LOCATION PORTMOUNT               NV

Established Series
Rev. WDM/ELS/RLB
11/2016

PORTMOUNT SERIES

The Portmount series consists of very deep, well drained soils that formed in alluvium derived from mixed rocks. The Portmount soils are on fan piedmonts. Slopes are 0 to 8 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Calciargids

TYPICAL PEDON: Portmount gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 60 percent gravel.

A--0 to 8 cm; pale brown (10YR 6/3) gravelly sandy loam, dark brown (10YR 3/3) moist; weak thin platy structure; soft, very friable, slightly sticky and slightly plastic; few medium and coarse roots; common fine and very fine vesicular pores; 15 percent gravel; moderately alkaline (pH 8.0); abrupt smooth boundary. (3 to 13 cm thick)

Bt--8 to 30 cm; pale brown (10YR 6/3) sandy loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common fine, medium and coarse roots; common fine interstitial and tubular pores; common moderately thick clay films on faces of peds and lining pores; 10 percent very fine and fine gravel; moderately alkaline (pH 8.0); clear wavy boundary. (15 to 30 cm thick)

2Btk--30 to 86 cm; light yellowish brown (10YR 6/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots on faces of peds; common fine interstitial and tubular pores; few thin clay films; 40 percent lime-coated gravel; moderately alkaline (pH 8.2); clear wavy boundary. (36 to 60 cm thick)

2Bk--86 to 152 cm; very pale brown (10YR 8/2) gravelly sandy loam, pale brown (10YR 6/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common interstitial and tubular pores; 20 percent very fine and fine lime coated gravel; violently effervescent; moderately alkaline (pH 8.4)

TYPE LOCATION: Nye County, Nevada; about 2,000 feet north and 100 feet west of the southeast corner of section 13, T. 10 N., R. 53 E.; latitude 38 degrees 43 minutes 39 seconds N and longitude 115 degrees 56 minutes and 55 seconds W; WGS84 Decimal Degrees 38.7276111 latitude, -115.9486111 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and spring, dry in summer and fall; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to the Btk horizon: 30 to 70 cm.

Particle-size control section - Clay content: Averages 12 to 18 percent.
Rock fragments: Averages 15 to 35 percent.

A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4

Bt horizon
Value: 5 through 7 dry, 3 through 5 moist
Chroma: 2 through 4
Texture: Sandy loam or sandy clay loam
Clay content: 12 than 22 percent
Rock fragments:10 to 35 percent.
Structure: Subangular blocky or massive.
Consistence: Soft or slightly hard, nonsticky through moderately sticky and nonplastic through moderately plastic.

Btk horizon
Value: 5 through 7 dry, 3 through 5 moist
Chroma: 2 through 4
Texture: Sandy loam or sandy clay loam
Clay content: 12 to18 percent
Rock fragments:15 to 45 percent.
Structure: Subangular blocky or massive.
Consistence: Soft or slightly hard, nonsticky through moderately sticky and nonplastic through moderately plastic.

2Bk horizon
Value: 6 through 8 dry, 4 through 7 moist
Chroma: 2 through 4
Texture: Sandy loam or loam
Rock fragments: 15 to 35 percent
Consistence: Soft to slightly hard, very friable to friable, nonplastic to plastic and nonsticky to slightly sticky.

COMPETING SERIES: This is the Poobaa series. Poobaa soils are moderately deep.

GEOGRAPHIC SETTING: Portmount soils are on fan piedmonts. These soils formed in mixed alluvium. Slopes are 0 to 8 percent. Elevations are 1,830 to 2,200 meters. The climate is cool, with hot summers and cool moist winters. The mean annual precipitation is 200 to 250 mm, mean annual temperature is 8 to 12 degrees C, and the frost-free season is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abgese, Allker and Yody soil. Abgese, Allker and Yody soils have more than 18 percent clay in the particle-size control sections.

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

USE AND VEGETATION: Livestock grazing and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, rabbitbrush, bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: Central Nevada. These soils are not extensive. MLRA 28B.

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

SERIES ESTABLISHED: Nye County, Nevada, Duckwater Planning Unit. 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 8 cm (A horizon)
Argillic horizon - The zone from 8 to 86 cm (Bt and 2Btk horizons)
Calcic horizon - The zone from 86 to 152 cm (2Bk horizon)
Particle-size control section - The zone from 8 to 58 cm (Bt and part of 2Btk horizon).

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National Cooperative Soil Survey
U.S.A.