LOCATION HOGMALAT ID+NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lithic Argicryolls
TYPICAL PEDON: Hogmalat extremely gravelly loam - on a slope of 4 percent under rangeland vegetation at 6,650 feet elevation. When described on August 10, 1981, the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; brown (10YR 5/3) extremely gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate thick platy structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; 70 percent gravel; strongly acid (pH 5.5); clear smooth boundary. (1 to 4 inches thick)
Bt1--3 to 9 inches; brown (10YR 4/3) very gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many common very fine tubular pores; few faint clay films on faces of peds and lining pores; 35 percent gravel; moderately acid (pH 5.8); gradual wavy boundary. (4 to 9 inches thick)
Bt2--9 to 15 inches; brown (10YR 4/3) very gravelly clay loam, dark brown (10YR 3/3) moist; moderate fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; few roots; few very fine tubular pores; common distinct clay films on faces of peds and lining pores; 40 percent gravel; strongly acid (pH 5.4); abrupt wavy boundary. (4 to 9 inches thick)
R--15 inches; brown (10YR 4/3) welded tuff, dark yellowish brown (10YR 3/4) moist.
TYPE LOCATION: Twin Falls County, Idaho; about 13 miles southwest of Rogerson and about 0.50 mile north of Corral Creek Canyon; in the southeast 1/4, of the northeast 1/4, of the northeast 1/4 of section 16, T. 15 S., R. 14 E.; USGS Browns Bench North 7.5 minute topographic quadrangle; approximately 42 degrees 07 minutes 32 seconds north latitude and 114 degrees 48 minutes 42 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist during late fall, winter, and spring; dry during summer and early fall; Xeric moisture regime that borders on aridic.
Mean annual soil temperature - 37 to 40 degrees F.
Mean summer soil temperature - 54 to 57 degrees F.
Mollic epipedon thickness - 9 to 20 inches; includes the Bt1 and Bt2 horizons.
Depth to base of argillic horizon - 9 to 20 inches.
Depth to bedrock - 9 to 20 inches to a lithic contact.
Particle-size control section - Clay content: 24 to 34 percent; Rock fragments: 35 to 55 percent, mainly gravel. Lithology of fragments are volcanic rock such as tuff.
Base saturation in control section - 50 to 55 percent
A horizon - Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Clay content: 12 to 20 percent.
Organic matter content: 2 or 3 percent.
Reaction: Strongly acid or moderately acid.
Bt1 and Bt2 horizons - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Very gravelly clay loam or very gravelly loam.
Clay content: 24 to 34 percent.
Organic matter content: 1 or 2 percent.
Reaction: Strongly acid or moderately acid.
Other features: Some areas have a thin subhorizon above the lithic contact that is very gravelly clay.
COMPETING SERIES: These are the Bushpark, Copenhaver, Donkehill (T), Layview, Maygal (T), Mosroc, Mountpatterson (T), Nielsen, Nieman, Notstew (T), and Thiefridge (T) series.
Bushpark soils have a udic moisture regime. Copenhaver and Nieman soils have an ustic moisture regime. Donkehill soils have horizons with identifiable secondary carbonates and are slightly alkaline or moderately alkaline. Layview soils are neutral or slightly alkaline and have mean annual soil temperature of 43 to 47 degrees F. Maygal soils average 60 to 80 percent rock fragments in the particle-size control section and have less than 24 percent clay in the particle-size control section. Mosroc soils have mean summer soil temperature of 54 to 59 degrees F., have argillic horizons that are neutral through moderately alkaline, and have rock fragments that are granitic rocks. Mountpatterson soils average 60 to 85 percent rock fragments in the particle-size control section and have mean summer soil temperature of 47 to 54 degrees F. Nielsen soils have 18 to 28 percent clay in the argillic horizon and are slightly acid or neutral. Notstew soils have ashy textures in the A horizons, have mean annual soil temperature of 42 to 47 degrees F., and have argillic horizons that are neutral or slightly alkaline. Thiefridge soils have O horizons, mean summer soil temperature of 50 to 54 degrees F., and a typic xeric moisture regime.
GEOGRAPHIC SETTING: Hogmalat soils are on plateaus and mountains. They typically occur on summit, shoulder, and backslope positions. These soils formed in residuum weathered from welded tuff. Slopes are 3 to 50 percent. Elevations range from 6,100 to 7,600 feet. The mean annual precipitation is 19 to 25 inches, the mean annual temperature is 36 to 44 degrees F., and the frost-free period is 20 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amboat, Brose, Dehana, Kavon, Keman, Player, and Rutherford soils. Amboat soils are clayey-skeletal and occur on summit positions. Brose soils are clayey and occur on summit positions. Dehana, Kavon, and Keman soils are deep and occur on backslope and summit positions. Player soils are on breaks, are very deep, and are clayey-skeletal. Rutherford soils are moderately deep to lithic contacts and occur on summit and dipslope positions.
DRAINAGE AND PERMEABILITY: Well drained; very high surface runoff; moderately slow permeability.
USE AND VEGETATION: Hogmalat soils are used for rangeland. The native vegetation is curlleaf mountainmahogany, mountain big sagebrush, Idaho fescue, bluebunch wheatgrass, Columbia needlegrass, Nevada bluegrass, and mountain brome.
DISTRIBUTION AND EXTENT: Southwestern Idaho and northeastern Nevada. These soils are not extensive with about 4,600 acres of the series mapped to date. MLRA 25.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Elko County (Northeast Part), Nevada, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 15 inches (A, Bt1, and Bt2 horizons).
Argillic horizon - The zone from 3 to 15 inches (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 15 inches to underlying hard bedrock (R layer).
Particle-size control section - The zone from 3 to 15 inches (Bt1 and Bt2 horizons).
ADDITIONAL DATA: Clay percentage by the hydrometer method: 0-3 inches=18 percent, 3-9 inches=30 percent, 9-15 inches=34 percent; base saturation: 0-3 inches=50 percent, 3-9 inches=52 percent, 9-15 inches=50 percent.