LOCATION PERSAYO                 CO+NM UT WY

Established Series
Rev. AJC/CRP/JCK
07/2017

PERSAYO SERIES

The Persayo series consists of shallow, well drained soils that formed in slope alluvium or colluvium over residuum derived from soft sedimentary bedrock. These soils are on hills, basin floor remnants, fan remnants, dipslopes, scarp slopes and escarpments. Slopes are 0 to 65 percent. Mean annual precipitation is about 203 mm, and mean annual air temperature is about 10.5 degrees C.

TAXONOMIC CLASS: Loamy, mixed, active, calcareous, mesic, shallow Typic Torriorthents

TYPICAL PEDON: Persayo silty clay loam in grassland. (Colors are for dry soil unless otherwise noted.)

A--0 to 10 cm; light yellowish brown (2.5Y 6/3) silty clay loam, light olive brown (2.5Y 5/3) moist; moderate fine granular structure, weak platy in the upper 1 cm; soft, very friable; strongly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (2.5 to 18 cm thick)

C--10 to 36 cm; light yellowish brown (2.5Y 6/4) silty clay loam, light olive brown (2.5Y 5/4) moist; weak medium subangular blocky structure parting to moderate fine granules; hard, very friable; few fine gypsum crystals; strongly effervescent; moderately alkaline (pH 8.2) gradual smooth boundary. (18 to 36 cm thick)

Cr--36 cm; calcareous gray and yellow shale and siltstone.

TYPE LOCATION: Montrose County, Colorado; 161 meters north of the southeast corner of Sec. 22, T. 51 N., R. 10 W.; 38 degrees, 39 minutes, 56 seconds N. 107 degrees, 58 minutes, 1 second W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 8 to 14 degrees C
Depth to paralithic contact - 25 to 50 cm
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent
Pararock fragments: 0 to 70 percent

A horizon
Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: silty clay loam, silt loam, clay loam or loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent; 0 to 35 percent gravel or channers, 0 to 15 percent cobbles, 0 to 10 percent flagstones or stones
Electrical conductivity: 0 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 8
Reaction: pH 7.6 to 9.0

C horizon
Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: silty clay loam, silt loam, loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent; 0 to 35 percent gravel or channers, 0 to 15 percent cobbles, 0 to 10 percent flagstones or stones
Electrical conductivity: 0 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 8
Reaction: pH 7.6 to 9.0

COMPETING SERIES:
Poncho (UT) - have hue redder than 10YR
Shalet (UT) - have a lithic contact; have hue redder than 10YR

GEOGRAPHIC SETTING:
Landform - hills, basin floor remnants, fan remnants, dipslopes, scarp slopes and escarpments
Elevation - 1,219 to 1,890 meters
Slope - 0 to 65 percent
Parent material - slope alluvium or colluvium over residuum derived from soft sedimentary bedrock
Mean annual precipitation - 152 to 229 mm
Mean annual temperature - 7.2 to 12.8 degrees C
Frost-free period - 110 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; moderate to moderately slow permeability.

USE AND VEGETATION: Persayo soils are used primarily for rangeland. Native vegetation is shadscale saltbush, Indian ricegrass, galleta, Gardner's saltbush, squirreltail and bud sagebrush.

DISTRIBUTION AND EXTENT: The series is extensive in western Colorado, northwestern New Mexico, eastern Utah and western Wyoming. MLRA 32, 34A, 34B, 35, 36.

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

SERIES ESTABLISHED: Western Colorado Reconnaissance, W95, 1939.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 10 cm
Paralithic contact - at 36 cm
Series control section - from 0 to 36 cm (A and C horizons)


Persayo soils have a mesic temperature regime and an aridic moisture regime.

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National Cooperative Soil Survey
U.S.A.