LOCATION GRIZZLE AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Ustic Calciargids
TYPICAL PEDON: Grizzle coarse sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 1 inch; reddish brown (5YR 5/3) coarse sandy loam, reddish brown (5YR 4/3) moist; weak fine granular structure; loose, nonsticky and nonplastic; common very fine and fine roots; common fine irregular pores; violently effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (1 to 2 inches thick)
Btk--1 to 6 inches; reddish brown (5YR 5/3) clay loam, reddish brown (5YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; common very fine and fine roots; common fine tubular pores; common distinct clay films between sand grains; common distinct calcium carbonate coatings on ped faces; violently effervescent, 24 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt smooth boundary. (3 to 8 inches thick)
2Cdk1--6 to 14 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; massive; hard, very firm and brittle, slightly sticky and moderately plastic; common very fine and fine roots; many distinct white (5YR 8/1) calcium carbonate coatings on plates and lining pores; violently effervescent, 18 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); clear smooth boundary.
2Cdk2--14 to 32 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; massive; very hard, very firm and brittle, slightly sticky and moderately plastic; common very fine and fine roots; many distinct white (5YR 8/1) calcium carbonate coatings on plates and lining pores; violently effervescent, 12 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); clear smooth boundary. (Combined thickness of the Cdk horizons is 26 to 40 inches)
3Crk--32 to 50 inches; weathered sandstone; many distinct calcium carbonate coatings between rock fractures; violently effervescent.
3R--50 inches; sandstone.
TYPE LOCATION: Walnut Gulch Experimental Watershed, Cochise County, AZ; located at a latitude of 32 degrees, 41 minutes, 02 seconds North and longitude of 109 degrees, 59 minutes, 40 seconds West; 200 feet west and 1,050 feet south from northeast corner of section 21, T. 20 S., R. 23 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: less than 35 percent
Reaction: slightly or moderately alkaline
Depth to compacted dense sediments: 4 to 20 inches
Depth to weathered bedrock: 20 to 40 inches
Depth to unweathered bedrock: 25 to 60 inches
Clay content: 18 to 35 percent
Depth to calcic horizon: 1 to 10 inches
A horizon
Hue: 7.5YR, 5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Effervescence: strong or violent, 5 to 10 percent calcium carbonate equivalent
Btk horizon
Hue: 5YR, 2.5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture: clay loam, loam
Effervescence: strong or violent, 15 to 30 percent calcium carbonate equivalent
Cdk horizon
Hue: 5YR, 2.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: When crushed, includes loam, clay loam
Effervescence: strong or violent, 10 to 25 percent calcium carbonate equivalent
Consistence: Brittle and firm or very firm when moist. Typically breaks down after prolonged soaking and shaking in water. Roots can enter the matrix when moist but is root restrictive when dry. Does not meet the requirements of a densic contact or densic materials.
Genesis: Thought to be sediments that were naturally compacted by a combination of paleo lake water loading and impregnation by calcium carbonate and low levels of silica.
COMPETING SERIES: These are the Amorose (NM), Gulch (AZ), Headquarters (NM), McAllister (AZ), McNeal (AZ), Redona (NM) and Tinney (NM) series. All of these soils are very deep.
GEOGRAPHIC SETTING: Grizzle soils are on hills at elevations of 4,500 to 5,000 feet. Slopes range from 3 to 8 percent. These soils formed in slope alluvium and residuum from sandstone and shale. 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 Mabray, Chiricahua, Monterosa, Mule and Sutherland soils. Mabray, Chiricahua, Sutherland and Monterosa soils are shallow. Mule soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used for experimental rangeland research, livestock grazing and wildlife habitat. Vegetation includes black grama, bush muhly, desert zinnia, Texas dogwood, creosotebush, tarbush, plains bristlegrass, knife-leaf condalia and whitethorn.
DISTRIBUTION AND EXTENT: Southern Arizona. Grizzle soils are of limited extent. MLRA is 41. Name derived from a nearby fruit orchard.
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 1 inch (A horizon)
Argillic horizon - The zone from 1 to 6 inches (Btk horizon)
Calcic horizon - The zone from 1 to 14 inches (Btk, 2Cdk1 horizons)
Compacted layers - The zone from 6 to 32 inches (2Cdk1, 2Cdk2 horizons)
Paralithic contact - The boundary at 32 inches (3Crk horizon)
Lithic contact - The boundary at 50 inches (3R horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.