LOCATION OUPICO                  NV

Established Series
Rev. DW-RLB-JVC-JBF
11/2016

OUPICO SERIES

The Oupico series consists of moderately deep to a duripan, well drained soils that formed in alluvium derived from mixed rocks. Oupico soils are on fan remnants. Slopes are 0 to 30 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 8 degrees C.

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 5 cm; 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; common very fine interstitial pores; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 13 cm thick)

A--5 to 10 cm; 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 5 cm thick)

Bk--10 to 33 cm; 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 gravel; violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (20 to 30 cm thick)

Bqk--33 to 64 cm; 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 gravel; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (25 to 64 cm thick)

Bqkm--64 to 124 cm; 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); clear smooth boundary. (50 to 100 cm thick)

Cqk1--124 to 142 cm; 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 gravel; 40 percent durinodes; violently effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (13 to 38 cm thick)

Cqk2--142 to 157 cm; 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; violently effervescent; 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; latitude 41 degrees 07 minutes and 53 seconds N and longitude 114 degrees 55 minutes and 0 seconds W; WGS84 Decimal Degrees 41.1313889 latitude, -114.9166667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry June through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 9 to 10 degrees C.
Depth to duripan: 50 to 100 cm.
Depth to bedrock: More than 200 cm.

Particle-size control section - Clay content: 8 to 18 percent.
Rock fragments: 5 to 25 percent, mainly gravel. 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, Tauncal, Taunton, and Ticeska series.

Doel soils do not have calcic horizons above the duripan. Jestrick and Ticeska soils have lithic contacts within 100 cm of the soil surface. Shalake soils have horizons above the duripan with 20 to 50 percent durinodes. Tauncal soils are calcareous throughout, do not have horizons with secondary silica above the duripan, and have mean annual soil temperatures of 10 to 13 degrees C. 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 1,680 to 2,075 meters. The mean annual precipitation is 200 to 300 mm, mean annual temperature is 8 to 9 degrees C, 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 SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high surface runoff; moderately high saturated hydraulic conductivity.

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

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 18 cm (Ap, A and part of Bk horizons).
Calcic horizon - The zone from 10 to 64 cm (Bk and Bqk horizons).
Duripan - The zone from 64 to 124 cm (Bqkm horizon).
Particle-size control section - The zone from 25 to 64 cm (Bqk and part of the Bk horizons).

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National Cooperative Soil Survey
U.S.A.