LOCATION VALLE AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Haplustolls
TYPICAL PEDON: Valle gravelly loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; brown (7.5YR 5/2) gravelly loam, dark brown (7.5YR 3/2) moist; weak thin platy structure parting to weak fine granular; soft, friable, nonsticky and nonplastic; few fine roots; many very fine vesicular and common very fine interstitial pores; 20 percent pebbles; moderately acid (pH 6.0); abrupt smooth boundary. (2 to 3 inches thick)
A2--3 to 8 inches; brown (7.5YR 4/2) gravelly loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine interstitial and few very fine tubular pores; 20 percent pebbles; neutral (pH 7.0); gradual wavy boundary. (5 to 6 inches thick)
A3--8 to 13 inches; brown (7.5YR 4/2) gravelly loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine interstitial and very fine tubular pores; 20 percent pebbles; neutral (pH 7.0); abrupt wavy boundary. (5 to 6 inches thick)
C1--13 to 28 inches; reddish brown (5YR 5/4) gravelly loam, reddish brown (5YR 4/4) moist; weak coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine roots; few fine interstitial and tubular pores; 20 percent pebbles; slightly alkaline (pH 7.5); diffuse wavy boundary. (13 to 21 inches thick)
2C2--28 to 60 inches; reddish brown (5YR 5/4) very gravelly clay loam, reddish brown (5YR 4/4) moist; massive; hard, firm, slightly sticky and plastic; few fine roots; few fine interstitial pores; 50 percent pebbles; slightly alkaline (pH 7.5).
TYPE LOCATION: Coconino County, Arizona; approximately 6 miles north and 3 miles east of Williams, Arizona, and 2 miles southeast of Red Lake; 1,500 feet east and 1,000 feet north of the SW corner of sec. 23, T. 23 N., R. 2 E.
RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in some parts of July-September, and December-February. Driest during May and June. Aridic ustic moisture regime.
Air temperature: 49 - 53 degrees F. Rock fragments: 10 - 35 percent pebbles in control section
A horizon
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: Gravelly loam, Gravelly silt loam (15 - 25 percent clay)
Reaction: Moderately acid to neutral
C horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6 dry, 3 or 4 moist
Texture: Very gravelly clay loam, Very gravelly loam (20 - 30 percent clay)
Reaction: Neutral to slightly alkaline
COMPETING SERIES: These are the Capps (TX), Chugter (MT), Deacon (NM), Shirk (WY), Shore (KS), and Tejana (NM) series. Capps soils have a calcic horizon. Chugter soils have hue of 5YR or redder in a majority of subhorizon and are calcareous above 40 inches. Deacon soils are calcareous above 40 inches and contain less than 15 percent rock fragments. Shirk soils are less than 20 to 40 inches deep. Shore soils occur on the Central High Tablelands (MLRA 72) and are more moist in May and June. Tejana soils derived from volcanic ash and cinders.
GEOGRAPHIC SETTING: Valle soils are on nearly level to gently sloping terraces. They formed in gravelly alluvium from basalt, andesite, rhyolite, and pyroclastics. Elevations are 6,000 to 7,000 feet. Mean annual precipitation is 14 to 18 inches. Average January temperature is 30 degrees F., and average July temperature is 68 degrees F; mean annual temperature is 49 to 52 degrees F. Frost-free season is 120 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aut and Ziegler soils. Aut soils have bedrock at depths of 20 to 40 inches; Ziegler soils are clayey over fragmental.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Used primarily for grazing and wildlife habitat. Vegetation is western wheatgrass, spike muhly, blue grama, fourwing saltbush and winterfat. Portions of this area have been cultivated and reseeded. Some areas of this soil were woodland which had been cleared.
DISTRIBUTION AND EXTENT: Northern Arizona. The series is of small extent. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Coconino County Area, Central Part, Arizona, 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 13 inches
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.