LOCATION KRUSE IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Vitrandic Haploxeralfs
TYPICAL PEDON: Kruse ashy silt loam, forest, on an east-facing slope of 5 percent at 2,700 feet elevation. (Colors are for dry soil unless otherwise stated.)
Oi--0 to 2 inches; partially decomposed needles and twigs.
Oe--2 to 3 inches; decomposed needles and twigs. (O horizons 1 to 3 inches thick)
A--3 to 9 inches; grayish brown (10YR 5/2) ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine to coarse roots; common very fine and fine irregular pores; moderately acid (pH 6.0); clear wavy boundary. (2 to 9 inches thick)
AB--9 to 16 inches; pale brown (10YR 6/3) ashy silt loam, brown (10YR 4/3) moist; weak medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine to coarse roots; common very fine and fine tubular pores; moderately acid (pH 5.8); clear wavy boundary. (0 to 19 inches thick)
Bt1--16 to 27 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to weak fine and medium subangular blocky; hard, very friable, slightly sticky and slightly plastic; common fine to coarse roots; common very fine and fine irregular and tubular pores; few faint clay films in pores; moderately acid (pH 5.8); clear wavy boundary. (7 to 11 inches thick)
Bt2--27 to 45 inches; very pale brown (10YR 7/3) clay loam, brown (10YR 5/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable, moderately sticky and slightly plastic; few fine to coarse roots; common very fine and fine irregular and tubular pores; common distinct clay films in pores and on faces of peds; two lamellae 1/8 to 1/4 inch thick; about 3 percent fine gravel; moderately acid (pH 5.6); abrupt smooth boundary. (10 to 31 inches thick)
2BC1--45 to 59 inches; pale brown (10YR 6/3) fine sandy loam, brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few medium and coarse roots; few fine tubular pores; few faint clay films in pores; moderately acid (pH 5.6); gradual wavy boundary. (4 to 14 inches thick)
2BC2--59 to 75 inches; yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 3/4) moist; massive; hard, friable; few faint clay films in pores; clay band 1/4 inch thick; few reddish brown and black iron-manganese concretions; 10 percent fine gravel; moderately acid (pH 5.6).
TYPE LOCATION: Kootenai County, Idaho; west of Mica; about 200 feet north and 2,400 feet west of the southeast corner of Section 1, T. 49 N., R. 5 W. Latitude - 47 degrees, 36 minutes, 54 seconds North; Longitude - 116 degrees, 55 minutes, 22 seconds West; USGS Rockford Bay quadrangle
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry for 45 to 70 consecutive days, moist November through July, dry August to October.
Average annual soil temperature - 41 to 46 degrees F.
Average summer soil temperature - 48 to 56 degrees F. with an 0 horizon (frigid temperature regime)
Depth to weathered bedrock - greater than 60 inches
Solum thickness - 40 to greater than 60 inches
Base saturation - 50 to 75 percent in the argillic
A horizon
Hue - 7.5YR or 10YR dry or moist
Value - 3 to 6 dry, 2 to 4 moist
Chroma - 2 to 4, dry, 1 to 3 moist
Texture - GRF-Ashy-SIL, Ashy-L, Ashy-SIL
Clay content - 8 to 20 percent
Rock fragments - 0 to 25 percent fine gravel
Reaction - strongly acid to neutral
Volcanic glass in the 0.02 to 2.0 mm fraction - 5 to 25 percent
Acid-oxalate extractable Al+1/2Fe - 0.4 to 1.0 percent
AB, Bw, BA horizons
Hue - 7.5YR or 10YR dry or moist
Value - 4 to 7 dry, 2.5 to 4 moist
Chroma - 2 to 4 dry, 2 to 6 moist
Texture - Ashy-SIL, Ashy-L, GRF-Ashy-SIL, Ashy-SL, GR-Ashy-SL, L
Clay content - 10 to 26 percent
Rock fragments - 0 to 20 percent fine gravel
Reaction - strongly acid to neutral
Volcanic glass in the 0.02 to 2.0 mm fraction - 5 to 25 percent
Acid-oxalate extractable Al+1/2Fe - 0.4 to 1.0 percent
E and EB horizons (where present)
Hue 7.5YR or 10YR dry or moist
Value 6 or 7 dry, 4 moist
Chroma- 3 or 4 dry, 3 to 6 moist
Texture SIL
Clay content 20 to 24 percent
Rock fragments 0 to 10 percent
Reaction strongly acid or moderately acid
Bt and 2Bt horizons
Hue - 10YR or 7.5YR dry or moist
Value - 4 to 7 dry, 3 to 5 moist
Chroma - 2 to 6 dry, 3 to 8 moist
Texture - L, SIL, CL, SCL, SICL, GR-L, GR-SIL, GR-CL, GR-SCL, GR-SICL, SL, GRX-SL, GRX-SIL, CBV-SIL, CBX-L
Rock fragments - 0 to 75 percent gravel, 0 to 35 percent cobbles, 0 to 75 percent total fragments (weighted average of the particle size control section is less than 35 percent)
Clay content - 15 to 36 percent (weighted average of the particle size control section is less than 35 percent)
Reaction - very strongly acid to neutral
2BC horizons
Hue - 5YR to 10YR dry or moist
Value - 5 to 8 dry, 3 to 5 moist
Chroma - 2 to 6 dry or moist
Texture - FSL, SL, SIL, L, GR-SL, GR-L, GRF-SL, GRF-L, SL, COSL, CL
Clay content - 18 to 32 percent
Rock fragments - 0 to 30 percent gravel, 0 to 5 percent cobbles
Reaction - very strongly acid to neutral
2C horizons (where present)
Hue - 2.5Y to 2.5YR dry or moist
Value - 4 to 8 dry, 3 to 8 moist
Chroma - 1 to 8 dry or moist
Textures - SL, FSL, GR-SL, GRV-SL, GRX-SL, L, LS, GR-LS, COSL, LFS
Clay content - 3 to 25 percent
Rock fragments - 0 to 60 percent gravel, 0 to 15 percent cobbles, 0 to 60 percent total fragments
Mica fragments 0 to 15 percent
Reaction - very strongly acid to moderately acid
COMPETING SERIES: These are the Eaglelake, Ketchly, Mcewen, Nahahum, Nard, Nardmont, Neuske, and Panak series. Eaglelake soils are deep to a paralithic contact. Ketchly soils have umbric epipedons 10 to 20 inches thick. Mcewen soils receive 16 to 24 inches of precipitation and formed in mixed alluvium. Nahahum, Nard, Nardmont, and Neuske soils have albic horizons. Panak soils have acid oxalate extractable Al + 1/2 Fe of 1 to 2 percent.
GEOGRAPHIC SETTING: Kruse soils are on mountain slopes, canyon sides, ridges and hills. Slopes range from 0 to 75 percent. These soils formed in residuum weathered from granite, gneiss, or mica schist with a mantle of loess and minor amounts of volcanic ash at elevations of 1,600 to 4,700 feet. The average annual temperature ranges from 40 to 45 degrees F., with an average annual precipitation of 25 to 40 inches. The average frost-free period is from 80 to 125 days (9 in 10 years to 1 in 10 years, respectively).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ardtoo, Lenz, Melder, Ulricher, Vassar, and Blackprince soils. Ardtoo and Blackprince soils are on east and west-facing convex mountain slopes and do not have argillic horizons. Lenz and Ulricher soils are on south-facing mountain slopes and are mesic. Melder soils are on south-facing mountain footslopes, are loamy-skeletal, and have bedrock at 40 to 60 inches. Vassar soils are on north-facing mountain slopes and have volcanic ash surface horizons.
DRAINAGE AND PERMEABILITY: Well drained. Slow to medium runoff on gentle slopes and rapid to very rapid runoff on steeper slopes. Moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production, livestock grazing, wildlife habitat, recreation, and watershed. Some cleared areas are used for the production of small grains, grass seed, hay, and pasture. Potential natural vegetation is mainly grand fir, Douglas-fir, western white pine, ponderosa pine, western larch, and lodgepole pine, with an understory of myrtle pachystima, Columbia brome, American trailplant, baldhip rose, starry false-Solomon's-seal, sweetscented bedstraw, pine reedgrass, common snowberry, elk sedge, mallow ninebark, creambush oceanspray, and white spirea.
DISTRIBUTION AND EXTENT: Northern Idaho and eastern Washington. MLRA 43. This soil is moderately extensive.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Kootenai County, Idaho, 1976
REMARKS: Diagnostic horizons and other features recognized in this pedon:
Ochric epipedon - The zone from 3 to 16 inches (A and AB horizons).
Argillic horizon - The zone from 16 to 45 inches (Bt horizons).
Vitrandic feature - The zone from 3 to 16 inches (A and AB horizons).
Particle-size control section - The zone from 16 to 36 inches (Bt1 and part of Bt2 horizon).
The ranges in values listed under the A and AB horizons for Volcanic glass content and Acid-oxalate extractable Al+1/2Fe are estimates only.