LOCATION BOXWELL MT+ND SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Haplustolls
TYPICAL PEDON: Boxwell silt loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 5 inches; grayish brown (2.5Y 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine interstitial pores; neutral (pH 7.0); abrupt smooth boundary. (A horizon is 3 to 8 inches thick)
Bw1--5 to 9 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure; slightly hard, friable, moderately sticky and moderately plastic; coatings of dark grayish brown (10YR 4/2); common fine roots; common fine tubular pores; neutral (pH 7.2); clear smooth boundary.
Bw2--9 to 14 inches; grayish brown (2.5Y 5/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure; slightly hard, very friable, moderately sticky and moderately plastic; common fine roots; common fine tubular pores; slightly effervescent; slightly alkaline (pH 7.6); clear wavy boundary. (Combined thickness of Bw horizons is 5 to 12 inches)
Bk--14 to 28 inches; white (5Y 8/2) silt loam, light gray (5Y 7/2) moist; weak coarse prismatic structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine roots; common fine pores; many fine masses of lime; violently effervescent; moderately alkaline (pH 8.4); gradual smooth boundary. (12 to 25 inches thick)
Cr--28 to 60 inches; light gray (5Y 7/2) semiconsolidated sandstone that crushes to a sandy loam, light olive gray (5Y 6/2) moist; upper part strongly effervescent.
TYPE LOCATION: Glacier County, Montana; 200 feet north and 1,600 feet east of the center of sec. 24, T. 26 N., R. 8 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches, dry in all parts less than five-tenths and dry in some parts more than six-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to Bk horizon - 8 to 16 inches.
Depth to Cr horizon - 20 to 40 inches.
Ap horizon - Hue: 10YR or 2.5Y
Chroma: 2 or 3
Texture: loam, silt loam, clay loam, or silty clay loam
Clay content: 15 to 30 percent
Rock fragments: 0 to 70 percent--0 to 70 percent cobbles and stones; 0 to 15 percent pebbles or channers
Reaction: pH 6.1 to 7.8
Bw horizons - Hue: 10YR or 2.5Y
Value: 4, 5, 6 or 7 dry; 3, 4, or 5 moist
Chroma: 2, 3, or 4
Texture: silt loam, clay loam, loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent pebbles or channers
Reaction: pH 6.6 to 7.8
Bk horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 6, 7, or 8 dry; 4, 5, 6, or 7 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam, silty loam, loam, and very fine sandy loam
Clay content: 15 to 30 percent
Rock fragments: 0 to 15 percent pebbles or channers
Calcium carbonate equivalent: 15 to 30 percent
Reaction: pH 7.4 to 8.4
Cr horizon - semicomsolidated sandstone, siltstone, mudstone, or a combination of these materials interbedded. They crush to a very fine sandy loam, sandy loam, silt loam, or silty clay loam.
COMPETING SERIES:
Anamac (MT) - does not have a paralithic contact at 20 to 40 inches.
Conn (MT) - does not have a paralithic contact at 20 to 40 inches.
Fortbenton (MT) - does not have a paralithic contact at 20 to 40 inches.
Kremlin (MT) - does not have a paralithic contact at 20 to 40 inches.
Littlemo (ND) - does not have a paralithic contact at 20 to 40 inches.
Waterhill (UT) - does not have a paralithic contact at 20 to 40 inches.
GEOGRAPHIC SETTING:
Landform - sedimentary plains; hills.
Elevation - 2,300 to 5,500 feet.
Slope - 0 to 60 percent.
Parent material - residuum derived from semiconsolidated sedimentary beds consisting of shale, siltstone, mudstone, and sandstone or an interbedded mixture of these materials. In some areas they formed in loam textured alluvial, eolian, or glacial deposits over these beds.
Climate - cold winters; moist springs; warm, dry summers.
Mean annual precipitation - typically 10 to 14 inches. In MLRA 58C and 58D it ranges to 16 inches.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 70 to 130 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability. The underlying shale beds are very slowly permeable.
USE AND VEGETATION: Boxwell soils are used mainly for dryland crops. Potential native vegetation is mainly needleandthread, bluebunch wheatgrass, green needlegrass, Sandberg bluegrass, and western wheatgrass.
DISTRIBUTION AND EXTENT: Boxwell soils are of moderate extent in northern, west-central, and south-central Montana. They are also in parts of North Dakota and South Dakota.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Glacier County (Blackfoot Reservation-Cut Bank Area), Montana, 1969.
REMARKS: Soil interpretations records: MT0070, MT1096, MT0867. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon when the surface layer is mixed to 7 inches; a cambic horizon from 5 to 14 inches (Bw1, Bw2 horizons); a calcic horizon from 14 to 28 inches (Bk horizon); a paralithic contact at 28 inches (Cr horizon). Boxwell soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.