LOCATION SPARMO IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Xeric Haplocalcids
TYPICAL PEDON: Sparmo loam--on a 6 percent convex, north-facing slope at 6,000 feet elevation in rangeland. (Colors are for dry soil unless otherwise noted. When described on June 12, 1986 the soil was moist throughout.)
A--0 to 3 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine irregular pores; 10 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 4 inches thick)
Bw--3 to 7 inches; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine and few coarse roots; common very fine and fine tubular pores; 15 percent gravel; slightly effervescent; moderately alkaline (pH 8.1); clear wavy boundary. (0 to 6 inches thick)
Bk1--7 to 19 inches; very pale brown (10YR 8/3) gravelly loam, pale brown (10YR 6/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; common very fine tubular pores; 20 percent gravel; lime coatings less than 1mm thick on undersides of some gravel; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (8 to 16 inches thick)
Bk2--19 to 38 inches; very pale brown (10YR 8/3) gravelly loam, pale brown (10YR 6/3) moist; moderate coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine tubular pores; 20 percent gravel; lime coatings less than 1 mm thick on undersides and some sides of gravel; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (16 to 30 inches thick)
2Bk3--38 to 60 inches; very pale brown (10YR 7/3) very gravelly sandy loam, yellowish brown (10YR 5/4) moist; weak moderate subangular blocky structure; slightly hard, friable; nonsticky and nonplastic common very fine roots; common very fine tubular pores; 45 percent gravel, 10 percent cobbles; lime coatings less than 1mm thick on undersides and some sides of rock fragments; strongly effervescent; moderately alkaline (pH 8.1).
TYPE LOCATION: Custer County, Idaho; about 5 miles southeast of Mackey, Idaho about 2,200 feet south and 1500 feet west of the northeast corner of section 18, T. 6N., R.25E.
Latitude - 43 degrees, 50 minutes, 28 seconds North
Longitude - 113 degrees, 31 minutes, 54 seconds West
RANGE IN CHARACTERISTICS:
Mean summer soil temperature - 59 to 63 degrees F.
Mean annual soil temperature - 42 to 45 degrees F.
Depth to bedrock over 60 inches
Depth to calcic horizon and secondary carbonates - 2 to 10 inches
Depth to discontinuity - 35 to 45 inches
The soil moisture control section is dry for one-half to three-fourths of the time when the soil temperature is above 41 degrees F. 70 to 85 consecutive days
Particle-size control section Total clay content - 10 to 18
Carbonate free clay - 5 to 15 percent
Rock fragments (weighted average) - 0 to 25 percent
A horizon Value - 5 or 6 dry and 3 or 4 moist
Chroma - 2 through 4 dry or moist
Bw horizon Value - 4 through 6 dry or moist
Chroma - 2 or 3 dry or moist
Texture - SIL, L, GR-L, GR-SIL
Coarse fragments - 0 to 20 percent, mainly gravel
Reaction - slightly or moderately alkaline
Bk horizon
Value - 6 through 8 dry and 4 through 7 moist
Chroma - 2 to 4 dry or moist
Texture - L, SIL, GR-L, GR-SIL
Coarse fragments - 0 to 25 percent, mainly gravel
Reaction - moderately or strongly alkaline
Calcium carbonate 15 to 40 percent
2Bk horizon
Value - 6 through 8 dry and 4 through 7 moist
Chroma - 3 or 4 dry or moist
Texture - GRV-SL, GRX-SL, GRV-L
Rock fragments - 35 to 85 percent
Reaction - moderately or strongly alkaline
Calcium carbonate 10 to 30 percent
COMPETING SERIES: These are the Atomic, Holsine, Lariat, Lidy, Malm, Matheson, Nargon, and Voltage series. Atomic soils are deep to bedrock. Holsine soils have extremely gravelly A and C1 horizons over unconformable lacustrine sediments at 12 inches. Lariat, Malm, and Nargon soils are moderately deep to bedrock. Lidy soils have sand and gravel at depths of 23 to 34 inches. Matheson soils are very fine sandy loam, fine sandy loam, or sandy loam in the particle-size control section and the depth to the calcic horizon is 11 to 20 inches. Voltage soils lack very gravelly or extremely gravelly textures in the lower part of the particle-size control section.
GEOGRAPHIC SETTING: Sparmo soils are on outwash fans, fan terraces, and stream terraces. These soils formed in glacial outwash and alluvium. Slopes are 0 to 12 percent. Elevations are 4,800 to 6,800 feet. The climate is cold and moist in winter and spring and cool and dry in summer. Average annual precipitation is 8 to 12 inches and average annual temperature is 37 to 43 degrees F. Frost-free period is 60 of 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bartonflat, Leadore, Paint, Simeroi, and Zer soils. Bartonflat soils are on stream terraces and fan terraces, have mollic epipedons and sandy-skeletal control sections. Leadore soils are on outwash fans and fan terraces and have sandy-skeletal control sections. Paint soils are on fan terraces and outwash fans and have duripans above 20 inches. Simeroi and Zer soils are on outwash fans and fan terraces and have loamy-skeletal control sections.
DRAINAGE AND PERMEABILITY: Well drained. Slow runoff; moderate permeability.
USE AND VEGETATION: Rangeland and small areas of irrigated cropland. The natural vegetation is mainly Wyoming big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: East-central Idaho. These soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Butte County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon -
Calcic horizon - the zone from 7 to 60 inches (Bk1, Bk2 and 2Bk3 horizons)
Particle size control section - the zone from 10 to 40 inches (part of the Bk1, the Bk2, and part of the 2Bk3 horizons)