LOCATION EAGLE                   ID

Established Series
IRD: JCB/ALH/MPR
07/2012

EAGLE SERIES

The Eagle series consists of very deep, moderately well drained soils that formed in alluvium mainly from granitic rocks. Slopes range from 0 to 1 percent in valleys. The average annual precipitation is about 280 mm and the average annual temperature is about 10.5 degrees C.

TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Oxyaquic Torrifluvents

TYPICAL PEDON: Eagle gravelly fine sandy loam -- on a nearly level stream terrace, in pastureland at 753 meters elevation. When described on October 20, 2006, the soil was dry to 153 cm and wet below. (Colors are for air-dry soil unless otherwise stated.)

A--0 to 8 cm; brown (10YR 5/3) gravelly fine sandy loam, dark brown (10YR 3/3) moist; weak medium platy structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine, common fine tubular and vesicular pores; 15 percent gravel; slightly acid (pH 6.5); clear smooth boundary. (5 to 20 cm thick)

AC--8 to 26 cm; pale brown (10YR 6/3) fine sandy loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine, few medium roots; many very fine, common fine tubular and vesicular pores; common fine faint brown (7.5YR 4/4) moist redox concentrations; 10 percent gravel; slightly acid (pH 6.1); clear smooth boundary. (10 to 20 cm thick)

C1--26 to 38 cm; pale brown (10YR 6/3) gravelly loamy fine sand, brown (10YR 4/3) moist; massive; moderately hard, friable, nonsticky and nonplastic; common very fine and fine, few medium roots with root mat at lower boundary; many very fine, common fine tubular and vesicular pores; many fine and medium distinct brown (7.5YR 4/4) moist redox concentrations; 15 percent gravel; slightly acid (pH 6.2); abrupt smooth boundary. (0 to 25 cm thick)

2C2--38 to 160 cm; multi-colored very gravelly sand; single grain; loose, nonsticky and nonplastic; 50 percent gravel, 5 percent cobbles; neutral (pH 6.6).

TYPE LOCATION: Ada County, Idaho; about one-half mile southeast of Star; 2,190 feet south and 2,530 feet west of the northwest corner of section 17, T.4 N., R.1 W; USGS Star Quadrangle; Latitude - 43 degrees, 41 minutes, 08 seconds N. and Longitude - 116 degrees, 29 minutes, 01 second W., NAD 83.

RANGE IN CHARACTERISTICS:
Organic matter - decreases irregularly with depth
Depth to lithologic discontinuity (sand & gravel) - 25 to 50 cm
Depth to bedrock - 150 cm or more
Reaction - slightly acid through slightly alkaline
Redoximorphic features - none to many Fe concentrations
Particle-size control section - 0 to 8 percent clay; 35 to 75 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 - 11 to 12 degrees C.

A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3 dry and moist
Clay content - 8 to 15 percent
Rock fragments - 5 to 35 percent gravel, 0 to 5 percent cobbles and 5 to 35 percent total

AC horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry and moist
Texture - FSL or SL
Clay content - 8 to 15 percent
Rock fragments - 5 to 35 percent gravel, 0 to 5 percent cobbles and 5 to 35 percent total

2C horizon
Texture - sand and gravel with 0 to 4 percent clay and 35 to 75 percent rock fragments

COMPETING SERIES: These are the Anvil and Numana series. Anvil soils are moderately alkaline with disseminated calcium carbonate throughout and have mean annual soil temperature of 8 to 10.5 degrees C. Numana soils have sandy textures and greater than 35 percent rock fragments throughout.

GEOGRAPHIC SETTING: Eagle soils are on stream terraces at elevations of 748 to 869 meters. Slopes range from 0 to 1 percent. These soils formed in alluvium (Holocene) mainly from granitic rocks. The average annual precipitation is 254 to 330 mm. The average annual temperature is 10 to 11 degrees C. The frost-free period is 145 to 155 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ballentine, LesBois, Moulton and Notus soils. Ballentine soils have a mollic epipedon and are on similar geomorphic positions. Lesbois, Moulton and Notus soils have normal seasonal high saturation between 50 and 100 cm and are on lower flood-plain steps.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained with normal seasonal high saturation at depths of 100 to 150 cm during the months of March through June; very high saturated hydraulic conductivity. Eagle soils are subject to rare flooding where not protected. Under flood irrigation these soils are regularly saturated to depths of less than 50 cm during the growing season.

USE AND VEGETATION: Eagle soils are used mainly for irrigated cropland and hayland/pasture. Principle crops are corn and small grains. Native vegetation is basin big sagebrush and basin wildrye. Some large tracts have been urbanized with river corridors used for recreation and wildlife habitat.

DISTRIBUTION AND EXTENT: Southwestern Idaho. MLRA 11. Eagle 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 profile:
Ochric epipedon - zone from 0 to 26 cm (A and AC horizons)
Particle-size control section - zone from 25 to 100 cm
Soil moisture regime - aridic bordering on xeric
The faint Fe concentrations that occur in the upper profile are assumed to be result of flood irrigation.
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National Cooperative Soil Survey
U.S.A.