LOCATION SAGUARO AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic Lithic Torriorthents
TYPICAL PEDON: Saguaro extremely gravelly fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 1 inch; pale brown (10YR 6/3) extremely gravelly fine sandy loam, brown (10YR 4/3) moist; weak fine granular structure, soft, very friable, slightly sticky and nonplastic; 60 percent gravel and 20 percent cobble; few fine roots; few fine irregular pores; strongly effervescent; moderately alkaline; abrupt smooth boundary. (1 to 4 inches thick)
C--1 to 4 inches; light yellowish brown (10YR 6/4) extremely gravelly fine sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, slightly sticky and slightly nonplastic; 60 percent gravel and 25 percent cobble; few fine roots; few fine irregular pores; strongly effervescent; moderately alkaline; abrupt irregular boundary. (3 to 12 inches thick)
R--4 inches; light gray (10YR 7/1) limestone, gray (10YR 5/1) moist; few fine fractures; few very fine roots in fractures.
TYPE LOCATION: Pima County, Arizona; 100 feet south and 2,500 feet east of the northwest corner of sec. 23, T. 12 S., R. 11 E; latitude 32 degrees, 22 minutes, 50 seconds N; longitude 111 degrees, 11 minutes, 28 seconds W.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during December - March and for more than 20 days cumulative from June through August. Driest during May and June. Typic aridic soil moisture regime.
Soil Temperature: 66 to 72 degrees F.
Depth to bedrock: 4 to 18 inches
Organic Matter: less than 0.5 percent
Calcium carbonate: strongly effervescent throughout. Calcium carbonate equivalent ranges from 40 to 50 percent
Rock Fragments: 35 to 85 percent by volume gravel and cobble
Clay Content: averages 5 to 20 percent
A and C horizons
Hue: 7.5YR, 10YR
Value: 6 to 8 dry, 3 to 5 moist
Chroma: 1 to 3, dry or moist
COMPETING SERIES: These are the Birdspring (NV), Dozer (NM), St. Thomas (NV), and Uberci (CA) series. Birdspring, St. Thomas, and Uberci soils are in the Mohave Desert (MLRA 30) and are moist in the soil moisture control section for less than 20 days cumulative between July and September. Dozer soils have 18 to 35 percent clay and hues range as yellow as 2.5Y.
GEOGRAPHIC SETTING: Saguaro soils are on hills and mountains. Slopes range from 15 to 45 percent. Elevation ranges from 2,000 to 3,800 feet. The soils formed in alluvium and colluvium weathered from limestone and marble. Mean annual precipitation is 10 to 12 inches. Mean annual air temperature is 64 to 70 degrees F. The frost-free period is about 220 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anthony and Greyeagle soils. Anthony soils are coarse-loamy and have mixed mineralogy. Greyeagle soils have duripans and mixed mineralogy.
DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation is creosote bush, broom snakeweed, and scattered Mormon-tea.
DISTRIBUTION AND EXTENT: Central and Southern Arizona. This soil occurs in LRR-D, MLRAs 40 and 41. The series is not extensive. Total extent is about 1,200 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Pima County, Arizona; Soil Survey of Pima County, Arizona, Eastern Part; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 1 inch (A horizon)
Lithic contact - the boundary at 4 inches (R horizon)
Entisol feature - the absence of diagnostic subsurface horizons
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
The type location was moved to Pima County, Arizona, Eastern Part, in June 2009, WWJ