LOCATION WICKENBURG AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic, shallow Typic Haplocambids
TYPICAL PEDON: Wickenburg gravelly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 1 inch; light reddish brown (5YR 6/3) gravelly sandy loam, reddish brown (5YR 4/3) moist; weak thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; 25 percent pebbles; noneffervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 4 inches thick)
Bw--1 to 12 inches; reddish brown (5YR 4/4) very gravelly sandy loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; 40 percent pebbles; slightly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (9 to 16 inches thick)
2Cr--12 to 60 inches; partially weathered granitic rock (grus); common very fine roots; few thin clay films coating bedrock and in fractures; fine lime coatings in fractures. (30 to 60 inches or more thick)
TYPE LOCATION: Maricopa County, Arizona; 2400 feet east and 2100 feet south of the NW corner of section 29, T. 7 N., R. 5 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in some part of the SMCS during July-September and December-February. Typic aridic moisture regime.
Rock fragments: Averages >35 percent pebbles in the control section
Depth to paralithic contact: 10 to 20 inches
Depth to bedrock: 40 to 60 inches or more
A horizon
Hue: 7.5YR or 5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: sandy loam, loam (10 to 25 percent clay)
Organic matter: less than 1 percent
Reaction: mildly or moderately alkaline
B horizon
Hue: 7.5YR or 5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 4
Texture: sandy loam, loam, sandy clay loam (15 to 25 percent clay)
Calcium carbonate: dominantly noneffervescent; effervescent in some pedons
Reaction: mildly or moderately alkaline
2Cr horizon
Partially weathered, highly fractured rock that is readily broken by hand. Becomes harder with depth.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Wickenburg soils are on pediment hillslopes and mountain slopes with gradients of 1 to 65 percent. They formed in alluvium-colluvium from granitic rock and minor areas of volcanic rock. Elevation is 1800 to 4000 feet. The climate is warm and semiarid continental. Average annual precipitation is 8 to 12 inches occurring as summer thunderstorms and gentle winter rain. Mean annual temperature is 66 to 70 degrees F. The frost-free period is about 220 to 275 days.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the similar Cellar and Lehmans soils, these are the Dixaleta and Gran soils. Gran soils have argillic horizons and Dixaleta soils lack cambic horizons.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for grazing. The present vegetation is ironwood, paloverde, shrubby buckwheat, catclaw, yucca, triangle bursage, saguaro, ocotillo, graythorn, canotia, bush muhly and range ratany.
DISTRIBUTION AND EXTENT: South central Arizona. The series is moderately extensive. MLRA 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Maricopa County, Arizona; 1982
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 1 inches (A horizon)
Cambic horizon - The zone from 1 to 12 inches (Bw horizon)
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.