LOCATION GESTRIN IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Typic Humicryepts
TYPICAL PEDON: Gestrin loam - pasture. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 8 inches; gray (10YR 5/1) loam, black (10YR 2/1) moist; moderate medium and coarse granular structure; slightly hard, friable, slightly sticky and slightly plastic; many medium and fine roots; strongly acid (pH 5.4); clear smooth boundary. (5 to 10 inches thick)
A--8 to 18 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots; strongly acid (pH 5.5); clear smooth boundary. (5 to 12 inches thick)
AB--18 to 24 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many fine pores; moderately acid (pH 5.6); clear smooth boundary. (4 to 10 inches thick)
Bw--24 to 32 inches; pale brown (10YR 6/3) coarse sandy loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to weak medium and fine subangular blocky; hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine pores; few thin patchy clay films on the vertical surfaces of peds and in the pores; moderately acid (pH 5.7); clear smooth boundary. (7 to 14 inches thick)
C1--32 to 41 inches; very pale brown (10YR 7/3) coarse sandy loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, slightly sticky; few fine roots; moderately acid (pH 5.6); clear smooth boundary. (6 to 12 inches thick)
C2--41 to 46 inches; very pale brown (10YR 7/4) coarse sandy loam, brown (10YR 4/3) moist; few fine distinct olive gray (5Y 4/2) moist redox depletions; massive; slightly hard, very friable, slightly sticky; few fine roots; moderately acid (pH 5.6); clear smooth boundary. (5 to 30 inches thick)
C3--46 to 60 inches; very pale brown (10YR 7/3) loamy coarse sand; brown (10YR 5/3) moist; single grain; loose; moderately acid (pH 5.9).
TYPE LOCATION: Valley County, Idaho; about 8 miles south of Donnelly; 20 feet east and 1,350 north of the southwest corner of section 25, T. 15 N., R. 3 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 38 degrees to 43 degrees F.
Average summer soil temperature - 53 degrees to 59 degrees F.
Umbric epipedon thickness - 15 to 24 inches
Depth to redox features - below 40 inches
Textural control section - 8 to 18 percent clay, less than 15 percent rock fragments
A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2, dry and moist
Base saturation - 30 to 45 percent
Bw horizon
Hue - 10YR or 7.5YR
Texture - L, SL, COSL
C horizon
Texture - L, SL, COSL, LS, GR-L, GR-SL, Stratified
COMPETING SERIES: These are the Donnel soils and the similar Blaquirre (T), Boze, Josie, Longval, Rarick, Suttler, and Weitas (T) series. Blaquirre soils have bedrock at 20 to 40 inch depth. Boze soils have 15 to 35 percent rock fragments in the control section, lack mottles in the lower part of the C horizon and are gravelly. Donnel and Weitas soils lack mottles between depths of 40 and 60 inches and are well drained. Josie soils lack mottles in the lower part of the C horizon and are somewhat excessively drained. Longval and Rarick soils have a lithic contact at a depth of 20 to 40 inches. Suttler soils have a B2t horizon with thin wavy horizontal clayey bands, and have micaceous material throughout the soil profile.
GEOGRAPHIC SETTING: Gestrin soils are on alluvial fans and terraces. Slopes are 0 to 12 percent. The soils formed in mixed alluvium from glacial outwash or glacial till. Elevations are 3,800 to 5,200 feet. The climate is humid continental, cool summers (Trewartha's modified Koppen system) with cold winters and dry summers. Average annual precipitation is 22 to 24 inches. Average January temperature is 20 degrees F.; average July temperature is 64 degrees F. Average annual temperature is 36 to 41 degrees F. Frost-free season is about 60 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Archabal, Blackwell, and Melton soils. Archabal soils are well drained. Blackwell and Melton soils are poorly drained and do not have a Bw horizon.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to slow runoff; moderate permeability.
USE AND VEGETATION: Used mainly for pasture, small grains, clover, and seed potatoes. Native vegetation is mainly grass, forbs, and some shrubs.
DISTRIBUTION AND EXTENT: High mountain valleys, mainly in Valley County, Idaho. The soil is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Valley Area, Idaho, 1977.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - zone from 0 to 24 inches (Ap, A, and AB horizons)
Cambic horizon - zone from 24 to 32 inches (Bw horizon)
Moisture regime - udic
The 3/2008 description reflects a change in classification from Coarse-loamy, mixed, superactive Humic Dystrocryepts to Coarse-loamy, mixed, superactive Typic Humicryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.