LOCATION NAPLENE UTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, calcareous, mesic Aridic Ustifluvents
TYPICAL PEDON: Naplene silt loam - on a 2 percent south facing slope--rangeland. (Colors are for air-dry soil unless otherwise stated.)
A1--0 to 2 inches; brown (7.5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; moderate thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common, fine vesicular pores; strongly effervescent (17 percent calcium carbonate equivalent), carbonates are disseminated; slightly alkaline (pH 7.7); abrupt smooth boundary. (2 to 6 inches thick)
A2--2 to 7 inches; brown (7.5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; moderate medium structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common fine and very fine vesicular pores; strongly effervescent (17 percent calcium carbonate equivalent), carbonates are disseminated; slightly alkaline (pH 7.6); abrupt smooth boundary. (0 to 5 inches thick)
C1--7 to 15 inches; brown (7.5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; moderate coarse subangular blocky structure parting to moderate medium subangular blocky; very hard, friable, sticky and plastic; few fine and medium roots; common fine and few medium tubular pores; strongly effervescent (18 percent calcium carbonate equivalent), carbonates are disseminated; slightly alkaline (pH 7.8); gradual wavy boundary. (5 to 26 inches thick)
C2--15 to 22 inches; reddish brown (5YR 5/4) silty clay loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; common fine and very fine roots; common fine tubular pores; strongly effervescent (16 percent calcium carbonate equivalent), carbonates are disseminated and veined; slightly alkaline (pH 7.8); gradual wavy boundary. (7 to 52 inches thick)
C3--22 to 39 inches; reddish brown (5YR 5/4) silt loam, reddish brown (5YR 5/4) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; few fine and very fine roots; common fine tubular pores; strongly effervescent (17 percent calcium carbonate equivalent), carbonates are disseminated; slightly alkaline (pH 7.8); gradual wavy boundary. (0 to 27 inches thick)
C4--39 to 60 inches; brown (7.5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; few very fine roots; common fine random tubular pores; strongly effervescent (19 percent calcium carbonate equivalent), carbonates are disseminated and veined; slightly alkaline (pH 7.7).
TYPE LOCATION: Iron County, Utah; 600 feet northwest of the New Harmony interchange on I-15; 2,100 feet west and 525 feet north of the southeast corner of sec. 17, T.38 S., R.12 W.; Kolob Arch Quadrangle; 37 degrees, 29 minutes, 00 seconds N. latitude; 113 degrees, 13 minutes, 25 seconds W. longitude.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 47 to 54 degrees F.
Mean summer soil temperature: 64 to 70 degrees F.
Soil moisture: Aridic ustic moisture regime..
The particle-size control section averages 18 to 35 percent clay and less than 15 percent sand coarser than very fine sand.
Effervescence: slightly effervescent to strongly effervescent throughout
Organic carbon: 0.2 to 0.5 percent at 50 inches or has an irregular distribution in the profile
Calcium carbonate equivalent: exceeds 10 percent.
A horizon
Hue: 7.5YR or 5YR
Chroma: 3 to 5
Texture: loam, silt loam, sandy clay loam or sandy loam
Reaction: slightly alkaline or moderately alkaline
C horizon
Hue: 7.5YR, 5YR or 2.5YR
Value: 4 to 6 dry, and 3 or 4 moist
Chroma: 3 to 6
Texture: dominantly silt loam or silty clay loam. It is commonly stratified, with textures that range from silty clay loam to fine sandy loam
Reaction: slightly alkaline to strongly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Naplene soils are on alluvial fans and stream terraces at elevations of 3,700 to 5,500 feet. Slopes are 1 to 6 percent. These soils formed in alluvium derived dominantly from sedimentary and igneous rocks. The mean annual air temperature is 45 to 52 degrees F. Average annual precipitation is 12 to 15 inches. The frost-free period is 90 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilton, Lavate, Redbank, and Schmutz soils. Chilton soils have more than 35 percent coarse fragments in the particle-size control section and occur upslope of the Naplene soils on strongly sloping alluvial fans. Lavate soils have mollic epipedons and argillic horizon and occur upslope of the Naplene soils on fan terraces. Redbank soils have less than 18 percent clay in the particle-size control section and occur on upper, smaller alluvial fans. Schmutz soils have gypsic mineralogy and occur on higher alluvial fans upslope of the Naplene soils.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow or slow permeability.
USE AND VEGETATION: These soils are used for dry or irrigated cropland or rangeland. The native vegetation is Wyoming big sagebrush, rubber rabbitbrush, snakeweed, Utah juniper, cheatgrass, galla and scattered gambel oak. Crops include irrigated alfalfa, small grains and dryland wheat.
DISTRIBUTION AND EXTENT: Southwestern Utah, MLRAs 29 & 35. These soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Washington County, Utah 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to a depth of about 7 inches (A horizon).
Fluvent feature - the organic carbon greater than 0.2 percent
This soil was previously classified as an Ustic Torrifluvents.
ADDITIONAL DATA: Laboratory data from type location S70UT-027-14. Laboratory data is published in the Soil Survey of Washington County Area, Utah, and in SSIR No. 39.