LOCATION RUGAR NVEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Pachic Argixerolls
TYPICAL PEDON: Rugar clay loam, rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with less than 5 percent pebbles, l percent cobbles and stones.
A1--0 to 2 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak very fine and fine subangular blocky structure parting to moderate fine and medium granular; slightly hard, very friable, sticky and plastic; many very fine, common fine, and few coarse roots; common very fine and few fine tubular pores; l0 percent pebbles; neutral (pH 7.0); clear smooth boundary. (2 to 4 inches thick)
A2--2 to 20 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; hard, friable, sticky and plastic; common very fine, fine, medium and few coarse roots; many very fine, fine and few medium tubular pores; 5 percent pebbles; neutral (pH 6.6); abrupt smooth boundary. (l6 to 20 inches thick)
Bt1--20 to 27 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; few, fine prominent reddish yellow (7.5YR 6/6) moist, iron mottles; moderate medium and coarse angular blocky structure; hard, firm, sticky and very plastic; few very fine, fine and coarse roots; common very fine, fine and few medium tubular pores; common stress surfaces; few, fine iron-manganese nodules; 10 percent soft pebbles and 2 percent cobbles; slightly acid (pH 6.2); clear wavy boundary. (6 to 12 inches thick)
Bt2--27 to 43 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; common fine and medium, prominent strong brown (7.5YR 5/6) moist, iron mottles; moderate coarse and very coarse angular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; common very fine, fine, and few medium tubular pores; common stress surfaces; few, fine iron-manganese nodules; 20 percent soft weathered pebbles slightly acid (pH 6.2); clear wavy boundary. (16 to 24 inches thick)
Cr--43 to 60 inches; highly weathered soft siltstone maintaining primarily rock structure; common fine iron manganese nodules.
TYPE LOCATION: Elko County, Nevada; approximately 2 miles south of Bull Run Reservoir, about 500 feet west and 400 feet south of the northeast corner of section 29, T. 43 N., R. 52 E.; 41 degrees, 36 minutes, 10 seconds north latitude and 116 degrees, 08 minutes, 50 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist, moist in winter and spring, dry late July through late October.
Soil temperature - 42 to 47 degrees F.
Mollic epipedon thickness - 24 to 36 inches.
Depth to base of argillic horizon - 40 to 60 inches.
Depth to paralithic contact - 40 to 60 inches.
Control section - Clay percent: 40 to 55 percent.
Rock fragments: 5 to 15 percent, mainly pebbles.
Reaction - Neutral to slightly acid.
Bt horizon - Value: 3 or 4 moist.
Chroma: 3 or 4 dry and moist.
Texture: Clay or gravelly clay.
Structure: Moderate medium, coarse and very coarse angular blocky; or weak medium prismatic.
Other features: Most fragments are siltstone, are soft and will slake after overnight soaking.
Cr horizon - Other features: Commonly has iron-manganese nodules.
COMPETING SERIES: These are the Arcia (NV), Arva (NV), Broadhead (UT), Cristo (UT), Henefer (UT) and Sweitberg (WA) series. The Arcia, Cristo and Sweitberg soils are moderately deep to bedrock. The Arva soils lack an abrupt boundary between the A and Bt, lack mottles and iron-manganese nodules in the Bt and have 15 to 30 percent coarse fragment in the particle-size control section. The Broadhead and Henefer soils are over 60 inches deep to bedrock and are well drained.
GEOGRAPHIC SETTING: Rugar soils are on fan piedmont remnants with rock core, concave side slopes and foot slopes of hills and mountains. These soils formed in residuum weathered from siltstone, tuff claystone and sandstone. Slopes are 2 to 30 percent. Elevations are 5,500 to 7,500 feet. The climate is cool semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 12 to 18 inches; the mean annual temperature is 40 to 45 degrees F.; and the frost-free season is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sumine, Quarz, Graley, Tusel and Erakatak soils. Graley soils have a lithic contact within 20 inches. Sumine, Quarz and Erakatak soils have a lithic contact within 20 to 40 inches. Tusel soils have a cryic temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. The vegetation is mainly mulesear wyethia, lupine, bluebunch wheatgrass, basin wildrye, bottlebrush squirreltail and oniongrass.
DISTRIBUTION AND EXTENT: Northeastern Nevada. These soils are of small extent.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Northwest Elko County Area, Nevada, l986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon (pachic) - The zone from the surface of the soil to a depth of 27 inches (A1, A2 and Bt1, horizons).
Argillic horizon - The zone from about 20 to 43 inches (Bt1 and Bt2 horizons)
Particle-size control section - The zone from 20 to 40 inches (Bt1 and part of Bt2 horizons).