LOCATION WUTOMA AZEstablished Series
TAXONOMIC CLASS: Ashy-skeletal over fragmental or cindery, mixed, mesic Vitrandic Haplustepts
TYPICAL PEDON: Wutoma extremely gravelly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (10YR 4/3) extremely gravelly loam, very dark gray (10YR 3/1) moist; weak fine granular structure; slightly hard, very friable; many very fine roots; many very fine tubular pores; 75 percent cinders; neutral (pH 7.3); abrupt smooth boundary. (1 to 4 inches thick)
Bw--2 to 12 inches; brown (10YR 4/3) extremely gravelly loam, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure; slightly hard, very friable; many fine roots; many fine tubular pores; 70 percent cinders; slightly alkaline (pH 7.8); abrupt smooth boundary. (5 to 14 inches thick)
2C--12 to 60 inches; black cinders; few medium roots; few pockets and stratifications of extremely cindery loam.
TYPE LOCATION: Mohave County, Arizona; about 6 miles south of Mt. Trumbull; 600 feet south and 2,000 feet west of the northeast corner of Section 20, T. 34 N., R. 8 W.
RANGE IN CHARACTERISTICS:
Soil Moisture - Intermittently moist in some part of the soil moisture control section during July-September and December-March. Driest during May and June. Aridic ustic soil moisture regime.
Soil temperature - 47 to 56 degrees F.
Rock Fragments - 60 to 80 percent cinders in the control section
Cinder lag on the surface - Up to 2 inches thick
Depth to cinders - 11 to 20 inches
Reaction: neutral to moderately alkaline
Effervescence- Ranges from noneffervescent to violently effervescent
A horizon
Hue: 10YR, 7.5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 3 or 4 dry, 1 through 4 moist
Bw horizon
Hue: 10YR, 7.5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 1 through 4, dry or moist
COMPETING SERIES: This is the Lozinta (AZ) series. Lozinta soils have cinders at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Wutoma soils are at elevations of 5,800 to 7,500 feet on strongly sloping to steep cinder cones. Slopes range from 1 to 60 percent. The soils formed in slope alluvium derived dominantly from pyroclastics and cinders. The climate is warm and semi-arid. The mean annual precipitation is 13 to 18 inches occurring as summer thunderstorms and winter rain and snow. Mean annual air temperature is 45 to 52 degrees F. The frost-free period is 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lozinta and the Moab series. Moab soils are loamy and have a calcic horizon.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; low runoff; moderate or moderately rapid permeability.
USE AND VEGETATION: Used mainly for livestock grazing. Vegetation is galleta, Mormon tea, blue grama, Indian ricegrass and big sagebrush.
DISTRIBUTION AND EXTENT: Northwestern Arizona. This soil is of minor extent. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of Mohave County Area, AZ, Northeastern Part, and Part of Coconino County; 1992.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches (A horizon)
Cambic horizon - The zone from 2 to 12 inches (Bw horizon)
Cinder deposit at a depth of 12 inches
Vitrandic subgroup - no available data in support of the subgroup other than known coarse fragment composition and correlator experience with Andisols.
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.