LOCATION OUPICO NVEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Haplodurids
TYPICAL PEDON: Oupico loam--rangeland. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 2 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; moderate very thin platy structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; very fine interstitial pores; slightly alkaline (pH 7.4); clear smooth boundary. (2 to 5 inches thick)
A--2 to 4 inches; light brownish gray (10YR 6/2) silt loam, brown (10YR 4/3) moist; weak thick platy structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine interstitial pores; slightly alkaline (pH 7.5); clear smooth boundary. (0 to 2 inches thick)
Bk--4 to 13 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine interstitial pores; 5 percent pebbles; violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 12 inches thick)
Bqk--13 to 25 inches; light gray (10YR 7/2) loam, brown (10YR 5/3) moist; massive; hard, firm and brittle, nonsticky and nonplastic; few very fine roots; few very fine interstitial pores; 10 percent pebbles; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (10 to 25 inches thick)
Bqkm--25 to 49 inches; very pale brown (10YR 8/2) indurated duripan with 1 to 3 millimeter laminar cap alternating with thin discontinuous strongly cemented laminae; extremely hard, extremely firm; violently effervescent; moderately alkaline (pH 8.4). (20 to 40 inches thick)
Cqk1--49 to 56 inches; very pale brown (10YR 8/3) sandy loam, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely firm and brittle, nonsticky and nonplastic; few very fine roots; few very fine interstitial pores; 10 percent pebbles; 40 percent durinodes; strongly alkaline (pH 8.6); clear smooth boundary. (5 to 15 inches thick)
Cqk2--56 to 62 inches; very pale brown (10YR 8/2) very fine sandy loam, light gray (10YR 7/2) moist; massive; hard, firm and brittle, nonsticky and nonplastic; 30 percent durinodes; strongly alkaline (pH 8.6).
TYPE LOCATION: Elko County, Nevada; about 3 miles northeast of Wells; approximately 1,600 feet north and 2,700 feet west of the southeast corner of section 36, T. 38 N., R. 62 E.; USGS Oxley Peak 7.5 minute topographic quadrangle; 41 degrees 07 minutes and 53 seconds north latitude and 114 degrees 54 minutes and 56 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring, dry June through October; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 48 to 50 degrees F.
Ochric epipedon thickness - 2 to 5 inches.
Depth to duripan - 20 to 40 inches.
Depth to bedrock - More than 80 inches.
Particle-size control section - Clay content: 8 to 18 percent; Rock fragments: 5 to 25 percent, mainly pebbles. Lithology of fragments are mixed rocks.
A horizon - Value: 6 or 7 dry.
Chroma: 2 through 4, dry or moist.
Effervescence: Noneffervescent to slightly effervescent.
Reaction: Slightly alkaline or moderately alkaline.
Bk horizon - Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Gravelly loam, loam, or sandy loam.
Identifiable secondary carbonates: Occurs as bridges or coats on mineral grains, masses in the matrix, or coats on rock fragments.
Calcium carbonate equivalent: 5 to 20 percent.
Bqk horizon - Hue: 7.5YR or 10YR.
Value: 6 through 8 dry, 5 through 7 moist.
Chroma: 2 through 4, dry or moist.
Texture: Gravelly loam, loam, or sandy loam.
Secondary silica: Thin coatings of silica or discontinuous weakly silica cemented layers.
Identifiable secondary carbonates: Occurs as bridges or coats on mineral grains, masses in the matrix, or coats on rock fragments.
Calcium carbonate equivalent: 5 to 20 percent.
COMPETING SERIES: These are the Doel, Jestrick, Shalake, Skull Creek, Tauncal, Taunton, and Ticeska series.
Doel soils do not have calcic horizons above the duripan. Jestrick and Ticeska soils have lithic contacts within 40 inches of the soil surface. Shalake soils have horizons above the duripan with 20 to 50 percent durinodes. Skull Creek soils have cambic horizons and do not have calcic horizons above the duripan. Tauncal soils are calcareous throughout, do not have horizons with secondary silica above the duripan, and have mean annual soil temperatures of 50 to 56 degrees F. Taunton soils have cambic horizons and 5 to 35 percent durinodes in the horizon above the duripan.
GEOGRAPHIC SETTING: Oupico soils are on fan remnants. These soils formed in alluvium derived from mixed rocks. Slopes are 0 to 30 percent. Elevation ranges from 5,500 to 6,800 feet. The mean annual precipitation is 8 to 12 inches, mean annual temperature is 46 to 48 degrees F., and the frost-free period is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Enko, Lisade, and Sanpete soils. Enko soils are very deep, have cambic horizons, and do not have duripans. Lisade soils are very deep and do not have duripans. Sanpete soils are loamy-skeletal, very deep, and do not have duripans.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; moderate permeability.
USE AND VEGETATION: Oupico soils are used for rangeland. Native vegetation is Wyoming big sagebrush, Indian ricegrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Eastern Nevada. These soils are moderately extensive. The series concept and main acreage is in MLRA 25, while other acreage occurs in MLRA 28B.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Elko County (Northeastern Part), Nevada, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 4 inches (Ap and A horizons).
Calcic horizon - The zone from 4 to 25 inches (Bk and Bqk horizons).
Duripan - The zone from 26 to 55 inches (Bqkm horizon).
Particle-size control section - The zone from 10 to 25 inches (Bqk horizon and part of the Bk horizon).