LOCATION KNOTT                   NV

Established Series
Rev. MJZ/TM/RLB/JBF
11/2015

KNOTT SERIES

The Knott series consists of shallow over duripan, well drained soils that formed in alluvium derived from mixed rocks with some influence from loess high in volcanic ash. Knott soils are on fan-piedmont remnants and partial ballenas. Slopes are 2 to 50 percent. The mean annual precipitation is about 180 mm and the mean annual temperature is about 9 degrees C.

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

TYPICAL PEDON: Knott gravelly very fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; pale brown (10YR 6/3) gravelly very fine sandy loam, brown (10YR 5/3) moist; moderate very thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine vesicular pores; 20 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.8); clear smooth boundary. (2 to 6 inches thick)

A2--5 to 10 cm; pale brown (10YR 6/3) gravelly very fine sandy loam, brown (10YR 4/3) moist; moderate very fine platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine vesicular pores; 15 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.8); abrupt smooth boundary. (0 to 10 cm thick)

Btn--10 to 28 cm; brown (7.5YR 5/4) clay, brown (7.5YR 4/4) moist; moderate medium prismatic structure; hard, firm, very sticky and very plastic; few very fine and fine roots; common very fine tubular pores; many faint clay films on ped faces and lining pores; 10 percent gravel; moderately alkaline (pH 8.4); gradual smooth boundary. (10 to 20 cm thick)

Btkn--28 to 46 cm; light brown (7.5YR 6/4) gravelly clay, brown (7.5YR 5/4) moist; moderate medium prismatic structure; hard, firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; many distinct clay films on ped faces and lining pores; 20 percent gravel and 5 percent cobbles; common medium lime seams; strongly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (8 to 20 cm thick)

Bkqm--46 to 86 cm; very pale brown (10YR 8/2) indurated duripan, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely firm; strongly effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (10 to 50 cm thick)

Ck--86 to 152 cm; light gray (10YR 7/2) very gravelly coarse sandy loam, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic; many fine interstitial pores; 45 percent gravel and 10 percent cobbles; lime coatings on rock fragments; strongly effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Pershing County, Nevada; approximately 16 miles southwest of Valmy in the north part of Buffalo Valley, about 1,900 feet west and 1,500 feet north of the southeast corner of section 21, T. 32 N., R. 41 E.; latitude 40 degrees 37 minutes 47 seconds N and longitude 117 degrees 21 minutes 53 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist for short periods in winter and spring, dry from June through November; typic aridic soil moisture regime.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to duripan: 25 to 50 cm.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: 10 to 30 percent, mainly gravel.

A horizon
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 2 or 3.
Reaction: Neutral through moderately alkaline.

Btn horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 through 6.
Texture: Gravelly clay, gravelly clay loam or clay.
Rock fragments: 5 to 30 percent, mainly gravel.
Reaction: Moderately alkaline through very strongly alkaline.
Exchangeable sodium: 15 to 35 percent.
Consistence: Friable or firm, moist; moderately sticky or very sticky and moderately plastic or very plastic.
Other features: Segregated lime is not present in the lower Bt subhorizon in some pedons.

Bkqm horizon
Hue: 10YR or 7.5YR.
Value: 6 through 8, dry or moist.
Chroma: 2 through 4.
Structure: Usually platy near the upper boundary and is massive below.
Reaction: Moderately alkaline or strongly alkaline.

Ck and Cqk horizon
Value: 6 or 7 dry, 4 through 6 moist.
Chroma: 2 through 4.
Texture: Very gravelly sandy loam, very gravelly coarse sandy loam, or very gravelly loamy sand.
Clay content: 4 to 10 percent.
Rock fragments: 40 to 60 percent, mainly gravel.
Structure: Massive or single grained.
Consistence: Loose or soft or slightly hard, dry; very friable, moist; nonsticky or slightly sticky and nonplastic or slightly plastic, wet.
Reaction: Moderately or strongly alkaline.
Other features: Weakly silica cemented lenses and lime and silica coatings on rock fragments are in some pedons.

COMPETING SERIES: These are the Knoss and Nemico series.

Knoss soils have a mean annual soil temperature of 12 to 15 degrees C, a duripan that extends below 100 cm and exchangeable sodium in the natric horizon that is greater than 35 percent. Nemico soils are underlain by bedrock at a depth of 28 to 64 cm.

GEOGRAPHIC SETTING: Knott soils are on summits and side slopes of fan-piedmont remnants and partial ballenas. These soils formed in alluvium derived from mixed rocks with a surface mantle of loess high in volcanic ash. Slopes are 2 to 50 percent. Elevations are 1,220 to 1,951 meters. The climate is arid, with cool, moist winters and warm, dry summers. The mean annual precipitation is 130 to 200 mm mean annual temperature is 7 to 10 degrees C, and the frost-free season is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cortez, Snapp, Sodhouse and Wholan series. Cortez soils are moderately deep to a duripan. Snapp and Wholan soils are very deep. Sodhouse soils have a loamy particle-size control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to rapid runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly shadscale, bud sagebrush, bottlebrush squirreltail and Sandberg bluegrass.

DISTRIBUTION AND EXTENT: North-central Nevada. These soils are not extensive. MLRA 23,24.

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 10 cm (A1 and A2 horizons).
Natric horizon - The zone from 10 to 46 cm (Btn and Btkn horizons).
Indurated duripan - The zone from 46 to 86 cm (Bkqm horizon).
Particle-size control section - The zone from 10 to 46 cm (Btn and Btkn horizons).

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National Cooperative Soil Survey
U.S.A.