LOCATION TERRAROSSA AZ

Established Series
Rev. WAS/CEM
10/2014

TERRAROSSA SERIES

The Terrarossa series consists of very deep, well drained soils that formed in fan alluvium from mixed sources. Terrarossa soils are on fan remnants. Slopes range from 0 to 45 percent. The mean annual precipitation is about 18 inches (457 mm) and the mean annual air temperature is about 60 degrees F (15.6 degrees C).

TAXONOMIC CLASS: Fine, mixed, superactive, thermic Aridic Paleustalfs

TYPICAL PEDON: Terrarossa sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches (0 to 5 cm); reddish brown (5YR 4/4) sandy loam, dark reddish brown (5YR 3/3) moist; weak thin platy structure; soft, very friable, nonsticky and nonplastic; common fine roots; common fine irregular pores; noneffervescent; moderately acid (pH 6.0); abrupt smooth boundary. (1 to 6 inches or 3 to 15 cm thick)

Bt1--2 to 9 inches (5 to 23 cm); reddish brown (5YR 4/4) sandy loam, dark reddish brown (5YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few medium roots; few fine irregular and tubular pores; common distinct clay films on ped faces; noneffervescent; slightly acid (pH 6.2); abrupt wavy boundary.

Bt2--9 to 17 inches (23 to 43 cm); yellowish red (5YR 5/6) clay, reddish brown (5YR 4/4) moist; moderate medium prismatic structure parting to strong medium angular blocky; hard, firm, very sticky and very plastic; few fine and coarse roots; few fine tubular pores; many distinct clay films on ped faces; noneffervescent; slightly acid (pH 6.2); abrupt smooth boundary.

Bt3--17 to 27 inches (43 to 69 cm); 70 percent yellowish red (5YR 5/6) and 30 percent red (2.5YR 4/6) clay, reddish brown (5YR 4/4) moist; moderate medium prismatic structure parting to strong medium angular blocky; very hard, very firm, very sticky and very plastic; few fine roots; few fine tubular pores; many distinct clay films on ped faces and coating gravel; common dark reddish brown (5YR 3/3) organic coatings and iron-manganese stains on ped faces; 5 percent gravel; noneffervescent; neutral (pH 6.8); clear smooth boundary.

Bt4--27 to 42 inches (69 to 107 cm); 70 percent dark red (2.5YR 3/6) and 30 percent yellowish red (5YR 4/6) clay, 70 percent dark red (2.5YR 3/6) and 30 percent yellowish red (5YR 4/6) moist; strong medium prismatic structure parting to strong medium angular blocky; very hard, very firm, very sticky and very plastic; few fine roots; few fine tubular pores; many distinct clay films on ped faces; many dark reddish brown (5YR 3/3) organic coatings and dark reddish brown (5YR 3/2) iron-manganese stains on ped faces; noneffervescent; neutral (pH 7.2); clear smooth boundary.

Bt5--42 to 60 inches (107 to 152 cm); 70 percent dark red (2.5YR 3/6) and 30 percent yellowish red (5YR 4/6) clay, 70 percent red (2.5YR 4/6) and 30 percent dark reddish brown (2.5YR 3/4) moist; moderate medium prismatic structure parting to strong medium angular blocky; hard, firm, moderately sticky and moderately plastic; few fine tubular pores; many distinct clay films and common organic coatings on ped faces; noneffervescent; neutral (pH 7.2). (Combined thickness of the Bt horizons is 35 to 56 inches or 89 to 142 cm)

TYPE LOCATION: Fort Huachuca, Arizona; located at a latitude of 31 degrees, 31 minutes, 30 seconds North and longitude of 110 degrees, 18 minutes, 30 seconds West.

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. Aridic ustic soil moisture regime.

Soil Temperature: 59 to 64 degrees F (15 to 17.8 degrees F).

Surface rock fragments: less than 55 percent

Rock fragments: less than 35 percent, but can range to 50 percent in any one horizon
Clay content: more than 35 percent
Depth to abrupt textural change: 5 to 15 inches (13 to 38 cm)
Effervescence: noneffervescent
Some pedons have a thin BA horizon above the argillic horizon

A horizon
Hue: 7.5YR, 5YR
Value: 3 to 5 dry, 3 or 4 moist
Chroma: 3 or 4 dry, 2 to 4 moist
Reaction: moderately acid to neutral

Bt horizon
Hue: 5YR, 2.5YR
Value: 3 to 5 dry, 3 or 4 moist
Chroma: 3 to 6 dry, 2 to 6 moist
Texture: sandy clay loam, clay, sandy clay, sandy loam
Reaction: slightly acid or neutral

COMPETING SERIES: This is the Sparks (NM) series. Sparks soils are moist in May and June and reside in LRR-H.

GEOGRAPHIC SETTING: Terrarossa soils are on fan remnants and relict fan remnants at elevations of 4,000 to 6,200 feet (1219 to 1890 meters). Slopes range from 0 to 45 percent. These soils formed in fan alluvium from mixed sources. The mean annual precipitation is 16 to 20 inches (406 to 508 mm) and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 57 to 62 degrees F (13.9 to 16.7 degrees C). The frost-free period is 150 to 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gardencan, Pyeatt, Blacktail and Lanque soils. Gardencan soils are fine-loamy. Pyeatt and Lanque soils do not have argillic horizons. Blacktail soils have mollic epipedons.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.

USE AND VEGETATION: Used for livestock grazing, military training, recreation and wildlife habitat. Vegetation includes sideoats grama, blue grama, plains lovegrass, Texas bluestem, cane beardgrass, tanglehead, Arizona cottontop, fall witchgrass, beggartickgrass, false mesquite, Palmer agave, velvetpod mimosa.

DISTRIBUTION AND EXTENT: Southern and Central Arizona. Terrarossa soils are of moderate extent. MLRAs 38 and 41, LRR-D.

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

SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Coronado National Memorial; 1996.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 2 inches (0 to 5 cm) (A horizon)
Argillic horizon - the zone from 2 to 60 inches (5 to 152 cm) (Bt1, Bt2, Bt3, Bt4, Bt5 horizons)
Pale feature - the abrupt textural change at 9 inches (23 cm)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, 12th Edition, 2014.

Revised for the correlation of AZ661, 2/2009, WWJ
Revised for the correlation of SDJR - MLRA 38 - Terrarossa-Blacktail Complex, 5 to 60 Percent Slopes; September, 2014, LJG2

National Cooperative Soil Survey
U.S.A.