LOCATION DENOGA OR
Tentative Series
IRD. AGG/KLM/MPR
02/2025
DENOGA SERIES
Landscape--Eastern Cascade mountains
Landform--lava flows, lava plains, mountain slopes
Slope--0 to 50 percent
Parent Material--volcanic ash mixed with colluvium and/or residuum weathered from basalt, andesite, or other hard extrusive volcanic rock over bedrock
Mean annual precipitation--around 700 mm
Mean annual air temperature--around 6 degrees C
Depth class--deep and very deep to bedrock
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy, glassy, frigid Humic Vitrixerands
TYPICAL PEDON: Denoga ashy sandy loam, forested, on a northeast-facing mountain slope, at an elevation of 1390 meters. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 centimeters; slightly decomposed plant material; strongly acid (pH 5.5); abrupt smooth boundary
A1--2 to 12 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), black (10YR 2/1) moist; moderate medium granular structure; soft, very friable, nonsticky, nonplastic; few very fine and fine roots; many fine irregular pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary
A2--12 to 67 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common medium and few fine roots; many fine irregular pores; 10 percent gravel; neutral (pH 6.9); gradual smooth boundary
Bw--67 to 96 centimeters; gravelly ashy sandy loam, yellowish brown (10YR 5/4), dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common medium and few fine and coarse roots; many medium irregular and many fine tubular pores; 25 percent gravel; neutral (pH 7.0); gradual smooth boundary
C--96 to 112 centimeters; very gravelly ashy sandy loam, yellowish brown (10YR 5/4), dark brown (10YR 3/3) moist; single grain; soft, very friable, nonsticky, nonplastic; very few fine roots; common fine tubular pores; 40 percent gravel; neutral (pH 7.0)
2R--112 centimeters; basalt bedrock
TYPE LOCATION: Deschutes County, Oregon; latitude 44.2909880, longitude -121.7141660, datum WGS84 (coordinates determined with a GPS).
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--around 7 degrees C
Soil Moisture--usually moist in winter and spring, dry in the moisture control section for 60 to 90 days in the 4 months following the summer solstice
Thickness of mollic epipedon--25 to 70 cm
Thickness of cambic horizon--30 to 85 cm
Depth to lithic contact--between 100 and 200 cm
Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
Thickness of ash influenced layers--100 to 200 cm
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + Fe--0.4 to 1.0 percent
*1500 kPa water content (air dry)--less than 15 percent
*0.02 to 2.0 mm fraction--50 to 90 percent
*Volcanic glass in the 0.02 to 2.0 mm fraction--50 to 80 percent
*P retention--40 to 70 percent
Particle-size control section: mineral surface to 100 cm
*Clay content (weighted average): 2 to 8 percent
*Rock fragment content (weighted average): 0 to 35 percent
A horizons
*Value--2 moist, 3 or 4 dry
*Chroma--1 or 2
*Fine earth texture--ashy sandy loam, ashy loamy sand
*Clay--2 to 8 percent
*Sand--60 to 85 percent
*Organic matter--1 to 5 percent
*Gravel--0 to 10 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--combined thickness of A horizons is 15 to 65 cm
Bw horizon (where present)
*Value--2 or 3 moist, 4 dry
*Chroma--2 or 3 moist, 3 dry
*Fine earth texture-- ashy sandy loam, ashy loamy sand
*Clay--1 to 8 percent
*Sand--65 to 90 percent
*Organic matter--0.50 to 1 percent
*Total rock fragment content--0 to 70 percent
*Gravel--0 to 35 percent
*Cobble--0 to 35 percent
*Stone--0 to 35 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--thickness of B horizon is 25 to 60 cm
C horizon
*Value--2 to 4 moist, 4 or 5 dry
*Chroma--2 to 4 moist, 3 to 6 dry
*Fine earth texture-- ashy sandy loam, ashy loamy sand
*Clay--1 to 8 percent
*Sand--65 to 90 percent
*Organic matter--0.50 to 1 percent
*Total rock fragment content--0 to 85 percent
*Gravel--0 to 75 percent
*Cobble--0 to 75 percent
*Stone--0 to 45 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--thickness of C horizon is 15 to over 100 cm
COMPETING SERIES:
Cobey--averages less than 50 percent sand throughout the particle size control section (loam and silt loam texture classes)
Drypok--50 to 100 cm to lithic contact
Ermabell--dry for 90 to 110 days following summer solstice; depth to bedrock greater than 150 cm
Laidlaw--dry for 90 to 110 days following summer solstice; has silica nodules in the lower horizons
Lundgren--greater than 150 cm to glacial outwash
Pilotbutte--depth to bedrock greater than 150 cm
Retep--50 to 100 cm to a paralithic contact
Suttle--endosaturation from 0 to 60 cm April to June (somewhat poorly drained)
Trailcreek--50 to 100 cm to a paralithic contact
Wanoga--50 to 100 cm to a lithic contact
Dryache--dry for 45 to 60 days following the summer solstice
Conelicker--gravel sized cinders throughout the particle size control section
GEOGRAPHIC SETTING:
Elevation--950 to 1700 meters
Slope--0 to 50 percent
Climate--cool, wet winters and warm, dry summers
Mean annual precipitation--400 to 1000 mm
Mean annual air temperature--5 to 7 degrees C
Frost-free period--50 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Skelwa--occurs on nearby outwash plains; greater than 35 percent fragments in the particle size control section
Wanoga--occurs on similar geomorphic positions; 50 to 100 cm to a paralithic or lithic contact; 90 to 110 dry days following the summer solstice
Fryrear--occurs on similar geomorphic positions; 50 to 100 cm to a paralithic or lithic contact; greater than 35 percent fragments in the particle size control section
Dryache--occurs at higher elevations on moraines; 45 to 60 dry days following the summer solstice
Sanagon--occurs at higher elevations on moraines; 45 to 60 dry days following the summer solstice; greater than 35 percent fragments in the particle size control section
Laidlaw--occurs on swales; dry for 90 to 110 days following the summer solstice
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--well drained
Saturated hydraulic conductivity (Ksat)--high to very high in all horizons
USE AND VEGETATION:
Use--timber production, wildlife habitat, recreation
Vegetation--grand fir, ponderosa pine, greenleaf manzanita, snowbrush ceanothus, long-stolon sedge
Typical USFS plant association--ABCO-ABGR/CAIN4 (white fir-grand fir/long-stolon sedge)
DISTRIBUTION AND EXTENT:
East slope of the Cascade Mountains in central Oregon; MLRA 6; minor extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED:
Deschutes County, Deschutes National Forest, Oregon 2023
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
*Particle-size control section--mineral soil surface to 102 cm
*Mollic epipedon--2 to 67 cm
*Andic soil properties--2 to 112 cm
*Cambic horizon--67 to 96 cm
*Lithic contact--around 112 cm
Laboratory data inferred from geographically associated Laidlaw series (Pedon#: 23NO202). This data is available from the NRCS-NSSC-Kellogg Soil Survey Laboratory, Lincoln, Nebraska.
National Cooperative Soil Survey
U.S.A.