LOCATION SCALA              WA
Established Series
Rev. ASZ/RJE
01/2002

SCALA SERIES


The Scala series consists of deep, well drained soils formed in glaciofluvial material mixed with volcanic ash and loess. These soils are on terraces and terrace escarpments. Slopes are 0 to 45 percent. The average annual precipitation is about 18 inches and the mean annual temperature is about 45 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Vitrandic Haploxerepts

TYPICAL PEDON: Scala ashy fine sandy loam-forested. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 0.5 inch; needles, leaves, twigs, and bark.

A--0.5 to 0.75 inches; grayish brown (10YR 5/2) ashy loamy fine sand, very dark grayish brown (10YR 3/2) moist; single grain; loose, nonsticky and nonplastic; slightly acid (pH 6.2); abrupt broken boundary. (0 to 4 inches thick)

Bw1--0.75 to 5 inches; brown (10YR 5/3) ashy fine sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine roots; slightly acid (pH 6.5); clear smooth boundary. (3 to 4 inches thick)

Bw2--5 to 13 inches; brown (10YR 5/3) ashy fine sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many fine, medium and coarse roots; slightly acid (pH 6.2); gradual wavy boundary. (6 to 14 inches thick)

Bw3--13 to 23 inches; pale brown (10YR 6/3) fine sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common fine, medium and coarse roots; common very fine pores; slightly acid (pH 6.4); clear wavy boundary. (9 to 12 inches thick)

Bw4--23 to 36 inches; light yellowish brown (10YR 6/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; few fine faint yellowish brown (10YR 5/6) stains; massive; slightly hard, very friable, nonsticky and slightly plastic; common fine and few coarse roots; common fine and few coarse roots; common very fine pores; one distinct wavy band; slightly acid (pH 6.4); gradual wavy boundary. (8 to 14 inches thick)

E and B--36 to 48 inches; light yellowish brown (10YR 6/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; (E part) several distinct brown (7.5YR 5/4) wavy bands (B part); massive; slightly hard, friable, nonsticky and slightly plastic; common fine and few medium and coarse roots; common very fine pores; neutral (pH 6.6); abrupt smooth boundary. (8 to 14 inches thick)

2Bw5--48 to 59 inches; pale olive (5Y 6/3) silt loam, olive brown (2.5Y 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine pores; neutral (pH 6.6); abrupt smooth boundary. (0 to 12 inches thick)

2Bt--59 to 60 inches; pale olive (5Y 6/3) silt loam, olive brown (2.5Y 4/4) moist; massive; hard, firm, sticky and plastic; few very fine and fine roots; many very fine pores; moderately thick clay films in pores; neutral (pH 6.6).

TYPE LOCATION: Ferry County, Washington; 1,980 feet west and 1,930 feet south of the northeast corner of sec. 32, T. 37N., R. 37 E., W.M.

RANGE IN CHARACTERISTICS: Mean annual soil temperature at a depth of 20 inches ranges from 47 to 52 degrees F. These soils are usually moist but are dry in all parts between depths of 8 and 24 inches for 75 to 90 consecutive days following the summer solstice. The upper 7 to 14 inches has an estimated moist bulk density of 1.30 to 1.60 g/cc, volcanic glass content of 5 to 20 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent, and 15-bar water retention of 5 to 10 percent for air dried samples. The particle-size control section has 5 to 12 percent clay, more than 15 per;cent particles coarser than very fine sand, and 0 to 5 percent pebbles. Reaction is slightly acid to neutral throughout.

The A horizon has value of 4 through 6 dry, 2 through 4 moist, and chroma of 2 or 3 dry, 1 or 2 moist.

The Bw and E/B horizons have hue of 10YR, 7.5YR or 2.5Y, value of 5 or 6 dry, 2 through 4 moist, and chroma of 2 through 4 dry or moist. The Bw and E part of the E/B horizon is fine sandy loam, sandy loam, or very fine sandy loam. The B part of the E/B horizon consists of 7.5YR band of clay accumulation. The bands of clay accumulation are less than 6 inches in total thickness.

The 2Bw and 2Bt horizon have hue of 5Y or 2.5Y, value of 5 or 6 dry, and chroma of 3 or 4 dry or moist. It is silt loam or silty clay loam. In some pedons the 2Bw and 2Bt horizon are at depths of 60 inches or more.

COMPETING SERIES: These are the Bestrom, Cassolary, Clayton, Hudnut and Kartar series. Similar soils in other families are Arrastre, Barron, Frailey, Green Bluff, Koerling, Koseth, Quiden, and Stoner series. Arrastre and Bestrom soils have a lithic contact at 20 to 40 inches. Barron soils have a solum 30 to 40 inches thick and a mean soil temperature of 54 to 56 F. Cassolary soils have a solum 15 to 30 inches thick and a 2C horizon above 40 inches that is stratified silt loam, silty clay loam, and clay loam.
Clayton soils are dry for 60 to 75 consecutive days. Frailey and Quiden soils have a loam or gravelly loam control section. Green Bluff soils have 35 to 60 percent pyroclastic material in the control section. Hudnut, Kartar, Koseth, and Stoner soils have 15 to 35 percent rock fragments in the particle-size control section. Koerling soils are calcareous below a depth of 24 to 40 inches.

GEOGRAPHIC SETTING: Scala soils are on terraces and terrace escarpments. These soils formed in glaciofluvial material mixed with volcanic ash and loess. Slopes are 0 to 45 percent. Elevations range from 1,400 to 2,000 feet. The climate is characterized by warm, dry summers and cool, wet winters. Average annual precipitation ranges from 15 to 20 inches. Mean annual air temperature is 45 degrees F. Frost-free season is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cedonia, Dart, Hunters, Lakesol, Marble, and Phoebe soils. Cedonia and Hunters soils are fine-silty. Dart and Marble soils are sandy. Lakesol soils have a mollic epipedon and are coarse-silty. Phoebe soils have a mollic epipedon.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately rapid permeability to 48 inches and moderate below.

USE AND VEGETATION: Used for cropland, woodland, grazable woodland, wildlife habitat, and recreation. Crops include winter and spring wheat, alfalfa hay, and grass-legume hay. Native vegetation is ponderosa pine and Douglas-fir, with an understory of common snowberry, bluebunch wheatgrass, pinegrass, dwarf rose, creeping Oregon-grape, tapertip hawksbeard, Idaho fescue, and western yarrow.

DISTRIBUTION AND EXTENT: Northeastern Washington. Scala series is of small extent.

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

SERIES ESTABLISHED: Ferry County (North Ferry Area), Washington, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 3/4 inch, a cambic horizon from 3/4 inch to 60 inches that includes bands and patches of clay accumulation less than 6 inches thick in total. The 2 material is lacustrine sediments from 48 to 60 inches. The description reflects a change in classification from coarse-loamy, mixed, mesic Vitrandic Xerochrepts to coarse-loamy, mixed, superactive, mesic Vitrandic Haploxerepts.


National Cooperative Soil Survey
U.S.A.