LOCATION YAKI UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, mesic Lithic Ustic Haplocalcids
TYPICAL PEDON: Yaki very cobbly loam - rangeland (Colors are for air dry soil unless otherwise noted.)
A1--0 to 2 inches; brown (7.5YR 5/4) very cobbly loam, brown (7.5YR 4/4) moist; weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; few fine roots; 55 percent cobbles over the surface; strongly effervescent, carbonates are disseminated; strongly alkaline (pH 8.6); abrupt smooth boundary. (2 to 5 inches thick)
A2--2 to 8 inches; brown (7.5YR 5/4) cobbly loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; common fine and medium, and few coarse roots; few fine and medium pores; 30 percent cobbles and gravel; strongly effervescent, carbonates are disseminated; moderately alkaline (pH 8.2); clear wavy boundary. (4 to 6 inches thick)
Bk1--8 to 12 inches; brown (7.5YR 5/4) cobbly loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky, plastic; common fine and medium, and few coarse roots; few fine pores; 40 percent cobbles and gravel; strongly effervescent, carbonates are disseminated in the soil matrix and concentrated on the undersides of cobbles; strongly alkaline (pH 8.6); gradual wavy boundary. (2 to 11 inches thick)
Bk2--12 to 19 inches; pinkish white (7.5YR 8/2) very cobbly loam, light brown (7.5YR 6/4) moist; massive; hard, friable, slightly sticky, slightly plastic; few fine pores; few fine and medium roots; 55 percent cobbles and gravel; violently effervescent, carbonates are disseminated in the soil matrix and concentrated on the undersides of cobbles; strongly alkaline (pH 8.8); gradual wavy boundary (0 to 8 inches thick)
R--19 inches; fractured limestone
TYPE LOCATION: Washington County, Utah; about 1 mile southeast of Hurricane School; about 825 feet south and 500 feet east of the center of sec. 2, T.42 S., R.13 W; Hurricane Quadrangle; lat. 37 degrees 9 minutes 39 seconds N. and long. 113 degrees 16 minutes 47 seconds W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 54 to 59 inches F.
Soil moisture: The soils are usually dry during the period the soil temperature is above 41 degrees F. They are moist in some part of the moisture control section for 30 to 40 days during the summer months and are dry for 70 to 85 days during the 120 days following the winter solstice. Ustic aridic moisture regime.
Depth to bedrock: 10 to 20 inches
Gravel and cobble content: 35 to 80 percent
Reaction: moderately to strongly alkaline
Calcium carbonate equivalent: 40 to 80 percent.
A horizon
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: cobbly loam to very cobbly loam
Bk horizon
Hue: 7.5YR or 10YR
Value: 5 through 8 dry, 4 through 6 moist
Chroma: 2 through 4
Texture: cobbly or gravelly loam to very cobbly loam
Thickness: 6 to 12 inches
COMPETING SERIES: These are the Scrappy (NV), Splimo (UT) and Winona (AZ) series. Scrappy soils are in the Mojave Desert of southern Nevada (MLRA 30) and are usually dry, moist in late winter and early spring and intermittently moist in the upper part following summer convection storms. Splimo soils have mean annual soil temperatures that range from 47 to 51 degrees F. Winona series have some pedons with Bw horizons, include 5YR hue in the range, and allow channers and flagstone rock fragments.
GEOGRAPHIC SETTING: Yaki soils are on mesas and upland slopes at elevations of 3,500 feet. Slopes range from 3 to 35 percent. These soils formed in residuum weathered from limestone and shale. The mean annual temperature is 52 to 57 degrees F., and the mean summer temperature is 73 to 79 degrees F. The average annual precipitation is 10 to 13 inches. Frost-free period is 160 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Tobish and Zukan soils. Tobish soils have argillic horizons and are 20 to 40 inches deep to lithic contact. Zukan soils lack calcic horizons and have less than 20 percent gravel and cobbles in the control section.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: Used as rangeland. Vegetation is blackbrush, sagebrush, Mormon tea, snakeweed, galleta and cheatgrass.
DISTRIBUTION AND EXTENT: Southern Utah and northern Arizona. MLRA 35. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Washington County, Utah, 1972.
REMARKS: Diagnostic horizons and features found in this pedon are:
Ochric epipedon - from a depth of 0 to 2 inches.
Calcic horizon - from a depth of 8 to 19 inches.
Lithic contact - at 19 inches.
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.
These soils were formerly classified as Lithic Calciorthids. The new placement as Lithic Ustic results in a significant overlap in soil properties with the Winona series. Additional investigation is needed to determine if there is a significant difference in concept.