LOCATION PORRONE                 NV

Established Series
Rev. DWW/PWB/RLB/JBF
10/2019

PORRONE SERIES

The Porrone series consists of very deep, well drained soils that formed in colluvium derived mainly from limestone with a component of loess and volcanic ash. Porrone soils are on side slopes of hills. Slopes are 15 to 50 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Durinodic Xeric Haplocambids

TYPICAL PEDON: Porrone very gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 35 percent gravel and 2 percent cobbles.

A1--0 to 5 cm; grayish brown (10YR 5/2) very gravelly loam, brown (10YR 4/3) moist; weak thin platy structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine interstitial and fine tubular pores; 40 percent gravel; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (2 to 10 cm thick)

A2--5 to 15 cm; light brownish gray (10YR 6/2) gravelly silt loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and few very fine roots; common very fine interstitial pores; 30 percent gravel; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (2 to 15 cm thick)

Bw--15 to 46 cm; light brownish gray (10YR 6/2) very gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine, few medium roots; common very fine interstitial pores; 35 percent gravel and 5 percent cobbles; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 38 cm thick)

Bqk1--46 to 66 cm; very pale brown (10YR 8/2) very gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine interstitial pores; 50 percent, 5 to 10 mm hard, firm durinodes; thick carbonate coats covering rock fragments; 40 percent gravel and 5 percent cobbles; violently effervescent; moderately alkaline (pH 8.3); clear wavy boundary. (15 to 100 cm thick)

Bqk2--66 to 165 cm; very pale brown (10YR 8/2) very gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; common very fine interstitial pores; 5 percent, 5 to 10 mm durinodes; thick carbonate coats covering rock fragments; 45 percent gravel and 5 percent cobbles; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Elko County, Nevada; approximately 10 miles southwest of Elko, about 900 feet north and 400 feet west of the southeast corner of section 1, T. 32 N., R. 54 E.; USGS White Flats 7.5 minute topographic quadrangle; latitude 40 degrees 40 minutes 6 seconds N and longitude 115 degrees 50 minutes 7 seconds W; WGS84 Decimal Degrees 40.6683333 latitude, -115.8352778 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and spring, dry June through early November; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Combined thickness of A and B horizons: 25 to 50 cm.
Depth to Bqk horizon: 25 to 50 cm.
Effervescence: The soil is effervescent throughout the profile.
Reaction: Slightly alkaline through very strongly alkaline, increasing with depth.

Particle-size control section - Clay content: 10 to 18 percent.
Rock fragments: 35 to 50 percent, mainly gravel.

A horizon
Value: 5 through 7 dry, 3 or 4 moist.
Structure: Platy or subangular blocky.
Consistence: Soft or slightly hard dry.
Reaction: Slightly alkaline or moderately alkaline.

Bw horizon
Value: 6 through 8 dry, 4 through 6 moist.
Chroma: 2 through 4.
Texture: Very gravelly loam or very gravelly sandy loam.
Clay content: 10 to 20 percent.
Rock fragments: 35 to 50 percent.
Structure: Weak subangular blocky or it is massive.
Calcium carbonate equivalent: 10 to 20 percent.
Reaction: Slightly alkaline or moderately alkaline.

Bqk horizon
Value: 7 or 8 dry, 5 or 6 moist.
Chroma: 2 through 4.
Texture: Very gravelly sandy loam or very gravelly loam.
Clay content: 10 to 18 percent.
Rock fragments: 35 to 50 percent, mainly gravel.
Durinodes: 20 to 50 percent, 5 to 20 mm hard or very hard in the upper subhorizons and less than 20 percent in the lower subhorizons.
Calcium carbonate equivalent: 20 to 40 percent. It generally remains constant throughout all subhorizons with no definite zone of increase or decrease.
Reaction: Strongly alkaline or very strongly alkaline.

COMPETING SERIES: These are the Catlow, Mina, and Zineb series.

The Catlow and Zineb soils have more than 50 percent gravel in the particle-size control section. Mina soils are 50 to 90 cm deep to carbonates.

GEOGRAPHIC SETTING: Porrone soils are on side slopes of hills. These soils formed in colluvium derived mainly from limestone with a component of loess and volcanic ash. Slopes are 15 to 50 percent. Elevations are 1,555 to 1,985 meters. The climate is cool, semiarid with cool, moist winters and warm dry summers. The mean annual precipitation is 200 to 250 mm; mean annual temperature is 7 to 9 degrees C, and the frost-free season is 95 to 120 day.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chiara, Izod and Samor series. Chiara soils are shallow to an indurated duripan. Izod and Samor soils are shallow to bedrock.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; rapid runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, Sandberg bluegrass and cheatgrass.

DISTRIBUTION AND EXTENT: Northeastern Nevada. These soils are not extensive. MLRA 25.

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

SERIES ESTABLISHED: Elko County, Nevada, Central Part, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 18 cm (A1, A2 and part of the Bw horizons).
Cambic horizon - The zone from about 15 to 46 cm (Bw horizon).
Duric horizon - The zone from about 46 to 66 cm (Bqk1 horizon).
Particle-size control section - The zone from 25 to 100 cm (all or part of Bw, Bqk1 and Bqk2 horizons).

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National Cooperative Soil Survey
U.S.A.