LOCATION ROND                    AZ

Established Series
Rev. WRM/YHH
12/2022

ROND SERIES

The Rond soils consists of deep, well drained, slowly permeable soils formed in residuum from cherty limestone and limestone with some local influence from quartzite. Rond soils are on gently sloping to moderately steep plains. Slopes range from 2 to 30 percent. Mean annual precipitation is about 17 inches, and mean annual temperature is about 53 degrees F.

TAXONOMIC CLASS: Fine, mixed, superactive, mesic Aridic Argiustolls

TYPICAL PEDON: Rond gravelly loam - rangeland (Colors for dry conditions unless otherwise noted.)

A--0 to 3 inches; brown (7.5YR 5/3) gravelly loam, dark brown (7.5YR 3/2) moist; weak thin and medium platy structure; soft, friable, nonsticky and nonplastic; plentiful fine roots; many fine vesicular pores; 20 percent chert gravel; noneffervescent; neutral (ph 7.0); clear smooth boundary. (2 to 4 inches thick.)

Bt1--3 to 14 inches; dark reddish gray (5YR 4/2) gravelly heavy clay loam, dark reddish brown (5YR 3/2) moist; weak fine subangular breaking to weak fine granular structure; slightly hard, friable, sticky and plastic; plentiful fine and a few coarse roots; common very fine interstitial pores; few thin clay films on ped faces and in pores; 15 percent chert gravel; noneffervescent; slightly alkaline (pH 7.5); clear wavy boundary. (4 to 12 inches thick.)

Bt2--14 to 20 inches; reddish brown (5YR 5/4) gravelly clay, reddish brown (5YR 4/4) moist; moderate medium angular blocky structure; hard, firm, sticky and very plastic; plentiful fine and a few coarse roots; few fine interstitial and tubular pores; many moderately thick clay films on ped faces and in pores; 20 percent chert gravel; slightly effervescent; slightly alkaline (pH 7.5); gradual wavy boundary. (6 to 8 inches thick)

Bt3--20 to 34 inches; yellowish red (5YR 4/6) gravelly clay, yellowish red (5YR 4/6) moist; strong medium angular blocky structure; very hard, firm, sticky and very plastic; few fine and very fine roots; few fine interstitial and tubular pores; thick clay films on ped faces; few small slickensides and pressure faces; 30 percent chert gravel; slightly effervescent; slightly alkaline (pH 7.5); gradual wavy boundary. (12 to 16 inches thick.)

Bt4--34 to 48 inches; yellowish red (5YR 4/6) gravelly clay, yellowish red (5YR 4/6) moist; moderate medium angular blocky structure; very hard, firm, sticky and very plastic; few very fine roots; few fine interstitial pores; many moderately thick c]ay films on ped faces; 30 percent chert gravel; slightly effervescent; slightly alkaline (pH 7.5); gradual wavy boundary. (12 to 20 inches thick.)

Btk--48 to 54 inches; mottled weak red (2.5YR 4/2), pinkish gray (5YR 7/2) and yellowish red (5YR 5/8) moist gravelly clay loam; massive; hard, firm, sticky and plastic; few very fine roots; few thin clay films line pores; 30 percent chert gravel; violently effervescent; moderately alkaline (pH 8.0). (4 to 8 inches thick).

R--54 to 56 inches; grayish brown (10YR 5/2), dark reddish gray (5YR 4/2) moist massive limestone bedrock, extremely hard.

TYPE LOCATION: Gila County, Arizona. NW 1/4 of Sec. 3, T6N, R16E, 1 mile north of Cottontail tank, Fort Apache Indian Reservation. (Note: - County is unsurveyed. Location is approximate and based on extended grid from surveyed areas.)

RANGE IN CHARACTERISTICS:

Depth to bedrock: more than 40 inches

Depth to the Btk horizon: 36 to 50 inches

Soil moisture: These soils are dry for 90 cumulative days or more in most years in some subhorizon of the soil between 7 and 20 inches but are not continuously dry in all parts of the soil between these depths for as long as 60 consecutive days in more than 7 out of 10 years. Aridic ustic moisture regime.

Reaction: neutral to moderately alkaline

Mean annual soil temperature: 48 degrees F. to 56 degrees F.

A1 horizon
Hue: 5YR thru 10YR
Value: 4 and 5 dry and 2 and 3 moist
Chroma: 2 and 3
Texture: loam, silt loam, gravelly silt loam, very fine sandy loam, gravelly loam, clay loam, gravelly clay loam and cobbly clay loam

upper Bt horizon
Hue:5YR and 7.5YR
Value: 4 and 5 dry and 3 moist
Chroma: 2 and 3.
Texture: clay loam, heavy gravelly clay loam, cobbly clay loam, clay, gravelly clay and cobbly clay

lower Bt horizons
Hue: 5YR and 2.5YR
Value: 4 and 5 dry and 3 and 4 moist
Chroma: 3 thru 6.
Texture: clay loam, heavy gravelly clay loam, cobbly clay loam, clay, gravelly clay and cobbly clay

COMPETING SERIES: These are the Abrazo (NM), Cantina (NM), Carnero (NM), Celsosprings (NM), Charette (NM), Concho (NM), Cueva (NM), Judd (NM), Remunda (NM), Roundtop (AZ) and Philmont (NM) series. Abrazo, Carnero, Cueva and Roundtop soils have bedrock are moderately deep. Celsosprings, Charette, Cocho, Judd, Remunda and Philmont soils are very deep. Cantina soils have a lithic contact of basalt bedrock at 54 inches.

GEOGRAPHIC SETTING: The Rond soils are on gently sloping to moderately steep plains. Slopes range from 2 to 30 percent. These soils are formed in place in residuum from cherty limestone and limestone with some local influence from quartzite. Elevations range from 4500 to 6000 feet. The average annual precipitation ranges from 14 to 20 inches, the mean annual temperature ranges from 48 degrees F. to 58 degrees F. The frost-free season ranges from 120 to 170 days.

GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the Roundtop, Showlow, Dye and Jacks series these include the Lynx and Tortugas series. Lynx and Tortugas soils are dark-colored and lack the argillic horizon that is characteristic of the Rond soils, and Tortugas soils are shallow to bedrock.

DRAINAGE AND PERMEABILITY: These soils are well-drained. Runoff is medium and permeability is slow.

USE AND VEGETATION: Used for grazing of livestock. Native vegetation includes pinon pine, juniper, shrub oak, blue grama, bear grass, mountain mahogany, ring muhly, sideoats grama and snakeweed with ponderosa pine at the higher elevations.

DISTRIBUTION AND EXTENT: Eastern Gila County, Arizona and possibly Navajo and Apache Counties. The series is moderately extensive. MLRA 39.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Ft. Apache Indian Reservation, Gila Co., Arizona, 1971. The name Rond is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: The zone from 0 to 14 inches. (A, Bt1 horizons)

Argillic horizon: The zone from 3 to 48 inches. (Bt1, Bt2, Bt3, Bt4 horizons)

Classified according to Keys to Soil Taxonomy Tenth Edition, 2006.

Classification changed to Aridic subgroup in 2007. The change was made to be consistent with the moisture regime.

The Rond series was created to be the deeper counterpart to the Roundtop series.

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National Cooperative Soil Survey
U.S.A.