LOCATION BRUNKCOW                AZ

Established Series
Rev. WAS/CEM
10/2013

BRUNKCOW SERIES

The Brunkcow series consists of very shallow and shallow, well drained soils that formed in material weathered from granite, gneiss and metamorphic rock. Brunkcow soils are on hills and mountains. Slopes range from 3 to 60 percent. The mean annual precipitation is about 14 inches (356 mm) and the mean annual air temperature is about 63 degrees F (17.2 degrees C).

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Ustic Haplargids

TYPICAL PEDON: Brunkcow coarse sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.) 30 to 50 percent surface cover of gravel and cobble.

A--0 to 2 inches (0 to 5 cm); brown (7.5YR 4/4) coarse sandy loam, dark brown (7.5YR 3/4) moist; moderate thick platy structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common fine irregular pores; noneffervescent; moderately acid (pH 6.0); abrupt smooth boundary. (1 to 3 inches and 3 to 8 cm thick)

Bt--2 to 8 inches (5 to 20 cm); reddish brown (5YR 4/4) sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; soft, friable, moderately sticky and moderately plastic; common very fine and fine roots; common fine irregular and tubular pores; common distinct clay films on ped faces and bridging sand grains; noneffervescent; slightly acid (pH 6.2); abrupt wavy boundar. (1 to 12 inches and 3 to 30 thick)

2Crt--8 to 12 inches (20 to 30 cm); partially weathered granite (grus), common distinct clay films coating the sand grains; common distinct organic stains on sand grains. (3 to 5 inches and 8 to 13 cm thick)

2R--12 to 60 inches (30 to 152 cm); granite.

TYPE LOCATION: Fort Huachuca, Arizona; located at a latitude of 31 degrees, 40 minutes, 00 seconds North and longitude of 110 degrees, 14 minutes, 20 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. Ustic aridic soil moisture regime.

Soil temperature: 62 to 69 degrees F (16.7 to 20.6 degrees C).

Surface rock fragments: 30 to 50 percent gravel and cobble.

Rock fragments (particle size control section): less than 35 percent

Clay content (particle size control section):18 to 35 percent

Reaction: moderately acid or neutral

Organic matter: 1 to 2 percent

Depth to bedrock: 5 to 20 inches (13 to 51 cm)

A horizon
Hue: 10YR, 7.5YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 2 to 4, dry or moist
Texture: coarse sandy loam, sandy loam, loamy coarse sand

Bt horizon
Hue: 7.5YR, 5YR
Value: 3 to 5, dry or moist
Chroma: 2 to 4, dry or moist
Texture: sandy loam, sandy clay loam, clay loam

COMPETING SERIES: This is the Oracle (AZ) series. Oracle soils do not have unweathered bedrock below the paralithic contact.

GEOGRAPHIC SETTING: Brunkcow soils are on hills and mountains at elevations of 4,000 to 5,400 feet (1,219 to 1,646 meters). Slopes range from 3 to 60 percent. These soils formed in alluvium from granite, gneiss, diorite, granodiorite and monzonite. The mean annual precipitation is 12 to 16 inches (304 to 406 mm) and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 60 to 67 degrees F (15.5 to 19.4 degrees C). The frost-free period is 180 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gulch, Major, Combate, Caralampi, and Tombstone soils. All of these soils are very deep.

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

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes Arizona cottontop, cane bluestem, tanglehead, whitethorn, black grama, sideoats grama.

DISTRIBUTION AND EXTENT: Southern Arizona. Brunkcow soils are of limited extent. MLRA is 41. Name derived from Brunkcow Hill.

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

SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Cochise County, AZ, Douglas-Tombstone Part; 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 8 inches (5 to 20 cm) (Bt horizon)
Paralithic contact - the boundary at 8 inches (20 cm) (2Crt horizon)
Lithic contact - the boundary at 12 inches (30 cm) (2R horizon)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, 11th Edition, 2010

Revised for the correlation of AZ661, 11/08, PDC

Revised for the correlation the SDJR - MLRA 41 - Brunkcow-Chiricahua-Andrada complex, 3 to 20 percent slopes project, September 2013, LJG2

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National Cooperative Soil Survey
U.S.A.