LOCATION OROVADA                 NV+ID OR

Established Series
Rev. DMC-MJZ-JVC-JBF
09/2019

OROVADA SERIES

The Orovada series consists of very deep, well drained soils that formed in loess high in volcanic ash over alluvium derived from mixed rocks. Orovada soils are on fan skirts, fan remnants, fan aprons, inset fans, calderas, and draws. Slopes are 0 to 15 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Durinodic Xeric Haplocambids

TYPICAL PEDON: Orovada fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 5 cm; light brownish gray (10YR 6/2) fine sandy loam, dark brown (10YR 3/3) moist; weak medium and thin platy structure; slightly hard, very friable, slightly sticky and nonplastic; few fine roots; many fine and medium vesicular, few very fine tubular pores; slightly alkaline (pH 7.5); abrupt smooth boundary. (5 to 20 cm thick)

Bw1--5 to 20 cm; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and few fine roots; many very fine interstitial, common very fine tubular pores; slightly alkaline (pH 7.8); clear smooth boundary. (10 to 23 cm thick)

Bw2--20 to 36 cm; light gray (10YR 7/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; many very fine, common fine, and few medium roots; many very fine interstitial, few very fine and fine tubular pores; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 28 cm thick)

Bq--36 to 66 cm; pale brown (10YR 6/3) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak coarse and medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine roots; common very fine interstitial, few very fine and fine tubular pores; 20 percent 2.5 cm durinodes that are very hard, firm and brittle; moderately alkaline (pH 8.4); clear wavy boundary. (0 to 30 cm thick)

Bqk1--66 to 86 cm; light brownish gray (2.5Y 6/2) very fine sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, very friable, slightly sticky and nonplastic; few very fine and fine roots; common very fine interstitial and few very fine tubular pores; 70 percent 1.9 to 3.8 cm durinodes that are very hard, firm and brittle; secondary carbonates segregated as common fine and medium white (10YR 8/1) masses; strongly effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (13 to 30 cm thick)

Bqk2--86 to 122 cm; light brownish gray (10YR 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, friable, slightly sticky and nonplastic; few very fine and fine roots; common very fine interstitial and few very fine tubular pores; 60 percent 1.3 to 2.5 cm durinodes that are hard, firm and brittle; secondary carbonates segregated as few medium and coarse white (10YR 8/1) masses; strongly effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (15 to 90 cm thick)

B'q--122 to 155 cm; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and nonplastic; few very fine roots; common very fine interstitial and few very fine tubular pores; 10 percent 1.3 to 2.5 cm durinodes that are hard, firm and brittle; strongly effervescent; strongly alkaline (pH 8.8).

TYPE LOCATION: Humboldt County, Nevada; about 2.3 miles west and 0.5 miles south of Orovada; about 200 feet west and 2,440 feet south of the northeast corner of section 32, T. 43 N., R. 37 E; USGS Orovada 7.5 minute topographic quadrangle; latitude 41 degrees 33 minutes 47 seconds N and longitude 117 degrees 49 minutes 47 seconds W; WGS84 Decimal Degrees 41.5630556 latitude, -117.8297222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry from late June through early November; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to base of cambic horizon: 25 to 70 cm.
Depth to horizons with durinodes: 25 to 70 cm.

Particle-size control section - Clay content: 5 to 18 percent.
Rock fragments: 0 to 15 percent, mainly gravel.

A horizon
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 or 4 moist; when mixed the value of the upper 18 cm is greater than 5 dry and greater than 3 moist.
Chroma: 2 through 4, dry or moist.
Reaction: Neutral through moderately alkaline.

Bw horizons
Hue: 10YR or 2.5Y.
Value: 6 through 8 dry; 3 through 6 moist.
Chroma: 2 through 6, dry or moist.
Texture: Fine sandy loam, very fine sandy loam, or loam.
Rock fragments: 0 to 15 percent gravel.
Structure: Subangular blocky or prismatic.
Consistence: Soft or slightly hard, dry; very friable or friable, moist; nonsticky or slightly sticky and nonplastic or slightly plastic, wet.
Reaction: Slightly alkaline or moderately alkaline.

Bq and Bqk horizons
Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 2 through 6, dry or moist.
Texture: Fine sandy loam, very fine sandy loam, loam, silt loam with strata of loamy fine sand or sandy loam in some pedons.
Rock fragments: Up to 30 percent gravel in some subhorizons of some pedons.
Consistence: Soft to hard dry, nonsticky or slightly sticky and nonplastic or slightly plastic, wet.
Reaction: Moderately alkaline through very strongly alkaline, commonly increasing with depth.
Durinodes: 20 to 80 percent; horizons with less than 20 percent durinodes are common below 100 cm in some pedons.
Other features: Gypsum crystals are below depths of 94 cm in some pedons; some pedons have very gravelly strata below depths of 100 cm.

COMPETING SERIES: These are the Enko, Kerrfield, Patter, Prineville, and Ultramont series.

Enko soils have a horizon within 100 cm of the soil surface with firm consistence in the matrix and a brittle manner of failure. Kerrfield soils are moderately deep to paralithic contacts. Patter soils are moist in the upper part of the moisture control section for 10 to 20 days cumulative between July and October and have calcareous and strongly alkaline Bw horizons. Prineville soils are deep to paralithic contacts and have 5 to 30 percent sand-size pumiceous ash grains in the upper part of the soil. Ultramont soils are moist in the upper part of the moisture control section for 10 to 20 days cumulative between July and October.

GEOGRAPHIC SETTING: Orovada soils are on fan skirts, fan remnants, fan aprons, inset fans, calderas, and draws. These soils formed in loess high in volcanic ash over alluvium derived from mixed rocks. Slopes are 0 to 15 percent. Elevations range from 1,160 to 2,140 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, the mean annual temperature is 7 to 10 degrees C, and the frost-free period is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bloor, Davey, McConnel, Misad, Oxcorel, Rad, Rebel, and Snapp soils. Bloor soils are fine-silty and have natric horizons. Davey soils are sandy. McConnel soils are sandy-skeletal. Misad soils are loamy-skeletal and do not have cambic horizons. Oxcorel soils are fine, have natric horizons, and a typic aridic moisture regime. Rad soils are coarse-silty. Rebel soils do not have horizons with 20 percent or more durinodes. Snapp soils are clayey over sandy or sandy-skeletal and have natric horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low or medium surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Orovada soils are used for livestock grazing and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, rabbitbrush, bottlebrush squirreltail, and Sandberg bluegrass.

DISTRIBUTION AND EXTENT: Northern and central Nevada, southwestern Idaho, and southeastern Oregon. These soils are extensive with about 359,000 acres of the series mapped to date. The series concept and main acreage is in MLRA 24, while other acreage occurs in MLRAs 25 and 28B.

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

SERIES ESTABLISHED: Nye County (Big Smoky Valley Area), Nevada, 1972.

REMARKS: The Orovada series became the official state soil for Nevada in June of 2001.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A horizon and part of the Bw1 horizon).
Cambic horizon - The zone from 5 to 36 cm (Bw1 and Bw2 horizons).
Durinodes - The zone from 36 to 155 cm (Bq1, Bqk1, Bqk2, and Bq2 horizons).
Identifiable secondary carbonates - The zone from 66 to 122 cm (Bqk1 and Bqk2 horizons).
Particle-size control section - The zone from 25 to 100 cm (Bq1 and Bqk1 horizons and part of the Bw2 and Bqk2 horizons).

ADDITIONAL DATA: SSIR No. 23 (NV).

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National Cooperative Soil Survey
U.S.A.