LOCATION JUANITA CO
Established Series
Rev. JPP/TWH/KLS
04/2018
JUANITA SERIES
The Juanita series consists of deep, well drained soils that formed in slope alluvium or colluvium derived from andesite. Juanita soils are on mesas or cuestas, and on hillslopes and scarp slopes on sides of mesas. Slopes range from 3 to 30 percent. Mean annual precipitation is about 559 mm and the mean annual air temperature is about 4.4 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ultic Haplustalfs
TYPICAL PEDON: Juanita loam, on an east facing, simple, 3 percent slope in woodland at an elevation of 2,775 meters. (Colors are for dry soil unless otherwise noted.) When described on May 26, 2004 the soil was very moist from 0 to 124 cm.
Oi--0 to 5 cm; slightly decomposed plant material, slightly acid. (3 to 8 cm thick)
A1--5 to 15 cm; dark brown (10YR 3/3) loam, weak fine granular structure; very dark gray (10YR 3/1) moist; soft, very friable, nonsticky, nonplastic; many very fine, fine, and medium roots; slightly acid (pH 6.4); clear smooth boundary. (5 to 20 cm thick)
A2--15 to 30 cm; dark brown (10YR 3/3) loam, weak fine granular structure; very dark grayish brown (10YR 3/2) moist; soft, very friable, nonsticky, nonplastic; common very fine, fine, and medium, and few coarse roots; common fine and very fine tubular pores; slightly acid (pH 6.4); clear smooth boundary. (combined thickness of A1, A2 - 50 to 45 cm)
Bt1--30 to 66 cm; brown (10YR 4/3) loam, weak medium subangular blocky structure; dark brown (10YR 3/3) moist; soft, very friable, slightly sticky, slightly plastic; common very fine, and fine, few medium, and few coarse roots; many fine and very fine tubular pores; few faint clay films on faces of peds; slightly acid (pH 6.2); clear smooth boundary.
Bt2--66 to 94 cm; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; common very fine and fine, and few medium and coarse roots; many fine and very fine tubular pores; common distinct clay films on faces of peds; 1 percent gravel and 3 percent channers; strongly acid (pH 5.4); clear smooth boundary.
Bt3--94 to 124 cm; reddish yellow (7.5YR 6/6) clay loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; few very fine, fine, medium, and coarse roots; many fine and very fine tubular pores; common distinct clay films on faces of peds; 1 percent gravel and 3 percent channers; strongly acid (pH 5.3); clear smooth boundary. (combined thickness of Bt1, Bt2, Bt3 - 60 to 130 cm)
R--124 to 135 cm; indurated andesite bedrock.
TYPE LOCATION: Archuleta County, Colorado; about 6 kilometers west of Edith; about 457 meters west and 732 meters south of the northeast corner of Section 8, T 32 N., R 1 W.; Lat. 37 degrees, 1 minutes, 13 seconds, N. and Long. 106 degrees, 58 minutes, 16 seconds, W.; USGS Edith quad; NAD 27.
RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral soil surface)
Mean annual soil temperature: 4.4 to 6.1 degrees C.
Mean summer soil temperature: 8.9 to 10.0 degrees C. with an O horizon.
Depth to lithic contact: 100 to 152 cm
Thickness of the mollic epipedon: 41 to 71 cm
Lithology of rock fragments: andesite
Particle-size control section: (weighted average)
Clay content: 25 to 30 percent
Rock fragments: 0 to 10 percent
A horizons
Hue: 7.5YR or 10YR
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 1 to 3, dry or moist
Clay content: 15 to 22 percent
Rock fragment content: 0 to 5 percent andesite channers
Reaction (pH): 6.1 to 7.3
Bt horizon, upper part
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3, dry or moist
Texture: loam, clay loam
Clay content: 22 to 30 percent
Rock fragment content: total content 0 to 5 percent;
0 to 5 percent andesite channers
0 to 5 percent andesite gravel
Reaction (pH): 5.6 to 6.5
Base saturation: Estimated 55 to 65 percent
Bt horizon, lower part
Hue: 7.5YR or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 to 6, dry or moist
Texture: loam, clay loam, sandy clay loam
Clay content: 25 to 32 percent
Fragment content: total content 0 to 10 percent;
0 to 10 percent andesite channers
0 to 5 percent andesite gravel
Electrical conductivity: 0 to 2 mmhos/cm
Reaction (pH): 5.6 to 6.5
Base saturation: Estimated 45 to 55 percent, less than 50 percent in some subhorizons.
COMPETING SERIES: None listed. A series in a closely related family is the
Jemez series. Jemez soils do not have low base saturation.
GEOGRAPHIC SETTING:
Landform - mesas, cuestas, or hillslopes and scarp slopes on sides of mesas or cuestas
Elevation - 2,650 to 2,800 meters
Slopes - 3 to 30 percent
Parent material - slope alluvium or colluvium derived from andesite
Precipitation pattern - July and August are the wettest months, receiving the most precipitation. May and June are the driest months, receiving the least precipitation, however the soils are still moist from snowmelt through mid-June.
Mean annual temperature - 3.9 to 5.6 degrees C.
Mean annual precipitation - 510 to 610 mm
Frost-free period - 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, low runoff, moderately slow permeability.
USE AND VEGETATION: Used for livestock grazing, timber production, and wildlife habitat. Native vegetation is white fir, quaking aspen, Arizona fescue, Thurber fescue, mountain brome, mountain snowberry, needlegrass, western wheatgrass, Kentucky bluegrass, sedge, and aspen peavine.
DISTRIBUTION AND EXTENT: Southwestern Colorado. LRR D, MLRA 36. This series is of small extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Archuleta County, Colorado, Archuleta soil survey area, 2004. The name is taken from the name of a community in the vicinity.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 5 to 81 cm (A1, A2, and Bt1 horizons)
Argillic horizon: 30 to 124 cm (Bt horizons)
Lithic contact: 124 cm to andesite bedrock (R layer)
Particle size control section: 30 to 80 cm (Bt1 and part of the Bt2 horizons)
Other features: Base saturation is estimated to be less than 50 percent in the Bt3 horizon (Alfisol rather than Mollisol), and less than 75 percent throughout the argillic horizon (Ultic subgroup).
Juanita soils have a frigid temperature regime and are in an ustic soil moisture regime bordering on udic.
National Cooperative Soil Survey
U.S.A.