LOCATION ELFKIN ID

Established Series
Rev. ALH/
07/2012

ELFKIN SERIES

The Elfkin series consists of moderately deep to a duripan, well drained soils that formed in silty alluvium from loess and volcanic ash over basalt bedrock. Slopes range from 0 to 12 percent on lava plains and valleys. The average annual precipitation is about 250 mm inches and the average annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Xeric Argidurids

TYPICAL PEDON: Elfkin silt loam - on a 3 percent slightly convex southwest-facing slope at 1,100 meters elevation in cropland. When described on September 1, 1988, the soil was dry to 13 cm and slightly moist below. (Colors are for air-dry soil unless otherwise noted.)

Ap--0 to 13 cm inches; brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; weak fine, medium and coarse subangular blocky structure parting to moderate fine and medium granular; hard, very friable, slightly sticky and slightly plastic; common very fine, few medium roots; many very fine, common fine and medium interstitial pores; 2 percent gravel, 2 percent cobbles; neutral (pH 6.6); clear wavy boundary. (10 to 28 cm thick)

Bt1--13 to 25 cm; yellowish brown (10YR 5/4) silty clay loam, dark yellowish brown (10YR 3/4) moist; strong fine, medium and coarse subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; many very fine, few fine roots; common very fine, few fine and medium tubular pores, common very fine interstitial pores; few faint clay films on faces of peds and in pores; 5 percent gravel, 5 percent cobbles; neutral (pH 6.6); clear wavy boundary.

Bt2--25 to 38 cm; light yellowish brown (10YR 6/4) silty clay loam, brown (10YR 4/3) moist; weak fine and medium prismatic structure parting to strong fine and medium subangular blocky; very hard, friable, moderately sticky and moderately plastic; many very fine, few fine roots; common very fine, few fine tubular pores; common faint clay films on faces of peds and in pores; 2 percent gravel; neutral (pH 6.9); clear wavy boundary. (combined Bt horizon - 20 to 40 cm thick)

Bk1--38 to 58 cm; yellowish brown (10YR 5/4) silt loam, dark yellowish brown (10YR 3/4) moist; moderate very fine to coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine roots; common very fine, few fine tubular pores, common very fine interstitial pores; slightly effervescent matrix with violently effervescent masses and threads of calcium carbonates; slightly alkaline (pH 7.4); clear wavy boundary.

Bk2--58 to 79 cm; very pale brown (10YR 7/3) loam, brown (10YR 5/3) moist; moderate very fine, fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine, few fine tubular pores, common very fine interstitial pores; violently effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary.

Bkq--79 to 91 cm; very pale brown (10YR 8/3) loam, light yellowish brown (10YR 6/4) moist; massive; discontinuous moderate cementation; few very fine roots; common very fine tubular pores, violently effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (combined Bk and Bkq horizons - 8 to 64 cm thick)

Bkqm1--91 to 99 cm; very pale brown (10YR 8/3) indurated duripan, very pale brown (10YR 7/4) moist with continuous indurated laminar cap and lamellae less than 2 mm thick, 2 to 3 cm apart; massive; violently effervescent; clear wavy boundary. (2 to 20 cm thick)

2Bkqm2--99 to 114 cm; very pale brown (10YR 8/4) indurated duripan, light yellowish brown (10YR 6/4) moist with continuous indurated laminar cap; massive; 25 percent gravel, 35 percent cobbles; violently effervescent; abrupt wavy boundary. (8 to 50 cm thick)

2R--114 cm; unweathered basalt.

TYPE LOCATION: Gooding County, Idaho; about 5 miles northwest of Gooding; 1,650 feet south and 400 feet east of the northwest corner of section 14, T.5 S., R.14 E.; USGS Gooding Quadrangle; Latitude - 42 degrees, 59 minutes, 31 seconds N. and Longitude - 114 degrees, 39 minutes, 09 seconds W., NAD83.

RANGE IN CHARACTERISTICS:
Depth to calcium carbonates - 45 to 65 cm
Depth to duripan - 50 to 100 cm
Depth to bedrock - 100 to 150 cm
Particle-size control section - 24 to 35 percent clay; 0 to 10 percent rock fragments
Moisture control section - moist less than 90 consecutive days when the soil temperature is greater than 8 degrees C.
Average annual soil temperature - 10 to 12 degrees C.

A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Reaction - neutral or slightly alkaline
Rock fragments - 0 to 5 percent gravel, 0 to 5 cobbles and 0 to 10 total

Bt horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - SIL or SICL
Clay content - 24 to 35 percent
Rock fragments - 0 to 5 percent gravel, 0 to 5 cobbles and 0 to 10 total
Reaction - neutral through moderately alkaline

Bk and Bkq horizons
Value - 5 through 8 dry, 3 through 6 moist
Chroma - 3 or 4 dry or moist
Texture - L or SIL
Clay content - 12 to 27 percent
Rock fragments - 0 to 10 percent gravel, 0 to 10 percent cobbles and 0 to 15 percent total
Paragravel - 0 to 35 percent duripan fragments
Reaction - slightly alkaline through strongly alkaline
Calcium carbonate equivalent - 3 to 40 percent

2Bkqm horizon
Structure - massive or platy
Cementation - very strong or indurated
Rock fragments - 15 to 90 percent total

COMPETING SERIES: These are the Elijah, McPan and Virtue series. Elijah and Virtue soils are greater than 150 cm to bedrock. McPan soils are 50 to 100 cm deep to bedrock.

GEOGRAPHIC SETTING: Elfkin soils are on lava flows on lava plains and in valleys at elevations of 700 to 1,400 meters. Slopes range from 0 to 12 percent. The soils formed in silty alluvium from loess and volcanic ash over basalt. Average annual precipitation is 200 to 300 mm. Average annual temperature is 9 to 11 degrees C. The frost-free season is 100 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bruncan, Gooding, Purdam and the competing McPan soils. Bruncan soils have bedrock above 100 cm. Gooding soils average more than 35 percent clay in the argillic horizon. Purdam soils do not have an indurated duripan. These soils are on similar geomorphic positions.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high Ksat.

USE AND VEGETATION: Elfkin soils are used mainly for irrigated cropland, irrigated hayland/pasture and rangeland. Crops grown include corn, small grains, potatoes and sugar beets. Native vegetation is Wyoming big sagebrush, bluebunch wheatgrass and Thurber needlegrass. Some areas have been urbanized.

DISTRIBUTION AND EXTENT: South-central Idaho. MLRA 11. Elfkin soils are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Ada County, Idaho, 2012.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - zone from 0 to 13 cm (Ap horizon)
Argillic horizon - zone from 13 to 38 cm (Bt1 and Bt2 horizons)
Indurated duripan - zone from 91 to 114 cm (Bkqm1 and 2Bkqm2 horizons)
Particle-size control section - zone from 13 to 38 cm
Soil moisture regime - aridic bordering on xeric

This soil was originally correlated as Elijah, bedrock substratum phase. As revised in 2010, Elijah soils must be greater than 150 cm to bedrock. Bedrock substratum phases of Elijah in Ada County Area, Canyon County Area, and Wood River Area soil surveys (Idaho) will be correlated to the Elfkin Series during MLRA updates.

National Cooperative Soil Survey
U.S.A.