LOCATION FOPIANO OR
Established Series
Rev. REH/ED/AON
02/2025
FOPIANO SERIES
Landscape--foothills
Landform--hillslopes, benches, landslides
Slope--2 to 50 percent
Parent material--residuum and colluvium derived from tuff with an influence of volcanic ash in the upper part
Mean annual precipitation--about 350 mm
Mean annual air temperature--about 6 degrees C
Depth class--shallow to paralithic contact
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass-- typic
TAXONOMIC CLASS: Clayey, smectitic, frigid, shallow Vitrandic Argixerolls
TYPICAL PEDON: Fopiano ashy loam, rangeland,
A1--0 to 12 cm, gray (10YR 5/1) dry, ashy loam, very dark gray (10YR 3/1) moist; weak medium subangular blocky parts to moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine and fine roots throughout; common very fine dendritic tubular pores; 10 percent gravel and 2 percent cobbles; neutral (pH 7.2); clear smooth boundary.
A2--12 to 19 cm, gray (10YR 5/1) dry, gravelly ashy loam, very dark gray (10YR 3/1) moist; weak medium subangular blocky parts to weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots throughout; common very fine dendritic tubular pores; 20 percent gravel and 5 percent cobbles; neutral (pH 7.2); abrupt smooth boundary.
2Bt--19 to 30 cm, brown (10YR 4/3) dry, gravelly clay, very dark gray (10YR 3/1) moist; moderate fine subangular blocky, and moderate fine angular blocky structure; very hard, very firm, very sticky, very plastic; common very fine and fine roots throughout; common very fine dendritic tubular pores; 70 percent distinct clay films on all faces of peds; 20 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary.
2Bt2--30 to 45 cm, brown (7.5YR 5/4) dry, cobbly clay, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; very hard, very friable, very sticky, very plastic; common very fine and fine roots throughout; common very fine dendritic tubular pores; 70 percent distinct clay films on all faces of peds; 10 percent gravels and 20 percent cobbles; slightly alkaline (pH 7.4); abrupt irregular boundary.
2Cr--45 cm; partially consolidated volcanic tuff; continuous and moderately coherent.
TYPE LOCATION: Wheeler County, Oregon; about 21 kilometers east of the town of Mitchell, about 4 kilometers southeast of the Waterman townsite; 400 meters south and 30 meters west of the Northeast corner of section 29, T.11S., R.24E.; WGS84 Decimal Degrees 44.5905685, -119.8587418
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 8 degrees C.
Soil moisture--Usually moist, but are dry in all parts from 10 centimeters to the paralithic contact for 60 to 90 consecutive days in most years
Thickness of mollic epipedon--18 to 38 cm; includes the Bt1 horizon in some pedons.
Thickness of argillic horizon--10 to 30 cm
Depth to paralithic contact--25 to 50 cm
Thickness of ash influenced layers--18 to 36 cm
Estimated properties of layers influenced by volcanic ash:
*Ammonium oxalate extractable Al + 1/2 Fe--0.3 to 0.5 percent
*0.02 to 2.0 mm fraction--30 to 70 percent
*Glass content in 0.02 to 2.0-mm fraction--5 to 30 percent
*1/3-bar bulk density--0.85 to 1.1 g/cm3
Particle-size control section:
*Clay--35 to 60 percent
*Total fragments--0 to 20 percent, mainly volcanic rocks such as tuff or basalt
A horizons
*Hue--10YR or 7.5YR
*Value--4 or 5 dry, 2 or 3 moist
*Chroma--1 through 3, dry or moist
*Fine-earth texture-- ashy loam, ashy silty clay loam, ashy clay loam
*Clay--18 to 35 percent
*Sand--15 to 45 percent
*Organic matter--2 to 4 percent
*Total fragments--0 to 20 percent
*Gravel--0 to 20 percent
*Cobble--0 to 20 percent
*Stone--0 to 5 percent
*Reaction--pH 6.6 to 7.8 (neutral to slightly alkaline)
Bt horizons
*Hue--10YR or 7.5YR
*Value--4 or 5 dry, 2 or 3 moist in upper horizons; 2 to 4 moist in lower horizons
*Chroma--1 to 3, dry or moist in upper horizons; 2 to 4 dry or moist in lower horizons
*Fine-earth texture--clay, clay loam
*Clay--35 to 60 percent
*Sand--15 to 40 percent
*Organic matter--0.5 to 2.0 percent
*Total fragments--0 to 25 percent
*Gravel--0 to 20 percent
*Cobble--0 to 20 percent
*Stone--0 to 5 percent
*Reaction--pH 6.6 to 7.8 (neutral to slightly alkaline)
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Elevation--1100 to 1525 meters
Climate--cold, wet winters and warm, dry summers
Mean annual precipitation--305 to 480 mm
Mean annual air temperature--4 to 7 degrees C
Frost-free period--40 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Anatone--occur on hillslopes, mountain slopes, and ridges; averages less that 35 percent clay in the particle size control section, 20 to 50 cm to lithic contact
Cogginsflat--occur on hillslopes and benches; 50 to 100 cm to duripan
Prag--occur on hillslopes and swales; 50 to 100 cm to paralithic contact
Smokers--occur on hillslopes, benches, and ridges; 10 to 25 cm to paralithic contact
DRAINAGE AND PERMEABILITY:
Drainage--well drained
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high in volcanic ash influenced surface horizons, moderately high in subsurface horizons
USE AND VEGETATION:
Use--livestock grazing and wildlife habitat
Potential native vegetation-- Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, low sagebrush
DISTRIBUTION AND EXTENT:
Distribution-- Eastern-central Oregon
Extent--moderately extensive; MLRA 10
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Grant County, Oregon, 1975
REMARKS: Diagnostic horizons and other features:
Mollic epipedon--0 to 30 centimeters
Argillic horizon--19 to 45 centimeters
Vitrandic feature--0 to 19 centimeters
3/2024--Original Fopiano type location was correlated to another soil. This update to the official series description includes a new representative profile and additions to the Range in Characteristics
ADDITIONAL DATA: S97OR-023-013
National Cooperative Soil Survey
U.S.A.