LOCATION POULRIDGE IDEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive Xeric Argicryolls
TYPICAL PEDON: Poulridge silt loam, on a northeast-facing, convex, 42 percent slope under a mixture of aspen and Douglas fir at an elevation of 1963 meters. (Colors are for dry soil unless otherwise noted. When described on August 16, 2001, the soil was dry to 38 centimeters and slightly moist below.)
Oi--0 to 8 cm; slightly decomposed needles, leaves and twigs. (1 to 8 cm thick)
A1--8 to 20 cm; dark gray (10YR 4/1) silt loam, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure parting to moderate fine granular; slightly hard, very friable, nonsticky and nonplastic; many fine and very fine root, common medium roots; many fine and very fine irregular pores, few fine tubular pores; 5 percent gravel; neutral (pH 6.6); clear wavy boundary.
A2--20 to 38 cm; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine and fine irregular and tubular pores; 5 percent gravel; neutral (pH 6.6); gradual wavy boundary. (Combined thickness of the A horizons range from 18 to 41 cm.)
Bt--38 to 79 cm; brown (10YR 5/3) clay loam, dark grayish brown (10YR 4/2) moist; strong medium subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common fine and very fine roots; many very fine and few medium tubular pores; common discontinuous distinct clay films on faces of peds and common faint clay films in pores, which are dark brown (10YR 3/3) moist; 5 percent gravel; slightly acid (pH 6.4); gradual wavy boundary. (33 to 51 cm thick)
2C--79 to 94 cm; light yellowish brown (2.5Y 6/3) paragravelly loamy very fine sand, light olive brown (2.5Y 5/3) moist; single grained; loose, nonsticky and nonplastic; few fine and very fine roots; common very fine irregular pores; 25 percent paragravel; neutral (pH 7.2); abrupt wavy boundary. (13 to 38 cm thick)
2Cr--94 to 152 cm; light gray (2.5Y 7/1) cemented volcanic ash crushing to loamy very fine sand, light olive brown (2.5Y 5/3) moist; neutral (pH 7.0).
TYPE LOCATION: Bear Lake County, Idaho; located about 1600 feet north and 200 feet west of the southeast corner of sec. 5, T. 12 S., R. 43 E; USGS Nounan, ID topographic quadrangle; lat. 42 degrees 24 minutes 20.1 seconds N. and long. 111 degrees 26 minutes 46.5 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 4 to 6 degrees C.
Mean summer soil temperature - less than 15 degrees C.
The soils are usually moist, and they are dry for more than 45 consecutive days in the moisture control section in the four months following the summer solstice. Xeric moisture regime.
Depth to paralithic contact - 51 to 102 cm
Thickness of the mollic epipedon - 18 to 41 cm
Some pedons may have a Bk horizon with less than 5% calcium carbonate equivalent below the argillic horizon
A horizons
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3 dry or moist
Clay content: 18 to 25 percent
Rock fragments: 1 to 15 percent gravel
Reaction: pH 6.2 to 7.3
Bt horizon
Value: 4 or 5 dry or moist
Chroma: 2 to 4 dry, 2 or 3 moist
Texture: silty clay loam or clay loam
Clay content: 28 to 35 percent
Rock fragments: 1 to 15 percent gravel
Reaction: pH 6.2 to 7.3
2C horizon
Hue: 10YR or 2.5Y
Value: 4 to 6 dry, 4 or 5 moist
Chroma: 3 or 4 dry or moist
Clay content: 5 to 15 percent
Pararock fragments: 10 to 50 percent paragravel
Reaction: pH 6.6 to 7.6
Calcium carbonate equivalent: 0 to 5 percent
COMPETING SERIES:
Driggs (ID, WY) - does not have paralithic contact within 102 cm
GEOGRAPHIC SETTING: The Poulridge soils are on hills, mountain slopes, summits and shoulders. Slope ranges from 5 to 45 percent. These soils formed in alluvium from loess over weakly cemented volcanic ash. Elevations are 1825 to 2175 meters. The climate is characterized by long, cold winters and warm dry summers. The mean annual precipitation is 430 to 610 mm which includes 91 to 152 cm of snow. The mean annual temperature is 4 to 6 degrees C. The frost-free period is 55 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bailcreek, Cedarhill, Dranburn, and Pavohroo soils. Bailcreek soils have 35 to 55 percent clay in the argillic horizon and are on an adjacent sideslopes. Cedarhill soils have a calcic horizon, have a loamy-skeletal particle size control section, and are on adjacent lower slopes. Dranburn soils have a mollic epipedon greater than 41 cm thick, are very deep, and are on similar positions as Poulridge soils. Pavohroo soils have a mollic epipedon greater than 41 cm thick, are very deep, have a loamy-skeletal particle size control section, and are on similar positions as Poulridge soils.
DRAINAGE AND PERMEABILITY: Well drained, low to moderate runoff, moderate over rapid permeability.
USE AND VEGETATION: These soils are used for wildlife habitat and rangeland. Native vegetation is quaking aspen, common snowberry, pine grass, mountain brome, mountain big sagebrush, elk sedge, and scattered Douglas fir.
DISTRIBUTION AND EXTENT: Poulridge soils are of small extent in southeastern Idaho. MLRA 43B and 47.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Bear Lake County, Idaho, 2008. The name is coined.
REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon - from a depth of 8 to 38 cm (A1 and A2 horizons);
Argillic horizon - from a depth of 38 to 79 cm (Bt horizon);
Particle-size control section - 38 to 94 cm (Bt and part of the 2C horizons);
Paralithic contact - from a depth of 94 to 152 cm (2Cr horizon);
Poulridge soils have a cryic temperature regime and a xeric moisture regime.