indurated duripan: 36 to 50 cm.

Particle-size control section - Clay content: 40 to 60 percent.
Rock fragments: Up to 15 percent, mainly gravel of mixed lithology.

A horizons
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Reaction: Moderately alkaline or strongly alkaline.
Other features: Some pedons are noneffervescent.

Btnk horizon
Hue: 7.5YR or 10YR.
Value: 5 or 6 dry.
Chroma: 3 or 4.
Identifiable secondary carbonates: Matrix is strongly effervescent with segregated lime common throughout the horizon.
Calcium carbonate equivalent: 1 to 3 percent.
Salinity (EC): 0 to 16 mmhos/cm.
Sodicity (SAR): 30 to 60.
Other features: Some pedons have thin gravelly subhorizons.

Bqkm horizon
Structure: Platy or horizon is massive.

Bk horizon
Calcium carbonate equivalent: 3 to 10 percent.

COMPETING SERIES: These are the Knott and Nemico series.

Knott soils have natric horizons with sodium adsorption ratios of 13 to 45 and duripans that extend to depths less than 100 cm. Nemico soils average 15 to 35 percent rock fragments in the particle-size control section and are underlain by hard bedrock at depths of 28 to 64 cm.

GEOGRAPHIC SETTING: Knoss soils are on fan remnants. They formed in alluvium derived from mixed rocks, loess, and volcanic ash. Slopes are 2 to 8 percent. Elevations range from 1,280 to 1,590 meters. The climate is cool-arid with cool, moist winters and hot, dry summers. The mean annual precipitation is 100 to 200 mm, the mean annual temperature is 9 to 11 degrees C, and the frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilper and Jerval soils. Chilper soils are clayey over loamy-skeletal, very deep, and do not have duripans. Jerval soils are fine-loamy, very deep, and do not have duripans.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high or very high surface runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Knoss soils are used for rangeland and wildlife habitat. The present vegetation is mainly shadscale, bud sagebrush, bottlebrush squirreltail, and pine bluegrass.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRAs 24 and 27.

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

SERIES ESTABLISHED: Pershing County, Nevada, East Part, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A1 and A2 horizons).
Natric horizon - The zone from 18 to 38 cm (Btnk horizon).
Indurated duripan - The zone from 38 to 132 cm (Bqkm horizon).
Particle-size control section - The zone from 18 to 38 cm (Btnk horizon).

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National Cooperative Soil Survey
U.S.A.