LOCATION GRABE AZ+NMEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, thermic Typic Torrifluvents
TYPICAL PEDON: Grabe loam - irrigated cropland (colors are for dry soil unless otherwise noted).
Ap1--0 to 10 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; few very fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary (8 to 14 inches thick).
Ap2--10 to 16 inches; grayish brown (10YR 5/2) loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and moderately plastic; few very fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary (6 to 14 inches thick).
C1--16 to 26 inches; grayish brown (10YR 5/2) very fine sandy loam, dark brown (7.5YR 3/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary (9 to 20 inches thick).
C2--26 to 62 inches; grayish brown (10YR 5/2) loam, dark brown (7.5YR 3/2) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; few very fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Graham County, Arizona; 6 miles northeast of Safford; 1,300 feet north and 1,450 feet west of the southeast corner of section 17, T.6 S, R.25 E.
RANGE IN CHARACTERISTICS:
Soil Moisture - Intermittently moist in some part of the soil moisture control section during July - September and December - March. Driest during May and June. The epipedon is moist in some part less than 90 days (cumulative) when the soil temperature is above 41 degrees F. in 7 out of 10 years. Typic aridic soil moisture regime.
Soil temperature - 59 to 72 degrees F.
Stratification- usually thin strata of finer or coarser material
Reaction - neutral to moderately alkaline
Organic matter - Greater than 1 percent in the surface that decreases irregularly with depth
A and C horizons
Hue: 7.5YR, 10YR
Value: 4 through 6 dry, 2 through 4 moist
Chroma: 2 through 4, dry or moist
Texture: loam, silt loam, very fine sandy loam containing less than 15 percent medium, coarse and very coarse sand.
Calcium carbonate: slightly to strongly effervescent as disseminated or as filaments and segregations
COMPETING SERIES: These are the Anthony (AZ), Excelsior (CA), Gila (AZ), Ireteba (NV), Junction (UT), Rucker (AZ), Tobler (UT) and Victorville (CA) series. Anthony, Excelsior, Tobler, and Gila soils contain less than 1 percent organic matter in the surface. Anthony and Rucker soils are coarse sandy loam, sandy loam or fine sandy loam with more than 15 percent medium or coarser sand in the control section. Ireteba soils contain horizons of distinct lime accumulations. Junction and Tobler soils have hue redder than 7.5YR and Junction soils contain gypsum. Excelsior, Victorville, Ireteba, and Junction are dry in some part of the soil moisture control section for more than 20 days cumulative between July and September.
GEOGRAPHIC SETTING: Grabe soils are on flood plains and alluvial fans at elevations of 2,500 to 5,500 feet. Slopes range from 0 to 3 percent. These soils formed in stratified alluvium from mixed sources. The mean annual precipitation is 10 to 12 inches. The mean annual air temperature is 57 to 70 degrees F. The frost-free period is 160 to 275 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Rucker soils and the Arizo, Brazito, Glendale and Hantz soils. Brazito soils are sandy. Glendale soils are fine-silty. Hantz soils are fine textured. Arizo soils are sandy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; medium or slow runoff; moderate permeability.
USE AND VEGETATION: Used for irrigated cropland, wildlife habitat and livestock grazing. Vegetation includes mesquite, catclaw, burroweed, threeawn, Arizona cottontop, bush muhly, and annual grasses.
DISTRIBUTION AND EXTENT: Southern Arizona. Grabe soils are extensive. This soil occurs in LRR-D, MLRAs 40, 41, and 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Santa Cruz County Area, Arizona; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 16 inches (Ap1, Ap2 horizons)
Entisol feature - the absence of diagnostic subsurface horizons
Fluvial feature - Irregular decrease in organic carbon in the zone from 16 to 62 inches (C1, C2 horizons)
Classified according to Soil Taxonomy, Second Edition, 1999.
Updated competing series section, 3/18/08, CEM