LOCATION AGUA                    AZ+NM

Established Series
Rev. SDH/JEJ
10/2013

AGUA SERIES

The Agua series consists of very deep, well drained soils that formed in recent stream alluvium from mixed sources. Agua soils are on flood plains, and alluvial fans. They have slopes of 0 to 3 percent. The average annual precipitation is about 9 inches (229 mm) and the mean annual air temperature is about 63 degrees F (17 degrees C).

TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, calcareous, thermic Typic Torrifluvents

TYPICAL PEDON: Agua loam, cultivated (colors are for dry soil unless otherwise noted).

Ap--0 to 12 inches (0 to 30 cm); light brownish gray (10YR 6/2) loam, dark brown, moist, massive; hard, friable, slightly plastic; many very fine roots; common fine tubular pores; 3 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); clear smooth boundary (12 to 25 inches and 30 to 64 cm thick).

C1--12 to 27 inches (30 to 69 cm); pale brown (10YR 6/3) weakly stratified loam, brown (7.5YR 4/4) moist; massive; hard, friable, slightly sticky, slightly plastic; few very fine roots; few very fine tubular pores; 10 percent gravel; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary (12 to 25 inches and 30 to 64 cm thick).

2C2--27 to 60 inches (69 to 152 cm); light yellowish brown (10YR 6/4) and varicolored stratified sand and very gravelly sand, yellowish brown (10YR 5/4) moist; single grain; loose; few very fine roots; common fine interstitial pores; 35 percent gravel; slightly effervescent; moderately alkaline (pH 8.0).

TYPE LOCATION: Graham County, Arizona; 1,150 feet north and 1,450 feet west of SE corner sec. 16, T.6S., R.25E.

RANGE IN CHARACTERISTICS:
Soil moisture: Soil moisture - Intermittently moist in the soil moisture control section during July-August and December-January. Driest during May and June. Typic aridic soil moisture regime.

Soil Temperature: 69 to 74 degrees Fahrenheit (20.5 to 23.5 degrees Celsius)

Reaction: slightly to strongly alkaline

Salinity: non-saline to strongly saline

Carbonates: disseminated or as thin filament or threads

Organic matter content: less than 1 percent

Rock fragments: The upper part has less than 35 percent gravel in any subhorizon and usually less than 15 percent; the lower part has less than 35 percent in any horizon but individual subhorizons range from 0 to 60 percent.

Depth to sandy substratum: 20 to 40 inches (51 to 100 cm)

A and C horizons
Hue: 7.5YR, 10YR
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 to 4 dry, 3 or 4 moist
Texture: stratified very fine sandy loam, loam, silt loam (averages less than 18 percent clay)

2C horizons
Hue: 10YR, 7.5YR
Value: 5 to 7 dry, 3 to 6 moist
Chroma: 2 to 4, dry or moist
Texture: stratified loamy sand, fine sand, or sand with some pedons having a few thin layers of finer textured materials.

COMPETING SERIES: This is the Maricopa (AZ) series. Maricopa soils have textures of loamy very fine sand, fine sandy loam, and sandy loam in the upper part of the control section.

GEOGRAPHIC SETTING: Agua soils are on nearly level to gently sloping flood plains, alluvial fans at elevations of 2,200 to 5,000 feet (56 to 127 meters). Slopes are dominantly 0 to 1 percent but range to 3 percent. These soils formed in recent stream alluvium from mixed sources. The climate is arid and semi-arid continental. The mean annual temperature ranges from 56 to 69 degrees F (13.3 to 21.0 degrees C) and the average annual precipitation ranges from 7 to 12 inches (177 to 305 mm). The frost-free season is 165 to 275 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arizo, Glendale, Mohave and Pima soils. Arizo soils have sandy-skeletal control sections. Glendale and Pima soils have fine-silty control section. In addition, Pima soils have value of 5 or less dry, 3 or less moist. Mohave soils have an argillic horizon and a fine-loamy control section.

DRAINAGE AND PERMEABILITY: Well drained; slow runoff, moderate 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. Agua 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: Graham County, Arizona; 1971.

REMARKS: diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 12 inches (0 to 30 cm) (Ap horizon)
Entisol feature - the absence of diagnostic subsurface horizons
Fluvial feature - irregular decrease in organic carbon in the zone from 12 to 60 inches (30 to 152 cm) (C1, 2C2 horizons)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010.

Updated competing series section 3/17/08, CEM

Revised for the correlation the SDJR - MLRA 42 - Agua Loam project, September 2013, LJG2

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National Cooperative Soil Survey
U.S.A.