LOCATION DENO WATentative Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Vitrandic Haploxerolls
TYPICAL PEDON: Deno ashy silt loam, on a 2 percent northeast facing, convex slope at an elevation of 2,420 feet in rangeland. When described on November 24,1999 the soil was moist to 28 inches and dry below. (Colors are for dry soil unless otherwise noted. All textures are apparent field textures)
A1--0 to 4 inches; grayish brown (10YR 5/2) ashy silt loam, very dark brown (10YR 2/2) moist; moderate coarse granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and few fine roots; common very fine tubular and irregular pores; 1 percent subrounded fine basalt gravel and 1 percent subrounded fine quartzite gravel; slightly acid (pH 6.5); clear smooth boundary.
A2--4 to 14 inches; grayish brown (10YR 5/2) ashy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine tubular pores; 2 percent subrounded fine basalt gravel and 3 percent subangular basalt gravel; neutral (pH 7.0); clear smooth boundary.
A3--14 to 28 inches; grayish brown (10YR 5/2) ashy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine tubular pores; 1 percent subrounded fine basalt gravel and 2 percent subangular basalt gravel; moderately alkaline (pH 8.4); abrupt smooth boundary. (combined thickness of A horizons is 20 to 30 inches)
Bw1--28 to 40 inches; light yellowish brown (10YR 6/4) loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; common very fine and few fine rootsroots; few very fine irregular, common very fine and few fine tubular pores; 2 percent subrounded fine basalt gravel and 1 percent subangular basalt gravel; moderately alkaline (pH 8.3); clear smooth boundary.
Bw2--40 to 48 inches; light yellowish brown (10YR 6/4) coarse sandy loam, brown (10YR 4/3) moist; moderate coarse subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few medium roots; few very fine irregular, common very fine, and few fine tubular pores; 1 percent subangular basalt gravel and 3 percent subrounded fine basalt gravel; slightly alkaline (pH 7.8); abrupt wavy boundary. (combined thickness of the 2Bw horizons is 15 to 25 inches thick)
R--48 inches; basalt bedrock, fractured at intervals of 4-18 inches; .
TYPE LOCATION: Spokane County, Washington; about 1 mile west southwest of Airway Heights; 2,300 feet south and 700 feet east of the northwest corner of section 27, T. 25 N., R. 41 E., W.M.; USGS Airway Heights, Wash. Topographic quadrangle; (Latitude 47 degrees, 38 minutes, 12.87 seconds N. and Longitude 117 degrees, 37 minutes, 14.65 seconds W.), NAD27
RANGE IN CHARACTERISTICS: Depth to diagnostic horizons and features are measured from the top of the first mineral layer.
Average annual soil temperature - 48 to 52 degrees F.
Moisture control section - dry 60 to 90 days after the summer solstice, July to September, moist October through June
Depth to basalt bedrock - 40 to 60 inches
Thickness of mollic epipedon - 20 to 30 inches
Clay content - 4 to 18 percent in the particle-size control section
Gravel content - 0 to 20 percent in particle size control section
Volcanic ash influence - 20 to 30 inches
Estimated properties of the volcanic ash influenced layers:
Volcanic glass content in the 0.02 to 2 mm fraction - 5 to 20 percent
Acid-oxalate extractable Al plus 1/2 Fe - 0.4 to 1.0 percent
Moist bulk density - 1.15 to 1.35 g/cc
15 bar water retention - 5 to 10 percent for air dried samples
Base Saturation - less than 75 percent (by sum of cations) in one or more horizon between 10 and 30 inches (estimated)
A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 to 3 dry or moist
Texture - ashy silt loam or ashy loam
Gravel content - 0 to 20 percent
Reaction slightly acid to moderately alkaline
Bw horizons
Value - 5 or 6 dry, 2 to 4 moist
Chroma - 3 or 4 dry or moist
Texture- silt loam, loam, or coarse sandy loam
Clay content - 4 to 18 percent
Gravel content - 0 to 20 percent
Reaction slightly alkaline or moderately alkaline
Some pedons have a BA horizon
BC or C horizon composed of glacial flood deposits present above the basalt bedrock in some pedons.
COMPETING SERIES: These are the Conconully, Fanal (T), Phoebe, Safety, Stevens, Uhlig and Usk soils. The Donavan, Fourmound (T), Goldlake, and Spokane series have a similar classification with isotic mineralogy rather than mixed. Conconully, Donavan, and Stevens soils are moderately deep to Cd horizons. Fanal and Goldlake soils are moderately well drained with redox concentrations in the lower part of the control section. Fourmound soils have mollic epipedons 10 to 20 inches thick. Phoebe and Uhlig soils are very deep. Safety, Spokane, and Usk soils have a paralithic contact at 20 to 40 inches.
GEOGRAPHIC SETTING: Deno soils are on outwash plains, outwash terraces and mima mounds on basalt plateaus in the Channeled Scablands. Slopes are 0 to 15 percent. These soils formed over basalt in glaciofluvial deposits mixed with loess and volcanic ash in the upper part. Elevations are 1,800 to 2,600 feet. The climate is characterized by warm, relatively dry summers and cool, moist winters. The mean annual precipitation is 15 to 18 inches. The mean annual temperature is 46 to 50 degrees F. The frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alecanyon, Cheney, Northstar, Rockly, and Stutler (T) soils. Alecanyon soils are sandy skeletal and are on outwash plains. Cheney soils are coarse-loamy over sandy or sandy-skeletal and are on outwash plains. Rockly soils are shallow to bedrock and are on outwash plains and basalt plateaus. Northstar soils are loamy skeletal, moderately deep to basalt bedrock, and are on basalt plateaus. Stutler soils are loamy skeletal and are on outwash plains and basalt plateaus.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used mostly for homesites, crop production, livestock grazing, with some areas used for wildlife habitat and watershed. Small grains, hay and pasture are common crops. Potential natural vegetation is basin wildrye, common snowberry, Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, Wyeth eriogonum, common yarrow, lupine, rose, and threadleaf sedge.
DISTRIBUTION AND EXTENT: Eastern Washington; MLRA B9. Series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Spokane County, Washington, 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 28 inches (A horizons) also qualifying for pachic
Cambic horizon - the zone from 28 to 48 inches (2Bw horizons)
Vitrandic feature - the zone from 0 to 28 inches (A horizons)
Lithic contact - the zone beginning at 48 inches (2R )
Particle-size control section - the zone from 10 to 40 inches (A horizons and the 2Bw1 horizon)
The Ritter series seems to be very similar to this proposed series and should be investigated further to determine vitrandic features.