LOCATION KEMAN ID+NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Pachic Argicryolls
TYPICAL PEDON: Keman very gravelly loam--on a west-facing slope of 3 percent under at 7,140 feet elevation--rangeland. (Colors are for dry soil unless otherwise stated. When described on September 22, 1981, the soil was dry throughout.)
A--0 to 5 inches; very dark gray (10YR 3/1) very gravelly loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 50 percent gravel; moderately acid (pH 5.6); gradual wavy boundary. (4 to 8 inches thick)
AB--5 to 14 inches; very dark grayish brown (10YR 3/2) very gravelly loam, black (10YR 2/1) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 50 percent gravel; moderately acid (pH 5.8); gradual wavy boundary. (6 to 12 inches thick)
Bt1--14 to 33 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; common faint clay films on faces of peds and lining pores; 55 percent gravel; moderately acid (pH 5.8); abrupt smooth boundary. (12 to 24 inches thick)
Bt2--33 to 60 inches; light brownish gray (10YR 6/2) extremely gravelly clay loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots; few very fine tubular pores; few distinct clay films on faces of peds and lining pores; 80 percent gravel; moderately acid (pH 5.6).
TYPE LOCATION: Twin Falls County, Idaho; about 26 miles southwest of Rogerson and about 0.75 mile north of the Idaho-Nevada state line between Chimney Creek and Wilson Creek; in the northwest 1/4, of the northeast 1/4, of the southeast 1/4 of section 26, T. 16 S., R. 12 E.; USGS Curtis Draw 7.5 minute topographic quadrangle; approximately 42 degrees 0 minutes 18 seconds north latitude and 115 degrees 0 minutes 44 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the moisture control section during late fall, winter, and spring; dry during summer and early fall; Xeric moisture regime that borders on aridic.
Mean annual soil temperature - 39 to 42 degrees F.
Mean summer soil temperature - 55 to 58 degrees F.
Mollic epipedon thickness - 30 to 50 inches; includes the Bt1 horizon.
Depth to base of argillic horizon - 60 inches or more.
Depth to bedrock - 60 inches or more to welded tuff or volcanic ash.
Particle-size control section - Clay content: 18 to 24 percent; Rock fragments: 40 to 75 percent. Lithology of fragments is welded tuff.
Reaction - Strongly acid through slightly acid.
Base saturation in the upper 40 inches - 50 to 70 percent.
A horizon - Value: 3 through 4 dry, 1 through 3 moist.
Chroma: 1 through 3, dry or moist
Organic matter content: 3 to 7 percent.
Bt1 horizon - Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Texture: Very gravelly loam or extremely gravelly loam.
Clay content: 18 to 24 percent.
Rock fragments: 40 to 70 percent gravel, 0 to 10 percent cobbles.
Clay films: Few to common on faces of peds and lining pores.
Organic matter content: 3 to 7 percent.
Bt2 horizon - Value: 4 through 6 dry, 2 through 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very gravelly loam or extremely gravelly clay loam.
Clay content: 24 to 34 percent.
Rock fragments: 40 to 65 percent gravel, 0 to 15 percent cobbles, 0 to 5 percent stones.
Clay films: Few to many, faint to distinct on faces of peds and lining pores.
COMPETING SERIES: These are the Angelwhine (T), Aspetill (T), Badwater, Bickmore, Bluebell, Booneville, Buena Vista, Dab (T), Delhew (T), Geemore, Hawkinspeak (T), Littlemud (T), Lostcannon (T), Monibasin (T), Parkalley (T), Parkay, Redbird, Rutherford, Sweetmount (T), and Woodhurst series.
Angelwhine soils have mollic epipedons that are 16 to 24 inches thick. Aspetill soils are dominated by cobbles in the particle-size control section and have mean summer soil temperature of 47 to 52 degrees F. Badwater soils have 25 to 35 percent clay and are dominated by boulders in the particle-size control section. Bickmore, Bluebell, Buena Vista, Hawkinspeak, Littlemud, Rutherford, and Woodhurst soils are moderately deep to lithic contacts. Booneville soils are dominated by cobbles in the particle-size control section, have mean summer soil temperature of 50 to 55 degrees F., and have thin O horizons. Dab soils have mean annual soil temperature of 42 to 45 degrees F. and have mollic epipedons that are 16 to 24 inches thick. Delhew soils have less than 18 percent clay, are dominated by fine gravel (2 to 5 mm diameter) in the particle-size control section, and have rock fragments that are granitic rocks. Geemore soils have calcic horizons and horizons with secondary silica and average 27 to 35 percent clay in the particle-size control section. Lostcannon soils have less than 18 percent clay in the particle-size control section and have rock fragments that are granitic rocks. Monibasin soils are dominated by stones in the particle-size control section and have mean annual soil temperature of 42 to 46 degrees F. Parkalley soils have mollic epipedons that are 16 to 30 inches thick, have the base of the argillic horizon between 28 and 35 inches from the soil surface, and are dominated by flagstones. Parkay soils average 27 to 35 percent clay in the particle-size control section and are neutral through slightly alkaline. Redbird soils average 27 to 35 percent clay in the particle-size control section and have horizons with identifiable secondary carbonates within 40 inches of the soil surface. Sweetmount soils are deep to paralithic contacts and have subhorizons of the argillic horizon with 35 to 50 percent clay.
GEOGRAPHIC SETTING: Keman soils are on mountains. They typically occur on all slope positions. These soils formed in till and colluvium derived from welded tuff and volcanic ash. Slopes are 2 to 50 percent. Elevations range from 6,200 to 7,700 feet. The mean annual precipitation is 16 to 25 inches, the mean annual temperature is 40 to 45 degrees F., and the frost-free period is 20 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amboat, Brose, Dehana, Hogmalat, and Kavon soils and the competing Rutherford soil. Brose and Hogmalat soils are shallow, and occur on summits and shoulders. Amboat soils are clayey-skeletal, and occur on lower summits. Dehana soils are not skeletal, and occur on footslopes, backslopes, and breaks. Kavon soils are on summit footslopes, and have a base saturation of less than 15 percent.
DRAINAGE AND PERMEABILITY: Well drained; medium or high surface runoff; moderate permeability.
USE AND VEGETATION: Keman soils are used for rangeland. Native vegetation is mountain big sagebrush, Idaho fescue, bluebunch wheatgrass, Columbia needlegrass, Nevada bluegrass, and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: Southwestern Idaho and northeastern Nevada. These soils are moderately extensive. MLRA 25.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Elko County (Northeastern Part), Nevada, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 33 inches (A, AB, and Bt1 horizons).
Argillic horizon - The zone from 14 to 60 inches (Bt1 and Bt2 horizons).
Particle-size control section - The zone from 14 to 34 inches (Bt1 horizon and part of the Bt2 horizon).