LOCATION ROMTOM OR
Tentative Series
IRD. AGG/MPR
02/2025
ROMTOM SERIES
Landscape--Eastern Cascade mountains
Landform--swales on glacial-valley floors
Slope--0 to 5 percent
Parent Material--volcanic ash
Mean annual precipitation-- 1250 mm
Mean annual air temperature-- 4 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy, amorphic Humic Vitricryands
TYPICAL PEDON: Romtom ashy sandy loam, forested, on a 1 percent slope at an elevation of 1268 meters. (Colors are for dry soil unless otherwise noted.)
A1--0 to 11 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), black (10YR 2/1) moist; moderate coarse granular structure; very friable, nonsticky, nonplastic; many very fine and fine, and few medium roots; many very fine irregular pores; neutral (pH 6.7); gradual smooth boundary
A2--11 to 56 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; very friable, nonsticky, nonplastic; many very fine and fine, common medium, and few coarse roots; many very fine irregular pores; 2 percent fine pumice paragravel; neutral (pH 6.8); clear smooth boundary
AB--56 to 89 centimeters; ashy fine sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure; friable, slightly sticky, nonplastic; few very fine, fine, and medium roots; many very fine irregular pores; neutral (pH 7.0); clear smooth boundary
Bw--89 to 134 centimeters; ashy fine sandy loam, dark yellowish brown (10YR 4/4), dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, friable, slightly sticky, nonplastic; few fine, medium, and coarse roots; many very fine irregular and common fine vesicular pores; neutral (pH 7.0); gradual smooth boundary
C--134 to 152 centimeters; ashy fine sandy loam, dark yellowish brown (10YR 4/4), dark brown (10YR 3/3) moist); structureless single grain; loose, nonsticky, nonplastic; few fine roots; many very fine irregular and few fine tubular pores; 2 percent fine pumice paragravel; neutral (pH 7.0)
TYPE LOCATION: Deschutes County, Oregon; Latitude 44.3584390, Longitude -121.7657830, datum WGS84 (coordinates determine with a GPS).
RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- 5 degrees C
Soil moisture--usually moist in winter and spring, dry in the moisture control section for less than 45 days in the 4 months following the summer solstice
Thickness of mollic epipedon--25 to 60 cm
Thickness of cambic horizon--15 to 65 cm
Reaction--6.1 to 7.3 (slightly acid to neutral)
Thickness of ash influenced layers--0 to 152 cm
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + Fe--0.4 to 2.0 percent
*1500 kPa water content (air dry)--less than 15 percent
*0.02 to 2.0 mm fraction--50 to 85 percent
*Volcanic glass in the 0.02 to 2.0 mm fraction--50 to 80 percent
*P retention--40 to 80 percent
*8Si + 2Fe (aox)--5 to 30 percent
*8Si - 2Fe (aox)--4 to 25 percent
Particle-size control section:
*Clay content, weighted average--2 to 15 percent
*Rock fragment content, weighted average--0 to 5 percent
A horizons
*Value--2 to 4
*Chroma--1 to 2
*Fine earth texture--ashy sandy loam, ashy fine sandy loam
*Clay--2 to 15 percent
*Sand--55 to 80 percent
*Organic matter--1 to 4 percent
*Gravel or paragravel--0 to 5 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--combined thickness of A horizons between 25 to 60 cm
AB horizon
*Value--2 to 6
*Chroma--1 to 3
*Fine earth texture--ashy sandy loam, ashy fine sandy loam
*Clay--2 to 10 percent
*Sand--55 to 80 percent
*Organic matter--0.5 to 1.5 percent
*Gravel or paragravel--0 to 5 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--thickness of AB horizon is 15 to 35 cm
Bw horizon
*Value--3 to 5
*Chroma--3 or 4
*Fine earth texture--ashy sandy loam, ashy fine sandy loam
*Clay--2 to 10 percent
*Sand--55 to 80 percent
*Organic matter--0.25 to 1.0 percent
*Gravel or paragravel--0 to 5 percent
*Reaction--6.6 to 7.3 (neutral)
*Thickness--thickness of Bw horizon is 30 to 50 cm
C horizon
*Value--3 to 8
*Chroma--3 to 6
*Fine earth texture--ashy sandy loam, ashy fine sandy loam
*Clay--2 to 10 percent
*Sand--50 to 85 percent
*Organic matter--0.25 to 0.50 percent
*Gravel or paragravel--0 to 5 percent
*Reaction--6.6 to 7.3 (neutral)
*Thickness--thickness of C horizon is 15 to 40 cm
COMPETING SERIES:
Belrick-- 5 to 35 percent fragments in the particle size control section; skeletal till material around 100 cm
Brado--50 to 100 cm to densic contact
Linksterly--lithologic discontinuity (till) around 100 cm; no cambic horizon; less than 50 percent base saturation in epipedon
GEOGRAPHIC SETTING:
Elevation--1200 to 2000 meters
Slope--0 to 5 percent
Climate--cold, wet winters and cool, moist summers
Mean annual precipitation--1000 to 1500 mm
Mean annual air temperature--3 to 5 degrees C
Frost-free period--30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Wetache--occurs on adjacent moraines; over 5 degrees C mean annual air temperature (Frigid temperature regime)
Linksterly--occurs on adjacent moraines
Douthit--occurs on adjacent moraines; greater than 35 percent fragments in the particle size control section
Toothcomb--occurs on flood plains on glacial-valley floors; aquic conditions within 50 cm from the soil surface
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--well drained
Saturated hydraulic conductivity (Ksat)--high to very high in all horizons
USE AND VEGETATION:
Use--wildlife habitat
Vegetation--quaking aspen, grand fir, ponderosa pine, lodgepole pine, pinegrass, princes pine, starflower, rattlesnake plantain, American vetch
DISTRIBUTION AND EXTENT:
East slopes 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--0 to 100 cm
*Mollic epipedon--0 to 56 cm
*Cambic horizon--89 to 134 cm
*Andic soil properties--0 to 152 cm
National Cooperative Soil Survey
U.S.A.