LOCATION OSHONE IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Durixerolls
TYPICAL PEDON: Oshone clay loam--on a slope of 2 percent under native vegetation at 5,780 feet elevation. (Colors are for dry soil unless otherwise stated.) When described on September 8, l983, the soil profile was slightly moist to 6 inches, and dry below.
A--0 to 2 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; slightly hard, friable, sticky and plastic; common very fine, fine and medium roots; common very fine and fine vesicular pores; 10 percent gravel; slightly acid; abrupt smooth boundary. (1 to 4 inches thick)
AB--2 to 6 inches; brown (10YR 5/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; common very fine, fine, and medium roots; common very fine and fine tubular pores; 10 percent gravel; slightly acid; gradual wavy boundary. (3 to 6 inches thick)
Bt1--6 to 16 inches; brown (10YR 5/3) clay, very dark grayish brown (10YR 3/2) moist; strong medium angular blocky structure; very hard, firm, very sticky and very plastic; common fine and medium roots; common very fine and fine tubular pores; many distinct clay films on the faces of peds and in pores; 10 percent gravel; slightly acid; abrupt smooth boundary. (8 to 14 inches thick)
Bt2--16 to 27 inches; brown (10YR 5/3) gravelly clay, dark brown (10YR 4/3) moist; moderate medium columnar structure parting to moderate medium angular blocky; very hard, very firm, very sticky and very plastic; few fine roots; few very fine and fine tubular pores; many prominent clay films on the faces of peds and in pores; 15 percent gravel; neutral; abrupt smooth boundary. (8 to 12 inches thick)
Bt3--27 to 38 inches; light brown (7.5YR 6/4) very gravelly clay loam, dark brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few fine roots; few very fine and fine tubular pores; many distinct clay films on the faces of peds and in pores; 40 percent gravel; neutral; abrupt smooth boundary. (0 to 14 inches thick)
Bqm--38 to 47 inches; very pale brown (10YR 8/3) indurated duripan, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely firm; continuous silica lamination cap over strongly cemented, extremely hard, extremely firm (moist) sand and gravel; few fine roots in fractures of the duripan; fractures are 1/4 inch wide and are 6 inches apart. (5 to 10 inches thick)
2Bkq--47 to 60 inches; multi-colored weakly cemented very gravelly sand; few fine roots; strong effervescence.
TYPE LOCATION: About 13 miles southeast of Rogerson, Twin Falls County; in the northeast 1/4, northeast 1/4, northwest 1/4 of section 2, T. 16 S., R. 17 E.
RANGE IN CHARACTERISTICS:
Depth to duripan - 20 to 40 inches
Average clay content in control section - 45 to 55 percent
Mollic epipedon thickness - 7 to 16 inches
Depth to bedrock - more than 60 inches
Average annual soil temperature - 43 to 45 degrees F.
Average summer soil temperature - 60 to 62 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Gravel - 5 to 15 percent
Bt1 horizon
Hue - 10YR or 7.5YR
Value - 4 through 6 dry, 2 through 4 moist
Chroma - 2 or 4 dry or moist
Textures - C, GR-C, CL
Structure, shape - subangular blocky, angular blocky, or columnar Reaction - neutral or slightly acid
Clay content - 37 to 50 percent
Gravel - 5 to 25 percent
Bt2 horizon
Hue - 10YR or 7.5YR
Value - 3 through 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Textures - C, GR-C
Structure, shape - subangular blocky, angular blocky, or columnar Clay content - 40 to 60 percent
Gravel - 5 to 25 percent
Bqm horizon
Has 1/8 to 1 inch thickness of first silica lamination
Has 1/8 to 2 inch thickness of subsequent laminations
Strong cementation between laminations
5 to 10 inch thickness of duripan
Fractures - 1/4 to 1/2 inch wide
Distance of 5 to 9 inches between fractures
COMPETING SERIES: These are the Budlewis (T), Forvic (T), Hatpeak (T), Manard, Peevywell (T), and Rastus (T) series. Budlewis and Manard soils are moderately deep to bedrock. Budlewis, Peevywell, and Rastus soils have an abrupt textural change between the A and B horizon. Forvic soils have a mollic epipedon that is 20 to 30 inches thick. Hatpeak and Peevywell soils have a duripan thickness of more than 10 inches. Manard soils have a duripan that is 1 to 4 inches thick, and have a lithic contact within 40 inches. In addition, Peevywell soils have a base saturation greater than 75 percent throughout the upper 75 cm.
GEOGRAPHIC SETTING: Oshone soils are on terraces. The slope ranges from 1 to 10 percent. The soils formed in alluvium and colluvium from welded tuff and volcanic ash. Elevations are 5,500 to 6,100 feet. The average annual precipitation ranges from 12 to 16 inches, and the average annual temperature is 42 to 45 degrees F. The frost free season is 90 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amboat, Aninto, Bancy, Brose, Chayson, Congle, Doodlelink, Forvic, Ruclick, Tock, and Tucker soils. Amboat and Brose soils occur on summits. Aninto soils occur on terrace sideslopes. Amboat and Aninto soils are very deep, and are clayey-skeletal. Brose soils are shallow to bedrock. Bancy, Chayson, and Tock soils occur on lower terraces. Bancy soils are shallow to a hardpan. Chayson soils are fine-loamy. Tock soils have 35 to 45 percent clay in the Bt horizon. Congle and Doodlelink soils occur on sideslopes and breaks, are pachic, and very deep. Forvic soils occur on higher terraces, and are pachic. Ruclick soils occur on dipslopes, are skeletal, and moderately deep to bedrock. Tucker soils occur on alluvial terraces, and are somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff; very slow permeability.
USE AND VEGETATION: Oshone soils are used for rangeland. Native vegetation is Idaho fescue, bluebunch wheatgrass, low sagebrush, and mountain big sagebrush.
DISTRIBUTION AND EXTENT: Oshone soils are of moderate extent in south central Idaho.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Twin Falls County, Idaho, l992.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 16 inches (A, AB, and Bt1 horizons)
Argillic horizon - the zone from 6 to 26 inches (Bt1 and Bt2 horizons)
Indurated duripan - the zone from 38 to 47 inches (Bqm horizon)