LOCATION BREKO                   NV

Established Series
Rev. RWW/RLB/JBF
06/2016

BREKO SERIES

The Breko series consists of very deep, well drained soils that formed in alluvium derived from mixed rocks. Breko soils are on fan remnants, fan piedmonts and alluvial fans. Slopes are 0 to 30 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Xeric Haplargids

TYPICAL PEDON: Breko gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 50 percent gravel and 10 percent with cobbles.

A1--0 to 8 cm; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 5/3) moist; weak very thin and thin platy structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine, few medium roots; common very fine and fine tubular and interstitial pores; 30 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (5 to 10 cm thick)

A2--8 to 15 cm; light yellowish brown (10YR 6/4) loam, yellowish brown (10YR 5/4) moist; moderate very thin and thin platy structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine, few medium roots; common very fine and fine tubular and interstitial pores; 5 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 13 cm thick)

Bt1--15 to 30 cm; light brown (7.5YR 6/4) very gravelly clay loam, brown (7.5YR 5/4) moist; strong medium and coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine, few medium roots; common very fine and fine tubular pores; many distinct clay films lining pores and on faces of peds; 35 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (10 to 20 cm thick)

Bt2--30 to 53 cm; light brown (7.5YR 6/4) very gravelly sandy clay loam, brown (7.5YR 5/4) moist; strong fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; few very fine and fine tubular pores; common distinct clay films lining pores and on faces of peds; 55 percent gravel; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (8 to 30 cm thick)

Bt3--53 to 74 cm; light brown (7.5YR 6/4) extremely gravelly sandy clay loam, brown (7.5YR 5/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; films in pores and on peds; few very fine and fine roots; few very fine and fine tubular pores; few faint clay films lining pores and on faces of peds; 70 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (0 to 25 cm thick)

Bk--74 to 107 cm; very pale brown (10YR 7/4) extremely gravelly coarse sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; few very fine and fine interstitial and tubular pores; 75 percent gravel; common fine soft carbonate masses; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (23 to 110 cm thick)

2Bqk--107 to 117 cm; white (10YR 8/1) extremely gravelly loamy coarse sand, very pale brown (10YR 7/3) moist; massive; very hard, very firm and brittle; nonsticky and nonplastic; few very fine tubular pores; weak continuous brittle matrix; 75 percent gravel; few fine soft carbonate masses; violently effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (0 to 50 cm thick)

3Bk'--117 to 152 cm; very pale brown (10YR 7/3) extremely gravelly coarse sandy loam, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine interstitial pores; 75 percent gravel; common fine soft carbonate masses; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Nye County, Nevada; approximately 1.5 miles southwest of Mud Springs; about 1,500 feet east and 2,500 feet north of the southwest corner of section 19, T. 11 S., R. 46 E.; USGS Beatty 7.5 minute topographic quadrangle; latitude 36 degrees 57 minutes 55 seconds N and longitude 116 degrees 52 minutes 24 seconds W; WGS84 Decimal Degrees 36.9652778 latitude, -116.8733333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in the winter and spring months, dry in summer and fall except for 10 to 20 days cumulative between July and October due to convection storms; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 13 to 15 degrees C.

Particle-size control section - Clay content: 25 to 35 percent.
Rock fragments: Average 35 to 60 percent.

A horizon
Value: 5 through 7 dry, 3 through 6 moist.
Chroma: 2 through 4 dry or moist.
Effervescence: Noneffervescent or slightly effervescent.

Bt horizon
Hue: 10YR, 7.5YR or 5YR.
Value: 5 through 7 dry, 3 through 6 moist.
Chroma: 2 through 4, dry or moist.
Texture of fine earth: Clay loam, loam or sandy clay loam.
Clay content: 25 to 35 percent.
Rock fragments: 35 to 80 percent, gravel and cobbles.
Structure: Weak to strong subangular blocky, massive in the lower part of some pedons.
Consistence: Soft or hard dry, very friable or firm moist, slightly sticky or moderately sticky and slightly plastic or moderately plastic wet.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Slightly effervescent or strongly effervescent.
Other features: Some pedons have few thin carbonate filaments and coats on undersides of rock fragments.

Bk horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 3 or 4.
Texture: Stratified sandy loam to loamy coarse sand.
Clay content: 5 to 15 percent.
Rock fragments: Average 55 to 75 percent.
Structure: Massive or single grained.
Consistence: Soft to hard dry, nonsticky or slightly sticky wet.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Strongly effervescent or violently effervescent.

2Bqk horizon (when present)
Value: 6 through 8 dry, 5 through 7 moist.
Chroma: 1 through 4, dry or moist.
Texture: Coarse sandy loam, loamy coarse sand or loamy sand.
Rock fragments: 35 to 75 percent, gravel and cobbles.
Reaction: Strongly alkaline or very strongly alkaline.
Cementation: Weak continuous brittle matrix or 30 to 50 percent durinodes in a friable matrix.
Consistence: Soft to very hard dry, very friable moist.

3Bk' horizon (when present)
Value: 6 or 7 dry, 4 through 6 moist.
Chroma: 2 or 3 dry or moist.
Texture of fine earth: Sandy loam or coarse sandy loam.
Rock fragments: 65 to 80 percent, gravel and cobbles.
Effervescence: Strongly effervescent or violently effervescent.

COMPETING SERIES: These are the Bairs, Basket, Chiefrange, Cowgil, Drino, Hefed, Huilepass, Hunewill, Jungo, Kayo, Lithgow, Plush, Schader, Stucky and Washoe series.

Bairs, Basket, Chiefrange, Cowgil, Drino, Hefed, Huilepass, Hunewill, Jungo, Kayo, Lithgow, Plush, Stucky and Washoe soils lack free carbonates in the A and upper part of the Bt. Bairs soils contain stones and boulders in the particle-size control section. Chiefrange, Cowgil, Drino, Hefed, Huilepass, Hunewill, Jungo, Kayo, Lithgow, Plush, Stucky, and Washoe soils have mean annual soil temperatures less than 13 degrees C. Schader soils are moderately deep to bedrock.

GEOGRAPHIC SETTING: Breko soils are on fan remnants, fan piedmonts and alluvial fans. These soils formed in alluvium from mixed rocks, mainly volcanic tuff with minor amounts of limestone and quartzite. Slopes are 0 to 30 percent. Elevations are 1.460 to 1,980 meters. The climate is cool, semiarid with cool moist winters and hot dry summers. The mean annual precipitation is 150 to 250 mm, mean annual temperature is 12 to 14 degrees C, and the frost-free season is 120 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Handpah, Veet and Wiskiflat series. Handpah soils are shallow over indurated duripans. Veet and Wiskiflat soils do not have argillic horizons.

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

USE AND VEGETATION: Livestock grazing and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, shadscale, spiny hopsage, ephedra, and Indian ricegrass.

DISTRIBUTION AND EXTENT: Southwestern Nevada. These soils are moderately extensive. MLRA 29, 30.

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

SERIES ESTABLISHED: Esmeralda County, Nevada, 1984.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 15 cm.(A1 and A2 horizon)
Argillic horizon - The zone from about 15 to 74 cm (Bt1, Bt2 and Bt3 horizon).
Xeric intergrades - Meets organic carbon requirement for Xeric.
Particle-size control section - The zone from about 15 to 65 cm. (Bt1, Bt2 and part of Bt3 horizon)

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National Cooperative Soil Survey
U.S.A.