LOCATION RIDIT NV

Established Series
Rev. WMA/RMW/ELS/JBF
11/2016

RIDIT SERIES

The Ridit series moderately deep, well drained soils that formed in residuum derived from basalt and andesite with additions of loess high in volcanic ash. Ridit soils are on foothills. Slopes are 8 to 30 percent. Mean annual precipitation is about 250 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Xeric Haplodurids

TYPICAL PEDON: Ridit gravelly loam - rangeland (Colors are for dry soil unless otherwise noted.) The surface is covered with 30 percent gravel

A1--0 to 8 cm; light brownish gray (10YR 6/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine interstitial pores; 15 percent angular gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 10 cm thick)

A2--8 to 20 cm; light brownish gray (10YR 6/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium and fine, and common very fine roots; many fine and very fine tubular and vesicular pores; 10 percent gravel; neutral (pH 6.8); clear wavy boundary. (5 to 15 cm thick)

Bw--20 to 38 cm; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, moderately sticky and slightly plastic; many very fine, common fine, and few medium roots; few fine, and many very fine tubular pores; 10 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (10 to 25 cm thick)

2Bqk1--38 to 53 cm; light brownish gray (10YR 6/2) very gravelly loam, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; many medium, few fine, and common very fine roots; few fine, and many very fine tubular pores; discontinuous unoriented silica laminae and durinodes; 55 percent gravel; silica and carbonate coating undersides of gravel; very slightly effervescent but strongly effervescent on coatings; moderately alkaline (pH 8.4); abrupt smooth boundary. (10 to 20 cm thick)

2Bqk2--53 to 79 cm; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and slightly plastic; few fine, common medium and very fine roots; few fine, and many very fine tubular pores; 65 percent gravel; thin and moderately thick silica-carbonate coating undersides of gravel; strongly effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (13 to 25 cm thick)

3Bqkm--79 to 86 cm; very pale brown (10YR 8/2) and light gray (10YR 7/2) indurated duripan, light gray (10YR 7/2) and brown (10YR 5/3) moist; massive; extremely hard, extremely firm; strongly effervescent; very strongly alkaline (pH 9.2); abrupt smooth boundary. (5 to 15 cm thick)

R-- 86 cm; andesite bedrock.

TYPE LOCATION: Elko County, Nevada; 1,250 feet west and 2,800 feet south of the NE corner of sec. 2, T. 26 N., R. 54 E.; USGS Sader Basin 7.5 minute topographic quadrangle; latitude 40 degrees 9 minutes 49 seconds N and longitude 115 degrees 51 minutes 18 seconds W; WGS84 Decimal Degrees 40.1636111 latitude, -115.8550000 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry moist in winter and early spring; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mean summer soil temperature: 16 to 17 degrees C.
Depth to indurated duripan: 50 to 75 cm.
Depth to bedrock: 55 to 100 cm.

Particle-size control section: - Clay content: Average 18 to 25
Rock fragment: Average 50 to 75 percent gravel, cobble, and stones.

A horizons
Value: 6 or 7 dry, 4 or 5 moist,
Chroma: 2 or 3.

Bw horizon
Value: 6 or 7 dry, 4 or 5 moist,
Chroma: 2 or 3.
Structure: Moderate or weak medium and fine subangular blocky, or it is massive.

2Bqk horizons
Texture: Loam or fine sandy loam.
Modifiers: Very gravelly or extremely gravely.
Reaction: Moderately alkaline or strongly alkaline
Bqkm horizon: Duripan has one to several (2 to 10 mm thick) continuous, indurated, silica-carbonate laminae between weakly or strongly carbonate-silica cemented layers.

COMPETING SERIES: These are the Lone and Westindian series.

Lone and Westindian soils have lack bedrock within 100 cm.

GEOGRAPHIC SETTING: Ridit soils are on foothills at elevations of 1,830 to 2,140 meters. Slope are 8 to 30 percent. The soils formed in residuum derived from basalt and andesite with additions of loess high in volcanic ash. The climate is cool, semiarid. Mean annual precipitation is 200 to 300 mm and comes mostly as snow. The mean annual temperature is 6 to 7 degrees C.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alpha, Pedoli and Rubyhill soils. Alpha soils are deep and have a mollic epipedon. Pedoli soils have argillic horizons, lack duripans, and have fine-loamy particle-size control sections. Rubyhill soils have strongly cemented duripans at 50 to 76 cm and fine-loamy particle-size control sections.

DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Livestock grazing and wildlife habitat. Vegetation is principally big sagebrush, with Indian ricegrass, bottlebrush squirreltail, bluebunch wheatgrass, and horsebrush.

DISTRIBUTION AND EXTENT: North central Nevada. The series is moderately extensive. MLRA 28B.

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

SERIES ESTABLISHED: Elko County (Diamond Valley Area), Nevada, 1971.

REMARKS: Ridit soils were formerly classified as Sierozems.

Diagnostic horizon and features recognized in this pedon are:
Xeric Intergrades - Meets organic carbon requirement for xeric.
Ochric epipedon - The zone from 0 to 18 cm (A1 and part of the A2 horizon).
Cambic horizon - The zone from 20 to 38 cm (Bw horizon).
Duric features - The zone from 38 to 79 cm (2Bqk1 and 2Bqk2 horizon).
Indurated duripan - The zone at 79 to 86 cm (3Bqkm horizon).
Bedrock - The layer at 86 (R layer).
Particle-size control section - The zone from 25 to 86 cm (2Bqk1, 2Bqk2 and part of the Bw horizon).

National Cooperative Soil Survey
U.S.A.