LOCATION GREEN BLUFF WA

Established Series
Rev. NCD/SHB/EMM
01/2011

GREEN BLUFF SERIES

The Green Bluff series consists of very deep, well drained soils that formed in glaciofluvial deposits with an influence of volcanic ash and loess in the upper part. Green Bluff soils are on outwash plains over basalt plateaus and have slopes of 0 to 15 percent. The average annual precipitation is about 20 inches and the average annual temperature is about 44 degrees F.

TAXONOMIC CLASS: Coarse-loamy, isotic, frigid Vitrandic Haploxerepts

TYPICAL PEDON: Green Bluff ashy silt loam - cultivated. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 7 inches; brown (10YR 5/3) ashy silt loam, dark grayish brown (10YR 4/2) moist; weak very thin platy and weak fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and medium roots; few fine tubular and irregular pores; 5 percent gravel; slightly acid (pH 6.4); abrupt smooth boundary. (6 to 9 inches thick)

E&Bt1--7 to 17 inches; pale brown (10YR 6/3) ashy silt loam (E part), brown (10YR 4/3) moist; few fine faint organic stains, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; 2 irregular wavy continuous 1/4 inch thick lamellae (Bt part), dark yellowish brown (10YR 4/4) moist; many fine roots; many fine tubular and irregular pores; 5 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (8 to 12 inches thick)

E&Bt2--17 to 29 inches; light gray (10YR 7/2) and very pale brown (10YR 7/3) silt loam (E part), dark brown (10YR 3/3) moist; common faint organic stains, brown (7.5YR 5/4) moist; weak fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; 3 irregular wavy continuous 1 inch thick horizontal bands of lamellae (Bt part), brown (10YR 4/3) moist with 10 percent distinct clay films in pores and on surfaces of peds; few fine roots; many fine tubular and irregular pores; 10 percent gravel; neutral (pH 6.6); gradual wavy boundary. (10 to 25 inches thick)

E&Bt3--29 to 55 inches; pale brown (10YR 6/3) gravelly loam (E part), brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; 3 dark grayish brown (10YR 4/2) moist and brown (7.5YR 4/3) moist lamellae (Bt part) 1/2 inch thick with 20 percent distinct clay films in pores and on faces of peds; few fine roots; many fine tubular and irregular pores; 15 percent rounded gravel and 2 percent subrounded cobbles; neutral (pH 7.2); abrupt wavy boundary. (16 to 30 inches thick)

C--55 to 60 inches; pale brown (10YR 6/3) fine sandy loam, brown (10YR 4/3) moist; massive; hard, firm, moderately sticky and moderately plastic; thin layers of sandy material 1/4 to 1/2 inch thick; discontinuous bands of lamellae 1/2 to 1 inch thick with 2 percent faint clay films in pores and root channels; very few fine roots; 2 percent brown (10YR 4/3) medium organic stains; few fine and medium tubular and irregular pores; 5 percent gravel; neutral (pH 7.2).

TYPE LOCATION: Spokane County, Washington; About 3.5 miles east of Colbert, WA; About 1,000 feet south and 400 feet west of the northeast corner of section 20, T. 27 N., R. 44 E. USGS Mead, WA. Topographic quadrangle; (Latitude 47 degrees, 49 minutes, 42 seconds N. and Longitude 117 degrees, 15 minutes, 47 seconds W.), NAD83

RANGE IN CHARACTERISTICS:
Average annual soil temperature - 45 degrees to 47 degrees F.
Soil moisture - Usually moist, dry for 60 to 80 consecutive days during the summer and autumn
Particle-size control section - 0 to 15 percent rock fragments, 5 to 15 percent clay, and more than 15 percent sand coarser than very fine sand.
Soil reaction - slightly acid or neutral.
Total combined thickness of lamellae is less than 6 inches
Volcanic ash influence thickness - 14 to 20 inches
Properties of the volcanic ash influenced layers:
Bulk density (at 1/3 bar water) - greater than 0.95g per cc
Volcanic glass content - 5 to 20 percent
Acid-oxalate extractable Al plus 1/2Fe - 0.4 to 1.0 percent.

Ap horizon
Hue - 10YR or 7.5YR
Value 5 or 6 dry, 3 to 5 moist
Chroma - 2 or 3, dry or moist

E&Bt1 horizon
E part (90 to 95 percent of the horizon):
Hue - 10YR or 7.5YR
Value - 5 or 6 dry, 3 to 5 moist
Chroma 3 or 4, dry or moist
Texture - ashy loam, ashy very fine sandy loam, or ashy silt loam with total rock fragment content of 0 to 10 percent
Gravel content - 0 to 10 percent
Cobble content - 0 to 5 percent
Bt Part (5 to 10 percent of the horizon)
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 to 4, dry or moist

E&Bt2 and E&Bt3 horizon
E part (90 to 95 percent of the horizon):
Hue - 10YR or 7.5YR
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 to 4, dry or moist
Texture - loam, very fine sandy loam, or silt loam with total rock fragment content of 0 to 20 percent
Gravel content - 0 to 15 percent
Cobble content - 0 to 5 percent
Bt Part (5 to 10 percent of the horizon)
Value - 4 to 6, moist or dry
Chroma - 2 to 4, dry or moist

C horizon
Hue - 10YR or 2.5Y
Value - 5 to 7 dry, 2 to 5 moist
Chroma - 3 or 4 moist or dry
Texture - silt loam, loam, fine sandy loam, sandy loam, or very fine sandy loam with total rock fragment content of 0 to 15 percent
Gravel content - 0 to 15 percent
Cobble content - 0 to 5 percent
Redox concentrations - none to common, fine or medium, faint or distinct
Lamellae - range from thin to thick (3mm to 25mm in thickness) and are loam or silt loam.

COMPETING SERIES: These are the Ardenmont, Cobbler, Downeygulch, Enson, Labuck, Micapeak, Quinnamose, and Stapaloop series. Ardenmont soils are 40 to 60 inches deep to a paralithic contact. Cobbler soils do not have E & Bt horizons (lamella) and have sandy loam and loamy sand substratum textures. Downeygulch soils are 20 to 40 inches to a lithic contact. Enson soils have densic material at 44 inches. Quinnamose soils are 40 to 60 inches to a paralithic contact. Labuck and Micapeak soils are 20 to 40 inches deep to a paralithic contact. Stapaloop soils have fine sandy loam and sandy loam textures in the surface and particle-size control section, a solum 15 to 25 inches thick, and lack lamella.

GEOGRAPHIC SETTING: Green Bluff soils are on outwash plains over basalt plateaus at elevations of 1,800 to 2,500 feet. These soils formed in glaciofluvial deposits with a component of loess and volcanic ash in the upper part. They are in a climate with warm, dry summers and cool, moist winters. The mean annual precipitation is 18 to 25 inches. The mean January temperature is about 24 degrees F., and the mean July temperature is about 66 degrees F. The mean annual temperature is about 44 degrees F. The frost-free season is 90 to 135 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clayton, Kaniksu, Klickson and Speigle soils. Clayton soils have fine sandy loam and sandy loam textures in the surface and in the control section and are on outwash terraces. Kaniksu soils are on outwash terraces and are sandy in the particle-size control section. Klickson and Speigle soils are on steep basalt plateau side slopes and have mollic epipedon and are loamy-skeletal in the particle-size control.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for cropland, timber production and homesite development. Cropland uses include small grains, grass, alfalfa, orchards, and truck crops. Potential natural vegetation is Douglas-fir, lodgepole pine, ponderosa pine, western larch, mallow ninebark, common snowberry, pinegrass and grasses.

DISTRIBUTION AND EXTENT: Northeastern Washington. MLRA 43A, 44A. Series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Spokane County, Washington, 1913.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from 0 to 7 inches (Ap horizon)

Lamellae - the zone from 7 to 55 inches (E&Bt horizons). Total thickness of the lamellae in the E&Bt horizons is less than 6 inches

Vitrandic feature - the zone from 0 to 17 inches (Ap and E&Bt1 horizons)

Particle-size control section - the zone from 10 to 40 inches (part of the E&Bt1, the E&Bt2, and the upper part of the E&Bt3 horizon)

Series reclassified from Coarse-loamy, mixed, mesic Typic Xerochrepts to Coarse-loamy, isotic, mesic Vitrandic Haploxerepts 10/01.

The description for the type location has been revised 03/03 based on revisiting the pedon type location and developing a more complete pedon description. The series was also reclassified from Coarse-loamy, isotic, mesic Vitrandic Haploxerepts to Coarse-loamy isotic, frigid Vitrandic Haploxerepts to reflect the correct temperature regime. Green Bluff soils are also mapped in Stevens County with similar vegetation.

Green Bluff soils should be further investigated to determine typical mineralogy (isotic vs. mixed).

ADDITIONAL DATA: Laboratory data available for Soil Survey Sample Number: 68WA063001 Spokane County, WA. NSSL Pedon Number: NL68ID01 Lincoln, NE. Riverside Lab. Nos. 68790 - 68795.

National Cooperative Soil Survey
U.S.A.