LOCATION DURAZO AZEstablished Series
TAXONOMIC CLASS: Mixed, thermic Ustic Torripsamments
TYPICAL PEDON: Durazo loamy sand - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; brown (7.5YR 5/4) loamy sand, brown (7.5YR 4/4) moist; weak thin platy structure parting to weak fine granular; soft, friable, nonsticky and nonplastic; common fine roots; many very fine interstitial pores; noneffervescent; moderately alkaline; abrupt smooth boundary.
C--8 to 48 inches; brown (7.5YR 5/4) loamy sand, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common fine roots; many fine interstitial pores; noneffervescent; moderately alkaline; abrupt wavy boundary.
2Btb--48 to 60 inches; reddish brown (5YR 5/4) sandy clay loam, reddish brown (5YR 4/4) moist; weak, medium subangular block structure; slightly hard, friable, sticky and nonplastic; few fine roots; many fine interstitial pores; few thin clay films on faces of peds; noneffervescent; moderately alkaline.
TYPE LOCATION: Cochise County, Arizona; about 4 miles northeast of Elfrida, 900 feet west, 29 feet north of the southeast corner of sec. 30, T. 19 S., R. 26 E.
RANGE IN CHARACTERISTICS: Soil moisture - Intermittently moist in some part of the soil moisture control section during December-March and July-September. Ustic Aridic soil moisture regime.
Soil temperature - Averages 62 to 69 degrees F. at a depth of 20 inches
Carbonates- Some pedons are effervescent at depths of 20 to 40 inches
A horizon
Hue: 7.5YR, 10YR
Value: 4 to 6 dry, 3 or 4 moist
Chroma: 2 to 4, dry or moist
Texture: Loamy sand and sandy loam, coarse sand
C horizon
Hue: 7.5YR, 5YR, 2.5YR
Value: 3 to 6 dry and moist
Chroma: 2 through 6, dry and moist
Texture: Loamy sand, sand, loamy coarse sand, loamy fine sand
2Btb horizon
Hue: 2.5YR, 5YR
Value: 3 through 5, dry or moist
Chroma: 3 through 6, dry or moist
Texture: sandy loam, sandy clay loam
Calcium carbonate equivalent: 0 to 5 percent
COMPETING SERIES: These are the Aguena (NM) and Roswell (NM) series. The Aguena and Roswell soils do not have a buried argillic (2Btb horizon).
GEOGRAPHIC SETTING: Durazo soils are on stream terraces, fan terraces, alluvial fans, and dunes. They formed in sandy stream and fan alluvium and eolian deposits. Slopes range from 0 to 15 percent. Elevations range from 3,900 to 4,600 feet. The average annual precipitation is 12 to 16 inches; mean annual air temperature is 60 to 67 degrees F., and the frost-free period is 180 to 240 days. Precipitation falls as intense summer thunderstorms and gentle winter rain or snow.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Courtland, Diaspar, Sasabe, and Forrest soils. Courtland soils are fine-loamy and occur on fan terraces. Diaspar soils are coarse-loamy. Sasabe and Forrest soils are fine and occur on fan terraces.
DRAINAGE AND PERMEABILITY: Excessively drained; slow runoff; rapid permeability.
USE AND VEGETATION: Durazo soils are used for livestock grazing and irrigated crops. Native vegetation includes black grama, mesa dropseed, sand dropseed, and fourwing saltbush, spike dropseed, threeawn, soaptree yucca, and Mormon tea.
DISTRIBUTION AND EXTENT: The Durazo soils are of moderate extent in southeast Arizona. MLRA 41.
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:
Ochric epipedon - The zone from the surface to 8 inches (A horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.