LOCATION PIOCHE NVEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Lithic Argixerolls
TYPICAL PEDON: Pioche extremely stony loam, woodland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 40 percent pebbles, 10 percent cobbles and 15 percent stones.
A--0 to 2 inches; brown (10YR 5/3) extremely stony loam, very dark grayish brown (10YR 3/2) moist; strong thin and medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine and fine vesicular pores; 40 percent pebbles, 10 percent cobbles, and 15 percent stones; slightly alkaline (pH 7.6); clear wavy boundary. (1/2 to 3 inches thick.)
Bt1--2 to 7 inches; brown (10YR 4/3) very cobbly clay loam, very dark grayish brown (10YR 3/2) moist; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine, medium and common coarse roots, common very fine, fine and few medium tubular pores; many faint clay films lining pores and on faces of peds; 30 percent pebbles; 20 percent cobbles; and 5 percent stones; slightly alkaline (pH 7.6); clear wavy boundary. (3 to 7 inches thick.)
Bt2--7 to 15 inches; dark yellowish brown (10YR 4/4) very cobbly clay, dark brown (10YR 3/3) moist; strong medium and coarse subangular blocky structure; slightly hard, friable, moderately sticky and very plastic; few very fine and fine, many medium and coarse roots; common very fine and fine tubular, and few medium interstitial pores; many faint clay films lining pores and on faces of peds; 30 percent pebbles, 20 percent cobbles, and 5 percent stones; slightly alkaline (pH 7.6); abrupt irregular boundary. (2 to 9 inches thick.)
R--15 inches; hard, fractured welded tuff.
TYPE LOCATION: White Pine County, Nevada; approximately 1.5 miles southeast of Lookout Springs; about 500 feet east and 2,800 feet south of the northwest corner of section 33 T. 26 N., R. 67 E.; USGS Chin Creek Spring 7.5 minute topographic quadrangle; 40 degrees, 04 minutes, 48 seconds north latitude and 114 degrees, 25 minutes, 33 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry, moist winter and spring, dry summer and fall. Aridic moisture regime bordering on xeric.
Soil temperature - 47 to 53 degrees F.
Depth to bedrock - 8 to 15 inches.
Thickness of mollic epipedon - 7 to 10 inches when the upper 7 inches of the soil is mixed. Bt2 horizons with colors that meet the requirements for mollic do not have sufficient organic carbon to be included in the epipedon except when mixed in the upper 7 inches.
Reaction - Neutral or slightly alkaline.
Control section - Clay content: 35 to 50 percent.
Rock fragments: 35 to 55 percent, dominantly cobbles; lithology of the fragments is mostly andesite, rhyolite, welded tuff or similar volcanic rocks.
A horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Bt horizons - Hue: 10YR, 7.5YR, 5YR.
Value: 4 or 5 dry, 2 through 4 moist.
Chroma: 2 through 4, dry or moist.
Structure: Weak or moderate prismatic; moderate or strong, fine or medium angular blocky; moderate or strong, fine to coarse subangular blocky.
Consistence: Slightly hard or hard, dry, friable or firm, moist, moderately sticky or very sticky and moderately plastic or very plastic, wet.
Clay films: Few to many.
COMPETING SERIES: These are the Camaspatch (WA), Flatron (ID), Gwinly (OR), Laufer (WA), Longcreek (CA), Loomer (NV), Lorella (OR), Radec (UT), Ruckles (OR), Vantage (WA), and Waterbury series (OR). Camaspatch, Gwinly, Laufer, Lorella and Waterbury soils have a xeric moisture regime. Flatron, Ruckles and Waterbury soils have 50 to 60 percent clay in the particle-size control section. Longcreek soils have slightly acid or neutral reaction in the A horizon and have 0.5 to 2 percent organic matter throughout the Bt horizon. Loomer soils have 60 to 80 percent rock fragments in the particle-size control section. Radec soils are periodically moist between July and October. Vantage soils have Btq horizons.
GEOGRAPHIC SETTING: Pioche soils are on hill and mountain side slopes. These soils formed in residuum and colluvium from volcanic rocks dominated by rhyolite, andesite and welded tuffs. Slopes are 8 to 50 percent. Elevations are 5,500 to 8,600 feet. The climate is cool, semiarid with warm, dry summers and cool, moist winters. The mean annual precipitation is 10 to 14 inches; mean annual temperature is 45 to 50 degrees F., and the frost-free season is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chen and Cropper series. Chen and Cropper soils have frigid soil temperature regimes.
DRAINAGE AND PERMEABILITY: Well drained; very high runoff; slow permeability.
USE AND VEGETATION: Woodland and wildlife habitat. The principal vegetation is mainly Utah juniper, singleleaf pinyon, mountain big sagebrush, bluebunch wheatgrass, Thurber's needlegrass, and Nevada ephedra.
DISTRIBUTION AND EXTENT: East-central Nevada. Pioche soils are moderately extensive, with about 75,000 acres mapped to date. MLRA 28B.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Lincoln County (Meadow Valley Area), Nevada, 1971.
REMARKS: The series concept has been revised to better represent the areas mapped to date. It does not have moisture in the control section for 10 to 20 days cumulatively in the summer. The type location is moved from Lincoln County to White Pine County, Nevada, in 2004.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 7 inches (A and Bt1 horizons).
Argillic horizon - The zone from 2 to 15 inches (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 15 inches (R layer).
Particle-size control section - The zone from 2 to 15 inches (Bt1, Bt2 horizons).