LOCATION ARCHABAL IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Humicryepts
TYPICAL PEDON: Archabal loam, pasture. (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak thin platy structure parting to moderate very fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots; strongly acid (pH 5.3); clear smooth boundary. (3 to 5 inches thick)
A2--4 to 8 inches; similar to the A1 except for having moderate fine and very fine granular structure; common very fine vesicular pores; strongly acid (pH 5.4); gradual smooth boundary. (3 to 8 inches thick)
A3--8 to 14 inches; brown (10YR 4/3) loam, very dark brown (10YR 2/2) moist; very weak medium prismatic structure parting to weak very fine and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots; common very fine vesicular pores; strongly acid (pH 5.5); clear irregular boundary. (4 to 7 inches thick)
Bt1--14 to 21 inches; yellowish brown (10YR 5/4) loam, dark brown (7.5YR 3/3) moist; weak prismatic structure parting to weak medium subangular blocky; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; common fine and very fine tubular pores; faint and patchy, dark brown (7.5YR 3/3) moist clay films on vertical faces of peds and in the pores; strongly acid (pH 5.5); gradual smooth boundary. (4 to 8 inches thick)
Bt2--21 to 31 inches; brown (7.5YR 5/4) loam, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine roots; many fine and very fine tubular pores; medium continuous brown (7.5YR 4/3) clay films on vertical and horizontal faces of peds and in pores; strongly acid (pH 5.5); gradual smooth boundary. (7 to 14 inches thick)
Bt3--31 to 52 inches; yellowish brown (10YR 5/4) coarse sandy loam, brown (7.5YR 4/3) moist; very weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine and common fine tubular pores; strongly acid (pH 5.5); gradual smooth boundary. (9 to 25 inches thick)
C--52 to 60 inches; pale brown (10YR 6/3) coarse sand, brown (7.5YR 4/3) moist; single grained; loose; strongly acid (pH 5.4).
TYPE LOCATION: Valley County, Idaho; about 5.5 miles Northeast of Donnelly, Idaho; 300 feet south of the Northeast corner of the SE1/4, sec. 23, R.17N., R.3E.
RANGE IN CHARACTERISTICS: Sand or gravel occur at depths of 40 to 60 inches or more. The thickness of solum ranges from 30 to 52 inches. Mean annual soil temperature is 38 degrees to 47 degrees F., and mean summer soil temperature is 52 degrees to 58 degrees F. Some pedons contain large stones in the lower part of the profile.
The A horizon ranges in thickness from 10 to 20 inches. Base saturation ranges from 35 to 50 percent. Color value is 4 or 5 dry, 2 or 3 moist, and chroma is 2 or 3.
The Bt horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4. It has about 18 to 25 percent clay.
COMPETING SERIES: These are the Domo and Packtrail series and the similar Gestrin series. Domo soils have an umbric epipedon more than 16 inches thick. Packtrail soils have a lithic contact at 20 to 40 inches. Gestrin soils average less than 18 percent clay in the control section and have mottles in the lower part of the C horizon.
GEOGRAPHIC SETTING: Archabal soils are on moderately dissected glacial outwash or alluvial terraces, fans, or plains. Slopes are 0 to 20 percent. The soils formed in mixed acid igneous and minor amounts of basic igneous material. Elevations are 4,800 to 5,000 feet. The climate is humid continental, cool summer (Trewartha's modified Koppen System), with moist, cold winters and dry summers. Mean annual precipitation is 22 to 24 inches. Average January temperature is 20 degrees F.; average July temperature is 64 degrees F. Mean annual temperature is 40 degrees to 45 degrees F. Frost-free season is about 60 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Melton soils and the competing Gestrin soils. Melton soils are poorly drained.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used mainly for pasture, small grains, alsike clover and seed potatoes. Vegetation is mainly grass, forbs and some shrubs.
DISTRIBUTION AND EXTENT: Central Idaho in the cooler areas of the Idaho Batholith. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Valley Area, Idaho, 1977.