LOCATION SCRIVER IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Alfic Argicryolls
TYPICAL PEDON: Scriver loam, forested. (Colors are for dry soil unless otherwise stated.)
Oe--0 to 1.5 inches; very dark brown (10YR 2/2) moderately decomposed needles, leaves, twigs, and cones; strongly acid (pH 5.5); abrupt wavy boundary. (0 to 3 inches thick)
A1--1.5 to 5 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine granular structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine and fine and common medium roots; many very fine tubular pores; about 10 percent angular gravel, mostly less than 5 mm. across; neutral (pH 6.6); clear wavy boundary. (2 to 12 inches thick)
A2--5 to 11 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak very fine subangular blocky structure, that parts to moderate medium, fine, and very fine granular structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine and fine and few medium roots; many very fine tubular pores; very few uncoated sand and silt particles; about 5 percent angular gravel mostly less than 5 mm. across; neutral (pH 6.6); clear wavy boundary. (0 to 11 inches thick)
E/Bt--11 to 15 inches; pale brown (10YR 6/3) and some brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak fine and very fine subangular blocky structure, that parts to weak medium and fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots; many very fine and few fine and medium tubular pores; about 10 percent angular gravel, mostly less than 5 mm. across; few thin clay films on peds and some clay bridges; very few uncoated particles; slightly acid (pH 6.2); clear wavy boundary. (2 to 5 inches thick)
Bt and E1--15 to 25 inches; brown (10YR 5/3) and 30 percent pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; weak fine and very fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine and few medium and coarse roots; many very fine and few fine and medium tubular pores; 10 percent angular gravel, mostly less than 5 mm. across; common thin clay films on peds and in channels in browner portion and in few thin lamellae; thin clay bridges; very few uncoated particles in paler portion and above lamellae; slightly acid (pH 6.2); gradual wavy boundary. (5 to 15 inches thick)
Bt and E2--25 to 41 inches; brown (10YR 5/3) gravelly loam, brown (7.5YR 4/3) moist; 25 percent pale brown (10YR 6/3) and light brownish gray (10YR 6/2) splotches and thin subhorizons immediately above the lamellae, that are brown (10YR 4/3) moist; weak fine and very fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots; many very fine and few fine tubular pores; 18 percent angular gravel, mostly less than 5 mm. across; common thin clay films on peds, in pores, and as bridges; 4 thin brown (7.5YR 5/3), horizontal lamellae containing more clay than the adjacent material; few uncoated particles; moderately acid (pH 5.9); gradual wavy boundary. (5 to 20 inches thick)
Bt and E3--41 to 58 inches; similar to B&A2 except gravelly coarse sandy loam, 9 lamellae, and moderately acid (pH 5.8); abrupt irregular boundary. (0 to 23 inches thick)
Cr--58 to 70 inches; very pale brown (10YR 7/3), moderately weathered, micaceous, quartz monzonite bedrock; consolidated; hard, very few very fine roots; several reddish brown (5YR 4/3), 5 mm. thick, horizontal, wavy lamellae; strongly acid (pH 5.5).
TYPE LOCATION: Boise County, Idaho; NE1/4 NW1/4 sec. 9, T.9N., R.5E.; Cow Creek road; coordinate from the fiducial center of aerial photograph ELD 44-93 is 1.6 inches east; 40 percent easterly slope in the edge of a midslope bench.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 38 degrees to 44 degrees F.; and the mean summer soil temperature at a depth of 20 inches ranges from 55 degrees to 59 degrees F., if without an O horizon. The depth to bedrock is more than 40 inches. The mollic epipedon is 10 to 16 inches thick. The base saturation of the mollic epipedon is about 60 to 75 percent and of the argillic horizon, about 65 to 80 percent. The organic matter in the upper 7 inches has a C:N ratio of 13.5 to 18.
The A horizon has value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3. The pH is 5.8 to 6.8.
The Bt and E horizon contains irregular splotches and thin subhorizons of lighter colored A2 horizon material immediately above the lamellae. The B horizon material is brown to pale brown or light brown in 10YR or 7.5YR hue and is loam to coarse sandy loam, which may be gravelly. The upper 20 inches of the argillic horizon has less than 18 percent clay and less than 35 percent coarse fragments. Clay films are few to common and thin on peds, in pores, and as bridges but are more distinct in the lamellae. The B horizon material ranges from moderate to weak, very fine to medium, subangular blocky structure and from pH 5.7 to 6.8. Brown (7.5YR 5/3 or 10YR 5/3) or reddish brown (5YR 4/3) horizontal, wavy lamellae 3 to 20 mm. thick are in the Bt and E horizon, and they commonly contain more clay than the adjacent material.
The Cr layer is commonly more acid than the solum and ranges from pH 5.4 to 6.5. Roots penetrate the more weathered portion but are mostly concentrated in fracture planes.
COMPETING SERIES: There are no other series in this family. The Bassel, Bryan, Burgess, Coski, Kanlee, and Suttler are similar series. Bassel soils have neutral or mildly alkaline sola, gravelly sandy clay loam Bt horizons, and Bk horizons. Bryan, Coski, and Suttler soils lack an argillic horizon. Burgess and Kanlee soils have a C:N ratio in the upper 7 inches of less than 13.5 and have more than 18 percent clay in the argillic horizon. Burgess soils have more than 80 percent base saturation in the Bt horizon. Kanlee soils have a mean summer soil temperature at depth of 20 inches warmer than 59 degrees F.
GEOGRAPHIC SETTING: The soils are on dominantly broad ridges, side slopes, toe slopes, benches, and saddles in strongly dissected uplands. Slopes range from 5 to 50 percent. The soils are most common in northerly slopes. The elevations range from 4,700 feet where the aspect is northerly to 6,500 feet or higher. The soils formed in residuum and colluvium derived from quartz monzonite, granodiorite, and related granitic bedrock. The mean annual precipitation is 25 to 35 inches, including 8 to 15 feet of snowfall. The average freeze-free period ranges from about 30 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bryan and Coski soils and the Koppes, Naz, Pyle, and Quartzburg soils. All lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well or somewhat excessively drained; medium or rapid runoff; moderate permeability.
USE AND VEGETATION: Used for forestry, watershed, wildlife, grazing, and recreation. The vegetation is mainly Douglas-fir, ninebark, snowberry, some ponderosa pine, and huckleberry. In places, there is some subalpine fir, grand fir, willow, Rocky Mountain maple, Oregon grape, chokecherry, snowbrush, wild rose, aspen, alder, mountain ash, meadowrue, aster, and (or) lupine.
DISTRIBUTION AND EXTENT: Idaho Batholith and probably elsewhere. Moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Middle Fork Payette River Area, Idaho, 1969.