LOCATION SECTION            AZ
Established Series
Rev. PDC
03/2007

SECTION SERIES


The Section series consists of very deep, well drained soils on hills and fan terraces. These soils formed in mixed alluvium and colluvium. Slope is 1 to 15 percent. Mean annual precipitation is about 16 inches. The mean annual air temperature is about 50 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Calciustolls

TYPICAL PEDON: Section gravelly loam - rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 2 inches; brown (7.5YR 4/4) gravelly loam, dark brown (7.5YR 3/2) moist; weak fine granular structure; slightly hard, very friable, slightly sticky; few very fine roots; many fine tubular pores; strongly effervescent; 20 percent gravel; slightly alkaline; abrupt smooth boundary. (2 to 7 inches thick)

Bw--2 to 6 inches; brown (7.5YR 4/4) loam, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky; many fine roots; common very fine tubular pores; violently effervescent; 1 percent gravel; slightly alkaline; clear wavy boundary. (3 to 10 inches thick)

Bk1--6 to 22 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; moderate fine subangular blocky structure; hard, firm, sticky and slightly plastic; few fine roots; common fine tubular pores; violently effervescent, few fine soft lime masses; 1 percent gravel, lime coating on undersides; moderately alkaline; clear wavy boundary.

Bk2--22 to 34 inches; light brown (7.5YR 6/4) loam, strong brown (7.5YR 5/6) moist; moderate fine subangular blocky structure; hard, firm, sticky and slightly plastic; few fine roots; common fine tubular pores; violently effervescent, common fine soft lime masses; 1 percent gravel; few cicada nodules; moderately alkaline; clear wavy boundary.

Bk3--34 to 60 inches; reddish brown (5YR 5/4) loam, yellowish red (5YR 4/6) moist; moderate fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine roots; common fine tubular pores; violently effervescent, common fine lime filaments and threads; 1 percent gravel; moderately alkaline. (Combined thickness of the Bk horizons is 32 to 55 inches)

TYPE LOCATION: Mohave County, Arizona; about 6 miles west of Nixon Springs; 1,700 feet east and 300 feet north of the southwest corner of section 22, T. 35 N., R. 9 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. Aridic ustic soil moisture regime.

Soil temperature - 50 to 54 degrees F.

Clay content - 18 to 35 percent

Depth to calcic horizon - 5 to 20 inches

Rock fragments - 0 to 35 percent

A horizon
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 3 or 4 dry, 2 or 3 moist

B horizon
Hue: 5YR, 7.5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 3 through 6, dry or moist
Carbonates: 15 to 25 percent calcium carbonate equivalent within the calcic horizon

COMPETING SERIES: These are the Dioxice (NM), Escabosa (NM), Jonale (NM), Oslo (TX), and Suglo (WY) soils. Dioxice soils have a calcic horizon at depths greater than 20 inches. Escabosa soils have bedrock at depths less than 40 inches. Jonale soils have 10YR hue, are dry for longer periods of time due to a lower rainfall and elevation component. Oslo and Suglo soils are moist in the soil moisture control section during May and June.

GEOGRAPHIC SETTING: Section soils are on hills and fan terraces. These soils formed in mixed alluvium and colluvium from limestone and pyroclastic rocks. Slopes range from 1 to 15 percent. Elevation is 5,800 to 6,400 feet. Mean annual precipitation is 14 to 18 inches. Mean annual air temperature is 48 to 52 degrees F. The frost-free period is 135 to 150 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Showlow series. Showlow soils are fine textured.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.

USE AND VEGETATION: Used for livestock grazing and fuelwood production. Vegetation is blue grama, needleandthread, galleta, juniper and pinyon pine.

DISTRIBUTION AND EXTENT: Northern Arizona. This series is of small extent. MLRA 35.

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

SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of Mohave County Area, Arizona, Northeastern Part, and Part of Coconino County; 1992.

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

Mollic epipedon - the zone from 0 to 7 inches (mixed) (A, Bw, Bk1 horizons)

Calcic horizon - the zone from 6 to 34 inches (Bk1, Bk2 horizons)


National Cooperative Soil Survey
U.S.A.