LOCATION XERIBRUSH CO
Established Series
Rev. CRP/JCK
04/2019
XERIBRUSH SERIES
The Xeribrush series consists of very deep, well drained soils that formed in slope alluvium, colluvium or slide deposits. These soils are on fan remnants, dipslopes, strike valleys, escarpments, scarp slopes and landslides. Slopes are 3 to 65 percent. Mean annual precipitation is about 356 mm, and mean annual air temperature is about 8.3 degrees C.
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Aridic Argiustolls
TYPICAL PEDON: Xeribrush loam, on a north facing, 21 percent slope in sagebrush at an elevation of 2,218 meters. The surface is covered by about 5 percent stones. (Colors are for dry soil unless otherwise noted.)
A--0 to 10 cm; very dark grayish brown (10YR 3/2) loam; very dark grayish brown (2.5Y 3/2) moist; weak fine and medium subangular blocky structure parting to weak fine granular; soft, very friable, slightly sticky and slightly plastic; many fine and very fine, and common medium and coarse roots; 5 percent gravel, 5 percent cobbles and 2 percent stones; neutral (pH 7.0); clear wavy boundary. (15 to 40 cm thick)
Bt1--10 to 30 cm; grayish brown (10YR 5/2) clay loam; very dark grayish brown (2.5Y 3/2) moist; weak coarse subangular blocky structure parting to weak fine and medium subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; many fine and very fine, and common medium and coarse roots; common fine dendritic tubular pores; 15 percent faint clay films on all ped faces; 2 percent gravel; neutral (pH 7.0); clear wavy boundary.
Bt2--30 to 38 cm; light olive brown (2.5Y 5/3) clay loam; dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure parting to moderate fine and medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common fine and very fine, and few medium and coarse roots; common fine dendritic tubular pores; 35 percent distinct clay films on all ped faces; 2 percent gravel; neutral (pH 7.0); clear wavy boundary. (Combined thickness of Bt horizons is 10 to 50 cm thick)
Btk1--38 to 69 cm; light olive brown (2.5Y 5/3) clay loam; olive brown (2.5Y 4/3) moist; weak coarse subangular blocky structure parting to strong medium subangular blocky; hard, firm, very sticky and moderately plastic; few fine, medium, and coarse roots; few fine dendritic tubular pores; 60 percent prominent clay films on all ped faces; 10 percent fine, medium and coarse irregular shaped calcium carbonate masses in the matrix and along root channels; 2 percent gravel; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary.
Btk2--69 to 112 cm; light yellowish brown (2.5Y 6/3) clay; light olive brown (2.5Y 5/3) moist; weak coarse subangular blocky structure parting to strong fine and medium subangular blocky; hard, firm, very sticky and very plastic; few fine and medium roots; few fine dendritic tubular pores; 80 percent prominent clay films on all ped faces; 30 percent medium and coarse irregular shaped calcium carbonate masses in the matrix and along root channels; 3 percent gravel and 2 percent cobbles; violently effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (Combined thickness Btk horizons is 20 to 75 cm)
Bk--112 to 152 cm; grayish brown (2.5Y 5/2) clay loam; dark grayish brown (2.5Y 4/2) moist; weak fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; very few fine roots; few fine dendritic tubular pores; 10 percent fine, medium and coarse calcium carbonate masses in the matrix; 5 percent gravel and 2 percent cobbles; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Montrose County, CO; located about 579 meters south and 457 meters east of the northwest corner of sec. 18, T. 47 N., R. 107 W.; Buckhorn Lakes USGS quad; lat. 38 degrees 19 minutes 46 seconds N. and long. 107 degrees 43 minutes 9 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 8 to 11 degrees C
Mollic epipedon thickness - 18 to 40 cm
Particle-size control section (weighted average):
Clay content - 35 to 50 percent
Rock fragments - 0 to 15 percent; 0 to 15 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones
A horizon
Hue: 10YR or 2.5Y
Value: 3, 4 or 5 dry; 2 or 3 moist
Chroma: 1, 2 or 3
Texture: loam or clay loam
Clay content: 15 to 30 percent
Rock fragments: 0 to 15 percent; 0 to 15 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones
Reaction: 6.8 to 7.6
Bt horizons
Hue: 10YR or 2.5Y
Value: 5 or 6 dry: 2, 3 or 4 moist
Chroma: 2, 3 or 4
Texture: clay loam, silty clay loam or clay
Clay content: 28 to 50 percent
Rock fragments: 0 to 15 percent; 0 to 15 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones
Reaction: 6.8 to 7.8
Btk horizons
Hue: 10YR or 2.5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: clay loam, silty clay loam, or clay
Clay content: 28 to 50 percent
Rock fragments: 0 to 15 percent; 0 to 15 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones
Calcium carbonate equivalent: 5 to 15 percent
Reaction: 8.0 to 8.6
Bk horizon (where present)
Hue: 10YR or 2.5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: clay loam or silty clay loam
Clay content: 28 to 40 percent
Rock fragments: 0 to 15 percent; 0 to 15 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones
Calcium carbonate equivalent: 5 to 15 percent
Reaction: 8.0 to 8.4
COMPETING SERIES:
Abrazo (NM) - have a lithic contact at depths 50 to 100 cm; do not have secondary calcium carbonate accumulation
Cantina (NM) - have a lithic contact at depth of 100 to 150 cm
Carnero - (NM) - have a lithic contact at depths 50 to 100 cm; do not have secondary calcium carbonate accumulation
Celsosprings (NM) - do not have secondary calcium carbonate accumulation; have hue redder than 10YR
Charette (NM) - have a lithologic discontinuity; have hue redder than 10YR
Concho (NM) - have slickensides and cracks; have calcium carbonate equivalent less than 5 percent
Judd (NM) - have a calcic horizon
Remunda (NM) - have hue redder than 10YR; have a mean annual soil temperature greater than 11 degrees C
Rond (AZ) - have a lithic contact at depths of 100 to 150 cm; have hue redder than 10YR
Roundtop (AZ) - have a lithic contact at depths of 50 to 100 cm; have hue redder than 10YR
GEOGRAPHIC SETTING:
Landform - fan remnants, dipslopes, strike valleys, escarpments, scarp slopes and landslides
Elevation - 1,829 to 2,286 meters
Slope - 3 to 65 percent
Parent material - slope alluvium, colluvium or landslide deposits
Mean annual air temperature - 7.2 to 10 degrees C
Mean annual precipitation - 305 to 406 mm
Frost-free period - 105 to 155 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow to slow permeability.
USE AND VEGETATION: Xeribrush soils are primarily used for rangeland and recreation with some areas in irrigated hay or pasture. Native vegetation is mainly western wheatgrass, Wyoming big sagebrush, yellow rabbitbrush, Indian ricegrass, scarlet globemallow and squirreltail.
DISTRIBUTION AND EXTENT: Xeribrush soils are of small extent in southwest Colorado. MLRA 36 and 48A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Montrose County, Colorado - Ridgway Area, Colorado, Parts of Delta, Gunnison, Montrose, and Ouray Counties, 2019.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 30 cm (A and Bt1 horizons)
Argillic horizon - from 10 to 112 cm (Bt1, Bt2, Btk1 and Btk2 horizons)
Secondary calcium carbonate accumulation - from 38 to 152 cm (Btk1, Btk2 and Bk horizons)
Particle-size control section - from 10 to 60 cm (Bt1, Bt2 and part of Btk1 horizon)
Xeribrush soils have a mesic temperature regime and an ustic moisture regime bordering on aridic.
National Cooperative Soil Survey
U.S.A.