LOCATION NEPALTO                 UT+NM

Established Series
Rev. WN/AJE/RLT
06/2013

NEPALTO SERIES

The Nepalto series consists of very deep, somewhat excessively drained, rapidly permeable soils. These soils formed in colluvium and alluvium from sandstone and shale on alluvial fans and drainageways on structural benches. Slopes range from 1 to 8 percent. The average annual precipitation is about 8 inches and the mean annual air temperature is about 55 degrees F.

TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Typic Torriorthents

TYPICAL PEDON: Nepalto gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 5 inches; yellowish red (5YR 5/6) gravelly sandy loam, yellowish red (5YR 5/6) moist; moderate medium platy structure parting to moderate thin platy; slightly hard; very friable; slightly sticky; few very fine and fine roots; many very fine and fine, few medium pores; 20 percent gravel, 5 percent cobbles, 5 percent stones and 5 percent boulders; moderately calcareous; carbonates are disseminated; moderately alkaline (pH 8.4); abrupt smooth boundary. (4 to 12 inches thick)

C1--5 to 12 inches; yellowish red (5YR 5/8) extremely stony loamy fine sand, yellowish red (5YR 4/6) moist; moderate coarse angular blocky structure; hard, very friable; few very fine, fine and medium roots; few very fine, common fine and medium pores; 10 percent gravel, 20 percent cobbles and 30 percent stones; moderately calcareous; carbonates are disseminated; strongly alkaline (pH 8.6); gradual wavy boundary. (6 to 22 inches thick)

C2--12 to 31 inches; yellowish red (5YR 5/6) extremely cobbly fine sand, yellowish red (5YR 5/6) moist; massive; hard, very friable; few very fine and fine roots; few very fine and fine pores; 20 percent gravel, 20 percent cobbles, 15 percent stones and 5 percent boulders; moderately calcareous; carbonates are disseminated; moderately alkaline (pH 8.2); gradual wavy boundary. (10 to 22 inches thick)

C3--31 to 70 inches; yellowish red (5YR 5/6) extremely gravelly fine sand, yellowish red (5YR 4/6) moist; single grain; loose; few very fine and fine roots; 65 percent gravel and 5 percent cobbles; moderately calcareous, carbonates are disseminated; moderately alkaline (pH 8.0).

TYPE LOCATION: San Juan County, Utah; about 3.5 miles north and 1.5 miles west of Hatch Point Campground, 2,500 feet north and 2,630 feet east of the southwest corner, sec. 29, T. 27 S., R. 21 E.

RANGE IN CHARACTERISTICS:

Soil moisture -The soils are dry in all parts above the base of the moisture control section for 75 to 85 percent of the time. Typic Aridic soil moisture regime.

Mean annual soil temperature ranges from: 53 to 61 degrees F.

Mean summer soil temperature ranges from: 74 to 79 degrees F.

Reaction: moderately alkaline to strongly alkaline

A horizon
Hue: 2.5YR, 5YR
Value: 5 to 6 dry, 4 to 5 moist
Chroma: 4 to 6, dry to moist

C horizon
Hue: 2.5YR, 5YR
Value: 4 to 6 dry, 4 to 5 moist
Chroma: 2 to 6, dry or moist
Texture: loamy fine sand, loamy sand, sand, with appropriate modifier
Rock fragments: 30 to 70 percent

COMPETING SERIES: These are the Bluewing (NV), Gynelle (NV), Inmo (NV), Ioka (UT), Itme (NV), Izamatch (NV), Izo (NV), Leo (NV), Wardenot (NV), and Willwood (NV) series. All of the above soils have 10YR hue or yellower. Bluewing, Gynelle, and Wardenot soils have visible carbonates accumulation in the series control section. Inmo, Izo, and Leo soils are stratified throughout the profile. Willwood soils contain 0 to 15 percent exchangeable sodium and neutral hue in the soil matrix. Itme soils have more than 50 percent rock fragments in the 2 to 5 millimeter size fragments and are moist in the moisture control section for 10 to 20 days following summer convection storms between July and October.

GEOGRAPHIC SETTING: Nepalto soils are on alluvial flats, alluvial fans, and in drainageways on structural benches at elevations of 3,820 to 5,200 feet. Slope gradients are 1 to 8 percent. These soils formed in colluvium and alluvium from sandstone and shale. The climate is arid and the average annual precipitation ranges from 5 to 10 inches. The mean annual temperature is 52 to 59 degrees F, and the freeze-free period ranges from 150 to 195 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Monue, Neskahi, and Pickrell soils. Monue soils have a cambic horizon. Neskahi soils have a coarse-loamy particle size control section. Pickrell soils have a lithic contact within 20 inches of the surface.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to medium runoff; rapid permeability.

USE AND VEGETATION: Nepalto soils are used for irrigated cropland and livestock grazing. Vegetation is blackbrush, Mormon-tea, shadscale, galleta grass, and snakeweed.

DISTRIBUTION AND EXTENT: Southeastern Utah and northern New Mexico. Nepalto soils are inextensive. MLRA is 35.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Navajo Indian Reservation, San Juan County, Utah, 1976.

REMARKS: The type pedon was moved in 1988 but no record is available concerning the circumstances involved in the relocation of the type pedon.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from the surface to 5 inches (A horizon)

Particle size control section - the zone from 10 to 40 inches (C1, C2, and C3 horizon)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010

Updated and revised for the correlation of Canyonlands National Park (UT688), October 2009, WWJ

Update and revisions for the correlation of Glen Canyon National Recreation Area, January 2010, CEM

---

National Cooperative Soil Survey
U.S.A.