LOCATION ELFRIDA AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Ustic Haplocalcids
TYPICAL PEDON: Elfrida silty clay loam, cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 13 inches; grayish brown (10YR 5/2) silty clay loam, dark brown (10YR 3/3) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; few fine and coarse roots; few fine interstitial and tubular pores; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary (10 to 14 inches thick).
A--13 to 22 inches; brown (10YR 5/3) silty clay loam, dark brown (7.5YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary (8 to 24 inches thick).
Bk1--22 to 33 inches; pinkish gray (7.5YR 7/2) loam, brown (7.5YR 5/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common very fine and fine tubular pores; violently effervescent; common fine pinkish white (7.5YR 8/2) soft lime masses and hard lime nodules; moderately alkaline (pH 8.2); abrupt wavy boundary (8 to 15 inches thick).
Bk2--33 to 50 inches; pinkish white (7.5YR 8/2) and pink (7.5YR 7/4) clay loam, pink (7.5YR 7/4) and light brown (7.5YR 6/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; common very fine and fine tubular pores; violently effervescent; many fine and medium pinkish white (7.5YR 8/2) soft lime masses and common fine lime nodules; moderately alkaline (pH 8.2).
TYPE LOCATION: Cochise County, Arizona; in Kansas Settlement; 700 feet west and 600 feet south of the northeast corner of sec. 11, T.16S., R.25E.
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during July-September and December-February and for less than 90 days cumulative in some part of the epipedon. Driest during May and June. Ustic aridic soil moisture regime.
Soil temperature: 59 to 68 degrees F.
Reaction: slightly to strongly alkaline
Rock fragments: 0 to 15 percent
Depth to calcic: 16 to 38 inches (dominantly 20 to 30 inches)
A horizons
Hue: 10YR, 7.5YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Effervescence: slight to strong
Organic matter: more than 1 percent
Bk horizons
Texture: loam, silt loam, clay loam and silty clay loam, less than 35 percent sand
Calcium carbonate equivalent: 15 to 50 percent (dominantly 15 to 40 percent)
Effervescence: strong to violent
Buried calcareous B horizons underlie the Ck2 horizon in some pedons.
COMPETING SERIES: These are the Chispa (TX), Kahn (AZ), Laborcita (NM), Pandale (TX), Ratliff (TX), Salado (NM), San Jon (NM), and Tuzigoot (AZ) series. Pandale, Ratliff, and San Jon soils are moist in the soil moisture control section during May and June and occur in the Great Plains. Kahn and Salado siols have less than 1 percent organic matter in the surface horizons. Chispa soils have textures that have more than 35 percent sand (silt clay loam, fine silt loam, loam, clayloam). Laborcita soils have more than 15 percent gravel. Tuzigoot soils have calcium carbonate concretions throughout.
GEOGRAPHIC SETTING: Elfrida soils are on level to nearly level alluvial fans, lower valley slopes, flood plains, and valley plains near old lake margins. Elevations are 3,800 to 4,600 feet. Slopes are dominantly less than 1 percent and range from 0 to 2 percent. The soils formed in mixed alluvium from acid and basic igneous rocks with some influence from limestone. The climate is warm semiarid continental. The mean annual precipitation ranges from 10 to 16 inches and occurs mainly as thundershowers from July through September and as gentle rains in the fall and winter. The mean annual air temperature ranges from 60 degrees to 67 degrees F. The frost-free period ranges from 155 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Guest, Swisshelm and Ubik soils.
DRAINAGE AND PERMEABILITY: Well drained; medium to slow runoff; moderately slow permeability.
USE AND VEGETATION: Used mostly for irrigated crops such as cotton, grain, alfalfa, and truck crops including lettuce. Native vegetation is mesquite, creosotebush, tobosa, fluffgrass, grama grasses, alkali sacaton, annual weeds, and grasses.
DISTRIBUTION AND EXTENT: Southeastern Arizona. These soils are of moderate extent. MLRA 41.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Sulphur Spring Valley Area, Arizona, 1942
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Calcic horizon - The zone from 22 to 50 inches (Ck1 and Ck2 horizon)
Classified according to Soil Taxonomy, Second Edition, 1999
Updated competing series section 3/17/08, CEM