LOCATION EAGAR AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Calciustolls
TYPICAL PEDON: Eagar gravelly loam, grassland. (Colors are for dry conditions unless otherwise noted.)
A1--0 to 3 inches; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; abundant very fine roots; many very fine interstitial pores; 15 percent pebbles; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (2 to 6 inches thick)
A2--3 to 9 inches; dark gray (10YR 4/1) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; abundant very fine roots; many very fine interstitial pores; 15 percent pebbles; strongly effervescent; moderately alkaline (pH 8.1); clear wavy boundary. (5 to 8 inches thick)
Bk1--9 to 14 inches; gray (10YR 5/1) very gravelly loam, dark brown (10YR 3/3) moist; weak very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; abundant very fine roots; many very fine interstitial pores; 40 percent pebbles with more than 15 percent segregated calcium carbonate; violently effervescent; moderately alkaline (pH 8.3); clear irregular boundary. (4 to 8 inches thick)
Bk2--14 to 21 inches; light gray (10YR 7/2) very gravelly loam, grayish brown (10YR 5/2) moist; massive; hard and weakly cemented; friable, slightly sticky and slightly plastic; plentiful very fine roots; common very fine tubular pores; 40 percent pebbles and a few cobbles; white coatings of calcium carbonate on lower sides of pebbles and cobbles. 20 percent calcium carbonate. Few clay loam balls 1/8 to 1/4 inch in diameter; violently effervescent; moderately alkaline (pH 8.3); clear wavy boundary. (5 to 8 inches thick)
Bk3--21 to 30 inches; white (10YR 8/1) extremely cobbly loam, light gray (10YR 7/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; many fine interstitial pores; common 1/8 to 1/4 inch thick lens of iron oxide stains; few small clay balls; 50 percent pebbles and cobbles; 20 percent calcium carbonate; violently effervescent; moderately alkaline (pH 8.3); clear wavy boundary. (7 to 11 inches thick)
2C--30 to 50 inches; light yellowish brown (10YR 6/4) extremely gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; many very fine interstitial pores; 70 percent pebbles and cobbles; violently effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Apache County, Arizona. Near gravel pit just east of county road about 1 mile northwest of Springerville. 1,200 feet west of center of sec. 29, T.9N., R.29E.
RANGE IN CHARACTERISTICS:
Soil moisture: Typic ustic moisture regime.
The soils are shallow to the calcic horizon, but have a thickness of over 40 inches.
Coarse fragment content of the control section averages over 50 percent.
Mean annual temperature: 44 degrees F. to 47 degrees F., with a mean summer soil temperature at a 20-inch depth of 59 degrees F. or more.
Reaction: slightly to moderately alkaline but is dominantly moderately alkaline.
A horizon and upper C horizon
Hue: 10YR and 7.5YR
Value: 3 through 5 dry and 2 or 3 moist
Chroma: 1 through 3
Texture: gravelly loam, clay loam or gravelly clay loam.
Lower C horizon
Hue: 10YR and 7.5YR
Value: 6 to 8 dry and 5 to 7 moist
Chroma: 1 to 4
Texture: sandy clay loam or loam, with more than 18 percent but less than 35 percent clay and averaging more than 50 percent coarse fragments.
COMPETING SERIES: These are the
Bigsheep (MT),
Saddlehorse (UT),
Tosca (UT) and
Winspect (MT) series.
Bigsheep - occurs below elevations of less than 3600 feet
Saddlehorse - has a paralithic contact at depths of 20 to 40 inches
Tosca - has less than 18 percent clay in the particle-size control section and has a lithic contact at depths of 40 to 60 inches
Winspect - does not have a 2C horizon
GEOGRAPHIC SETTING: The Eagar soils are on nearly level to moderately steep terraces of fans. Slopes range from 0 to 20 percent but are dominantly 0 to 2 percent. The soils are formed in mixed alluvium from basalt basic tuff with some influence from old alluvium. These soils are at elevations of 6,900 to 7,800 feet in a continental climate. The average annual precipitation ranges from 12 to 20 inches and the mean annual temperature ranges from about 44 degrees F. to about 48 degrees F. The frost-free season ranges from 90 to 128 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Apache, Nutrioso, Clover Springs and Luth series. All of these have less than 50 percent coarse fragments in the control section and lack the calcic horizon that is characteristic of the Eagar soils. Apache soils are shallow over bedrock and the Nutrioso soils are stratified and members of a fine-loamy family. Clover Springs soils are in a fine-silty family, and Luth soils are fine-textured.
DRAINAGE AND PERMEABILITY: Well-drained. Runoff is slow to medium. Permeability of the soil is moderate.
USE AND VEGETATION: Used for grazing. Some of these soils have been irrigated and farmed. Vegetation on the range portion is sideoats grama, blue grama and ring muhly.
DISTRIBUTION AND EXTENT: East central Arizona. The soils are inextensive. MLRAs 35 & 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: St. Johns-Springerville Area, Apache Co., Arizona, 1971. Eagar is the name of a local town.
REMARKS: Diagnostic horizon and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 14 inches (A1, A2, and Bk1 horizon)
Calcic horizon - The zone from 9 to 30 inches (Bk1, Bk2 and Bk3 horizon)