LOCATION MARICOPA AZ+NMEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, calcareous, thermic Typic Torrifluvents
TYPICAL PEDON: Maricopa sandy loam-cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 12 inches; brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and slightly plastic; few very fine and fine roots; common very fine and fine tubular and few interstitial pores; 5 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); clear smooth boundary (1 to 14 inches thick).
C1--12 to 26 inches; pale brown (10YR 6/3) stratified sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots; few very fine and fine tubular and interstitial pores; 5 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); clear smooth boundary (10 to 26 inches thick).
2C2--26 to 48 inches; brown (10YR 5/3) and varicolored stratified very gravelly sand, brown (10YR 4/3) moist; single grained; loose, nonsticky and nonplastic; few very fine roots; common fine and medium interstitial pores; 50 percent gravel; slightly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Graham County, Arizona; 450 feet south and 1,900 feet west of the NE corner of sec. 7, T.6S., R.25E.
RANGE IN CHARACTERISTICS:
Soil moisture: Typic aridic moisture regime
Depth to the coarse-textured horizon: 20 to 40 inches
Texture: thin strata of silt loam or loam occur in the control section. The upper part of the control section is loamy very fine sand, fine sandy loam, and sandy loam
Clay content: less than 18 percent
Calcium carbonate filaments are common immediately above the contrasting layer
Reaction: slightly to strongly alkaline
Mean annual soil temperature: 58 degrees to 72 degrees F
Organic matter content: less than one percent in the upper 20 inches
A horizon
Hue: 10YR, 7.5YR
Value: 4 through 7 dry, 3 or 4 moist
Chroma: 2 through 4, dry or moist
Texture: loamy very fine sand, fine sandy loam, sandy loam
C1 horizon
Hue: 10YR, 7.5YR
Value: 4 through 7 dry, 3 or 4 moist
Chroma: 2 through 6, dry or moist
Texture: sandy loam, loamy sand, sand
Gravel content ranges from 5 to 60 percent by volume
2C2 horizon
Hue: 10YR, 7.5YR
Value: 5 through 7 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture: loamy sand, sand
Gravel content: 5 to 60 percent
COMPETING SERIES: This is the Agua (AZ) series. Agua soils have textures of loam, silt loam or very fine sandy loam in the upper part of the control section.
GEOGRAPHIC SETTING: Maricopa soils are on nearly level to gently sloping flood plains, alluvial fans and low stream terraces at elevations of 2,200 to 5,000 feet. Slopes are dominantly 0 to 3 percent but range to 5 percent. These soils have formed in moderately coarse and coarse-textured recent alluvium from mixed sources. The climate is arid and semi-arid continental. The mean annual air temperature ranges from 56 degrees to 69 degrees F. and the average annual precipitation ranges from 7 to 12 inches. The frost-free period is 180 to 275 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Agua soils and the Anthony, Queen Creek, Brazito, Gila, Glendale, and Vinton soils. Queen Creek soils are sandy-skeletal. Anthony and Gila soils are coarse-loamy and do not have strongly contrasting textures in the lower part of the control section. Brazito and Vinton soils are sandy. Glendale soils are fine-silty.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: Nonirrigated areas are used for livestock grazing. Irrigated areas are used for growing cotton, grain sorghum, small grains and alfalfa. Native vegetation consists of creosotebush, triangle bursage, mesquite, catclaw and cacti, with an understory of bush muhly, black grama, sand dropseed and Arizona cottontop.
DISTRIBUTION AND EXTENT: Southern Arizona and New Mexico. Maricopa soils are moderately extensive. This soil occurs in LRR-D, MLRAs 40, 41, and 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Maricopa County (Salt River Valley), Arizona, 1900.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 12 inches (Ap horizon)
Entisol feature - The absence of diagnostic subsurface horizons
Fluvial feature - Irregular decrease in organic carbon in the zone from 12 to 48 inches (C1, 2C2 horizons)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.