LOCATION JETT OR+IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Haploxerolls
TYPICAL PEDON: Jett silt loam, on a 2 percent slope in a
cultivated field. (Colors are for moist soil unless
otherwise noted.)
Ap--0 to 8 inches; black (10YR 2/1) silt loam, dark gray
(10YR 4/1) dry; weak fine granular and weak fine subangular
blocky structure; soft, friable, slightly sticky and
slightly plastic; many very fine roots; many very fine
irregular pores; many earthworm casts; strongly
effervescent; moderately alkaline (pH 8.2); clear smooth
boundary. (5 to 9 inches thick)
A--8 to 24 inches; black (10YR 2/1) silt loam, gray
(10YR 5/1) dry; weak medium subangular blocky structure;
soft, friable, slightly sticky and slightly plastic; many
very fine roots; common very fine to coarse tubular pores;
many earthworm casts; strongly effervescent; moderately
alkaline (pH 8.2); gradual smooth boundary. (10 to 20
inches thick)
C1--24 to 38 inches; very dark brown (10YR 2/2) silt
loam, gray (10YR 5/1) dry; massive; slightly hard, friable,
slightly sticky and slightly plastic; common very fine and
fine roots; common very fine and fine tubular pores;
moderately alkaline (pH 7.9); clear smooth boundary. (10 to
15 inches thick)
C2--38 to 51 inches; very dark grayish brown (10YR 3/2)
silt loam, grayish brown (10YR 5/2) dry; massive; slightly
hard, friable, slightly sticky and slightly plastic; common
fine roots; common very fine, fine and medium tubular pores;
mildly alkaline (pH 7.7).
C3--51 to 60 inches; dark brown (10YR 3/3) silt loam,
light brownish gray (10YR 6/2) dry; massive; slightly hard,
friable, slightly sticky and slightly plastic; few fine
roots; common very fine, fine and medium tubular pores;
mildly alkaline (pH 7.7).
TYPE LOCATION: Baker County, Oregon; located 2,240 feet
east and 2,290 feet south of the northwest corner of sec.
26, T. 12 S., R. 40 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature
is 47 to 54 degrees F. The soils are usually moist but are
dry between depths of 4 to 12 inches for at least 60
consecutive days following the summer solstice. The soil is
greater than 60 inches deep. The mollic epipedon is more
than 20 inches thick, and the organic matter content of the
mixed upper 7 inches is estimated to be more than 3.5
percent and decreases irregularly with increasing depth.
The soil is neutral to moderately alkaline in the A horizon
and mildly to moderately alkaline below. It is calcareous
in all or in some part of the A horizon and decreases in
lime content with increasing depth. The particle-size
control section is silt loam and averages 18 to 27 percent
clay and less than 15 percent coarser than very fine sand.
The A horizon has value of 2 or 3 moist and 4 or 5 dry and
chroma of 1 or 2 moist and dry.
The C horizon has value of 2 through 4 moist and 4 through 6
dry and chroma of 1 through 3 moist and dry. Some pedons
have faint fine mottles in the C horizon below a depth of 40
inches. It is silt loam to a depth of 50 inches or more but
some pedons grade to silty clay loam below this depth.
COMPETING SERIES: These are the
Caldwell,
Harana,
Keigley,
Red Rock and
Snow soils. Caldwell and Snow soils are
neutral to moderately acid and are noncalcareous throughout.
Harana soils have 27 to 35 percent clay in the control
section. Keigley soils are strongly calcareous throughout
and have more than 15 percent calcium carbonate equivalent.
Red Rock soils are noncalcareous in the A and B horizons and
have a calcareous C horizon.
GEOGRAPHIC SETTING: Jett soils are on flood plains. Slopes
range from 0 to 3 percent. Elevation is 2,200 to 4,200 feet
in Oregon and up to 5,100 feet in Idaho. The soils formed
in mixed alluvium high in volcanic ash. The mean annual
temperature is 45 to 57 degrees F. The mean annual
precipitation is 8 to 14 inches. The frost-free period is
115 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Powder and
Wingville soils and the competing
Harana soils. Powder
soils are coarse-silty. Wingville soils are somewhat poorly
drained.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff;
moderate permeability.
USE AND VEGETATION: Jett soils are used for irrigated hay
and pasture and small grains. The native vegetation is
giant wildrye, bunchgrasses and big sagebrush.
DISTRIBUTION AND EXTENT: Baker and Union counties of
Eastern Oregon and Cassia County, Idaho. The series is of
moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Baker County Area, Oregon, 1979.
REMARKS: Diagnostic horizons and features in this pedon
are:
Mollic epipedon, the zone from the surface of the soil to a
depth of approximately 51 inches (Ap, A, and C1 horizons).
Cumulic feature - organic carbon content decreases
irregularly with increasing depth.
These soils have a mesic soil temperature regime (47 to 51
degrees F).