LOCATION ROVAL                   NV

Established Series
Rev. BKP/JBF
06/2016

ROVAL SERIES


Roval series consists of shallow to a duripan, well-drained soils that formed in loess and alluvium derived from welded tuff and mixed lacustrine sediments. Roval soils are on eroded fan remnants. Slopes range from 2 to 15 percent. The mean annual precipitation is 250 mm and the mean annual temperature is 8 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Xeric Argidurids

TYPICAL PEDON: Roval very gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered by 55 percent gravel.

A--0 to 5 cm, light brown (7.5YR 6/3) very gravelly loam, dark brown (7.5YR 3/3) moist; moderate very coarse subangular blocky structure; moderately hard, very friable, moderately sticky and slightly plastic; common fine and very fine roots; many very fine interstitial and very fine vesicular pores; 40 percent gravel; noneffervescent; neutral (pH 6.9); clear, smooth boundary. (4 to 8 cm thick)

Bt--5 to 30 cm, brown (7.5YR 5/4) gravelly clay loam, dark brown (7.5YR 3/4) moist; moderate very coarse subangular blocky structure; moderately hard, very friable, moderately sticky and moderately plastic; common fine, medium and coarse roots; common fine interstitial pores; few faint clay films on faces of peds and clay bridging between sand grains; 25 percent gravel and 5 percent cobbles with approximately 3 percent of the total gravel as duripan fragments; duripan fragments are strongly cemented to indurated; neutral (pH 6.9); clear smooth boundary. (8 to 25 cm thick)

Btk--30 to 44 cm, brown (7.5YR 5/3) gravelly sandy clay loam, brown (7.5YR 4/3) moist; moderate medium angular blocky structure; moderately hard, friable, moderately sticky and slightly plastic; common very fine, fine and medium roots; common very fine and fine interstitial pores; few faint clay films on faces of peds; few fine calcium carbonate concretions and common coarse calcium carbonate masses; prominent, strongly cemented white (10YR 8/1) and light gray (10YR7/1) moist, on the bottom of rock fragments and around rock fragments; 33 percent gravel and 1 percent cobbles, with approximately 5 percent of the total gravel as duripan fragments; duripan fragments are strongly cemented to indurated; violently effervescent; moderately alkaline (pH 7.9); abrupt, smooth boundary. (12 to 30 cm thick)

2Bqkm1--44 to 60 cm, light brown (7.5YR 6/3) very strongly cemented duripan, brown (7.5YR 4/3) moist; strong very thick platy structure and few inter-beds of moderate, thick platy structure; rigid, brittle; few discontinuous lenses of white (10YR 8/1) loamy sand, light gray (10YR 7/1) moist; very hard, extremely firm, nonsticky and nonplastic; common fine interstitial pores in noncemented lenses; common fine white (10YR 8/1) and light gray (10YR 7/1) moist, calcium carbonate laminae along the tops of strata surfaces; fine continuous pale brown (10YR 6/3) silica laminae; 55 percent gravel, 15 percent cobbles and 5 percent stones;; violently effervescent; strongly alkaline(pH 8.8); slightly alkaline in the noncemented lenses (pH 7.6); abrupt, wavy boundary.

2Bqkm2--60 to 110 cm, white (10YR 8/1) very strongly cemented duripan, light gray (10YR 7/1) moist; strong very thick platy structure; extremely hard and slightly rigid, brittle; common coarse platy calcium carbonate bands along strata surfaces; common medium platy silica masses and concretions on the bottom of rock fragments; violently effervescent; strongly alkaline (pH 8.8); clear, smooth boundary. (Combined thickness of 2Bqkm horizons is 40 to 80 cm thick)

3Cq--110 to 152 cm, light brown (7.5YR 6/3) gravelly sandy loam, brown (7.5YR 4/3) moist; massive; slightly sticky and nonplastic; moderate excavation difficulty; few, fine, faint threadlike calcium carbonate concentrations between peds; 20 percent gravel; strongly effervescent; slightly alkaline (pH 7.6).

TYPE LOCATION: Lincoln County, Nevada; about 1,700 feet north and 1,450 feet east of the SW corner of sec. 23, T. 1 N., R. 69 E.; USGS Ursine 7.5 minute topographic quadrangle; latitude 37 degrees 55 minute 41 seconds N and longitude 114 degrees 13 minutes 20 seconds W; WGS84 Decimal Degrees 37.9280556 latitude, -114.2222222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the winter and spring; dry in summer and fall, except intermittently moist for 10 to 20 days in the summer due to convection storms; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Ochric epipedon thickness: 4 to 8 cm thick.
Depth to the argillic horizon: 4 to 8 cm.
Depth to secondary calcium carbonate: 12 to 33 cm.
Depth to the duripan: 36 to 50 cm.
Duripan thickness: 40 to 80 cm.
Mineralogy: Approximately 10 to 20 percent volcanic glass content in the 0.02 to 2.0 mm mineral fraction and 0.01 to 0.05 percent A+1/2Fe extracted by ammonium oxalate.
Carbonate development stage: Stage IV

Particle-size control section - Clay content: Averages 18 to 27 percent.
Rock fragments: 15 to 35 percent mainly gravel.

A horizon
Hue: 10YR or 7.5YR.
Chroma: 2 or 3 dry and moist.

Bt horizon
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Clay content: 27 to 35 percent.
Rock fragments: 15 to 35 percent.
Texture: clay loam or sandy clay loam.
Structure: Weak or moderate, medium or coarse, prismatic or subangular blocky structure.
Effervescence: Noneffervescent or slightly effervescent.

Btk horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry and 3 through 5 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 18 to 27 percent.
Rock fragments: 15 to 35 percent with some pedons containing thin sub-horizons that average greater than 35 percent.
Texture: Loam, or sandy clay loam.
Structure: Moderate or strong, thin to thick platy, or massive structure.
Reaction: Slightly alkaline or moderately alkaline.
Effervescence: Slightly effervescent through violently effervescent.
Calcium carbonate equivalent: 5 to 15 percent (<2 mm fraction).

2Bqkm horizons
Hue: 7.5YR and 10 YR.
Value: 6 through 8 dry, 6 and 7 moist.
Chroma: 1 through 4 dry and moist.
Structure: Thick platy or massive.
Cementation: Discontinuous 1 mm to 3 mm thick silica and calcium carbonate laminae, with some individual lamellae up to 8 mm thick. Duripans are strongly cemented through indurated with thin sub-horizons of moderately cemented lenses throughout.

3Cq horizons
Consistence: hard and very hard, very friable and firm.
Cementation class: discontinuously weakly cemented to moderately cemented.
Rock fragments: 15 to 35 percent mainly gravel with some pedons containing thin sub-horizons that range from 35 to 80 percent.
Effervescence: Moderately effervescent through violently effervescent.
Other features: Cq horizons consist of lacustrine sediments of varying textures and composition that differ with changes in the depositional environment.

COMPETING SERIES: These are the Argalt, Bigfrog, Bruncan, Chuckridge, Chuska, Colthrop, Dewar, Grassval, Handpah, Minu, Packwood, Pipeline, Roseworth, Thoms, and Wellington series.

Argalt soils have duripans within 36 cm and lithic contacts within 25 to 50 cm of the soil surface. Bigfrog soils average 25 to 35 percent clay in the control section and do not contain calcium carbonate accumulations above the duripan. Bruncan, Colthorp, and Packwood soils have lithic contacts within 100 cm of the soil surface. Chuska soils average 27 to 35 percent clay in the particle-size control section and have a lithic contact between 100 and 150 cm. Chuckridge and Grassval soils have duripans at less than 36 cm from the soil surface. Dewar soils have silty clay loam Bt horizons, and are not intermittently moist in summer. Handpah soils have a mean annual soil temperature that averages 12 to 14 degrees C. Minu soils have secondary calcium carbonate at 4 to 10 cm. Pipeline and Roseworth soils average less than 15 percent rock fragments in the particle-size control section. Thoms soils do not have calcium carbonate accumulations above the duripan and are not intermittently moist for 10 to 20 days from August through September due to convection storms. Wellington soils contain less than 15 percent rock fragments in the control section and are not intermittently moist in summer.

GEOGRAPHIC SETTING: Roval soils are on summits and shoulders of eroded fan remnants at elevations of 1,750 to 1,950 meters. Slopes are 2 to 15 percent. Roval soils formed in loess and alluvium from welded tuff and mixed lacustrine sediments. The climate is cool, continental with a mean annual temperature of 7 to 11 degrees C. The mean annual precipitation is 200 to 300 mm and the frost free season is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acana, Lojet, and Minu soils. Acana soils have weakly to strongly cemented duripans. Lojet soils have duripans at 50 to 100 cm. Minu soils have secondary calcium carbonate at 4 to 10 cm.

DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderately slow permeability, and very slow permeability in the duripan; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Present vegetation is Wyoming big sagebrush, Stansburry Cliffrose, blue grama, galleta, and needleandthread. This pedon is correlated to ecological site number R029XY167NV, Gravelly Loam 8-10 P.Z.

DISTRIBUTION AND EXTENT: East-central Nevada. Roval soils are of moderate extent. MLRA 29.

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

SERIES ESTABLISHED: Lincoln County (Meadow Valley Area), Nevada, 1971.

REMARKS: In older surveys, Roval soils were formerly classified as Brown soils and later classified as Argiduridic Durixerolls. The type location was moved and the soil reclassified in 2009 to better reflect the soil characteristics of the landscape.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 5 cm (A horizon).
Argillic Horizon - The zone from 5 to 44 cm (Bt and Btk horizons).
Duripan - The zone from 44 to 110 cm (2Bqkm1 and 2Bqkm2 horizons).
Particle-size control section- The zone from 5 to 44 cm (Bt and Btk horizons).

ADDITIONAL DATA: Additional Authors: HJB/LNL/ELS.
Pedon ID number: 2009NV017003.


National Cooperative Soil Survey
U.S.A.