LOCATION MOHAVE AZ+CA NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Calciargids
TYPICAL PEDON: Mohave sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; light yellowish brown (10YR 6/4) sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine and fine tubular and common very fine irregular pores; noneffervescent; neutral (pH 7.2); clear wavy boundary. (1 to 7 inches thick)
Bt1--4 to 11 inches; brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine and fine tubular and very fine irregular pores; few faint clay films lining pores and bridging mineral grains; noneffervescent; slightly alkaline (pH 7.5); clear wavy boundary. (3 to 8 inches thick)
Bt2--11 to 28 inches; brown (7.5YR 5/4) clay loam, brown (7.5YR 4/4) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; hard, friable, moderately sticky and moderately plastic; many very fine roots; few very fine and fine tubular and few fine irregular pores; few faint clay films on faces of peds and lining pores; noneffervescent; moderately alkaline (pH 8.0); clear wavy boundary. (8 to 22 inches thick)
Bt3--28 to 39 inches; strong brown (7.5YR 5/6) loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and moderately plastic; few very fine roots; common fine tubular and few fine irregular pores; few faint clay films on faces of peds and lining pores; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 15 inches thick)
Btk--39 to 55 inches; brown (7.5YR 5/4) clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine roots; common fine tubular pores; common distinct clay films on faces of peds and lining pores; violently effervescent, many fine calcium carbonate accumulations as filaments and soft masses; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 16 inches thick)
2C--55 to 60 inches; reddish brown (5YR 5/4) gravelly loamy coarse sand, reddish brown (5YR 4/4) moist; massive; slightly hard, friable; common fine irregular pores; moderately alkaline (pH 8.0).
TYPE LOCATION: Yavapai County, Arizona; 1,960 feet west and 1,476 feet north of the southeast corner of section 32, T. 10 N., R. 6 W.
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during December-February and for more than 20 days cumulative during July-September. Driest during May and June. Typic aridic soil moisture regime.
Soil temperature - 59 to 72 degrees F.
Rock fragments - Less than 15 percent gravel in the control section
Depth to carbonates: 6 to 36 inches. Some pedons are slightly or strongly effervescent in the A and B horizons
Organic matter: Less than 1 percent in the upper 15 inches
Depth to calcic horizon: 20 to 40 inches
Sand content: Less than 50 percent in the control section
A horizon
Hue: 10YR, 7.5YR
Value: 4 through 7 dry, 3, 4, or 5 moist
Chroma: 2, 3, 4, or 6, dry or moist
Reaction: Neutral to moderately alkaline
B horizon
Hue: 7.5YR, 5YR
Value: 4, 5, 6, or 7 dry, 3, 4, 5, or 6 moist
Chroma: 3, 4, or 6, dry or moist
Texture: Loam, sandy clay loam, silt loam, clay loam. The Bt1 horizon is sandy loam in some pedons (averages 27 to 40 percent clay)
Reaction: Slightly alkaline or moderately alkaline
C horizon
Hue: 7.5YR, 5YR, N8/
Value: 5, 6, 7, or 8 dry, 3 through 8 moist
Chroma: 2, 3, 4, or 6, dry or moist
Texture: loam, sandy loam, loamy coarse sand, loamy fine sand, sandy clay loam (3 to 30 percent clay)
Rock fragments: 0 to 15 percent gravel, ranging to 80 percent below 40 inches in some pedons
Cementation: Weak calcium carbonate cementation in some pedons
Reaction: Moderately alkaline or strongly alkaline
COMPETING SERIES: These are the Blackmagic (CA), Brenda (NM), Cornville (AZ), Dona Ana (NM), Elizario (NM), Hap (NM), Jagerson (AZ), Kidwell (NV), Lanip (NV), Madurez (NM), McNew (NM), Nutt (NM), Poachie (AZ), Tres Hermanos (NM) series. Blackmagic soils have an accumulation of gypsum within 40 inches of the surface. Brenda soils have gravelly coarse sand in the lower part of the profile below the argillic horizon. Cornville soils have greater than 50 percent sand in the control section. Dona Ana and Tres Hermanos soils have calcic horizons at depths less than 20 inches. Elizario soils have more than 50 percent sand in the series control section and are in the Chihuahuan Desert (MLRA 42) and have a summer maximum precipitation pattern. Hap and Tres Hermanos soils average more than 15 percent gravel in the argillic horizon. Madurez soils have argillic horizons less than 10 inches thick and sola less than 25 inches thick. McNew soils have 18 to 27 percent clay. Blackmagic, Jagerson, Kidwell, Lanip and Poachie soils receive most of the precipitation in the winter are moist for less than 20 days cumulative in the summer and occur in MLRA 30.
GEOGRAPHIC SETTING: Mohave soils are on basin floors, fan terraces, and stream terraces. Slopes range from 0 to 8 percent. They formed in mixed alluvium from acid and basic igneous rocks. Elevation is 1800 to 5000 feet. The mean annual precipitation is 7 to 12 inches. Mean annual air temperature is 57 to 70 degrees F. The frost-free period is 180 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing Dona Ana and Tres Hermanos soils, are the Guest and Pinaleno soils. Guest soils are fine. Pinaleno soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: Used for livestock grazing and irrigated cropland. The present vegetation is mesquite, paloverde, creosotebush, bursage, cactus, bush muhly, threeawns, Arizona cottontop, plains bristlegrass, sixweeks grama and Indianwheat. Irrigated areas are planted to alfalfa, cotton, citrus, vegetables and other crops.
DISTRIBUTION AND EXTENT: Arizona, and New Mexico. The Mohave series is extensive. MLRA is 40, 41 & 42. This series has been used in the Mojave Desert (MLRA 30) in California. Continued use of this series in MLRA 30 in California is discouraged.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Middle Gila Valley Area, Arizona; 1917.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 4 inches (A horizon)
Argillic horizon - The zone from 4 to 55 inches (Bt1, Bt2, Bt3, Btk horizons)
Calcic horizon - The zone from 39 to 55 inches (Btk horizon)
Soil Taxonomy Second edition, 1999