LOCATION JIMBO OR
Established Series
Rev. WRP/JGM/KMS
02/2025
JIMBO SERIES
Landscape--western Cascade Mountains
Landform--stream terraces, strath terraces, high flood plains
Slope--0 to 15 percent
Parent material--loamy alluvium over coarse textured alluvium
Drainage class--well drained
Depth class--very deep
Mean annual precipitation--about 1800 mm
Mean annual air temperature--about 10 degrees C
Soil moisture regime--udic
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-loamy, isotic, mesic Andic Humudepts
TYPICAL PEDON: Jimbo silt loam, forested
A--0 to 20 cm; silt loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; moderate very fine granular structure; soft, friable, nonsticky and nonplastic; weakly smeary; many very fine and fine roots; many irregular pores; 10 percent firm and very firm medium and fine concretions; moderately acid (pH 5.8); clear smooth boundary
AB--20 to 34 cm; silt loam, brown (10YR 5/3) dry, dark brown (7.5YR 3/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; weakly smeary; many very fine and fine roots; many irregular pores; 10 percent fine concretions; moderately acid (pH 5.9); clear smooth boundary
Bw--34 to 56 cm; loam, brown (10YR 5/3) dry, dark yellowish brown (10YR 3/4) moist; weak very fine subangular blocky and granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine irregular pores; 5 percent fine concretions; strongly acid (pH 5.4); clear smooth boundary
BC--56 to 79 cm; loam, light yellowish brown (10YR 6/4) dry, dark yellowish brown (10YR 3/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine and medium roots; many very fine irregular pores; strongly acid (pH 5.4); clear smooth boundary
C1--79 to 109 cm; loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine irregular pores; strongly acid (pH 5.2); abrupt wavy boundary
2C2--109 to 150 cm; multicolored very cobbly sand; single grain; loose, nonsticky and nonplastic; many irregular pores; 30 percent gravel and 25 percent cobbles; strongly acid (pH 5.2)
TYPE LOCATION: Lane County, Oregon, in a cutbank 12 m north of Goodpasture Road; in the NW1/4SW1/4SW1/4 of section 32, T. 16 S., R. 3 E; latitude 44.1304168, longitude -122.4826192, datum WGS 84 (coordinates estimated from PLSS details)
RANGE IN CHARACTERISTICS:
Dry days--less than 45 consecutive days following summer solstice
Mean annual soil temperature--8 to 12 degrees C
Thickness of umbric epipedon--25 to 50 cm
Depth to sandy-skeletal material--100 to 150 cm
Reaction--pH 5.1 to 6.0
Estimated properties of layers meeting andic subgroup criteria
*1/3-bar bulk density--0.7 to 1.0 g/cm3
*Phosphate retention--50 to 100 percent
*Ammonium oxalate extractable Al plus 1/2 Fe--1 to 2 percent
*Volcanic glass content in the coarse silt fraction--5 to 10 percent
*Thickness--18 to 50 cm
O horizon (when present)
*Thickness--0 to 6 cm
A and AB horizons
*Hue--10YR, 7.5YR
*Value--2 or 3 moist, 4 or 5 dry
*Chroma--2 or 3 moist or dry
*Fine-earth texture--silt loam, loam, fine sandy loam
*Clay content--10 to 18 percent
*Total fragment content--0 to 10 percent
*Gravel content--0 to 10 percent
*Thickness--25 to 50 cm
Bw, BC, and C1 horizons
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 5 or 6 dry
*Chroma--3 or 4 moist or dry
*Fine-earth texture--loam, fine sandy loam, sandy loam
*Clay content--10 to 18 percent
*Total fragment content--0 to 35 percent
*Gravel content--0 to 35 percent
*Cobble content--0 to 10 percent
*Thickness--50 to 125 cm
2C horizon
*Fine-earth texture--sand, loamy sand
*Total fragment content--35 to 70 percent
*Clay content--0 to 8 percent
*Gravel content--15 to 35 percent
*Cobble content--20 to 45 percent
COMPETING SERIES:
Clevescove--paralithic contact at a depth of 100 to 150 cm
Silcox--moderately coarse textured throughout
GEOGRAPHIC SETTING:
Elevation--150 to 910 m
Climate--mild, wet winters; warm, dry summers
Mean annual precipitation--1400 to 2400 mm
Mean annual air temperature--7 to 11 degrees C
Frost-free period--80 to 210 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Cupola--ochric epipedon; greater than 35 percent gravel and cobbles in the particle-size control section; located on high terraces and footslopes
Haflinger--sandy-skeletal particle-size family; located on flood plains and low terraces
Saturn--greater than 18 percent clay; located on terraces and in drainageways
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high over very high
USE AND VEGETATION:
Use--filbert cultivation, pasture, recreation, wildlife habitat, timber production
Potential natural vegetation--Douglas-fir, western hemlock, red alder, bigleaf maple, western redcedar, salal, vine maple, California blackberry, western swordfern
DISTRIBUTION AND EXTENT: Western Cascade mountains, Oregon; MLRA 3; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lane County Area, Oregon; 1981
REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 25 to 100 cm
*Umbric epipedon--zone from 0 to 34 cm
*Cambic horizon--zone from 34 to 56 cm
*Andic subgroup feature--zone from 0 to 34 cm
*Depth to lithologic discontinuity--109 cm
9/2023--laboratory data for geographically associated soils support andic subgroup criteria in the 13th edition of Keys to Soil Taxonomy.
ADDITIONAL DATA:
Unpublished laboratory data--Oregon State University sample number S68 Oregon 20-4
Type location user site ID--1981OR039027
National Cooperative Soil Survey
U.S.A.