LOCATION SHOAT OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Haploxerepts
TYPICAL PEDON: Shoat loam, rangeland. (Colors are for moist
soil unless otherwise noted.)
A--0 to 4 inches; dark brown (7.5YR 3/2) loam, brown (7.5YR
4/4) dry; weak fine subangular blocky structure parting to weak
very fine granular; slightly hard, friable, nonsticky and
nonplastic; common very fine roots; many very fine irregular
pores; 14 percent gravel; neutral (pH 6.7); clear smooth
boundary. (3 to 7 inches thick)
Bw1--4 to 15 inches; dark brown (7.5YR 3/4) loam, brown
(7.5YR 5/4) dry; weak fine and medium subangular blocky
structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; 10 percent gravel; neutral (pH 6.6); gradual smooth boundary. (6 to
19 inches thick)
Bw2--15 to 24 inches; dark brown (7.5YR 3/4) loam, brown
(7.5YR 5/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many fine and medium tubular
pores; 10 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary. (5 to 21 inches thick)
2R--24 inches; basalt.
TYPE LOCATION: Jackson County, Oregon; approximately 750 feet
north and 200 feet east of the southwest corner of sec. 11, T. 41
S., R. 4 E., W.M.
RANGE IN CHARACTERISTIC: These soils are usually moist but are
dry in the moisture control section for 80 to 110 consecutive
days in the four months that follow the summer solstice. The
mean annual soil temperature is 47 to 53 degrees F. Depth to a lithic contact is 20 to 40 inches. The particle-size control
section averages 18 to 30 percent clay and 0 to 15 percent rock fragments. It is slightly acid or neutral.
The A horizon has hue of 10YR or 7.5YR, value of 3 moist, 4 or 5
dry, and chroma of 3 moist, 3 or 4 dry. It has 12 to 20 percent
clay and 0 to 15 percent gravel.
The Bw horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 5
or 6 dry, and chroma of 3 or 4 dry and 4 moist. It has 18 to 30 percent clay, 0 to 15 percent gravel, and 0 to 5 percent cobbles.
It is a clay loam, loam, or silt loam.
COMPETING SERIES: These are the
Debenger,
Hohmann,
Kerby,
Offenbacher,
Springwater and
Wamic series. Kerby and Wamic soils
are deep. Debenger and Springwater soils are moderately deep to
a paralithic contact. Hohmann soils have a mean annual soil temperature of 53 to 57 degrees F, contain over 15 percent gravel throughout the profile and typically have hue of 5YR in some part
of the solum. Offenbacher soils lack the lithologic
discontinuity, and lack the "mollic" colors (moist and dry) in
the A horizon.
GEOGRAPHIC SETTING: Shoat soils are on plateaus at elevations of 2,000 to 3,800 feet. This landscape consists of patterned ground with the Shoat soils being the mound component and the Randcore
soils being the intermound. These soils formed in loess over
basalt. The mean annual precipitation is 18 to 25 inches and the mean annual temperature is 45 to 52 degrees F. The frost-free
period is 100 to 150 days. Slopes range from 0 to 5 percent.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
McMullin,
Randcore, and
Skookum soils. McMullin and Randcore soils are
less than 20 inches to bedrock. Skookum soils are
clayey-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: The soils are used for range and wildlife habitat. Native vegetation includes bluebunch wheatgrass, Idaho fescue, pine bluegrass, wooly eriophyllum, and lupine.
DISTRIBUTION AND EXTENT: Southwestern Oregon. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County Area, Oregon, 1988.
REMARKS: Diagnostic horizons and features:
- Ochric epipedon - "Mollic colors" only extend to a depth of 4 inches; moist chroma of 4 at 4 to 24 inches.
- Cambic horizon - 4 to 24 inches.