LOCATION ELIJAH IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Xeric Argidurids
TYPICAL PEDON: Elijah silt loam - at 2,575 feet elevation in a cultivated field. (Colors are for air-dry soil unless otherwise noted.)
Ap--0 to 9 inches; brown (10YR 5/3) (10YR 6/3 crushed) silt loam, brown (10YR 4/3) moist; weak fine and very fine granular structure; hard, friable, moderately sticky and slightly plastic; few roots; many very fine pores; neutral (pH 7.0); abrupt smooth boundary. (5 to 11 inches thick)
Bt1--9 to 15 inches; pale brown (10YR 6/3) light silty clay loam, brown (10YR 4/3) moist; about 15 percent of ped faces have coatings of dark brown (10YR 3/3) moist; weak medium prismatic structure, parting to moderate medium and fine subangular blocky; hard, friable, moderately sticky and moderately plastic; few faint clay films on faces of peds and in pores; few roots; many very fine and fine tubular pores; neutral (pH 7.0); gradual smooth boundary. (3 to 12 inches thick)
Bt2--15 to 19 inches; pale brown (10YR 6/3) and light gray (10YR 7/2) silt loam, brown (10YR 4/3) moist; about 10 percent of ped faces have slightly darker brown coatings; moderate fine and very fine subangular blocky structure; hard, friable, moderately sticky and slightly plastic; few roots; many faint clay films on faces of peds and in pores; many very fine and fine tubular pores; few fine dark concretions; neutral (pH 7.0); abrupt wavy boundary. (3 to 13 inches thick)
Bk--19 to 22 inches; pale brown (10YR 6/3) silt loam containing few basaltic gravel, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few roots; common very fine pores; contains small pieces of duripan from horizon below; few nodules of dense soil material; strongly effervescent with many veins, splotches, and coatings of calcium carbonate; slightly alkaline (pH 7.7); abrupt broken boundary. (5 to 16 inches thick)
2Bkqm--22 to 40 inches; white (10YR 8/2) continuous, indurated duripan, light gray (10YR 7/2) moist; upper part fractured and tending toward platy; top and bottom of plates coated with 1 mm. of white material; beneath the top coating is a light brown (7.5YR 6/3) wavy laminar layer 1-3 mm. thick, which is brown (7.5YR 5/3) moist; similar material is in places within the plates as wavy lenses and 2-5 mm. pockets; violently effervescent; moderately alkaline (pH 8.3). (3 to 40 inches thick)
TYPE LOCATION: Canyon County, Idaho; about 1 mile northeast of Nampa and 150 feet north of right-of-way boundary of Interstate Highway 80 N.; 1,350 feet east and 1,840 feet south of the northwest corner of section 13, T. 3 N., R. 2 W.; USGS Nampa Quadrangle; (Latitude - 43 degrees, 36 minutes, 00 seconds N. and Longitude - 116 degrees, 31 minutes, 38 seconds W.)
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 56 degrees F.
Depth to duripan - 20 to 40 inches
Depth to calcium carbonate - 10 to 30 inches
Depth to bedrock - 40 to more than 60 inches
Particle-size control section - 24 to 35 percent clay; 0 to 5 percent gravel
Moisture control section - moist less than 90 consecutive days when the soil temperature is greater than 47 degrees F.
Ap (or A)horizon
Value - 5 through 7 dry, 3 through 5 moist
Chroma - 2 to 4 dry or moist
Reaction - neutral or slightly alkaline
Rock fragments - 0 to 5 percent gravel, 0 to 5 cobbles and 0 to 5 total
E horizons occur in some pedons.
Bt horizon
Hue - 7.5YR or 10YR
Value - 5 through 7 dry, 3 through 5 moist
Chroma - 2 through 4 dry or moist
Texture - SIL or SICL
Clay content - 24 to 35 percent
Reaction - neutral through moderately alkaline
Rock fragments - 0 to 5 percent gravel
Bk (or Bkq) horizon
Hue - 7.5YR or 10YR
Value - 5 through 8 dry, 3 to 6 moist
Chroma - 3 or 4 dry or moist
Texture - L or SIL
Rock fragments - 0 to 10 percent gravel
Clay content - 12 to 27 percent
Reaction - slightly alkaline through strongly alkaline
Calcium carbonate equivalent - 15 to 40 percent
Bkqm horizon
Cementation of plates - very strong or indurated
Thickness of first laminar cap - 1 to 5 mm thick
Thickness of plates - 1 to 8 inches
Cementation between plates - weak to strong
Thickness of duripan - 18 to 40 inches
Other features - material underlying the duripan is stratified medium textured material or sand and gravel.
COMPETING SERIES: These are the McPan and Virtue series. McPan soils are 20 to 40 inches to bedrock. Virtue soils have secondary calcium carbonates in some part of the argillic horizon.
GEOGRAPHIC SETTING: Elijah soils are on dissected high terraces in valleys and on plug domes (buttes), lava flow lobes and troughs on shield volcanoes and lava plains. Elevations are 2,300 to 5,200 feet. Slopes range from 0 to 15 percent. The soils formed in loess or silty alluvium from loess and weathered volcanic ash over medium to coarse textured alluvium or lacustrine sediments. The climate is semiarid and has dry summers and moist winters. Average annual precipitation is 8 to 12 inches, including up to 2 feet of snowfall. Average annual temperature is 45 to 54 degrees F. The frost-free season is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilcott, Pigtail, Power, Purdam, and Vickery soils. Chilcott and Pigtail soils average more than 35 percent clay in the B2t horizon. Power soils lack a duripan. Purdam soils lack a thick indurated duripan. Vickery soils lack a Bt horizon. These soils all occupy landscape positions similar to the Elijah soil.
DRAINAGE AND PERMEABILITY: Well drained; medium or slow runoff; moderately slow permeability in the Bt horizon and very slow or none in the duripan.
USE AND VEGETATION: Elijah soils are used mainly for irrigated cropland and rangeland. The principal crops are small grains, corn, potatoes, sugar beets, alfalfa, and pasture. Potential vegetation in the natural plant community is Wyoming big sagebrush, Sandberg bluegrass, bluebunch wheatgrass, and Thurber needlegrass.
DISTRIBUTION AND EXTENT: Southwestern and south central Idaho; MLRA 11. It is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Canyon County, Idaho, 1967.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 9 inches (Ap horizon)
Argillic horizon - the zone from 9 to 22 inches (Bt horizon)
Calcic horizon - the zone from 19 to 40 inches (Bk and 2Bkqm horizons)
Indurated duripan - the zone from 22 to 40 inches (2Bkqm horizon)
Particle-size control section - the zone from 9 to 19 inches
Soil moisture regime - aridic bordering xeric
The classification of this pedon has been revised as of 4/00 from fine-silty, mixed, mesic Xerollic Durargids to fine-silty, mixed, superactive, mesic Xeric Argidurids based on revisions to Soil Taxonomy.
As mapped in 8 soil surveys, most of this series is greater than 60 inches to bedrock. Areas in Wood River Area soil survey and Ada County Area soil survey recognize bedrock substratum phases with bedrock at 40 to 60 inches. In the Canyon County Area (where series is established), the substratum is commonly stratified deposits, but bedrock above 60 inches is mentioned and is suspected at the type location. However, depth to bedrock cannot be checked at the type location due to present use as a golf course.
The term silty alluvium used in this series concept infers a localized influence on the mixed loess and weathered ash soil mantle by overland flow of running water.
Geographic setting - terms used throughout MLRA 11 to identify the setting of this soil are quite varied although all equate to the same landscape. There will be further investigation from an MLRA project level as to the accepted terms for use.