LOCATION AZAAR MT
Established Series
Rev. COC/JAL/RJS
05/2013
AZAAR SERIES
The Azaar series consists of moderately deep, well drained soils that formed in slope alluvium or colluvium over calcareous siltstone and sandstone residuum. These soils occur on fan remnants, escarpments, hillslopes and mountain slopes. Slopes are 0 to 60 percent The mean annual precipitation is about 16 inches and the mean annual air temperature is about 5.0 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Azaar fine sandy loam, cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 18 cm; dark grayish brown (10YR 4/2) fine sandy loam, very dark brown (10YR 2/2) moist; weak fine and very fine crumb structure and weak medium and fine blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many fine and very fine roots and very fine pores; neutral (pH 7.0); clear wavy boundary.
Bw--18 to 33 cm; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak coarse and medium prismatic structure; slightly hard, very friable, slightly sticky and nonplastic; many fine and very fine roots; many fine and very fine pores, few medium pores; slightly alkaline (pH 7.4); clear wavy boundary. (0 to 25 cm thick)
2Bk1--33 to 56 cm; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; weak coarse prismatic structure parting to weak coarse and medium subangular blocky structure; hard, very friable, moderately sticky and slightly plastic; many fine and very fine roots; many fine and very fine pores; few medium pores; few fine faint lime masses; few fine angular sandstone fragments with lime crusts on underside; violently effervescent; moderately alkaline (pH 8.0); diffuse wavy boundary.
2Bk2--56 to 81 cm; grayish brown (2.5Y 5/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; very hard, friable, moderately sticky and moderately plastic; many fine and very fine roots; many fine and very fine pores; common medium distinct lime masses; few fine angular lime coated sandstone fragments; violently effervescent; strongly alkaline (pH 8.5); abrupt wavy boundary. (combined thickness of 2Bk1, 2Bk2 - 28 to 56 cm)
2R--81 cm; fractured indurated sandstone.
TYPE LOCATION: Cascade County, Montana; 200 meters east and 185 meters south of the NW corner of SW quarter of section 34, T.19N., R.2E.
RANGE IN CHARACTERISTICS:
Mollic epipedon - 25 to 40 cm thick
Depth to a calcic horizon - 25 to 50 cm
Depth to a lithic contact - 50 to 100 cm
The control section averages 24 to 30 percent clay and more than 15 percent fine sand or coarser
Mean annual soil temperature - 5.5 to 8.0 degrees C.
Note: Some pedons may have a BC horizon below the calcic layer.
A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 10 to 27 percent
Texture: fine sandy loam, loam, silt loam
Rock fragments: 0 to 15 percent
Reaction: pH 6.6 to 7.8
Bw horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 20 to 27 percent
Texture: silt loam or loam
Rock fragments: 0 to 15 percent
Reaction: pH 7.9 to 8.6
2Bk1, 2Bk2 horizons
Hue: 10YR to 5Y; dry or moist
Value: more than 6 dry
Chroma: 2 or 3; dry or moist
Clay content: 18 to 35 percent
Texture: silt loam, loam, clay loam or silty clay loam
Rock fragments: 5 to 35 percent
Calcium carbonate equivalent: 15 to 25 percent
Reaction: pH 7.9 to 8.6
COMPETING SERIES:
Amor (ND) - are moderately deep to a paralithic contact
Diagulch (UT) - have hues of 7.5YR or redder throughout
HiBar (MT) - do not have a calcic horizon
Max (ND) - do not have a discontinuity above a depth of 150 cm that have 30 percent or more rock fragments
Peerless (MT) - have a discontinuity above a depth of 100 cm that have more than 35 percent rock fragments
Prospect (MT) - are very deep
Quigley (MT) - are very deep
Shambo (MT)- are very deep
Tansem (MT)- are very deep
Tewfel (MT)- are moderately deep to a paralithic contact
Twincreek (MT) - are very deep
GEOGRAPHIC SETTING:
Landform - fan remnants, escarpments, hillslopes and mountain slopes
Elevation - 790 to 1,500 meters
Slopes - 0 to 60 percent
Parent material - slope alluvium or colluvium over calcareous siltstone and sandstone residuum
Climate - cool, moist-semiarid with long cold dry winters and moist springs and summers
Mean annual precipitation - 350 to 500 mm
Mean annual air temperature - 5.0 to 7.5 degrees C.
Frost-free period - 80 to 135 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow or slow permeability.
USE AND VEGETATION: These soils are used for nonirrigated cropland and for rangeland. The principal native vegetation is bluebunch wheatgrass and needle-and-thread grass.
DISTRIBUTION AND EXTENT: The Azaar soils occur mainly in central Montana. They are of small extent. MLRAs - 43B, 44B, 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Cascade County, Montana, 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 33 cm (A, Bw horizons)
Calcic horizon - from 33 to 81 cm (2Bk1, 2Bk2 horizons)
Lithic contact - at a 81 cm (2R horizon)
Particle-size control section from 25 to 81 cm (part of Bw, 2Bk1, 2Bk2 horizons)
Azaar soils have a frigid temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.