LOCATION ROLOC                   NV

Established Series
Rev. GJS/RLB/JBF
02/2023

ROLOC SERIES

The Roloc series consists of shallow, well drained soils formed in residuum derived from granitic rock. Roloc soils are on mountain back slopes and ridges. Slopes are 15 to 75 percent. The mean annual precipitation is about 330 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Aridic Argixerolls

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

Oi--0 to 3 cm; pine needle mat.

A1--3 to 10 cm; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark brown (10YR 2/2) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; common very fine tubular pores; 5 percent 2 to 5 mm and 15 percent 5 to 76 mm gravel, neutral (pH 6.8); abrupt smooth boundary. (5 to 18 cm thick)

A2--10 to 25 cm; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; few very fine tubular pores; 5 percent 2 to 5 mm and 5 percent 5 to 76 mm gravel, neutral (pH 6.8); abrupt smooth boundary. (5 to 18 cm thick)

A3--25 to 30 cm; brown (10YR 5/3) very gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplast1c; common very fine, fine and few medium roots; few very fine and medium tubular pores; 35 percent 2 to 5 mm and 5 percent 5 mm to 76 mm gravel, neutral (pH 6.8); abrupt smooth boundary. (3 to 15 cm thick)

Bt1--30 to 43 cm; pale brown (10YR 6/3) very gravelly coarse sandy loam, brown (10YR 4/3) moist; moderate coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine, and medium roots; common very fine and few medium tubular pores; common faint clay films coating sand grains; 35 percent 2 to 5 mm and 10 percent 5 to 76 mm gravel; neutral (pH 6.6); abrupt smooth boundary. (8 to 23 cm thick)

Bt2--43 to 48 cm; pale brown (10YR 6/3) very gravelly coarse sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few medium roots; common very fine tubular pores; few faint clay films coating sand grains and lining pores; 20 percent 2 to 5 mm and 20 percent 5 to 76 mm gravel, neutral (pH 6.6); abrupt wavy boundary. (5 to 10 cm thick)

Cr--48 cm; partially weathered granitic bedrock, with clay films along fracture planes.

TYPE LOCATION: Douglas County, Nevada; 18 miles east and 6 miles north of Gardnerville, Nevada; about 500 feet south and 500 feet east of the northwest corner of section 19, T. 14 N., R. 23 E.; USGS Mount Como 7.5 minute topographic quadrangle; latitude 39 degrees 4 minutes 11 seconds N and longitude 119 degrees 27 minutes 6 seconds W; WGS84 Decimal Degrees 39.0696111 latitude, -119.4515278 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring; dry late June through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Mollic epipedon thickness: 18 to 30 cm.
Depth to paralithic contact: 36 to 50 cm.

Particle-size control section - Clay content: 10 to 18 percent.
Rock fragments: Average 35 to 50 percent gravel, mostly 2 mm to 5 mm.

A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 through 3.

Bt1 horizon
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 or 3.
Textures: Coarse sandy loam or loam.

Bt2 horizon
Value: 5 or 6 dry, 3 through 5 moist
Chroma: 2 through 4.
Texture: Coarse sandy loam or sandy loam.
Rock fragments: 35 to 60 percent gravel, mostly 2 mm to 5 mm.

COMPETING SERIES: These are the Acrelane, Erastra, Koontz, Tulecan and Ubehebe series.

Acrelane, Erastra, Koontz, Tulecan and Ubehebe soils have an argillic horizon with more than 18 percent clay.

GEOGRAPHIC SETTING: Roloc soils are on back slopes of mountains and ridges. Elevations are 1,676 to 2,286 meters. Slopes are 15 to 75 percent. The soils formed in residuum derived from granitic rock. The mean annual temperature is 7 to 9 degrees C and average annual precipitation is 300 to 360 mm. The frost-free season is 85 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Drit, Glean, and Trid solls. Drit and Glean soils are deep and lack an argillic horizon. Trid soils are moderately deep and have an argillic horizon with 27 to 35 percent clay.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is Wyoming big sagebrush, antelope bitterbrush, currant and Thurbers needlegrass, with invasion of pinyon-juniper.

DISTRIBUTION AND EXTENT: These soils are of small extent in western Nevada. MLRA 26.

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

SERIES ESTABLISHED: Douglas County Area, Nevada, 1981.

REMARKS: Diagnostic horizon and features recognized in this pedon are:
Mollic epipedon - The zone from 3 to 25 cm (A1, A2 and A3 horizon).
Argillic horizon - The zone from 30 to 48 cm (Bt1 and Bt2 horizon).
Paralithic contact - The zone at 48 cm (Cr layer).
Particle-size control section - The zone from 25 to 48 cm (Bt1 and Bt2 horizon).

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National Cooperative Soil Survey
U.S.A.