LOCATION TRIX AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, hyperthermic Typic Torrifluvents
TYPICAL PEDON: Trix clay loam - cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 14 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and plastic; many fine and medium roots; common very fine tubular pores; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (10 to 16 inches thick)
C--14 to 24 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; massive; hard, friable, slightly sticky and plastic; common fine roots; many very fine tubular pores; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (10 to 24 inches thick)
2Btkb1--24 to 37 inches; light reddish brown (5YR 6/4) clay loam, reddish brown (5YR 4/4) moist; weak fine subangular blocky structure; very hard, friable, slightly sticky and plastic; few fine roots; common very fine pores; common faint clay films on faces of peds; few fine calcium carbonate accumulations and soft masses; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (10 to 15 inches thick)
2Btkb2--37 to 51 inches; light reddish brown (5YR 6/4) clay loam, reddish brown (5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, friable, slightly sticky and plastic; few fine roots; many very fine tubular pores; common faint clay films on faces of peds and lining pores; common fine calcium carbonate accumulations and soft masses; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (12 to 16 inches thick)
2Btkb3--51 to 60 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; weak coarse subangular blocky structure; very hard, friable, slightly sticky and plastic; many very fine tubular pores; few faint clay films on faces of peds and lining pores; few fine calcium carbonate accumulations in roots channels; violently effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Maricopa County, Arizona; about 3 miles west of Williams Air Force Base; 60 feet east and 40 feet south of the northwest corner of section 4, T. 2 S. R. 6 E.
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during July-August and December-January. Driest during May and June. Typic aridic soil moisture regime.
Soil temperature - 72 to 76 degrees F
Salinity- nonsaline to strongly saline
Sodicity- nonsodic to strongly sodic
Depth to buried argillic horizon - 20 to 40 inches
Rock fragments (particle-size control section) - Less than 35 percent in any one horizon
A horizon
Hue: 10YR, 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2, 3, or 4, dry or moist
Organic matter: Less than 1 percent; decreases irregularly
Reaction: Mildly or moderately alkaline
Calcium Carbonate: Slightly to violently effervescent
C horizon
Hue: 10YR, 7.5YR
Value: 5, 6, or 7 dry, 3, 4, or 5 moist
Chroma: 2, 3, 4, or 6, dry or moist
Texture: Clay loam, loam, sandy clay loam, silt loam; minor strata of finer textures
Reaction: Mildly to very strongly alkaline
Calcium Carbonate: Strongly or violently effervescent; occurs as filaments in some pedons
Stratification: Thin strata of contrasting textures are common
2Btkb horizons
Hue: 5YR, 7.5YR
Value: 4 through 7 dry, 3 through 7 moist
Chroma: 3, 4, 5, or 6, dry or moist
Texture: Silty clay loam, clay loam, loam, sandy clay loam, (25 to 35 percent clay); also includes silt loam
Reaction: Mildly to very strongly alkaline
Calcium Carbonate: Strongly or violently effervescent; occurs as filament accumulations and soft masses (5 to 10 percent calcium carbonate equivalent)
COMPETING SERIES: These are the Avondale (AZ) and Estrella (AZ) series. Avondale soils do not have buried argillic horizons within 40 inches. Estrella soils are coarser textured above the buried argillic horizons.
GEOGRAPHIC SETTING: Trix soils are on alluvial fans and flood plains. Elevations range from 400 to 2000 feet. Slopes range from 0 to 5 percent. These soils formed in stratified mixed alluvium that includes volcanic, granitic, metamorphic and sedimentary rock. The mean annual precipitation is 2 to 10 inches, occurring as summer thunderstorms and gentle winter rain. The mean annual air temperature is 71 degrees F. The frost-free period is 240 to 325 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Antho, Gilman, Glenbar and Valencia series and the competing Estrella series. Antho, Gilman, and Valencia are coarse-loamy. Glenbar soils are fine-silty.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing and irrigated cropland. Vegetation is creosotebush, mesquite, paloverde, ironwood, salt cedar, cacti, annual weeds and grasses. Irrigated crops are alfalfa, cotton, small grains and vegetables.
DISTRIBUTION AND EXTENT: Southern Arizona. The Trix soil is inextensive. MLRA 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Maricopa County (Eastern Maricopa-Northern Pinal Counties Area), Arizona; 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 14 inches (Ap horizon)
Entisol feature - The absence of diagnostic subsurface horizons
Buried paleosol - The zone from 24 to 60 inches (2Btkb1, 2Btkb2, 2Btkb3 horizons)
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.