LOCATION SHAVANO                 CO+NM

Established Series
Rev. AJC//CRP/JCK
12/2017

SHAVANO SERIES

The Shavano series consist of moderately deep, well drained soils formed in slope alluvium or colluvium over residuum derived from sedimentary rock. Shavano soils are on dip slopes, escarpments, strath terraces, fan remnants and pediments. Slopes are 0 to 35 percent. Mean annual precipitation is about 279 mm, and mean annual air temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ustic Haplocambids

TYPICAL PEDON: Shavano sandy clay loam, on a northeast-facing 10 percent slope at an elevation of 1,914 meters. (Colors are for dry soil unless otherwise noted.)

A--0 to 12 cm; brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; weak fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; 5 percent gravel and 2 percent cobbles; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (12 to 25 cm thick)

Bw--12 to 53 cm; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 5/4) moist; weak fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; 10 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (20 to 46 cm thick)

BCk--53 to 84 cm; pink (7.5YR7/4) sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; 5 percent fine calcium carbonate masses in the matrix and carbonate coats on bottom of rock fragments; 10 percent gravel and 2 percent cobbles; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (10 to 30 cm thick)

R--84 cm; hard sandstone bedrock.

TYPE LOCATION: Montrose County, Colorado; located about 274 meters east and 579 meters south of the northwest corner of section 20, T. 48 N., R. 9 W. Latitude 38 degrees, 24 minutes 6 seconds N, longitude 107 degrees, 53 minutes 10 seconds W. NAD 1927.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 9 to 13 degrees C
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent

A horizon
Hue: 7.5YR or 10YR
Value: 4, 5 or 6 dry or moist
Chroma: 3 or 4 dry or moist
Texture: sandy clay loam, loam or sandy loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent
Reaction: pH 7.4 to 8.2

Bw horizon
Hue: 7.5YR or 10YR
Value: 4, 5, 6 or 7 dry or moist
Chroma: 4 or 6 dry or moist
Texture: sandy clay loam, loam or sandy loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent
Reaction: pH 7.4 to 8.2

BCk horizon:
Hue: 7.5YR or 10YR
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 4 or 6 dry or moist
Texture: sandy loam, loam or sandy clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent
Calcium carbonate equivalent: 5 to 15 percent
Sodium adsorption ratio: 0 to 4
Reaction: pH 8.0 to 8.4

COMPETING SERIES:
Aquima (NM) - are very deep
Atrac (NM) - are very deep
Bullpen (UT) - are deep to a paralithic contact
LaFonda (NM) - are very deep
Pultney (CO) - have a paralithic contact; have a horizon of secondary salt accumulation
Querencia (NM) - are very deep
Zigweid (WY) - are very deep

GEOGRAPHIC SETTING:
Elevation - 1,585 to 2,134 meters
Landform - dip slopes, escarpments, strath terraces, fan remnants and pediments
Slope - 0 to 35 percent
Parent material - slope alluvium or colluvium over residuum
Mean annual air temperature - 8 to 12 degrees C
Mean annual precipitation - 203 to 305 mm
Precipitation pattern - even yearly distribution with slight increase in spring and significant increase in late summer
Frost-free period - 120 to 165 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lazear, Barboncito and Cameo soils.

DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.

USE AND VEGETATION: Shavano soils are used mainly for rangeland with some irrigated pasture and hayland. Native vegetation is James' galleta, Indian ricegrass, Wyoming big sagebrush, fourwing saltbush and squirreltail.

DISTRIBUTION AND EXTENT: Shavano soils are of moderate extent in western Colorado and northwestern New Mexico. MLRA 34B and 36.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Uncompahgre Valley Area, Montrose County, Colorado, 1910.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon from - 0 to 12 cm (A horizon)
Cambic horizon from - 12 to 53 cm (Bw horizon)
Secondary calcium carbonate accumulation from - 53 to 84 cm (BCk horizon)
Particle-size control section from - 25 to 84 cm (Bw and BCk horizons)

Shavano soils have a mesic temperature regime and an aridic moisture regime bordering on ustic.

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National Cooperative Soil Survey
U.S.A.