LOCATION MAY DAY UTEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Petrocalcic Palexerolls
TYPICAL PEDON: May Day very cobbly loam--rangeland. (Colors are for air dry soil unless otherwise stated).
A--0 to 13 cm; dark grayish brown (10YR 4/2) very cobbly loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure that parts to weak medium granular structure; soft, friable, slightly sticky and moderately plastic; common fine and few medium roots; common fine and few medium tubular pores; noneffervescent; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 20 cm thick)
Bt--13 to 30 cm; dark grayish brown (10YR 4/2) cobbly sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine, medium, and few coarse roots; common fine, medium and few coarse tubular pores; few thin clay films; noneffervescent; moderately alkaline (pH 8.4); clear wavy boundary. (8 to 20 cm thick)
Btk--30 to 43 cm; brown (10YR 4/3) cobbly sandy clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure that parts to weak medium granular structure; hard, firm, moderately sticky and moderately plastic; few fine medium and coarse roots; common fine, few medium and coarse tubular pores; few thin clay films; strongly effervescent; secondary lime accumulations; moderately alkaline (pH 8.4); abrupt irregular boundary. (13 to 25 cm thick)
Bkkm--43 cm; indurated carbonate cemented hardpan.
TYPE LOCATION: Beaver County, Utah; about 4.5 miles southwest of Kents Lake; 2,150 feet east and 2,000 feet south of the northwest corner of sec. 9, T. 30 S., R. 6 W.; USGS Kane Canyon, Utah 7.5 minute quadrangle; latitude 38 degrees 12 minutes 54 seconds N and longitude 112 degrees 32 minutes 21 seconds W; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring and continuously dry in all parts for significant periods in summer and fall; xeric soil moisture regime bordering aridic.
Mean annual soil temperature: 5.0 to 8 degrees C.
Mean annual summer soil temperature: 15.5 to 18 degrees C.
Depth to the petrocalcic horizon: 38 to 50 cm.
Thickness of the mollic epipedon: 18 to 50 cm.
Particle-size control section - Clay content: 20 to 35 percent.
Rock fragments: 20 to 35 percent
A horizon
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
Calcium carbonate equivalent: 0 to 5 percent.
Reaction: Slightly alkaline or moderately alkaline.
Bt horizon
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
Texture: Clay loam, sandy clay loam, or loam.
Rock fragments: 20 to 35 percent, dominantly gravel and cobble.
Structure: Moderate medium subangular blocky structure or moderately fine subangular structure.
Calcium carbonate equivalent: 0 to 5 percent.
Btk horizon
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 2 through 4 moist.
Chroma: 2 or 3.
Texture: Clay loam, sandy clay loam, or loam.
Rock fragments: 20 to 35 percent dominantly gravel and cobbles.
Structure: Moderate medium subangular blocky structure or moderately fine subangular structure.
Calcium carbonate equivalent: 10 to 30 percent.
Secondary carbonates: Soft masses or hard fragments and concretions.
Reaction: Moderately alkaline or strongly alkaline.
COMPETING SERIES: This is the Pomade series. Pomade soils do not have an argillic horizon.
GEOGRAPHIC SETTING: May Day soils are on mountain slopes, alluvial fans, outwash plains, terraces and ridges at elevations of 1,950 to 2,280 meters. Slopes are from 2 to 30 percent. They formed in alluvium and colluvium derived dominantly from sedimentary and intermediate igneous rocks. The climate is moist subhumid. Mean annual air temperature is about 4 to 7 degrees C., and the mean annual summer air temperature is about 16.0 to 18.5 degrees C. The average annual precipitation is about 300 to 400 mm, distributed fairly uniform throughout the year except for June which is drier. The frost-free period is about 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Deer Creek and Pavant soils. Deer Creek soils are more than 100 cm to bedrock, have more than 35 percent clay in the argillic horizon and have calcic horizons that are not indurated. Pavant soils lack argillic horizons and have mean annual soil temperatures of more than 8.5 degrees C.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderate to slow permeability in the argillic horizon and very slow to none through the hardpan; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: These soils are used for watershed, wildlife grazing, and summer grazing by cattle. Present vegetation includes juniper, pinyon, bitterbrush, cliffrose, snakeweed, big sagebrush, bluebunch wheatgrass, Indian ricegrass, squirreltail, tall native bluegrass, and blue grama. These soils are correlated to upland ecological sites in Utah.
DISTRIBUTION AND EXTENT: Mountainous areas of Southern Utah. MLRA 28A. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Richfield Area, Utah, 1947.
REMARKS: This soil is not well defined. Further investigation is needed to determine the thickness of the petrocalcic horizons and the nature of the material below the pan.
The diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to a depth of 43 cm (A, Bt, Btk horizons).
Argillic horizon - The zone from 13 to 43 cm (Bt, Btk horizons).
Secondary carbonates - The zone from 30 to 43 cm (Btk horizon).
Petrocalcic horizon - An indurated carbonate hardpan at a depth of about 43 cm (Bkkm horizon).
Particle-size control section - The zone from 13 to 43 cm. (Bt, Btk horizons).