LOCATION FRODO                   NV

Established Series
Rev. OWB/JBF/JVC
03/2017

FRODO SERIES

The Frodo series consists of shallow, well drained soils that formed in residuum and colluvium derived from basaltic rock. Frodo soils are on remnants of lava plateaus. Slopes are 2 to 30 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Paleargidic Durixerolls

TYPICAL PEDON: Frodo extremely stony loam--rangeland. (Colors are for dry soils unless otherwise noted.)

A1--0 to 3 cm; very dark grayish brown (10YR 3/2) extremely stony loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky parting to weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots; few very fine and fine tubular pores; 10 percent gravel, 30 percent cobbles, and 25 percent stones; neutral (pH 6.8); abrupt smooth boundary. (3 or 5 cm thick)

A2--3 to 15 cm; dark grayish brown (10YR 4/2) loam, dark brown (10YR 3/3) moist; strong medium subangular blocky parting to weak thin and medium platy structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine and fine tubular pores; 5 percent gravel and 5 percent cobbles; neutral (pH 6.8); abrupt smooth boundary. (10 to 15 cm thick)

Bt--15 to 41 cm; brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; strong medium prismatic parting to strong medium subangular blocky structure; extremely hard, firm, very sticky and very plastic; common very fine and fine roots; few very fine and fine tubular pores; common distinct clay films on faces of peds; 5 percent stones; slightly alkaline (pH 7.4); clear smooth boundary. (13 to 30 cm thick)

Btk--41 to 46 cm; dark yellowish brown (10YR 4/4) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine angular blocky structure; very hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; few very fine and fine tubular pores; common distinct clay films on faces of peds; 25 percent gravel; slightly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 or 8 cm thick)

Bkqm--46 to 58 cm; very pale brown (10YR 7/3) cemented material, pale brown (10YR 6/3) moist; massive; extremely hard; continuous strongly silica-cemented; strongly effervescent; moderately alkaline (8.4); abrupt wavy boundary. (10 to 30 cm thick)

R--58 to 107 cm; hard, fractured bedrock.

TYPE LOCATION: Washoe County, Nevada; between Spanish Springs Valley and the Pah Rah Range; approximately 900 feet west and 500 feet south of the northeast corner of section 32, T. 21 N., R. 21 E.; USGS Griffith Canyon 7.5 minute topographic quadrangle; latitude 39 degrees 38 minutes 56 seconds N and longitude 119 degrees 38 minutes 38 seconds W; WGS84 Decimal Degrees 39.6488889 latitude, -119.6438889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist for short periods during the winter and spring; dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 12 degrees C.
Mollic epipedon thickness: 25 to 50 cm; includes the upper part of the argillic horizon.
Depth to duripan: 36 to 50 cm.
Depth to bedrock: 46 to 76 cm to a lithic contact.
Other features: There is a clay increase of 20 percent or more between the A2 and Bt horizons accompanied by a clear horizon boundary.

Particle-size control section - Clay content: 35 to 60 percent.
Rock fragments: Average 5 to 35 percent.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Slightly acid or neutral.
Organic matter content: 1 or 2 percent.

Bt horizon or Bt1 horizon (when present)
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Clay or clay loam.
Clay content: 35 to 45 percent.
Organic matter content: 1 or 2 percent.

Bt2 horizon (when present)
Hue: 7.5YR or 10YR.
Value: 4 or 6, dry or moist.
Texture: Clay.
Clay content: 45 to 60 percent.
Rock fragments: 5 to 25 percent.

Btk horizon
Texture: Gravelly clay or gravelly clay loam
Rock fragments: 15 to 35 percent.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Frodo soils are on remnants of lava plateaus. These soils formed in residuum and colluvium derived from basaltic rocks. Slopes are 2 to 30 percent. Elevations range from 1,375 to 2,135 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 300 mm, the mean annual temperature is 7 to 10 degrees C., and the frost-free period is 80 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barshaad, Tristan, and Xman soils. Barshaad and Xman soils do not have duripans. Tristan soils are loamy-skeletal.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow permeability; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Frodo soils are used for rangeland. The native vegetation is low sagebrush, Douglas rabbitbrush, bottlebrush squirreltail, and Thurber's needlegrass.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive with about 9,300 acres of the series mapped to date. MLRA 26.

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 41 cm (A1, A2, and Bt horizons).
Argillic horizon - The zone from 15 to 46 cm (Bt and Btk horizons).
Paleargidic subgroup feature - The clay increase of 20 percent or more at 15 cm. (between the A2 and Bt horizons).
Duripan - The zone from 46 to 58 cm (Bkqm horizon).
Lithic contact - The boundary at 58 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from 15 to 46 cm (Bt and Btk horizons).

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National Cooperative Soil Survey
U.S.A.