LOCATION NEBONA CA

Established Series
Rev. GAW/JWF/GWH
12/2015

NEBONA SERIES

The Nebona series consists of shallow, well drained soils that formed in mixed alluvium. Nebona soils are on terraces and have slopes of 2 to 9 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 63 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Typic Haplodurids

TYPICAL PEDON: Nebona sandy loam, on a northwest facing convex slope of 6 percent under sparse creosotebush and yucca at an elevation of 2,600 feet. (Colors are for dry soil unless otherwise stated. When described the soil was dry throughout.) The soil surface has a well developed gravel desert pavement. Some pebbles and cobbles have a dark colored desert varnish on exposed surfaces.

A1--0 to 2 inches; light yellowish brown (10YR 6/4) sandy loam, yellowish brown (10YR 5/4) moist; moderate very thin and thin platy structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial and few very fine vesicular pores; about 3 to 5 percent (1/2 to 3/4 inch) pebbles; strongly effervescent with disseminated lime; slightly alkaline (pH 7.8); abrupt smooth boundary. (2 to 4 inches thick)

C1ca--2 to 8 inches; light yellowish brown (10YR 6/4) fine sandy loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few fine medium and coarse roots; few very fine interstitial and tubular pores; few thin clay films as bridges between mineral grains; about 10 percent (1/4 to 1 inch) pebbles and 3 percent cobbles; violently effervescent with disseminated lime; slightly alkaline (pH 7.8); abrupt wavy boundary. (4 to 10 inches thick)

C2sicam--8 to 12 inches; white (10YR 8/2), very pale brown (10YR 7/3) moist; very hard, indurated, continuous, massive silica pan; few very fine flattened roots on top of pan; clear wavy boundary. (4 to 26 inches thick)

C3sica--12 to 29 inches; very pale brown (10YR 7/3) gravelly sand, brownish yellow (10YR 6/6) moist; weak fine subangular blocky structure; slightly hard, very friable; common very fine and few coarse roots; few very fine interstitial pores; has 1 or 2 discontinuous silica cemented l3lenses (1 to 2 inches thick); about 25 to 30 percent pebbles (1/4 to 1/2 inches); violently effervescent with disseminated lime, few fine soft lime masses; moderately alkaline (pH 8.0); clear wavy boundary. (4 to 21 inches thick)

C4ca--29 to 44 inches; very pale brown (10YR 8/3) gravelly loamy sand, yellow (10YR 7/6) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable; few very fine and fine roots; common very fine interstitial pores; about 25 to 35 percent (1/4 to 1/2 inch) pebbles; violently effervescent with disseminated lime, few fine soft lime masses; moderately alkaline (pH 8.0); clear wavy boundary. (12 to 18 inches thick)

C5--44 to 65 inches; yellow (10YR 7/6) sandy loam near loam, yellowish brown (10YR 5/6) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine interstitial pores; slightly effervescent with disseminated lime; strongly alkaline (pH 8.6).

TYPE LOCATION: San Bernardino County, California; about 10 miles northwest of Victorville on Interstate 15 west of the Hidge Road turnoff and about 2.5 miles north of intersection of Hodge Road and gas line access maintenance road; near the center of the NW1/4 NE1/4 section 13, T.8N., R.3W.

RANGE IN CHARACTERISTICS: Depth to the duripan ranges from 6 to 14 inches. Nebona soils contain less than 0.2 percent organic matter above the duripan. The mean annual soil temperature is 63 to 67 degrees F. and the soil temperature usually is not below 47 degrees F. at any time. The soil is usually dry and is not continuously moist for as long as 60 days. It is usually nonsaline in the upper 1 or 2 inches but the horizons beneath the A horizon range from slightly to strongly saline or alkali. The SAR is greater than 13.

The A1 horizon underlies the desert pavement. It is very pale brown, pale brown, or light yellowish brown (10YR 7/3, 7/4, 6/3, 6/4). Moist colors are light yellowish brown, brown, or yellowish brown (10YR 6/4, 5/3, 5/4). This horizon is sandy loam or loam and averages 5 to 10 percent fine gravel. It is mildly alkaline or moderately alkaline.

The C1 horizon color is similar to that of the A horizon . The control section ranges from sandy loam to fine sandy loam with 5 to 15 percent fine gravel and 7 to 18 percent clay. The duripan ranges in thickness from 4 and 26 inches and is usually massive, continuous and indurated with opal caps. The soil beneath the duripan ranges from gravelly loamy sand to loam.

COMPETING SERIES: These are the Alko, Muroc and Stewart series in the same family and the Sodhouse (T) and Tybo series. Alko soils have a SAR of less than 13 percent and an A1 horizon that is not covered by an erosion pavement. Muroc soils have a paralithic contact with weathered granite under the duripan. Stewart soils are somewhat poorly drained, are gleyed below the duripan and the moisture control section is intermittently moist in summer. Sodhouse and Tybo soils have mesic soil temperature.

GEOGRAPHIC SETTING: Nebona soils formed on old gravelly desert pavement covered terraces derived from nonmarine mixed alluvium, and have slopes of 2 to 9 percent. Elevation ranges from 2,200 to 3,000 feet. The climate is arid with hot, dry summers and cool, somewhat moist winters. The mean annual precipitation is about 4 or 5 inches, most of the moisture occurring as rain in late autumn and winter, though some falls as snow. The mean annual January temperature is 46 degrees F.; the mean July temperature is 84 degrees F.; and the mean annual temperature is 65 degrees F. The frost free season is 210 to 255 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cuddeback, Joshua and Mirage soils. Cuddeback soils have an argillic horizon underlain by a duripan. Joshua and Mirage soils have an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately rapid permeability in the upper part but very slow in the duripan.

USE AND VEGETATION: Used mainly for wildlife habitat and recreation. Native vegetation is very sparse stands of creosotebush, white bursage, yucca species, some salt bush, annual grasses and forbs.

DISTRIBUTION AND EXTENT: Terraces of the Mojave Desert. The soils are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: San Bernardino County, California, Mojave River Area, 1978.

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 1/2003. ET

National Cooperative Soil Survey
U.S.A.