LOCATION KUYKENDALL AZEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, thermic Aridic Lithic Argiustolls
TYPICAL PEDON: Kuykendall clay - rangeland. (Colors are for dry soil unless otherwise noted.) 30 to 60 percent of the surface is covered with gravel.
A--0 to 1 inch; dark brown (7.5YR 3/2) clay, dark brown (7.5YR 3/2) moist; weak very fine and fine subangular blocky parting weak fine granular structure; soft, very friable, very sticky and very plastic; common very fine and fine roots; many very fine tubular pores; noneffervescent; neutral (pH 7.0); clear smooth boundary. (1 to 3 inches thick)
Bt1--1 to 7 inches; dark reddish brown (5YR 3/3) clay, dark reddish brown (5YR 3/2) moist; strong fine and medium subangular blocky structure; slightly hard, friable, very sticky and very plastic; common very fine, fine, and medium roots; many very fine and fine tubular pores; many distinct clay films on faces of peds; many distinct pressure faces; noneffervescent; neutral (pH 7.2); abrupt smooth boundary.
Bt2--7 to 18 inches; dark reddish brown (5YR 3/3) clay, dark reddish brown (5YR 3/4) moist; strong fine and medium angular blocky structure; extremely hard, firm, very sticky and very plastic; common very fine and fine roots; many very fine and fine tubular pores; many distinct clay films on faces of peds; many distinct pressure faces; 10 percent gravel; slightly effervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (Combined thickness of the Bt horizon is 8 to 15 inches)
R--18 inches; unweathered basalt.
TYPE LOCATION: Cochise County, Arizona; located about 2,300 feet north and 800 feet west of the southeast corner of section 9, Township 20 S., Range 28 E.; Bruno Peak Topographic map; latitude 31 degrees, 42 minutes, 25 seconds North and longitude 109 degrees, 28 minutes, 30 seconds West.
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during July - September and December - February. Driest during May and June. Aridic Ustic soil moisture regime.
Soil Temperature: 59 to 64 degrees F.
Reaction: slightly acid to slightly alkaline
Clay content: averages more than 35 percent in control section
Organic matter: 0.5 to 3 percent
Depth to unweathered bedrock: 4 to 20 inches
A horizon
Hue: 7.5YR, 5YR
Value: 3 to 5 dry, 2.5 to 4 moist
Chroma: 1 through 3, dry or moist
Texture: clay, clay loam, sandy clay loam, loam, silty clay
Bt horizon
Hue: 5YR, 2.5YR, 7.5YR
Value: 3 or 4 dry, 2.5 to 4 moist
Chroma: 1 through 4, dry or moist
Texture: clay, silty clay, clay loam
COMPETING SERIES: There are no competitors.
GEOGRAPHIC SETTING: The Kuykendall soils are on hills and mountains at elevations of 4,200 to 6,200 feet. Slope ranges from 2 to 60 percent. These soils formed from slope alluvium and residuum derived from basalt and other volcanic rocks. The mean annual precipitation is 16 to 20 inches and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 57 to 62 degrees F. The frost-free period is 160 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Terrarossa, Blacktail, Pyeatt, Ashcreek, and Stanford soils. All of these soils are very deep.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; very slow permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes sideoats grama, blue grama, tobosa, hairy grama, purple grama, cane beardgrass, plains lovegrass, Texas bluestem, shrubby buckwheat and sacahuista.
DISTRIBUTION AND EXTENT: Southeastern Arizona portion of the Chihuahuan desert. MLRAs are 38 and 41. Kuykendall soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona; Soil Survey of Cochise County, Arizona, Douglas-Tombstone Part; 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 7 inches (A and Bt horizons)
Argillic horizon - the zone from 1 to 18 inches (Bt1 and Bt2 horizons)
Lithic contact - the boundary at 18 inches (R horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Revised for the correlation of AZ675, 5/2009, WWJ