LOCATION BANNER IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Calcic Argixerolls
TYPICAL PEDON: Banner silt loam, grassland - on a 10 percent south-facing slope at 2,100 feet elevation. (Described on November 8, 1974. Colors are for dry soil unless otherwise noted.)
Ap1--0 to 3 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate thin platy structure parting to moderate very fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; neutral (pH 7.0); abrupt smooth boundary. (3 to 4 inches thick)
Ap2--3 to 7 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common medium roots; many very fine tubular pores; moderately alkaline (pH 7.9); abrupt smooth boundary. (3 to 10 inches thick)
Bt--7 to 19 inches; very dark grayish brown (10YR 3/2) silty clay, dark brown (7.5YR 3/2) moist; moderate medium prismatic structure parting to strong medium angular blocky; extremely hard, firm, very sticky and very plastic; common very fine and medium roots; common very fine tubular pores; common distinct clay films; 3 percent gravel and 3 percent cobbles concentrated in lower part; organic stains on peds; moderately alkaline (pH 8.4); gradual smooth boundary. (6 to 12 inches thick)
Btk--19 to 32 inches; brown (7.5YR 5/4) silty clay, brown (7.5YR 4/4) moist; strong medium angular blocky structure; hard, firm, very sticky and very plastic; few very fine and medium roots, common very fine tubular pores; many prominent clay films; strongly effervescent, lime is in soft masses; strongly alkaline (pH 8.6); gradual smooth boundary. (5 to 15 inches thick)
Bk--32 to 54 inches; very pale brown (10YR 7/3) silty clay loam, pale brown (10YR 6/3) moist; weak fine subangular blocky structure parting to weak fine granular; slightly hard, friable, very sticky and very plastic; few very fine roots; many very fine tubular pores; violently effervescent, lime is in soft masses and fine veins, and filaments; strongly alkaline (pH 8.6); abrupt smooth boundary. (10 to 24 inches thick)
2C--54 to 60 inches; yellowish brown (10YR 5/4) gravelly loam, dark brown (10YR 4/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine tubular pores; 30 percent gravel; violently effervescent; strongly alkaline (pH 8.6).
TYPE LOCATION: Idaho County, Idaho; about 2 miles northeast of White Bird, Idaho; about 1,670 feet north and 2,640 feet west of the southeast corner of sec. 1, T.28.N., R.1E.; Latitude - 45 degrees, 47 minutes, 30 seconds North; Longitude - 116 degrees, 16 minutes, 27 seconds West; USGS White Bird Quadrangle.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 9 to 20 inches
Average annual soil temperature - 53 to 55 degrees F
Days dry, moisture control section - 45 to 90
Depth to secondary carbonate - 15 to 35 inches
Particle-size control section (weighted averages)
Clay content - 35 to 50 percent percent
Rock fragment content - 0 to 10 percent
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2, dry or moist
Structure - upper part lacks platy structure in some pedons; lower part has medium granular or weak medium subangular blocky
Reaction - neutral through moderately alkaline
Bt and Btk horizons
Hue - 7.5YR or 10YR
Value - 3 through 5 dry, 3 or 4 moist
Chroma - 2 through 4, dry or moist
Textures - SIC, SICL, C
Rock fragment content - 0 to 10 percent, mostly in lower part
Clay content - 35 to 50 percent
Sodium adsorption ratio - 0 to 5
Reaction - slightly alkaline through strongly alkaline
Bk horizon
Value - 5 to 7 dry, 4 to 6 moist
Chroma - 3 or 4 dry or moist
Texture - SICL, L
Calcium carbonate equivalent - 5 to 15 percent
Reaction - moderately or strongly alkaline
C horizon
Clay content - 15 to 25 percent
Rock fragment content - 15 to 30 percent
Calcium carbonate equivalent - 1 to 15 percent
Reaction - moderately alkaline or strongly alkaline
COMPETING SERIES: These are the Flowell, Gem, and Gemson series. Flowell soils are underlain by a horizon of strong lime cementation at depths of 12 to 38 inches. Gem soils are 20 to 40 inches to bedrock. Gemson soils have a average annual soil temperature of 47 degrees to 53 degrees F. and the solum is 40 to 70 inches thick.
GEOGRAPHIC SETTING: Banner soils are on benches and long sloping ridges and have slopes of 3 to 25 percent. The soils formed in loess and the underlying residuum form basalt. The elevation ranges from 2,000 to 2,600 feet. The average annual precipitation is about 14 to 16 inches. The average annual temperature is 52 degrees to 54 degrees F. The frost-free period ranges from 150 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Tannahill and Lawyer soils. Tannahill soils are loamy-skeletal. Lawyer soils are on north-facing slopes, are clayey-skeletal and have thick A horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium and rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for production of hay and pasture. Small acreage is used for range. The natural vegetation is mainly bluebunch wheatgrass and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: North-central Idaho. The soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Idaho County, Idaho, Western Part, 1976.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 19 inches (Ap1, Ap2, and Bt horizons).
Argillic horizon - The zone from 7 to 32 inches (Bt and Btk horizons).
Secondary carbonate accumulation - The zone from 19 to 54 inches (Btk and Bk horizons).
Particle-size control section - The zone from 7 to 27 inches (Bt and part of the Btk horizon).
This pedon was not placed in the Vertic subgroup because no slickensides were described. The morphology of this pedon appears to be influenced somewhat by sodium; SAR may be higher than estimated. 11/76 OSD gave soil depth as 40 to 60 or more inches; the only Banner SIR has depth of greater than 60 inches, so series was revised to include only very deep soils.