LOCATION SEBREE IDEstablished Series
The Sebree series consists of moderately deep over a duripan, well
drained soils on terraces or alluvial plains. They formed in loess
over unconsolidated alluvial sediments. Permeability is slow. Slopes
are 0 to 12 percent. The average annual precipitation is about 10
inches and the average annual air temperature is about 49 degrees F.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Xeric Natridurids
TYPICAL PEDON: Sebree silty clay loam - rangeland. (Colors are for
dry soil unless otherwise noted.)
E--0 to 1 inch; light gray (10YR 7/2) silt loam, grayish brown
(10YR 5/2) moist; massive; slightly hard, friable, slightly sticky and
slightly plastic; strongly vesicular, vesicles as large as 2 or 3 mm;
slightly acid (pH 6.5); abrupt smooth boundary. (0 to 2 inches thick)
Bt--1 to 3 inches; pale brown (10YR 6/3) silty clay loam, dark
brown (10YR 4/3) moist; moderate very fine prismatic structure parting
to moderate very fine subangular blocky; hard, firm, sticky and
plastic; few roots; thin clay films; neutral; common thin silt coatings
on ped faces; abrupt smooth boundary. (1 to 3 inches thick)
Btn--3 to 12 inches; pale brown (10YR 6/3) silty clay loam, dark
brown (10YR 4/3) moist; moderate fine and very fine subangular blocky
structure; very hard, firm, sticky and plastic; few roots; few very
fine pores; moderately thick continuous clay films; mildly alkaline;
common thin silt coatings on ped faces from 3 to 7 inches; many white
spots of salts below 7 inches; clear wavy boundary. (4 to 10 inches
thick)
Btkn--12 to 32 inches; pale brown (10YR 6/3) silt loam, brown (10YR
5/3) moist; weak fine subangular blocky structure; hard, firm, sticky
and plastic; few roots; common very fine pores; large splotches of
lime; many spots of salt; violently effervescent; mildly alkaline;
abrupt wavy boundary. (10 to 25 inches thick)
2Bqkm--32 to 51 inches; pinkish white (7.5YR 8/2) indurated
silica-calcium carbonate duripan containing lenses of slightly darker
material; indurated part is plates of 2 to 3 inches thick and extremely
dense and nonporous; tops of plates are light brown (7.5YR 6/3) and
relatively smooth or slightly glazed; bottoms (0.2 to 0.5 inch) of
plates are pale brown (10YR 6/3) and contain common fine and medium
discontinuous pores; bottoms of plates are very rough and have short
pendants, less cemented material between indurated plates; lower part
of duripan is less cemented; moderately alkaline; abrupt wavy
boundary. (10 to 25 inches thick)
3Bk--51 to 58 inches; very pale brown (10YR 7/3) loamy sand,
yellowish brown (10YR 5/4) moist; massive; strongly effervescent;
moderately alkaline; gradual boundary. (5 to 15 inches thick)
3C--58 to 60 inches; very pale brown (10YR 7/3) loamy sand; single
grain; slightly effervescent; mildly alkaline (continues to
undetermined depth).
TYPE LOCATION: Canyon County, Idaho; about 6 miles north of Caldwell
in the Black Canyon experimental tract; about 330 feet north and 115
feet west of the SW corner of the plots, SW1/4 NW1/4 SW1/4 section 4,
T.5N., R.3W.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 54 degrees F
Depth to duripan - 20 to 40 inches
Depth to calcium carbonate - 7 to 20 inches
E horizon
Value- 5 through 7 dry, 3 through 5 moist
Chroma- 2 or 3
Reaction - slightly acid to mildly alkaline
Bt horizon
Value- 4 through 6 dry, 3 through 5 moist
Chroma- 3 or 4
Texture - SICL, CL, SIC
Clay content - 27 to 35 percent
Exchangeable sodium - greater than 15 percent
Reaction - mildly to strongly alkaline
COMPETING SERIES: This is the Malheur series. Malheur soils lack an E
horizon and a high accumulation of salts in the lower part of the
natric horizon.
GEOGRAPHIC SETTING: Sebree soils are generally on terraces and basalt
plains. Slopes range from 0 to 12 percent. Elevations range from
2,000 to 4,500 feet. The soil formed in loess overlying unconsolidated
fan or fluviatile sediments. The climate is semiarid and summers are
dry. The frost-free period is 110 to 170 days, and the mean annual
precipitation is 8 to 13 inches, including 0.5 to 3 feet of snow.
Average annual air temperature is 45 to 52 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilcott and Purdam
soils. Chilcott soils have more than 35 percent clay in the B2t
horizon. Purdam soils have less than 15 percent exchangeable sodium in
the B2t horizon. Chilcott and Purdam soils are on landscape positions
similar to Sebree soils.
DRAINAGE AND PERMEABILITY: Well-drained; rapid runoff; slow
permeability in the soil above the duripan and very slow permeability
through the duripan.
USE AND VEGETATION: Used for rangeland and irrigated cropland. Crops
are small grains, corn, alfalfa and pasture. Under natural conditions
the soil is barren or nearly so; some cheatgrass, pepperweed, and
stunted big sagebrush are around the edges of individual areas.
DISTRIBUTION AND EXTENT: Southwestern Idaho and southeastern Oregon.
The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Gem County Area, Idaho, 1962.
National Cooperative Soil Survey