LOCATION PHYLLIS ID

Established Series
IRD: JCB/ALH
07/2012

PHYLLIS SERIES

The Phyllis series consists of very deep, very poorly drained soils with moderately high saturated hydraulic conductivity that formed in alluvium from granitic rocks. Slopes range from 0 to 1 percent in valleys. The average annual precipitation is about 279 mm and the average annual temperature is about 10.5 degrees C.

TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Fluvaquentic Endoaquolls

TYPICAL PEDON: Phyllis fine sandy loam -- on a nearly level flood-plain step, in a pasture, at 755 meters elevation. When described on October 5, 2006, the soil was moist to 38 cm and wet below. (Colors are for air-dry soil unless otherwise stated.)

A--0 to 18 cm; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine, common medium roots; many very fine and fine, few medium tubular and vesicular pores; common very fine faint dark yellowish brown (10YR 4/6) iron concentrations, common fine and medium distinct dark gray (2.5Y 4/1) iron depletions; slightly effervescent; neutral (pH 7.0); clear smooth boundary. (18 to 25 cm thick)

Ag--18 to 27 cm; gray (2.5Y 5/1) very fine sandy loam, very dark gray (2.5Y 3/1) moist; weak fine and medium subangular blocky structure; moderately hard, friable, nonsticky and slightly plastic; common very fine, fine and medium roots; many very fine tubular and vesicular pores; common fine prominent dark yellowish brown (10YR 4/6) moist redox concentrations; slightly acid (pH 6.3); clear smooth boundary. (0 to 38 cm thick)

Cg1--27 to 56 cm; light brownish gray (2.5Y 6/2) fine sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; moderately hard, friable, nonsticky and nonplastic; few very fine, common fine and medium roots; many very fine tubular and vesicular pores; common medium and coarse prominent dark yellowish brown (10YR 4/6) moist redox concentrations along root channels; slightly acid (pH 6.2); clear smooth boundary.

Cg2--56 to 74 cm; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; moderately hard, friable, nonsticky and nonplastic; few very fine and common fine and medium roots; many very fine tubular and vesicular pores; common medium and coarse prominent dark yellowish brown (10YR 4/6) moist redox concentrations along root channels; slightly acid (pH 6.4); clear smooth boundary. (combined Cg horizon - 25 to 37 cm thick)

2C--74 to 150 cm; multi-colored very gravelly loamy sand; single grain; loose, nonsticky and nonplastic; few very fine and fine roots; 45 percent gravel, 5 percent cobbles; neutral (pH 6.6).

TYPE LOCATION: Ada County, Idaho; about one and one-half miles southeast of Star; 80 feet south and 50 feet east of the center of section 20, T.4 N., R.1 W; USGS Star Quadrangle; Latitude - 43 degrees, 40 minutes, 11 seconds N. and Longitude - 116 degrees, 29 minutes, 00 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 25 to 64 cm
Depth to discontinuity (sand & gravel) - 50 to 100 cm
Depth to bedrock - greater than 180 cm
Particle-size control section (upper part) - 8 to 18 percent clay; less than 50 percent fine sand or coarser sand; 0 to 15 percent gravel
Particle-size control section (lower part) - 0 to 8 percent clay; 0 to 70 percent rock fragments
Average annual soil temperature - 11 to 12 degrees C.

A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2 dry and moist
Clay content -8 to 20 percent
Rock fragments - 0 to 5 percent gravel
Reaction - slightly acid or neutral
Effervescence - none or slight
Redoximorphic features - distinct or prominent iron concentrations; faint or distinct depletions

Ag horizon (when present)
Hue - 10YR through 10Y
Texture - VFSL, FSL or L
Clay content -8 to 20 percent
Rock fragments - 0 to 5 percent gravel
Reaction - slightly acid or neutral
Redoximorphic features - distinct or prominent iron concentrations

Cg horizon
Hue - 10YR through 10Y
Value - 5 or 6 dry, 3 or 4 moist
Texture - VFSL, FSL or SL
Clay content - 7 to 12 percent
Rock fragments - 0 to 5 percent gravel
Reaction - slightly acid or neutral
Redoximorphic features - distinct or prominent iron concentrations

2C horizon
Texture - stratified LFS to S
Clay content - 0 to 8 percent
Rock fragments - 0 to 60 percent gravel, 0 to 10 percent cobbles and 0 to 70 percent total
Reaction - slightly acid or neutral

COMPETING SERIES: This is the Craigmile series. Craigmile soils have less than 7 percent gravel in the lower 63 cm of the control section, and the Cg horizon does not have hue yellower than 10YR. Chance soils are similar but do not have a mollic epipedon.

GEOGRAPHIC SETTING: The Phyllis soils are on fluves or depressions of flood plain-steps at elevations of 748 to 876 meters. Slopes range from 0 to 1 percent. These soils formed in recent alluvium from granitic rocks with minor influence of other igneous materials. 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 Moulton and Notus soils. Moulton and Notus soils are somewhat poorly drained and on smooth or convex geomorphic positions. Notus soils do not have mollic epipedons, and are less than 50 cm deep to sand and gravel.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained with normal seasonal high saturation less than 25 cm from the surface; slow runoff; moderately high over very high saturated hydraulic conductivity. Phyllis soils are subject to frequent ponding and flooding where not protected for brief periods from December to June. These soils are commonly saturated to the surface during the growing season due to flood irrigation.

USE AND VEGETATION: Phyllis soils are used mainly for hayland/pasture, parkland and golf courses. Native vegetation is sedges, bulrushes and cattails.

DISTRIBUTION AND EXTENT: Southwestern Idaho. MLRA 11. Phyllis soils are of small extent.

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

SERIES ESTABLISHED: Ada County, Idaho, 2012.

REMARKS: Diagnostic horizons and features recognized in this profile:
Mollic epipedon - zone from 0 to 27 cm (A and Ag horizons)
Redoximorphic features - zone from 0 to 74 cm (A, Ag, Cg1 and Cg2 horizons)
Lithologic discontinuity - at 74 cm
Particle-size control section - zone from 25 to 100 cm
Soil moisture regime - aquic

Hydric soil indicator - A11 (Field Indicators of Hydric Soils in the United States - Version 6.0, 2006)

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National Cooperative Soil Survey
U.S.A.