LOCATION HOBBY              ID
Established Series
Rev. MSB/CLM
02/97

HOBBY SERIES


The Hobby series consists of moderately deep, well drained soils on basalt plains, plateaus and mesas. Hobby soils formed in loess and alluvium. Permeability is very slow. Slopes range from 2 to 35 percent. The average annual precipitation is about 11 inches and the average annual air temperature is about 47 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Typic Haploxererts

TYPICAL PEDON: Hobby extremely stony silty clay - rangeland at an elevation of 5,130 feet. (Colors are for dry soil unless otherwise noted.)

A--0 to 4 inches; very dark grayish brown (10YR 3/2) extremely stony silty clay, very dark brown (10YR 2/2) moist; weak fine and medium platy structure parting to fine and very fine granular; slightly hard, very friable, sticky and plastic; common very fine and fine and few medium and coarse roots; many fine and very fine irregular and few very fine and fine tubular pores; common 1 cm wide cracks; 5 percent gravel, 60 percent cobbles, 15 percent stones; slightly acid (pH 6.3); clear smooth boundary. (2 to 7 inches thick)

Bss1--4 to 12 inches; dark brown (7.5YR 3/2) silty clay, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine, fine, common fine and very fine roots; few very fine and fine irregular pores; few intersecting slickensides and pressure faces; common 1 cm wide cracks; 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (5 to 15 inches thick)

Bss2--12 to 17 inches; dark brown (7.5YR 4/2) silty clay, dark brown (7.5YR 3/2) moist; moderate medium and coarse prismatic structure; extremely hard, firm; sticky and plastic; few very fine roots; few fine irregular pores; few intersecting slickensides and pressure faces; common 1 cm wide cracks; 5 percent gravel; neutral (pH 6.6); gradual wavy boundary. (0 to 12 inches thick)

Bss3--17 to 21 inches; dark brown (7.5YR 4/2) very cobbly clay, dark brown (7.5YR 3/4) moist; strong fine and medium subangular blocky structure parting to moderate fine and medium subangular blocky; extremely hard, firm, sticky and plastic; few very fine, fine, medium and coarse roots in cracks; few fine very fine tubular pores; common intersecting slickensides and pressure faces; common 1 cm wide cracks; 20 percent gravel, 30 percent cobbles; slightly acid (pH 6.2); abrupt wavy boundary. (3 to 6 inches thick)

2Cr--21 to 27 inches; highly weathered basaltic bedrock with weathered discontinuous silica coatings filling some fractures and cementing some of the more stable bedrock. (0 to 8 inches thick)

2R-- 27 inches; basaltic bedrock

TYPE LOCATION: Gooding County, Idaho; about 13 miles north of Bliss, about 1350 feet south and 250 feet east of the NW corner of Sec. 26, T3S, R12E, southeast of a dirt road. Lat. 43 degrees North, 8 minutes, 16 seconds; Long. 115 degrees West, 0 minutes, 7 seconds.

RANGE IN CHARACTERISTICS:

Soil temperature - 47 to 50 degrees F.
Thickness of mollic epipedon - 7 to 19 inches
Depth to bedrock - 20 to 40 inches
Clay (control section average) - 40 to 55 percent
Intersecting slickensides - few to common in the Bss horizons
Cracks - open July through October; closed during winter; 1 to 3 cm wide at a depth of 50 to 65 cm and extending upwards to the surface

Present in some pedons - Bq horizons

A horizon
Value - 3 to 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Rock fragments - 5 to 20 percent gravel, 5 to 70 percent cobbles, 5 to 20 percent stones

Bss1 and Bss2 horizons
Hue - 10YR or 7.5YR
Value - 3 or 4 dry; 2 or 3 moist
Chroma - 2 through 4 dry; 2 or 3 moist
Texture - SIC, C
Clay content - 40 to 60 percent
Reaction - slightly acid to neutral
Rock fragments - 0 to 5 percent gravel, 0 to 5 percent cobbles

Bss3 horizon
Hue - 5YR or 7.5YR
Value - 3 through 5 dry or moist
Chroma - 2 through 4 dry or moist
Texture - CBV-C, C, CB-SIC
Clay content - 40 to 60 percent
Reaction - slightly acid to neutral
Rock fragments - 5 to 25 percent gravel, 5 to 30 percent cobbles, 0 to 10 percent stones

COMPETING SERIES: These are no other series in this family.

GEOGRAPHIC SETTING: Hobby soils are on basalt plains, plateaus and mesas. Hobby soils are underlain by basalt and formed in loess and alluvium. Slopes are 2 to 35 percent. Elevations range from 3,900 to 5,200 feet. The average annual precipitation is 11 to 13 inches. The average annual air temperature is 45 to 48 degrees F. and the frost free period is 90 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: On plateaus and mesas, these are the Tschamman soils in broad drainageways and the Bray soils in concave positions. Tschamman soils are moderately deep to a duripan and deep to bedrock. Bray soils have an ochric epipedon and an argillic horizon and do not crack. On escarpments, Hobby soils are associated with rubble land and rock outcrop and Mchan soils. Mchan soils have intersecting slickensides and a granular surface which partially fills soil cracks.

DRAINAGE AND PERMEABILITY: Well drained; runoff is rapid; permeability is very slow.

USE AND VEGETATION: Hobby soils are used for rangeland. Potential native vegetation is low sagebrush and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Hobby soils are moderately extensive in south central Idaho.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Gooding County, Idaho, 1993.

REMARKS: This revision changes the classification from Vertic Haploxerolls to Typic Haploxererts.

Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: the zone from 0 to 17 inches (A, Bss1 and Bss2 horizons)

Cambic horizon: the zone from 17 to 21 inches (Bss3 horizon)

The particle-size control section: the zone from 10 inches to 21 inches (Part of the Bss1, the Bss2 and the Bss3 horizons)

ADDITIONAL DATA: This pedon was sampled to determine if the B horizon contains illuvial clay. (The soil survey sample number is: S91ID-063-303 and the NSSC pedon number is: 91P116)


National Cooperative Soil Survey
U.S.A.