LOCATION ELMA WA
Established Series
IRD. DRU/EED
02/2024
ELMA SERIES
Landscape--river valleys
Landform--natural levees, alluvial terraces, flood plains
Slope--0 to 15 percent
Parent material--alluvium over glacial outwash
Mean annual precipitation--about 1500 mm
Mean annual air temperature--about 11 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy over sandy or sandy-skeletal, isotic over mixed, superactive, mesic Andic Humixerepts
TYPICAL PEDON: Elma silt loam in an area of hayland (When described on October 1, 2015, the soil was dry to a depth of 67 cm and moist below that depth.)
Ap1--0 to 9 cm; silt loam, very dark brown (10YR 2/2) moist, dark grayish brown (10YR 4/2) dry; strong fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common fine and few medium irregular pores and common very fine tubular pores; 5 percent gravel; strongly acid (pH 5.3); abrupt smooth boundary
Ap2--9 to 38 cm; silt loam, very dark brown (10YR 2/2) moist, brown (10YR 4/3) dry; strong fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few medium roots; common very fine, fine, and medium tubular pores; 5 percent gravel; strongly acid (pH 5.5); abrupt wavy boundary
Bw1--38 to 55 cm; loam, dark brown (10YR 3/3) moist, pale brown (10YR 6/3) dry; strong fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common very fine roots; common very fine and medium tubular pores; 5 percent gravel; moderately acid (pH 6.0); clear wavy boundary
Bw2--55 to 67 cm; gravelly fine sandy loam, dark yellowish brown (10YR 3/4) moist, light yellowish brown (10YR 6/4) dry; moderate very fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine roots; common very fine tubular pores; 20 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary
2C--67 to 150 cm; extremely gravelly coarse sand, very dark grayish brown (2.5Y 3/2) moist, olive brown (2.5Y 4/3) dry; single grain; loose, nonsticky and nonplastic; common very fine interstitial pores; 65 percent gravel and 5 percent cobbles; slightly acid (pH 6.5)
TYPE LOCATION: Thurston County, Washington, about 3.5 km southwest of Rochester; about 265 m north and 335 m east of the southwest corner of section 9, T. 15 N., R. 3 W., Willamette Meridian; Rochester, Washington, U.S. Geological Survey quadrangle; latitude 46.7953820 , longitude -123.0721110, WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--10 to 12 degrees C
Soil moisture control section--dry 60 to 75 days following summer solstice
Mollic epipedon thickness--25 to 50 cm
Ap1 horizon
Hue--10YR, 7.5YR
Value--2, 2.5, or 3 moist, 3 to 5 dry
Chroma--1 to 3 moist, 2 to 4 dry
Volcanic glass content--5 to 10 percent
1/3-bar bulk density--0.80 to 0.95 g/cm3
Ammonium oxalate extractable Al plus 1/2 Fe--1 to 3 percent
Fine-earth texture--silt loam, loam
Clay content--10 to 25 percent
Gravel content--0 to 10 percent
Reaction (pH)--5.1 to 6.5
Thickness--5 to 15 cm
Ap2 horizon
Hue--10YR, 7.5YR
Value--2, 2.5, or 3 moist, 3 to 5 dry
Chroma--1 to 3 moist, 2 to 4 dry
Volcanic glass content--5 to 10 percent
1/3-bar bulk density--0.80 to 0.95 g/cm3
Ammonium oxalate extractable Al plus 1/2 Fe--1 to 3 percent
Fine-earth texture--silt loam, loam, fine sandy loam
Clay content--10 to 25 percent
Gravel content--0 to 10 percent
Reaction (pH)--5.1 to 6.5
Thickness--20 to 40 cm
Bw horizon
Hue--10YR, 7.5YR, 2.5Y
Chroma--3 or 4 moist or dry
Fine-earth texture--loam, silt loam, fine sandy loam
Clay content--5 to 20 percent
Gravel content--0 to 25 percent
Reaction (pH)--5.6 to 6.5
Combined thickness--10 to 40 cm
2C horizon
Hue--2.5Y, 10YR, 7.5YR
Value--3 or 4 moist
Chroma--2 or 3 moist, 2 to 4 dry
Fine-earth texture--coarse sand, sand, loamy sand
Clay content--0 to 10 percent
Sand content--80 to 100 percent
Total rock fragment content--10 to 80 percent
Gravel content--10 to 80 percent
Cobble content--0 to 20 percent
Reaction (pH)--5.6 to 7.3
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--5 to 55 m
Mean annual precipitation--1200 to 1800 mm
Mean annual air temperature--10 to 11 degrees C
Frost-free period--150 to 200 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Chehalis--less than 15 percent sand in particle-size control section; in linear to slightly convex flood plain positions
Eld--less than 15 percent rock fragments in particle-size control section; in slightly convex to linear flood plain positions
Scatter--less than 10 percent rock fragments in particle-size control section; in similar landform positions
Fordprairie,
Maytown--aquic conditions at a depth of 50 to 75 cm from the soil surface; in concave to linear flood plain positions
Rennie--aquic conditions to the soil surface; frequently flooded; frequently ponded; in oxbows and backswamps
Roundtree--aquic conditions to the soil surface; frequently flooded; frequently ponded; in concave depressions and overflow stream channels
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Flooding--very rare to occasional, very brief periods in November through March
Saturated hydraulic conductivity (Ksat)--moderately high or high in A and Bw horizons, very high in 2C horizon
USE AND VEGETATION:
Use--hay production and livestock grazing in cleared areas, wildlife habitat
Native vegetation--Douglas-fir, bigleaf maple, black cottonwood, red alder, common snowberry, beaked hazelnut, salmonberry, red elderberry, vine maple, Indian plum, Cascade Oregon grape, trailing blackberry, western swordfern, brackenfern
DISTRIBUTION AND EXTENT: Western Washington; MLRA 2; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: BOZEMAN, MONTANA
SERIES PROPOSED: Grays Harbor County, Washington; 1912; name from Elma, Washington
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 25 to 100 cm
*Mollic epipedon--zone from the surface to a depth of 38 cm
*Cambic horizon--zone from 38 to 67 cm
*Depth to lithologic discontinuity--67 cm
10/2016--The Elma series was inactive prior to 2016. It was re-established as part of an update project. The official series description was developed according to SSR01 Technical Note--Content and Format of Official Series Descriptions (revised 12/2015). Further field investigation and laboratory sampling of the flood plains of glacially modified river valleys in MLRA 2 is recommended to determine the distribution and influence of volcanic ash.
National Cooperative Soil Survey
U.S.A.