LOCATION BILGRAY AZ

Established Series
Rev. BAL/PDC
08/2012

BILGRAY SERIES

The Bilgray series consists of very deep, well drained soils that formed in residuum and alluvium from sandstone. These soils are on rock pediments and have slopes of 3 to 8 percent. The mean annual precipitation is about 13 inches and the mean annual air temperature is about 62 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Ustic Haplocalcids

TYPICAL PEDON: Bilgray loamy fine sand - rangeland (colors are for dry soil unless otherwise noted).

A--0 to 4 inches; reddish brown (5YR 5/4) loamy fine sand, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine tubular pores; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (2 to 5 inches thick).

Bk1--4 to 15 inches; yellowish red (5YR 5/6) loamy sand, yellowish red (5YR 4/6) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine irregular pores; common fine hard nodules of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (10 to 15 inches thick).

Bk2--15 to 33 inches; reddish yellow (5YR 6/6) sandy loam, yellowish red (5YR 5/6) moist; massive; soft, very friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine irregular pores; common medium soft masses of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (15 to 17 inches thick).

Bk3--33 to 46 inches; light reddish brown (5YR 6/4) sandy loam, reddish yellow (5YR 6/6) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine and fine roots; many very fine and fine irregular pores; many coarse soft masses of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (12 to 15 inches thick).

Bk4--46 to 50 inches; light red (2.5YR 6/6) loamy fine sand, red (2.5YR 4/6) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine irregular pores; common coarse filaments of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (0 to 10 inches thick).

Cdk--50 to 60 inches; light red (2.5YR 6/6) loamy fine sand, red (2.5YR 4/6) moist; massive; hard, firm, nonsticky and nonplastic; few very fine roots; few very fine irregular pores; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Yavapai County, Arizona; located about 935 feet north and 960 feet west of the SE corner of sec. 5, T.15N., R.4E.; 34 degrees, 43 minutes, 12.4 seconds north latitude and 111 degrees, 56 minutes, 31.5 seconds west longitude.

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 65 degrees F.

Clay content: Averages 5 to 18 percent in the particle-size control section

Rock fragments: Averages less than 5 percent in the particle-size control section

Depth to calcic horizon: 4 to 10 inches

Depth to Cd horizon: 45 to 55 inches

A horizon
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Organic matter: 1 to 3 percent
Calcium carbonate equivalent: 2 to 5 percent

Bk horizons
Hue: 5YR, 7.5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 4 through 6, dry or moist
Organic matter: 0.5 to 1 percent
Calcium carbonate equivalent: 10 to 25 percent
Texture: fine sandy loam, sandy loam, loam, loamy sand, loamy fine sand, very fine sandy loam

Cdk horizon
These are dense sediments that are intergrades between soft sediments (C material) and soft bedrock (Cr material). These naturally compacted sediments have been subjected to a slow reduction in volume and increase in density from deep water loading in the geologic past. These materials easily break down in water and roots can penetrate when moist. They are root restrictive when dry.
Hue: 7.5YR, 5YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 4 through 6, dry or moist
Organic matter: 0.1 to 0.5 percent
Calcium carbonate equivalent: 10 to 25 percent
Texture: loamy fine sand

COMPETING SERIES: These are the Geta (AZ), Kinco (TX), Luckyhills (AZ), Potrillo (TX), and Stronghold (AZ) series. These soils do not have dense compacted root-limiting horizons (Cd horizons). In addition, Geta soils are in the Mohave Desert and are moist in the soil moisture control section less than 20 days cumulative between July and September.

GEOGRAPHIC SETTING: Bilgray soils are on pediments and have slopes of 3 to 8 percent. These soils formed in residuum and alluvium from sandstone of the Verde Formation. Elevations range from 3000 to 4500 feet. The mean annual precipitation ranges from 12 to 14 inches. The mean annual air temperature ranges from 60 to 63 degrees F. The frost-free period is 180 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gyberg, Fetch and Pagesprings soils. Gyberg soils have an argillic horizon. Pagesprings soils are very shallow to limestone and are loamy-skeletal. Fetch soils are very shallow to hard sandstone bedrock.

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

USE AND VEGETATION: Bilgray soils are used for livestock grazing and wildlife habitat. The present vegetation is mesquite, mimosa, threeawn, sand dropseed, tobosa, black grama and Indian ricegrass.

DISTRIBUTION AND EXTENT: Central Arizona. This series is of small extent. MLRA is 38. The name is derived from nearby Bill Gray Road.

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

SERIES ESTABLISHED: Yavapai County, Arizona; Soil survey of Black Hills-Sedona Area, Arizona, Parts of Coconino and Yavapai Counties; 1996.

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

Ochric epipedon - the zone from 0 to 4 inches (A horizon)

Calcic horizon - the zone from 4 to 50 inches (Bk1, Bk2, Bk3, Bk4 horizons)

Dense layer - the zone from 50 to 60 inches (Cdk horizon)

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

Updated competing series section 3/17/08, CEM

Revised for the correlation of Black Hills-Sedona, AZ, August 2012, CEM

National Cooperative Soil Survey
U.S.A.