LOCATION AKHONI NM+AZ

Established Series
Rev. CDH-JVC-LWH-WWJ-LJGII
10/2011

AKHONI SERIES

The Akhoni series consists of shallow, well drained soils on footslopes of hills and summits of high plateaus, mesas, and structural benches. Akhoni soils formed in alluvium and residuum derived from sandstone. Permeability is moderately rapid. Slopes are 1 to 30 percent. Mean annual precipitation is about 21 inches and the mean annual air temperature is about 40 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid Lithic Haplustolls

TYPICAL PEDON: Akhoni fine sandy loam -- on the summit of a structural bench sloping 3 percent to the northeast at 8,950 feet elevation -- forest. (Colors are for dry soil unless otherwise noted.) The surface is covered with 1 inch of slightly decomposed pine needles and other forest litter.

A--0 to 3 inches; brown (7.5YR 4/2) fine sandy loam, dark brown (7.5YR 3/2) moist; moderate thick platy structure parting to moderate fine granular; soft, very friable, slightly sticky and nonplastic; common very fine and few medium roots; common very fine and few fine irregularly shaped pores; 5 percent channers; slightly acid; clear smooth boundary. (3 to 6 inches thick)
BA--3 to 8 inches; brown (7.5YR 4/2) fine sandy loam, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and few coarse roots; common very fine and few fine tubular pores; 5 percent channers; slightly acid; clear smooth boundary. (3 to 7 inches thick)
Bw--8 to 17 inches; brown (7.5YR 5/3) fine sandy loam, brown (7.5YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and few coarse roots; common very fine and few fine tubular pores; 10 percent channers; slightly acid; clear wavy boundary. (4 to 9 inches thick)
2R--17 inches; sandstone bedrock.

TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 8 miles south-southwest of Toadlena; 800 feet south and 2,100 feet east of the northwest corner of sec. 23, T.22N., R.20W.; Latitude 36 degrees 7 minutes 52 seconds N and Longitude 108 degrees 56 minutes 42 seconds W .

RANGE IN CHARACTERISTICS:
Soil moisture - Typically, the soil moisture control section is moist in all parts from January to May and intermittently moist in some part from June to December. Dry in all parts of the moisture control section less than 25 percent of the time the soil temperature at 20 inches is above 41 degrees F. Typic ustic moisture regime.

Soil temperature - 41 to 44 degrees F.
Rock fragments - averages less than 15 percent
Soil depth - 10 to 20 inches to hard sandstone bedrock
Depth to base of Mollic epipedon - 7 to 20 inches; dark colors are present in at least 1/3 of the solum
Silicate clay content, control section weighted average - 5 to 18 percent
Reaction - slightly acid to neutral

A Horizon
Hue: 7.5YR or 10YR
Value: 2 or 5 dry, 2 or 3 moist
Chroma: 1 or 3
Rock fragments: Total range is 0 to 10 percent
0 to 5 percent small channers or pebbles
0 to 5 percent flagstones

BA and Bw Horizons
Hue: 7.5YR or 10YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 through 4
Texture: fine sandy loam or sandy loam
Rock fragments: Total range is 0 to 10 percent
0 to 5 percent small channers or pebbles
0 to 5 percent flagstones

COMPETING SERIES: These are the Ansari (CO), Corpening (WY), Falcon (CO), and Falconry (CO) series. Ansari soils have more than 18 percent clay and are dry in the moisture control section for substantially longer periods. Corpening soils are in LRR-G and moist in the moisture control section for substantially longer periods in July to September. Falcon soils have a particle-size control section dominated by coarse sand. Falconry soils are gravelly.

GEOGRAPHIC SETTING: Akhoni soils are on footslopes of hills, and on summits of high plateaus, mesas, and structural benches. They formed in alluvium and residuum derived from Tertiary sandstone. Slopes are 1 to 30 percent. Elevation ranges from 7,700 to 9,500 feet. Average annual precipitation is 18 to 26 inches. The mean annual temperature is 39 to 42 degrees F. The average frost-free period is 60 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Berland, Bikeyah, Captom, Klizhin, and Retaw soils. Berland soils have argillic horizons, are very shallow to sandstone, and occur on non-wooded areas. Bikeyah soils are very deep, somewhat poorly drained, and occur on non-wooded toeslopes. Captom soils are deep, have sandy non-mollic epipedons, and occur on backslopes. Klizhin soils are deep and very deep, have thick mollic epipedons, and occur on footslopes. Retaw soils are very deep, very poorly drained, and occur on adjacent rock basins.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.

USE AND VEGETATION: Akhoni soils are used for timber production and livestock grazing. Present vegetation is ponderosa pine, Douglas fir, and quaking aspen, with an understory of Kentucky bluegrass, earth sedge, mountain muhly, pine dropseed, pussytoes, and Gambel oak.

DISTRIBUTION AND EXTENT: Akhoni soils are of moderate extent on the Defiance Uplift-Chuska Mountains portion of the Colorado Plateau province in northwest New Mexico and northeast Arizona. LRR-D; MLRA 39, 35.

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

SERIES ESTABLISHED: Shiprock Area, Parts of San Juan County, New Mexico and Apache County, Arizona; 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to a depth of about 8 inches. (A and BA horizons)
Lithic contact - The presence of hard sedimentary bedrock at about 17 inches.
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.
Update and revisions for the correlation of Chinle Area (AZ713), August 2011, LJGII

________________________________________

National Cooperative Soil Survey
U.S.A.