LOCATION ESTRELLA                AZ

Established Series
Rev. EDA/DLR/PDC
02/2017

ESTRELLA SERIES

The Estrella series consists of very deep, well drained soils that formed in stratified mixed alluvium. Estrella soils are on alluvial fans and have slopes of 0 to 5 percent. The mean annual precipitation is about 7 inches and the mean annual air temperature is about 71 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, hyperthermic Typic Torrifluvents

TYPICAL PEDON: Estrella loam - cultivated. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 11 inches; brown (10YR 5/3) loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; slightly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (10 to 14 inches thick)

C--11 to 24 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common medium tubular pores; few fine mycelia-like calcium carbonate veins in lower part; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (10 to 26 inches thick)

2Btkb1--24 to 35 inches; brown (7.5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; many fine tubular pores; many faint clay films on faces of peds and lining pores; many medium distinct mycelia-like calcium carbonate veins; strongly effervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (8 to 12 inches thick)

2Btkb2--35 to 48 inches; yellowish red (5YR 4/6) clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; many fine tubular pores; many faint clay films on faces of peds and lining pores; few soft masses and common fine distinct calcium carbonate accumulations in root channels, strongly effervescent; moderately alkaline (pH 8.1); abrupt wavy boundary. (10 to 14 inches thick)

2Bkb--48 to 60 inches; light brown (7.5YR 6/4) gravelly clay loam, brown (7.5YR 5/4) moist; massive; hard, friable, slightly sticky and plastic; many fine tubular pores; many medium distinct calcium carbonate masses; violently effervescent; moderately alkaline (pH 8.2)

TYPE LOCATION: Maricopa County, Arizona; 45 feet west and 540 feet north of the southwest corner of the southwest 1/4 of section 16, T. 3 N., R. 1 W.

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. Typic aridic soil moisture regime.

Rock fragments - Less than 35 percent in any one horizon

Depth to buried argillic horizon - 20 to 40 inches

Calcium carbonate - Slightly to violently effervescent throughout. Occurs as accumulations, filaments, veins, and soft masses in the buried horizons.

Reaction - Usually mildly alkaline or moderately alkaline but some pedons are strongly alkaline and saline.

Organic matter - Less than 1 percent

A and C horizons
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: Loam, silt loam, very fine sandy loam (less than 18 percent clay); some pedons have .5 to 1 inch thick strata of finer or coarser material.

Bt horizon
Hue: 5YR, 7.5YR
Value: 4 through 7 dry, 3 through 7 moist
Chroma: 3, 4, or 6, dry or moist
Texture: Loam, sandy loam, sandy clay loam, clay loam; minor strata of coarse sandy loam, loamy sand, or fine sandy loam.
Calcium carbonate: Occurs as disseminated or accumulations as veins and soft masses.

Bk horizon
Hue: 7.5YR, 5YR
Value: 5, 6, 7, or 8, dry or moist
Chroma: 2, 3, 4, or 6, dry or moist
Texture: Loam, sandy loam, sandy clay, sandy clay loam, clay loam
Calcium carbonate: Few to many soft masses.

COMPETING SERIES: These are the Avondale (AZ) and Trix (AZ) series. Avondale soils do not have buried argillic horizons within 40 inches. Trix soils average more than 18 percent clay above the buried argillic horizon.

GEOGRAPHIC SETTING: Estrella soils are on alluvial fans. Elevations range from 100 to 2700 feet. Slopes range from 0 to 5 percent. These soils formed in stratified and 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 rains. The mean annual air temperature is 70 to 76 degrees F. Frost-free period is 240 to 325 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Antho, Gilman, Glenbar and Valencia series and the competing Trix soils. Antho, Gilman, Glenbar and Valencia soils are coarse-loamy.

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability in the A and C horizons and moderately slow in the buried argillic horizon.

USE AND VEGETATION: Used for livestock grazing and irrigated cropland. Irrigated areas are used for growing alfalfa, cotton, small grains, sugar beets and various truck crops. Vegetation is mesquite, catclaw, big galleta, creosotebush, arrowweed, saltbush and annuals.

DISTRIBUTION AND EXTENT: Southern Arizona. Estrella soils are moderately extensive. MLRAs 31 & 40.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Eastern Maricopa and Northern Pinal Counties Area, Arizona; 1969.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from 0 to 11 inches (Ap horizon)

Entisol feature - The absence of diagnostic subsurface horizons

Soils classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy, Twelfth Edition, 2014

Revised for the correlation of SDJR - MLRA 40 - Estrella loam, July, 2016, NMS

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National Cooperative Soil Survey
U.S.A.