LOCATION BERNHILL WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, mesic Vitrandic Haploxeralfs
TYPICAL PEDON: Bernhill ashy silt loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; partially decomposed ponderosa pine needles, twigs, and cones.
A--1 to 5 inches; grayish brown (10YR 5/2) ashy loam, very dark grayish brown (10YR 3/2) moist) weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common fine irregular pores; 5 percent gravel; neutral; clear wavy boundary. (4 to 12 inches thick)
Bw--5 to 15 inches; pale brown (10YR 6/3) ashy loam, brown (10YR 4/3) moist weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, medium, and coarse roots; common fine irregular pores; 5 percent gravel; neutral; clear wavy boundary. (0 to10 inches thick)
2EB--15 to 28 inches; light gray (10YR 7/2) loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; few fine tubular pores; 10 percent gravel; neutral; clear wavy boundary. (0 to 15 inches)
2Bt--28 to 37 inches; light yellowish brown (2.5Y 6/4) clay loam, olive brown (2.5Y 4/4) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and slightly plastic; common distinct clay films on ped faces and in pores; common very fine, fine, and few medium and coarse roots; few fine tubular pores; 10 percent gravel; neutral; clear wavy boundary. (9 to 26 inches thick)
2C--37 to 61 inches; light gray (2.5Y 7/2) gravelly sandy loam, grayish brown (2.5Y 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine, fine and medium roots; few fine tubular pores; 20 percent gravel and 10 percent cobbles; neutral.
TYPE LOCATION: Ferry County, Washington; 2 miles northeast of Disautel, 1,900 feet north and 2,000 feet west of the southeast corner of section 8, T. 33 N., R. 29 E., W.M.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 47 to 50 degrees F.
Soil moisture - dry in all parts between 4 and 12 inches for 60 to 90 days following the summer solstice
Particle-size control section - 10 to 35 percent rock fragments, 18 to 35 percent clay, and more than 20 percent fine sand or coarser
Depth to bedrock greater than 60 inches
Reaction - neutral or slightly acid
Volcanic ash influence - 7 to 15 inches
Estimated properties of ash influenced layer:
Volcanic glass content 5 to 20 percent
Acid oxalate extractable Al + Fe 0.4 to 1.0 percent
Moist bulk density 1.30 to 1.55 g/cc
15-bar water retention 5 to 10 percent
A horizon
Value - 4 to 6 dry, 2 to 5 moist
Chroma - 1 to 4 moist and dry
Texture ashy loam, ashy silt loam
Rock fragments - 0 to 35 percent total
Gravel content 0 to 25 percent
Cobble content 0 to 10 percent
Stone content 0 to 15 percent
Bw horizon (when present)
Value 6 or 7 dry, 4 or 5 moist
Chroma 3 or 4 dry or moist
Texture loam, fine sandy loam, sandy loam
Rock fragments 0 to 10 percent total
Gravel content 0 to 10 percent
2EB or 2BA horizon (when present)
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 2 or 3 dry or moist
Texture - silt loam, loam, fine sandy loam
Rock fragments - 5 to 25 percent total
Gravel content 5 to 20 percent
Cobble content 0 to 5 percent
2Bt horizon
Hue - 10YR or 2.5Y
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 to 4 dry or moist
Texture - loam, silt loam, clay loam
Rock fragments - 10 to 35 percent total
Gravel content - 10 to 30 percent
Cobble content 0 to 5 percent
C horizon
Hue - 10YR or 2.5Y
Value - 6 or 7 dry, 3 to 6 moist
Chroma - 2 to 4 dry or moist
Texture - silt loam, fine sandy loam, sandy loam
Rock fragments - 15 to 35 percent total
Gravel content 10 to 30 percent
Cobble content 0 to 15 percent
COMPETING SERIES: These are the Underwood and Wilkeson soils. Soils with similar classification having mixed mineralogy are the Kephart and McGowan (T) series. Kephart soils are dry for 90 to 130 days. McGowan soils are dry for 45 to 60 consecutive days and have hue of 7.5YR or redder in the Bt horizon. Underwood and Wilkeson soils are dry 45 to 60 consecutive days in the moisture control section.
GEOGRAPHIC SETTING: Bernhill soils are on glaciated uplands at elevations of 1,500 to 3,000 feet. Slopes are 0 to 65 percent. They formed in glacial till with a component of loess and volcanic ash in the upper part. The climate is characterized by warm, dry summers and cool, moist winters. The mean annual precipitation is 15 to 25 inches. The average January temperature is about 26 degrees F. and average July temperature is about 66 degrees F. The mean annual temperature is 45 to 48 degrees F. The frost-free season is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Cedonia, Donavan, Glenrose, Green Bluff, and Spokane soils. Cedonia soils are fine-silty and are on lake terraces. Donavan soils are 20 to 40 inches to a densic contact and are on toeslopes, footslopes and backslopes of glaciated foothills. Glenrose soils are very deep, have a mollic epipedon and are on foothills and outwash plains.Green Bluff soils are coarse-loamy and are on outwash plains over basalt plateaus. Spokane soils are coarse-loamy, have a paralithic contact at a depth of 20 to 40 inches and are on foothills, mountains and ridgetops.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used for timber production, livestock grazing, non-irrigated cropland, hay and pasture, homesite development and wildlife habitat. Potential natural vegetation is mainly ponderosa pine with scattered Douglas fir, with an understory of redstem ceanothus, mallow ninebark, common snowberry, pinegrass, baldhip rose, Saskatoon serviceberry, creeping Oregon-grape, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Northeastern and north central Washington; MLRA 43. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Spokane County, Washington, 1961.
REMARKS: Diagnostic horizons and features recognized in this soil include:
Ochric epipedon - from 1 to 5 inches
Argillic horizon - from 28 to 37 inches
Particle-size control section the zone from 28 to 37 inches (2Bt horizon)
Vitrandic feature the zone from 1 to 14 inches (A and Bw1 horizon)
The classification of this series revised as of 5/00 with addition of superactive cation exchange activity class.
The classification of this series revised as of 10/01 with addition of isotic mineralogy.
Investigation has been initiated to determine the modal concept of this series. It had been recognized in Spokane, Stevens, and Colville Indian Reservation soil surveys and ranges over moderately deep to very deep depth classes and multiple parent materials. The type location has been moved to the Colville Indian Reservation soil survey to reflect the very deep depth and its development in glacial till. The Bernhill concept has been correlated to the ( ) series which reflects a deep depth to bedrock and origin from residuum and colluvium weathered from saprolitic gneiss, quartzite and Latah Formation. Further evaluation is still needed in Stevens County to determine the extent of Bernhill soils.