LOCATION JIMBO OR
Established Series
Rev. WRP/JGM/KMS
01/2017
JIMBO SERIES
Landscape--western Cascade Mountains
Landform--low stream terraces and other stream terraces, high flood plains
Slope--0 to 15 percent
Parent material--alluvium mixed with volcanic ash in upper part
Drainage class--well drained
Depth class--very deep
Mean annual precipitation--1800 mm
Mean annual air temperature--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; medial 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; medial 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
2Bw--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; about 5 percent fine concretions; strongly acid (pH 5.4); clear smooth boundary
2BC--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
2C1--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
3C2--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 45 cm (below mineral soil surface)
Thickness of andic soil properties--18 to 34 cm (below mineral soil surface)
Reaction--5.0 to 6.0 throughout all mineral horizons
Estimated properties of layers with andic soil properties
*1/3-bar bulk density--0.70 to 0.95 g/cm3
*Phosphate retention--greater than 85 percent
*Ammonium oxalate extractable Al + Fe--2.0 to 4.0 percent
*15-bar water retention--30 to 70 percent (undried samples); greater than 15 percent (dried samples)
*0.02- to 2.0-mm fraction--greater than 30 percent
*Volcanic glass in 0.02- to 2.0-mm fraction--5 to 30 percent
O horizon
*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--medial silt loam, medial loam, medial 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 34 cm
2Bw and 2BC 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 10 percent
*Gravel content--0 to 10 percent
*Thickness--25 to 50 cm
2C1 horizon
*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
*Clay content--10 to 18 percent
*Total fragment content--0 to 10 percent
*Gravel content--0 to 10 percent
3C2 horizon
*Fine-earth texture--sand, loamy sand
*Total fragment content--40 to 60 percent
*Clay content--2 to 8 percent
*Gravel content--15 to 30 percent
*Cobble content--20 to 45 percent
COMPETING SERIES:
Clevescove--paralithic contact at a depth of 100 to 150 cm; no sandy-skeletal substratum
Silcox--10 to 35 percent rock fragments in particle-size control section, including some pumice; no lithologic discontinuity with sandy-skeletal material
GEOGRAPHIC SETTING:
Elevation--150 to 700 m
Climate--warm, wet winters; hot, moist 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; more than 35 percent gravel and cobbles
Haflinger--sandy-skeletal particle-size class
Saturn--greater than 18 percent clay
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, trailing blackberry, western swordfern
DISTRIBUTION AND EXTENT: Along streams in western Cascade Range, Oregon; MLRA 3; small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lane County Area, Oregon; 1981
REMARKS:
Diagnostic horizons and features recognized in this pedon
*Umbric epipedon--zone from 0 to 34 cm
*Cambic horizon--zone from 34 to 56 cm
*Andic soil properties--zone from 0 to 34 cm
*Volcanic glass--zone from 0 to 34 cm
*Particle-size control section--zone from 25 to 100 cm
*Depth to lithologic discontinuity--34 cm, 109 cm
8/2016--In Willamette National Forest, layers with andic soil properties are assumed to meet criteria 2 (no ash required) in the 12th edition of Keys to Soil Taxonomy. It is also assumed that enough ash is present for those layers to meet criteria 3. Additional lab data is needed to confirm the degree of ash influence.
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.