LOCATION JURVANNAH IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed Typic Cryaquents
TYPICAL PEDON: Jurvannah sandy loam, pasture. (Colors are for dry soil unless otherwise noted.)
A1--0 to 6 inches; grayish brown (10YR 5/2) sandy loam, very dark gray (10YR 3/1) moist; weak fine granular structure; loose; common very fine roots; many very fine interstitial pores; medium acid (pH 6.0); abrupt smooth boundary. (5 to 9 inches thick)
C1--6 to 10 inches; very pale brown (10YR 7/3) sand, brown (10YR 5/3) moist; common distinct medium and fine dark brown (7.5YR 4/4) and few fine faint light yellowish brown (10YR 6/4) mottles; weak granular structure; loose; few very fine roots; medium acid (pH 5.6); abrupt smooth boundary. (4 to 24 inches thick)
C2--10 to 22 inches; white (10YR 8/1) and brownish yellow (10YR 6/6) gravelly sand, brownish yellow (10YR 6/6) moist; single grained; loose; medium acid (pH 5.9); clear smooth boundary. (6 to 16 inches thick)
C3--22 to 38 inches; pink (7.5YR 7/4) and yellowish red (5Y 4/6) very gravelly sand, yellowish red (5YR 4/6) moist; single grained; loose; slightly acid (pH 6.2); abrupt smooth boundary. (16 to 22 inches thick)
C4--38 to 60 inches; very pale brown (10YR 7/3) and pale brown (10YR 6/3) very gravelly sand, pale brown (10YR 6/3), very pale brown (10YR 7/3) and dark yellowish brown (10YR 4/4) moist; single grained; loose; slightly acid (pH 6.2).
TYPE LOCATION: Valley County, Idaho; about 1 mile south of Cascade, Idaho; 100 feet east and 460 feet south of the NW corner of sec. 6, T.12N., R.4E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 40 degrees to 42 degrees F. The mean summer soil temperature is 53 degrees to 55 degrees F. A fluctuating water table ranges from about 18- to 36-inch depth in spring and early summer for about two months. Base saturation ranges from about 50 to 75 percent throughout the profile.
The A horizon has value of 5 or 6 dry, 3 through 5 moist, and chroma of 1 through 3.
The C horizon is stratified with sand, gravelly sand or very gravelly sand and contains 5 to 50 percent gravel. This horizon has thin strata of sandy loam in some pedons. Between depths of 10 and 40 inches the soil averages 35 to 45 percent fine gravel. Mottles occur between depths of 6 and 20 inches.
COMPETING SERIES: These are the Apeldorn and Eachuston series. Apeldorn soils are moderately alkaline or strongly alkaline in the control section and calcareous throughout the profile. Eachuston soils have O horizons and have a base saturation of 80 to 100 percent.
GEOGRAPHIC SETTING: Jurvannah soils are on alluvial fans, low stream terraces, or flood plains and have slopes of 0 to 2 percent. They formed in coarse textured alluvium from granitic rocks. Elevations are 4,800 to 5,100 feet. Mean annual precipitation is 22 to 24 inches. mean annual temperature is 38 degrees to 40 degrees F., and mean summer temperature is 53 degrees to 55 degrees F. Frost-free season is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blackwell, Gestrin, Kangas, Melton, and Roseberry soils. Blackwell soils have mollic epipedons. Gestrin soils have cambric horizons and are moderately well drained. Kangas soils are somewhat excessively drained. Melton soils are medium textured to about a 20-inch depth. Roseberry soils have less than 35 percent coarse fragments in the control section.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; moderately rapid permeability.
USE AND VEGETATION: Pasture or range. Vegetation is mainly sedges, redtop, fescues, willows and scattered lodgepole pine.
DISTRIBUTION AND EXTENT: Valley County, Idaho. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Valley Area, Idaho, 1977.