LOCATION LUCKYHILLS AZ

Established Series
Rev. DJB/PDC/CEM
08/2012

LUCKYHILLS SERIES

The Luckyhills series consists of very deep, well drained soils that formed in mixed calcareous fan alluvium. Luckyhills soils are on fan remnants. Slopes range from 0 to 20 percent. The mean annual precipitation is about 13 inches and the mean annual air temperature is about 65 degrees F.

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

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

A--0 to 2 inches; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3) moist; weak thin platy structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common fine vesicular and interstitial pores; 37 percent gravel; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (1 to 4 inches thick)

Bk1--2 to 13 inches; 70 percent pale brown (10YR 6/3) and 30 percent very pale brown (10YR 8/2) gravelly sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; few fine interstitial and tubular pores; many distinct calcium carbonate coatings on rock fragments; 29 percent gravel; violently effervescent, 25 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); abrupt wavy boundary.

Bk2--13 to 31 inches; 70 percent pinkish white (7.5YR 8/2) and 30 percent pinkish gray (7.5YR 7/2) sandy loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; common very fine and fine roots; few fine tubular pores; many distinct calcium carbonate coatings on rock fragments; common fine soft masses of calcium carbonate; 12 percent gravel; violently effervescent, 28 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); gradual wavy boundary.

Bk3--31 to 39 inches; 80 percent light brown (7.5YR 6/3) and 20 percent pinkish white (7.5YR 8/2) gravelly sandy loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common fine tubular pores; many distinct calcium carbonate coatings on ped faces and on rock fragments; common fine soft masses of calcium carbonate; 27 percent gravel; violently effervescent, 22 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); gradual wavy boundary.

Bk4--39 to 60 inches; 80 percent light brown (7.5YR 6/3) and 20 percent pink (7.5YR 8/3) gravelly loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; common fine tubular pores; many distinct calcium carbonate coatings on rock fragments and on ped faces; common fine soft masses of calcium carbonate; 29 percent gravel; strongly effervescent, 18 percent calcium carbonate equivalent; moderately alkaline (pH 8.2). (Combined thickness of the Bk horizons is 35 to 56 inches)

TYPE LOCATION: Walnut Gulch Experimental Watershed, Cochise County, Arizona; located at a latitude of 31 degrees, 41 minutes, 35 seconds North and longitude of 110 degrees, 03 minutes, 02 seconds West; 1,520 feet south and 75 feet east from the northwest corner of section 36, T. 19 S., R. 22 E.

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.

Rock fragments: About 10 to 55 percent gravel on the surface. Rock fragments average less than 35 percent in the particle-size control section

Reaction: slightly to moderately alkaline

Depth to calcic horizon: 2 to 20 inches

Clay content: 5 to 18 percent

Effervescence: strongly to violently

Calcium carbonate equivalent: 5 to 35 percent

Organic matter: less than 1 percent

A horizon
Hue: 10YR, 7.5YR
Value: 5 through 7 dry, 3 through 5 moist
Chroma: 3 or 4, dry or moist
Texture: coarse sandy loam, fine sandy loam, sandy loam, loamy sand

Bk horizon
Hue: 10YR, 7.5YR
Value: 5 through 8 dry, 4 through 7 moist
Chroma: 2 through 4 dry, 3 through 6 moist
Texture: sandy loam, loam, fine sandy loam, silt loam, loamy sand

COMPETING SERIES: These are the Bilgray (AZ), Geta (NV), Kinco (TX), Potrillo (TX), and Stronghold (AZ) series. Bilgray soils have dense compacted sediments at depths of 45 to 55 inches. Geta soils are in the Mohave Desert and are moist in the soil moisture control section for less than 20 days cumulative between July and September. Kinco soils have a calcic horizon at depths more than 20 inches. Potrillo soils are inactive. Stronghold soils have greater than 1 percent organic matter in the surface.

GEOGRAPHIC SETTING: Luckyhills soils are on fan remnants at elevations of 3,100 to 4,800 feet. Slopes range from 0 to 20 percent. These soils formed in mixed calcareous fan alluvium. The mean annual precipitation is 12 to 16 inches 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. The frost-free period is 180 to 250 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blakeney, Kahn, McNeal, Mule, and Sutherland series. Blakeney and Sutherland soils have petrocalcic horizons. Kahn soils are fine-loamy. McNeal soils have argillic horizons. Mule soils are carbonatic.

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

USE AND VEGETATION: Use for experimental rangeland research, livestock grazing and wildlife habitat. Vegetation includes bush muhly, fluffgrass, slim tridens, creosotebush, whitethorn, desert zinnia, mariola, tarbush, javelina bush, ratear coldenia, black grama and sand dropseed.

DISTRIBUTION AND EXTENT: Southern Arizona. Luckyhills soils are of moderate extent. MLRA is 41. Name derived from an experimental watershed in the area.

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

SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Cochise County, Arizona, Douglas-Tombstone Part; 1996.

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

Ochric epipedon - The zone from 0 to 2 inches (A horizon)

Calcic horizon - The zone from 2 to 60 inches (Bk1, Bk2, Bk3, Bk4 horizons)

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

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

National Cooperative Soil Survey
U.S.A.