LOCATION BANCROFT ID+WYEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Calcic Argixerolls
TYPICAL PEDON: Bancroft silt loam, cultivated, on a fan remnant with a 2 percent slope at an elevation of 1,882 meters. (Colors are for dry soil unless otherwise noted.)
A--0 to 10 cm; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, and fine and common medium and coarse roots; many very fine irregular pores; neutral (pH 7.0); clear wavy boundary. (5 to 30 cm thick)
AB--10 to 30 cm; brown (10YR 5/3) silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure parting to strong coarse granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, and common medium and coarse roots; many very fine tubular pores; neutral (pH 7.0); abrupt wavy boundary. (13 to 30 cm thick)
Bt1--30 to 46 cm; yellowish brown (10YR 5/4) silt loam, dark yellowish brown (10YR3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine, and common medium roots; common very fine and fine tubular pores; common (30 percent) discontinuous distinct clay films on ped faces and in pores; neutral (pH 7.2); clear wavy boundary.
Bt2--46 to 81 cm; yellowish brown (10YR 5/4) silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; many very fine and common fine tubular pores; common (35 percent) discontinuous distinct clay films on ped faces and in pores; neutral (pH 7.3); abrupt smooth boundary.
Bt3--81 to 99 cm; yellowish brown (10YR 5/4) silt loam, dark yellowish brown (10YR 4/4) moist; weak fine prismatic structure parting to moderate fine angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine tubular pores; common (30 percent) discontinuous distinct clay films on ped faces and in pores; 2 percent fine gravel; slightly alkaline (pH 7.4); abrupt wavy boundary. (Combined thickness of the Bt horizons is 23 to 69 cm)
Bk1--99 to 117 cm; very pale brown (10YR 7/4) silt loam, dark yellowish brown (10YR 4/4) moist; weak very fine prismatic structure parting to moderate fine angular blocky; slightly hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and few fine tubular pores; common (15 percent) fine irregular calcium carbonate masses throughout; common (10 percent) cicada krotovinas; 2 percent gravel; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary.
Bk2--117 to 152 cm; very pale brown (10YR 7/3) loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few very fine roots; common very fine and fine tubular pores; common (25 percent) fine irregular calcium carbonate masses throughout; 5 percent gravel; violently effervescent; strongly alkaline (pH 8.5). (Combined thickness of the Bk horizons is 38 to greater than 71 cm)
TYPE LOCATION: Bear Lake County, Idaho; about 18 km southeast of Soda Springs; 345 meters east and 620 meters north of the southwest corner of section 15, T. 10 S., R. 43 E.; Fossil Canyon USGS topographic quadrangle; lat. 42 degrees, 33 minutes, and 7.7 seconds N. and long. 111 degrees, 25 minutes, 21.9 seconds W., NAD83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness: 25 to 48 cm
Depth to calcic horizon: 48 to 100 cm
Depth to the 2Bk or C horizon: greater than 100 cm
Particle size control section clay: 18 to 32 percent
Soil moisture regime: xeric
Mean annual soil temperature: 5.6 to 8.0 degrees C. (frigid soil temperature regime)
Mean summer soil temperature: 15.0 to 18.3 degrees C.
A or Ap horizon
Hue: 7.5YR or 10YR moist
Value: 2 or 3 moist; 4 or 5 dry
Chroma: 2 or 3 moist or dry
Reaction: slightly acid to slightly alkaline
Organic matter: 2 to 3 percent
Bt horizon
Hue: 7.5YR or 10YR moist or dry
Value: 3 to 5 moist, 4 to 6 dry
Chroma: 2 to 4 moist or dry
Texture: SIL or SICL
Reaction: slightly acid to moderately alkaline
Bk horizon
Value: 4 to 7 moist, 6 to 8 dry
Chroma: 2 to 4 moist or dry
Texture: SIL or L
Reaction: slightly alkaline to strongly alkaline
Calcium carbonate equivalent: 15 to 30 percent
C or 2Bk horizon (when present)
Value: 4 to 6 moist, 7 or 8 dry
Chroma: 3 or 4 moist or dry
Reaction: slightly alkaline to strongly alkaline
Texture: SIL, LS, or L with 0 to 25 percent fragments
COMPETING SERIES: These are the Chatburn, Elevator, and Thatcher series. Chatburn soils have calcium carbonates at 33 to 48 cm. Elevator soils are moderately well drained. Thatcher soils are formed in alluvium, colluvium, and lake sediments, and have stratified textures in the Bk and C horizons.
GEOGRAPHIC SETTING:
Landscape: mountains and plateaus
Landform: terraces, mountain slopes, hills, lava plains, and fan remnants
Elevation: 1,463 to 2,026 meters
Slope: 0 to 30 percent
Parent material: loess and silty alluvium from loess
Mean annual air temperature: 4.4 to 7.2 degrees C.
Mean annual precipitation: 305 to 406 mm
Frost free period: 60 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buist, Joes, Lanoak, McBiggam Manila, and Rexburg series. Buist soils lack an argillic horizon, have a loamy-skeletal particle size class, and occur in drainages. Joes, Lanoak, Manilla, and Rexburg soils all occur on the same landforms as Bancroft soils. Joes soils lack argillic horizons, are calcareous to the surface, and occur on slightly convex positions. Lanoak soils lack an argillic horizon, have a mollic epipedon greater than 51 cm thick, and occur on north facing slopes or linear/concave positions. McBiggam soils lack a calcic horizon are are on adjacent slopes. Manila soils have a fine particle size class, lack a calcic horizon within 102 cm, and occur on fan remnants. Rexburg soils have a coarse-silty particle size class, lack an argillic horizon, and occur on south and west facing slopes.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well
Runoff: low
Saturated hydraulic conductivity: moderately high
USE AND VEGETATION:
Major uses: irrigated and non-irrigated cropland
Dominant native vegetation: mountain big sagebrush, bluebunch wheatgrass, slender wheatgrass, Idaho fescue, and three-tip sagebrush.
DISTRIBUTION AND EXTENT:
Distribution: Southeastern Idaho, MLRA 13
Extent: the series is of moderate extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Bannock County, Idaho, 1983; Bannock County Area Soil Survey, Idaho
REMARKS:
Diagnostic horizons and soil characteristics recognized in this pedon are:
Mollic epipedon: from a depth of 0 to 30 cm
Argillic horizon: from a depth of 30 to 99 cm
Calcic horizon: from a depth of 99 to 152 cm
Particle size control section: from a depth of 30 to 80 cm
Soil temperature regime: frigid
Soil moisture regime: xeric
Typical location relocated from Caribou County, Idaho to Bear Lake County, Idaho in 2010.
ADDITIONAL DATA:
Typical pedon was not sampled.
Additional reference samples are PEDON ID:
S59ID-013-008 and S59ID-013-009