LOCATION ARIMO IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Calcic Haploxerolls
TYPICAL PEDON: Arimo silt loam on a 2 percent slope on a stream terrace at an elevation of 1433 meters. (Colors are for dry soil unless otherwise noted. When described on June 16, 1976, the soil was moist throughout.)
A1--0 to 15 cm; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure; soft, very friable, slightly sticky and slightly plastic; many fine and very fine, and few medium roots; many very fine irregular pores; 5 percent gravel; neutral (pH 7.1); clear smooth boundary.
A2--15 to 46 cm; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak coarse and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine, and few medium roots; common fine and very fine tubular pores; 5 percent gravel; neutral (pH 7.3); abrupt smooth boundary. (Combined thickness of the A horizons is 20 to 46 cm)
Bk--46 to 84 cm; very pale brown (10YR 8/2) silt loam, pale brown (10YR 6/3) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few medium, fine and very fine roots; few fine and very fine tubular pores; 5 percent gravel; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (18 to 47 cm thick)
2Bkq--84 to 152 cm; multicolored extremely gravelly coarse sand; single grain; loose; few fine and very fine roots; many interstitial pores; few discontinuous pockets of weakly cemented sands and gravel; calcium carbonate coats on bottoms of rock fragments; 70 percent gravel and 5 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4)
TYPE LOCATION: Bannock County, Idaho; about 2.4 kilometers south of the city of Arimo; 90 meters north and 175 meters east of the southwest corner of sec. 20, T. 10 S., R. 37 E.; Arimo USGS topographic quadrangle; lat. 42 degrees, 32 minutes, 0.3 seconds N. and long. 112 degrees, 10 minutes, 0.6 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness and depth to calcic (Bk) horizon: 20 to 46 cm
Control section total clay range: 12 to 18 percent above the discontinuity and 1 to 8 percent below the discontinuity
Carbonate clay: 0 to 8 percent in the calcic horizon
Control section rock fragments: 0 to 15 percent average above the discontinuity and 50 to 90 percent below the discontinuity
Depth to calcic horizon: 20 to 46 cm
Calcium carbonate equivalent: 15 to 40 percent throughout the calcic horizon
Depth to sandy-skeletal material (2Bkq horizon): 50 to 85 cm
Mean annual soil temperature: 6 to 8 degrees C.
Mean summer soil temperature: 15 to 18.9 degrees C. (frigid soil temperature regime)
A and Ap horizons
Hue: 7.5YR or 10YR moist or dry
Value: 2 or 3 moist, 4 or 5 dry
Chroma: 2 or 3 moist or dry
Texture: SIL or L with 0 to 15 percent gravel and more than 15 percent particles coarser than very fine sand
Reaction: neutral to moderately alkaline
Bk horizon
Value: 4 to 7 moist, 6 to 8 dry
Chroma: 2 or 3 dry
Texture: SIL, L or SL with 0 to 40 percent gravel; any horizon with a SL texture is less than 12.5 cm thick
Effervescence: strong to violent
2Bk or 2Bkq horizon
Texture: COS, S or LS
Rock fragments: 40 to 90 percent total fragments; 40 to 90 percent gravel; 0 to 5 percent cobbles
Discontineous cementation: commonly weakly cemented by carbonates in the upper part or in irregular lenses in the lower part
Effervescence: slight to violent above 152 cm and commonly noneffervescent below
COMPETING SERIES: This are the Altaby and Downey series. Altaby soils have a calcic horizon that begins below 47 cm. Downey soils are less than 50 cm to sandy-skeletal material.
GEOGRAPHIC SETTING:
Landscape: alluvial and outwash plains
Landform: fan remnants and stream terraces
Elevation: 1,400 to 1,856 meters
Slope: 0 to 20 percent
Parent material: mixed alluvium with loess influence
Mean annual air temperature: 3.3 to 7.2 degrees C
Mean annual precipitation: 305 to 457 mm
Frost free period: 40 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arbone, Hondoho, Joevar, Ririe, and Wursten soils and the competing Downey soils. The Arbone soils do not have a lithologic discontinuity. The Hondoho soils have a loamy-skeletal particle size class. The Joevar and Ririe soils have a coarse-silty particle size class. The Wursten soils are calcareous to the surface. Arbone, Hondoho, and Wursten soils are on escarpments. Downey soils are on the same landscape position as the Arimo soils. Joevar soils are on stream terraces. Ririe soils are on loess mantled fan remnants, stream terraces and hills.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Runoff: low to medium
Saturated hydraulic conductivity: moderately high in the upper part and very high in the lower part
USE AND VEGETATION:
Major uses: irrigated cropland, nonirrigated cropland and rangeland
Dominant native vegetation: Wyoming big sagebrush, mountain big sagebrush, bluebunch wheatgrass, and streambank wheatgrass.
DISTRIBUTION AND EXTENT:
Distribution: Southeastern Idaho, MLRA 13
Extent: the series is not extensive
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Bannock County, Idaho, 1983.; Bannock County Area, Idaho, Parts of Bannock and Power Counties, Soil Survey.
REMARKS: Diagnostic horizons and soil characteristics recognized in this pedon are: Mollic epipedon: from a depth of 0 to 46 cm; some pedons meet mollic criteria by being 20 to 25 centimeters thick and one-third or more of the total thickness between the mineral soil surface and the upper boundary of any identifiable secondary carbonates.
Calcic horizon:from a depth of 46 to 152 cm
Particle size control section: from a depth of 25 to 100 cm
Soil temperature regime: frigid
Soil moisture regime: xeric