LOCATION BENALLY                 NM

Established Series
Rev. JVC/WRJ/RJA
04/2014

BENALLY SERIES

The Benally series consists of deep and very deep, well drained, moderately slow and slowly permeable soils that formed in alluvium and stream alluvium derived from sandstone and shale. Benally soils are in small depressions and swales of mesas, fan remnants, cuestas, valley floors and structural benches. Slopes range from 0 to 5 percent. Average annual precipitation is about 7 inches (178 mm) and average annual air temperature is about 53 degrees F (12 degress C).

TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Natrigypsids

TYPICAL PEDON: Benally sandy clay loam--rangeland. (Colors are for dry soil unless otherwise noted.) Soil surface broken by one half-inch wide cracks to a depth of 4 inches.
A--0 to 1 inch (0 to 3 cm); brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; strong coarse platy structure and moderate fine granular; soft, very friable, slightly sticky and slightly plastic; few very fine roots; few very fine vesicular pores; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 2 inches or 3 to 5 cm thick)

E/Btn --1 to 4 inches (3 to 10 cm); light brown (7.5YR 6/4) clay loam, brown (7.5YR 5/4) moist; strong medium prismatic structure; very hard, firm, sticky and plastic; few fine and very fine roots; many very fine continuous vertical tubular pores; upper 2 inches (5 cm) of the prisms have uncoated sand grains; few thin clay films and clay bridging sand grains on the faces of prisms; strongly effervescent; very strongly alkaline (pH 9.4); abrupt smooth boundary. (0 to 3 inches 0 to 8 cm thick)

Btkn --4 to 11 inches (10 to 28 cm); light brown (7.5YR 6/4) clay loam, brown (7.5YR 5/4) moist; moderate medium prismatic structure parting to moderate coarse blocks; hard, firm, sticky and plastic; few fine and common very fine roots; few very fine discontinuous interstitial pores; few thin clay films on faces of peds and in pores; 5 percent gravel; strongly effervescent; secondary carbonates segregated in few, fine irregularly shaped soft masses; very strongly alkaline (pH 9.4) clear smooth boundary. (7 to 19 inches or 18 to 48 cm thick)

Byn --11 to 19 inches (28 to 48 cm); light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; moderate coarse and medium subangular blocky structure; hard, friable, sticky and plastic; few fine and common very fine roots; few very fine discontinuous interstitial pores; 5 percent gravel; secondary very fine sized gypsum crystals segregated in common fine irregularly shaped soft masses and filaments; strongly effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (0 to 8 inches or 0 to 20 cm thick)

By--19 to 31 inches (48 to 79 cm); very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; weak coarse and moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; few very fine discontinuous interstitial pores; 5 percent gravel secondary very fine sand sized gypsum crystals segregated in common fine irregularly shaped soft masses and filaments, primary coarse sand sized gypsum crystals in common fine masses; slightly effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (12 to 24 inches or 30 to 61 cm thick)

2BCy--31 to 52 inches (79 to 132 cm); very pale brown (10YR 7/3) channery sandy clay loam, yellowish brown (10YR 5/4) moist; massive; platy rock structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; 15 percent soft sandstone and shale fragments; 25 percent channers and 5 percent hard sandstone gravel; secondary very fine sand sized gypsum crystals segregated in few fine filaments and on the undersides of rock fragments, primary coarse sand sized gypsum crystals in few fine masses; slightly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (20 to 30 inches to 51 to 76 cm thick)

2Cr--52 to 60 inches (132 to 152 cm); soft sandstone bedrock.

TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 7 miles northeast of Sheep Springs; 2,000 feet west and 725 feet south of the northeast corner of Section 6, T. 22 N., R. 16 W. (Projected from BLM cadastral survey, 1983, 1984)

RANGE IN CHARACTERISTICS:
Soil Moisture: Typically, the soil moisture control section is intermittently moist in some part from July to October and December to March. The soil moisture control section is assumed to be dry in all parts greater than 75 percent of the time (cumulative) that the soil temperature at 20 inches is greater than 41 degrees F. Typic aridic moisture regime.

Soil temperature: 54 to 57 degrees F (12 to 14 degrees C).

Depth to secondary gypsum and base of natric horizon: 8 to 24 inches (20 to 61 cm)

Electrical conductivity: 2 to greater than 16(mmhos/cm)

Reaction: moderately to very strongly alkaline in upper part, neutral to moderately alkaline lower part of profile

Depth to paralithic contact: 40 to 60 inches (102 to 152 cm) or more

There are commonly 2 to 4 lithologic discontinuities within the profile

A horizon
Hue: 7.5YR, 10YR, 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy clay loam, fine sandy loam, loam, loamy sand

E/Btn horizon
Hue: 7.5YR, 10YR, 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy clay loam, clay loam, loam, fine sandy loam
Rock fragments: 0 to 5 percent gravel
Sodium adsorption ratio: 13 to 50

Btkn horizon
Hue: 7.5YR, 10YR, 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: clay loam, sandy clay loam, loam
Clay: 18 to 35 percent
Rock fragments: 0 to 10 percent gravel
Calcium carbonate equivalent: less than 15 percent
Sodium adsorption ratio: 13 to 50

By or Byn horizon
Hue: 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 3 to 6 dry, 4 to 6 moist
Texture: clay loam, sandy clay loam
Clay: 30 to 35 percent
Rock fragments: 0 to 10 percent gravel
Gypsum: 5 to 15 percent, present as both primary and secondary sand sized crystals
Sodium adsorption ratio: 13 to 50

BCy and C horizons
Hue: 10YR, 2.5YR
Value: 6 or 7 dry, 4 to 6 moist
Chroma: 2 to 6 dry, 2 to 8 moist
Texture: sandy clay loam, clay loam; some pedons contain thin layers of clay, silty clay loam or silty clay below 40 inches
Rock fragments: 0 to 25 channers, 0 to 10 gravel; some pedons contain thin layers of very channery sandy clay loam, very channery clay loam or
Soft fragments: 0 to 30 percent soft sandstone and shale
Sodium adsorption ratio: 5 to 80
Gypsum: 5 to 15 percent, present as both primary and secondary sand sized crystals

COMPETING SERIES: This is the Taqoci (CO) series. Taqoci soils are very deep and have a calcic horizon.

GEOGRAPHIC SETTING: Benally soils are on small depressions and swales of mesas, cuestas, valley floors and structural benches. The upper portions of the profile of Benally soils formed in alluvium and stream alluvium derived from sandstone and shale. The lower portions of the profile formed in weathered sandstone and shale over a base of interbedded soft sandstone and shale. Slopes range from 0 to 5 percent. Elevation ranges from 4,620 to 6,800 feet (1,409 to 1,820 meters). The average annual precipitation is 5 to 10 inches (127 mm) with 35 to 60 percent falling as rain from high intensity thunderstorms between July and October. The average annual temperature is 51 to 55 degrees F (11 to 13 degrees C). The average frost-free period is 130 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brimhall, Genats, Hamburn and Werito soils. Brimhall soils are on adjacent knolls and have calcic and gypsic horizons. Genats soils are moderately deep and occur on adjacent hillslopes. Hamburn soils lack natric horizons and have less clay and more soil moisture. Werito soils are moderately deep and occur on adjacent toeslopes.

DRAINAGE AND PERMEABILITY: Well drained, slow to medium runoff, moderately slow and slow permeability.

USE AND VEGETATION: Benally soils are used for livestock grazing. Present vegetation is a sparse stand of alkali sacaton, galleta, mound saltbush, ribscale, and Russian thistle.

DISTRIBUTION AND EXTENT: Benally soils are of small extent in the western San Juan Basin portion of the Colorado Plateau in northwest New Mexico and southwest Colorado. MLRA 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 horizon and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 1 inch (0 to 3 cm) (A horizon)
Natric horizon - the zone from 1 to 11 inches (3 to 28 cm) (Btn horizon)
Gypsic horizon - the zone from 11 to 52 inches (28 to 132 cm) (Byn, By horizons)
Paralithic contact - the boundary with soft sandstone bedrock at 52 inches (2Cr horizon)

ADDITIONAL DATA: Selected properties of the type location were determined by the NSSL as User Pedon ID 84NM045003 (Lab Pedon Number 84P0589).. Soil profile 4504-1 from the Soil and Range Inventory Report of District 12; U.S.D.I., BIA, Shiprock Agency, 1978 is a similar soil to Benally.
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, 11th Edition, 2010.
Updates and revisions for MLRA consistency, February 26, 2008, DWD.
Update and revisions for the correlation of the SDJR - MLRA 35 - Benally fine sandy loam, 1 to 5 percent slopes project, March 2014 LJG2

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National Cooperative Soil Survey
U.S.A.