LOCATION MARTELLA WAEstablished Series
TAXONOMIC CLASS: Fine-silty, isotic, frigid Andic Haploxeralfs
TYPICAL PEDON: Martella ashy silt loam, forested. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2.5 inches; very dark grayish brown (10YR 3/2) moist; loose, partially decomposed organic litter composed of needles, leaves and twigs; moderately acid (pH 6.0); abrupt smooth boundary. (1 to 4 inches thick)
A1--2.5 to 2.75 inches; light gray (10YR 7/1) ashy very fine sandy loam, dark gray (10YR 4/1) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 1/2 inches thick)
A2--2.75 to 12 inches; very pale brown (10YR 7/3) ashy silt loam, dark brown (7.5YR 3/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; man roots; many fine pores; less than 5 percent gravel; neutral (pH 6.6); clear wavy boundary. (5 to 10 inches thick)
E--12 to 16 inches; very pale brown (10YR 7/3) ashy silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many roots; many fine pores; less than 5 percent gravel; neutral (pH 6.6); clear wavy boundary. (2 to 4 inches thick)
2BE--16 to 27 inches; light gray (2.5Y 7/2) silt loam, light olive brown (2.5Y 5/4) moist; moderate medium prismatic structure; very hard, firm, moderately sticky and moderately plastic; many roots; few fine pores; few thin silt flour coatings in pores; less than 5 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (8 to 12 inches thick)
2Bt--27 to 33 inches; light gray (2.5Y 7/2) silty clay loam, light olive brown (2.5Y 5/4) moist; moderate medium and coarse prismatic structure; very hard, firm, moderately sticky and moderately plastic; common roots; few fine pores; few thin clay films on peds and in pores; less than 5 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (4 to 8 inches thick)
2C1--33 to 43 inches; light gray (2.5Y 7/2) silt loam, grayish brown (2.5Y 5/2) moist; massive and laminated; very hard, very firm, slightly sticky and slightly plastic; few roots; few fine pores; neutral (pH 7.2); clear smooth boundary. (8 to 12 inches thick)
2C2--43 to 60 inches; light gray (2.5Y 7/2) silt loam, grayish brown (2.5Y 5/2) moist; massive and laminated; very hard, firm, slightly sticky and slightly plastic; few roots; few fine pores; slightly alkaline (pH 7.6).
TYPE LOCATION: Stevens County, Washington; 1,600 feet south and 1,450 feet east of the NW corner of sec. 22, T.30N., R.40E.; 400 feet east from a point where Road No. 175 crosses a railroad track, 90 feet north of old logging road and then 10 feet west of logging road.
RANGE IN CHARACTERISTICS: Martella soils are more than 60 inches deep. The thickness of the volcanic ash mantle is 7 to 14 inches and has an estimated moist bulk density of 0.65 to 1.0 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1.0 to 2.0 percent, and 15-bar water retention of 5 to 12 percent for air dried samples. The soil is usually moist in all horizons but is dry in all parts between depths of 4 and 12 inches for 45 to 75 consecutive days following the summer solstice. The mean annual soil temperature is from 44 to 47 degrees F. The particle-size control section has 18 to 35 percent clay, and 0 to 5 percent rounded gravel.
The A horizon has hue of 7.5YR or 10YR, value of 5 to 7 dry, 3 to 5 moist and chroma of 1 to 4. It is ashy silt loam or ashy fine sandy loam. The horizons with high value and low chroma are Mt. St. Helen's 'T' or 'W' volcanic ash.
The E horizon has hue of 7.5YR or 10YR, value of 6 or 7 dry, 4 or 5 moist, and chroma of 2 to 4 dry or moist. It is ashy very fine sandy loam, ashy silt loam, or ashy loam and has 0 to 10 percent gravel. This horizon has weak or moderate, fine to coarse granular or subangular blocky structure. It is neutral or slightly acid. Some pedons have a 2E horizon.
The 2BE horizon has hue of 10YR or 2.5Y, value of 5 to 7 dry, 4 or 5 moist, and chroma of 2 to 4 dry or moist. It is very fine sandy loam or silt loam, and has 0 to 5 percent gravel. This horizon has weak or moderate fine, medium, or coarse subangular blocky, angular blocky or prismatic structure. It is slightly acid or neutral. Some pedons do not have a 2BE horizon.
The 2Bt horizon has hue of 10YR or 2.5Y, value of 5 to 7 dry, 3 to 6 moist, and chroma of 2 to 4 dry or moist. It is silt loam or silty clay loam and has 0 to 5 percent gravel. This horizon has fine, medium, or coarse subangular blocky, angular blocky, or prismatic structure. It is slightly acid to slightly alkaline.
Some pedons have a 2BC horizon.
The 2C horizon has hue of 10YR, 2.5Y, or 5Y, value of 5 to 8 dry, 3 to 6 moist, and chroma of 2 to 4 dry or moist. It is very fine sandy loam, silt loam, or silty clay loam and has 0 to 5 percent gravel. It is massive or varved. It is neutral or slightly alkaline.
COMPETING SERIES: There are no other series in this family. Similar series in other familes are the Benewah, Lovell, Cedonia, Kewach, and Laketon series. Benewah soils are strongly or very strongly acid and lack a mantle of volcanic ash. Lovell soils lack a volcanic ash mantle and are somewhat poorly drained. Cedonia and Laketon soils are mesic. Kewach soils are fine.
GEOGRAPHIC SETTING: Martella soils are on terraces at elevations of 2,000 to 4,800 feet. Slopes range from 0 to 40 percent, but predominant slopes are 0 to 25 percent. These soils formed in glacial lake sediments of mixed mineralogy with a mantle of volcanic ash and loess. Martella soils are in a continental climate having warm, dry summers and cool, moist winters. The mean temperature in January is 27 degrees F, and in July 67 degrees F. The average precipitation for January is as high as 3 inches, and for July less than 1 inch. The mean annual temperature ranges from 40 to 45 degrees F. The average annual precipitation ranges from 18 to 30 inches. The frost-free season is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aits, Anglen, Bonner, Clayton, Elbowlake, Eloika, Hodgson, Karamin, Louploup, Newbell, Scrabblers, Stapaloop, and Waits soils and the competing Cedonia and Kewach soils. Aits, Clayton, Stapaloop and Waits soils are coarse-loamy. Aits soils are on glaciated mountains. Cedonia soils are on lake terraces and terrace breaks. Anglen and Hodgson soils are fine. Anglen soils are on glacial lake terraces and escarpments. Waits soils are on foothills and mountains. Bonner soils are coarse-loamy over sandy or sandy-skeletal. Eloika soils are medial over coarse- loamy. Karamin and Scrabblers soils are sandy. Louploup soils are ashy over loamy and are on till plains and mountains. Bonner, Clayton, Eloika, Hodgson, Karamin, Kewach, Scrabblers, and Stapaloop soils are on terraces. Newbell and Elbowlake soils are loamy-skeletal and are on mountain backslopes, footslopes and toeslopes.
DRAINAGE AND PERMEABILITY: Moderately well drained; very slow to rapid runoff; moderate permeability.
USE AND VEGETATION: Used primarily for timber production, grazing and wildlife habitat. Some areas are cultivated for the production of alfalfa, small grains and grasses. Native overstory vegetation is Douglas-fir, lodgepole pine, western larch, grand fir, ponderosa pine, and western redcedar. Understory vegetation is Saskatoon serviceberry, creambush oceanspray, mountain alder, willow, common snowberry, ribes, mallow ninebark, wild rose and Oregon grape. Ground vegetation is mostly white spirea, strawberry, pippsisewa, pachystima, kinnikinnick, meadow rue, and pinegrass.
DISTRIBUTION AND EXTENT: Valleys and some mountain areas in northcentral and northwestern Washington. MLRA 43A. Series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Stevens County, Washington, 1978.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mantle of volcanic ash from 2.5 to 16 inches. An argillic horizon from 27 to 33 inches which averages 18 to 35 percent clay. Base saturation (by sum of cations) is estimated to be less than 75 percent in some subhorizon within 30 inches of the upper boundary of the argillic horizon. Further lab data is needed to verify these estimates. This description reflects a change in classification from Fine-silty, mixed, frigid Andic Haploxeralfs to Fine-silty, isotic, frigid Andic Haploxeralfs.