LOCATION TUKUHNIK UT
Established Series
REV: DAL/RLT
01/2023
TUKUHNIK SERIES
The Tukuhnik series consists of deep, well drained, slowly permeable soils that formed in residuum derived dominantly from interbedded shale, siltstone and sandstone. These soils are on cuestas and benches at elevations of 7,800 to 8,600 feet. Slopes are 3 to 10 percent. Average annual precipitation is about 18 inches and the mean annual temperature is about 41 degrees F.
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Argiustolls
TYPICAL PEDON: Tukuhnik loam--woodland. (Colors are for air-dry soil unless otherwise stated.)
A--0 to 7 inches; brown (7.5YR 4/3) loam, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; common fine, medium and coarse roots; few fine pores; 3 percent pebbles; slightly alkaline (pH 7.4); clear smooth boundary. (4 to 14 inches thick)
Bw--7 to 13 inches; reddish brown (5YR 4/4) clay loam, dark reddish brown (5YR 3/3) moist; weak medium subangular blocky structure; slightly hard, firm, sticky and plastic; common fine, medium and coarse roots; few fine pores; 5 percent pebbles and 2 percent cobbles; slightly alkaline (pH 7.6); clear wavy boundary. (0 to 7 inches thick)
Bt--13 to 34 inches; reddish brown (5YR 4/4) silty clay loam, reddish brown (5YR 4/4) moist; strong coarse prismatic structure parting to strong medium subangular blocky; hard, very firm, very sticky and plastic; few fine and medium roots; few fine pores; many thick clay films on faces of peds; 5 percent pebbles; moderately alkaline (pH 8.0); clear wavy boundary. (20 to 28 inches thick)
Btk1--34 to 41 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky; very hard, very firm, very sticky and plastic; few fine roots; few fine pores; common thick clay films on faces of peds; 5 percent pebbles; moderately calcareous; carbonates are in common medium filaments and threads; strongly alkaline (pH 8.7); abrupt smooth boundary.
Btk2--41 to 51 inches; reddish brown (5YR 5/6) silty clay, yellowish red (5YR 4/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, extremely firm, very sticky and plastic; few very fine roots; few fine pores; many moderately thick clay films on faces of peds; 10 percent pebbles; strongly calcareous; carbonates are disseminated; strongly alkaline (pH 8.7); abrupt smooth boundary. (The Btk horizons combined are 10 to 28 inches thick)
R--51 inches; siltstone.
TYPE LOCATION: San Juan County, Utah about 4.5 miles north of Old LaSal, 1,600 feet south and 50 feet east of the northwest corner of sec. 1, T. 28 S., R. 25 E.
RANGE IN CHARACTERISTICS: The mollic epipedon is 10 to 15 inches thick. The argillic horizon is 20 to 40 inches thick. The mean annual soil temperature is 43 to 45 degrees F. and the mean summer soil temperature at a depth of 20 inches is 60 to 62 degrees F. These soils are moist in some part of the moisture control section more than half the time the soil temperature at 20 inches is higher than 41 degrees F. These soils are dry in some part of the moisture control section for more than 90 cumulative days in most years. Depth to soft sandstone or shale is 40 to 60 inches. Hues are 5YR or 7.5YR. Depth to secondary carbonates is 30 to 40 inches.
The A horizon has value of 3 or 4 dry, 2 or 3 moist, and chroma of 2 or 3 dry and 1 or 2 moist. This horizon is neutral or mildly alkaline.
The Bt horizon has value of 4 or 5 dry. Texture is silty clay loam, silty clay and clay. Rock fragments are 0 to 5 percent pebbles. This horizon is mildly alkaline or moderately alkaline.
The Btk horizon has value of 5 to 7 dry, 4 to 6 moist and chroma of 3 to 6. Texture is silty clay loam, silty clay and clay. Rock fragments range from 0 to 15 percent pebbles and cobbles. This horizon is moderately calcareous or strongly calcareous and moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the
Absarokee,
Bearpaw,
Brolliar,
Danvers,
Delson,
Herm,
Mondamin,
Quilt,
Regent,
Ricot,
Wyola,
Tamaneen,
Tomasaki (T), and
Work series. Absarokee, Brolliar and Regent soils have bedrock at depths of 20 to 40 inches. Delson, Herm, Quilt, and Tomasaki are noncalcareous. Bearpaw soils have dense till at depths of less than 40 inches and have 10YR or 2.5Y hues. Danvers, Mondamin, Wyola, Tamaneen, and Work soils have visible secondary carbonates at depths of less than 30 inches. Ricot soils have litological discontinuities below depths of 16 inches and are formed in calcareous glacial till.
GEOGRAPHIC SETTING: Tukuhnik soils are on structural benches and cuestas. Elevations range from 7,800 to 8,600 feet. These soils formed in residuum from interbedded sandstone, siltstone and shale. Mean annual temperature is 41 to 43 degrees F. and the average annual precipitation is 17 to 20 inches. The freeze-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Herm and
Tomasaki soils and the
Falcon,
Skylick, and
Harpole soils. The Falcon soils have bedrock at depths 10 to 20 inches. Skylick soils have cryic temperature regimes and have a fine-loamy particle size control section. Harpole soils have a loamy-skeletal particle size control section.
DRAINAGE AND PEREMABILITY: Well drained; slow permeability; slow runoff.
USE AND VEGETATION: Used mainly for woodland, rangeland and wildlife habitat. The potential vegetation is an overstory of ponderosa pine with an understory of muttongrass, elk sedge, bottlebrush squirreltail, snowberry, and Gambel oak.
DISTRIBUTION AND EXTENT: Southeastern Utah. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Canyonlands Area, Parts of Grand and San Juan Counties, Utah, 1983. The name is from Mount Tukuhnikivatz.
National Cooperative Soil Survey
U.S.A.