LOCATION ORR NV+CA
Established Series
Rev. WED-JVC
04/2017
ORR SERIES
The Orr series consists of very deep, well drained soils that formed in alluvium derived from mixed igneous rocks. Orr soils are on fan remnants, stream terraces, inset fans, and hills. Slopes are 0 to 15 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 10 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argixerolls
TYPICAL PEDON: Orr stony sandy loam--pastureland. (Colors are for dry soil unless otherwise noted).
Ap--0 to 13 cm; brown (10YR 5/3) stony sandy loam, very dark grayish brown (10YR 3/2) moist; moderate thin and medium platy structure; slightly hard, friable, slightly sticky and nonplastic; many very fine through medium roots; many very fine and fine tubular pores; 5 percent stones and 10 percent gravel; neutral (pH 6.8); clear wavy boundary. (8 to 20 cm thick)
A--13 to 25 cm; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine to medium roots; many very fine and fine tubular pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (13 to 30 cm thick)
Bt1--25 to 79 cm; pale brown (10YR 6/3) sandy loam, brown (10YR 4/3) moist; weak medium angular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few faint very dark grayish brown (10YR 3/2) clay films on faces of peds; many very fine and fine tubular pores; 10 percent gravel; neutral (pH 6.8); gradual wavy boundary. (10 to 64 cm thick)
Bt2--79 to 99 cm; light yellowish brown (10YR 6/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak medium angular blocky structure; very hard, firm, moderately sticky and moderately plastic; few fine and medium roots; many very fine and fine tubular pores; common faint clay films on faces of peds and lining pores; 10 percent gravel; neutral (pH 6.8); gradual wavy boundary. (15 to 33 cm thick)
Bt3--99 to 127 cm; light yellowish brown (10YR 6/4) gravelly sandy clay loam, yellowish brown (10YR 5/4) moist; weak medium angular blocky structure; hard, firm, moderately sticky and slightly plastic; few fine and medium roots; common very fine and fine tubular pores; common faint clay films on faces of peds; 20 percent gravel; neutral (pH 6.8); gradual wavy boundary. (0 to 51 cm thick)
C--127 to 157 cm; very pale brown (10YR 7/3) gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common very fine and fine tubular pores; 30 percent gravel; neutral (pH 6.8).
TYPE LOCATION: Washoe County, Nevada; about 1 mile northeast of Verdi; approximately 1,800 feet south and 1,200 feet east of the northwest corner of section 8, T. 19 N., R. 18 E.; USGS Verdi 7.5 minute topographic quadrangle; 39 degrees latitude 31 minutes 46 seconds N and longitude 119 degrees 59 minutes 17 seconds W; WGS84 Decimal Degrees 39.5294444 latitude, -119.9880556 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the late winter and spring, dry in summer and fall; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 10 to 12 degrees C.
Mollic epipedon thickness: 25 to 50 cm; includes the Bt1 horizon in some pedons.
Depth to base of argillic horizon: 89 to 127 cm.
Particle-size control section - Clay content: 18 to 25 percent.
Rock fragments: Averages 10 to 25 percent. Lithology of fragments are mainly igneous rocks such as andesite and granodiorite.
A horizons
Hue: 10YR or 7.5YR.
Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Bt horizons
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 2 through 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Sandy loam, sandy clay loam, loam, gravelly sandy loam, or gravelly sandy clay loam.
Rock fragments: 0 to 35 percent.
Structure: Weak subangular blocky, prismatic, or massive.
C horizon
Hue: 10YR or 7.5YR.
Value: 6 or 7 dry, 4 through 6 moist.
Chroma: 3 or 4, dry or moist.
Texture: Sand, loamy fine sand, sandy loam, fine sandy loam, sandy clay loam, clay loam and is gravelly or very gravelly in some pedons.
Rock fragments: 0 to 20 percent gravel and cobbles.
Other features: Some pedons have secondary carbonate coats on bottom of rock fragments.
Other features: Some pedons have durinodes averaging less than 20 percent.
COMPETING SERIES: These are the
Bissell,
Bjork,
Cowiche,
Dodes,
Fernpoint,
Hullsgulch,
Indiano,
Jerusalem,
Madras,
Margerum,
Noslo,
Pahrange,
Quailridge,
Quiero,
Ralls,
Shoebend,
Simcoe,
Springmeyer,
Truax,
Uhaldi, and
Wenatchee series.
Bissell,
Noslo,
Springmeyer, and
Wenatchee soils have 25 to 35 percent clay in the particle-size control section.
Bjork,
Dodes,
Indiano,
Madras,
Pahrange,
Quiero,
Shoebend,
Simcoe, and
Uhaldi soils have bedrock within 100 cm.
Cowiche soils have an A horizon and an upper Bt horizon formed in loess 46 to 100 cm thick over unconformable residuum and are slightly alkaline or moderately alkaline.
Fernpoint soils have argillic horizons that are less than 89 cm thick and have extremely gravelly or extremely cobbly 2C horizons.
Hullsgulch soils have horizons with lamellae below the argillic horizon.
Jerusalem soils have rock fragments that are mainly fine gravel of granitic lithology.
Margerum soils have 20 to 40 percent ash and pumice.
Quailridge soils are 30 to 64 cm to the base of the argillic horizon and have horizons with lamellae below the argillic horizon.
Ralls soils are slightly alkaline or moderately alkaline and are influenced by loess.
Truax soils have argillic horizons less than 81 cm thick, silica cementation in the C horizon, and average less than 15 percent rock fragments.
GEOGRAPHIC SETTING: Orr soils are on fan remnants, stream terraces, inset fans, and hills. These soils formed in alluvium derived from mixed igneous rocks or in colluvium derived from sandstone and shale. Slopes are 0 to 15 percent. Elevations range from 1,341 to 2,134 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, the mean annual temperature is 9 to 11 degrees C, and the frost-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Oest and
Reno soils along with the competing
Springmeyer soil. Oest soils are loamy-skeletal. Reno soils are fine textured, moderately deep to duripans, and have ochric epipedons.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Orr soils are used for rangeland or irrigated cropland and pasture. Crops are small grains, alfalfa, and pasture. Vegetation in rangeland is principally Wyoming big sagebrush, Sandberg's bluegrass, cheatgrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Western and central Nevada and northeastern California. These soils are moderately extensive. The series concept and main acreage is in MLRA 26, while other acreage occurs in MLRAs 23 and 28B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Washoe County (South Part), Nevada, 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 25 cm (Ap and A horizons).
Argillic horizon - The zone from 25 to 127 cm (Bt1, Bt2, and Bt3 horizons).
Particle-size control section - The zone from 25 to 75 cm (part of the Bt1 horizon).
ADDITONIAL DATA: User Pedon ID: 2006NV019016.
National Cooperative Soil Survey
U.S.A.