LOCATION MALOY AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Ustic Haplargids
TYPICAL PEDON: Maloy extremely stony loam-rangeland (colors are for dry soil unless otherwise noted).
A--0 to 2 inches; brown (7.5YR 5/4) extremely stony loam, dark reddish brown (5YR 3/4) moist; weak fine platy structure; slightly hard, very friable, slightly sticky, slightly plastic; few very fine and fine roots; many very fine and fine vesicular pores; 40 percent cobbles, 25 percent stones and 20 percent gravel; slightly acid (pH 6.2); clear smooth boundary (1 to 2 inches thick).
Bt1--2 to 8 inches; reddish brown (5YR 4/4) extremely cobbly sandy clay loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; common very fine and fine roots; many very fine and fine interstitial and tubular pores; few thin clay films on faces of peds, in pores and bridging sand grains; 45 percent cobbles, 5 percent stones and 30 percent gravel; slightly acid (pH 6.2); clear smooth boundary (4 to 6 inches thick).
Bt2--8 to 20 inches; reddish brown (5YR 4/4) extremely cobbly sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine and fine and few medium roots; many very fine and fine interstitial and tubular and few medium tubular pores; few thin clay films in pores and bridging sand grains; 35 percent cobbles, 5 percent stones and 30 percent gravel; slightly acid (pH 6.5); clear wavy boundary (8 to l2 inches thick).
Bt3--20 to 38 inches; yellowish red (5YR 5/6) extremely cobbly sandy clay loam, yellowish red (5YR 4/6) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine and fine roots; many very fine and fine tubular and interstitial pores; few thin clay films on faces of peds and in pores; 40 percent cobbles, 5 percent stones and 30 percent gravel; neutral (pH 7.0); clear wavy boundary (12 to 20 inches thick).
C--38 to 60 inches; light brown (7.5YR 6/4) extremely cobbly sandy loam, strong brown (7.5YR 4/6) moist; massive; slightly hard, very friable; few very fine and fine roots; many very fine and fine interstitial pores; 50 percent gravel and 5 percent stones; few thin lime coatings on gravel; slightly alkaline (pH 7.5).
TYPE LOCATION: Graham County, Arizona; 2,000 feet south and 2,200 feet east of the NW corner of section l9, T. 7 S., R. 24 E.; about 8 miles southwest of the town of Pima.
RANGE IN CHARACTERISTICS:
Thickness of the solum: 25 to 40 inches
Rock fragments: greater than 35 percent rock fragments
Soil moisture: These soils are dry more than half the time in most years. Ustic aridic moisture regime
Organic matter content: l to 2 percent in the surface l0 inches
A horizon
Hue: 7.5YR
Value: 5 or 4 dry, 4 or 3 moist
Chroma: 3 or 4, dry or moist
Texture: sandy loam, loam
Rock fragments: greater than 35 percent coarse fragments, dominantly stones and cobbles.
B2t horizon
Hue: 5YR, 2.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist
Texture: very cobbly, very stony, extremely cobbly or extremely stony sandy clay loam
Reaction: slightly acid to neutral
C horizon
Hue: 7.5YR, l0YR
Value: 4 through 6 dry, 4 or 5 moist
Chroma: 4 through 6, dry or moist
Texture: sandy loam, loam
Rock fragments: greater than 35 percent coarse fragments
Effervescence: some pedons are slightly effervescent
COMPETING SERIES: These are the Caralampi (AZ), Coxwell (NM), Hartpeak (CA), Holliday (NM), Hoppswell (NV), Hyrhy (AZ) and Monza (NM) series. Caralampi soils have dominantly fine and medium gravel as the coarse fragments in the control section. Coxwell, Hartpeak, and Monza soils have bedrock at moderate depths. Holliday soils contain less than 18 percent clay. Hoppswell soils have base of argillic horizons at 11 to 25 inches and 1 to 10 percent calcium carbonate in the Bk horizon.are moist in the soil moisture control section less than 20 days cumulative during July-September.
GEOGRAPHIC SETTING: Maloy soils are on gently to moderately sloping broad alluvial fans at elevations of 3,000 to 5,000 feet. Slopes range from 2 to l5 percent. These soils developed in dominantly granitic alluvium. The climate is semiarid continental. The mean annual temperature ranges from 57 1/4to 64 1/4F., and the average annual precipitation ranges from l0 to l4 inches. Precipitation occurs mainly as summer thunderstorms and as gentle winter rains. The frost-free season is l80 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alsco (T) soils, and the Comoro, Eloma (T), Santo Tomas, and Selevin (T) soils. Comoro and Santo Tomas soils lack argillic horizons. Eloma, and Selevin soils have clayey-skeletal control sections.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Used as livestock grazing. Native vegetation is bush muhly, black grama, slim tridens, Arizona cottontop, sideoats grama, plains bristlegrass, whitethorn, mesquite, catclaw, wolfberry, paloverde, Mormon tea, range ratany, spicebush, amusia and cacti.
DISTRIBUTION AND EXTENT: Southeastern Arizona. Maloy soils are of small extent. MLRA 41.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Gila-Duncan Area, Graham County, Arizona; 1979.
REMARKS:
Updated competing series section 3/13/08, CEM