LOCATION JOSHUA                  CA

Established Series
Rev. GAW/JWF/GWH
09/2015

JOSHUA SERIES

The Joshua series consists of moderately deep, well drained soils that formed in material derived from mixed sources. Joshua soils are on old terraces with a well developed erosion pavement and have slopes 2 to 15 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 63 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Argidic Argidurids

TYPICAL PEDON: Joshua loam, on a 3 percent slope under creosotebush and bursage at 2,960 feet elevation. (Colors are for dry soil unless otherwise stated. When described the soil was dry throughout.) The soil surface is covered with a well developed, varnished desert pavement consisting of rounded to subangular pebbles and cobbles.

A1--0 to 3 inches; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; moderate very thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; slightly effervescent with disseminated lime; slightly alkaline (pH 7.8); abrupt smooth boundary. (2 to 4 inches thick)

B1t--3 to 6 inches; brown (7.5YR 5/4) gravelly light sandy clay loam, dark brown (7.5YR 4/4) moist; moderate very fine subangular blocky structure; slight hard, very friable, slightly sticky and slightly plastic; common very fine roots; few very fine interstitial pores; few moderately thick clay films o peds, many moderately thick clay films as bridges between mineral grains; about 15 to 20 percent pebbles (1/2 to 3/4 inch), about 5 percent pebbles (1/2 to 1 inch); slightly alkaline (pH 7.8); clear smooth boundary. (1 to 7 inches thick)

B21t--6 to 13 inches; reddish brown (5YR 5/4) gravelly sandy clay loam, reddish brown (5YR 4/4) moist; moderate very fine subangular blocky structure; hard, firm, sticky and plastic; few very fine roots; few very fine interstitial pores; few moderately thick clay films on faces of peds, common moderately thick clay films in pores and as bridges between mineral grains ; about 25 to 30 percent pebbles (1/2 to 3/4 inch); slightly alkaline (pH 7.8); gradual smooth boundary. (3 to 11 inches thick)

B22t--13 to 20 inches; reddish brown (5YR 5/4) gravelly sandy loam, reddish brown (5YR 4/4) moist; moderate medium angular blocky structure; hard, firm, sticky and plastic; few very fine roots; few very fine interstitial pores; few moderately thick clay films on peds and as bridges between mineral grains, common moderately thick clay films lining pores; about 25 to 30 percent pebbles (1/2 to 3/4 inch); slightly alkaline (pH 7.8); diffuse smooth boundary. (7 to 18 inches thick)

C1sica--20 to 39 inches; white (10YR 8/2) very gravelly coarse sandy loam, light gray (10YR 7/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; discontinuous white (10YR 8/2) silica lenses 1/2 to 3/4 inch wide;, 1 to 2 mm thick; about 35 to 50 percent pebbles (1/2 to 3/4 inch); strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 20 inches thick)

C2sica--39 to 55 inches; white (10YR 8/2) duripan that crushes to very gravelly loamy coarse sand, very pale brown (10YR 7/3) moist; massive; very hard and firm matrix, extremely hard and extremely firm silica lenses; about 35 to 50 percent pebbles (1/2 to 3/4 inch); strongly effervescent with disseminated lime; moderately alkaline (pH 8.4).

TYPE LOCATION: San Bernardino County, California; south of Helendale, 2 miles east of Bryman Road, 100 feet west of the gas pipeline maintenance trail; in the NE1/4 NW1/4 section 28, T.7N., R.4W.

RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the duripan (Csics horizon) are 20 to 40 inches. The duripan consists of discontinuous silica lenses in more than 50 percent of the horizon or has more than 50 percent very firm or extremely firm durinodes and/or pendants on the underside of rock fragments. 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. The soil is moderately to strongly saline alkali. SAR is 13 to 35.

The A horizon is light yellowish brown, pale brown or very pale brown (10YR 6/4, 6/3, 7/4). Moist colors are light yellowish brown, brown, dark yellowish brown or dark brown (10YR 6/4, 5/3, 4/4, 4/3). Structure is weak to strong and thin to thick platy. This horizon is sandy loam or loam and averages about 5 percent gravel and 5 to 10 percent cobbles. It is mildly alkaline to moderately alkaline. Some pedons are noncalcareous.

The B2t horizon is reddish brown, yellowish red, or strong brown (5YR 5/4, 4/4, 5/6; 7.5YR 5/6). Moist colors are reddish brown, yellowish red, or dark brown (5YR 4/4, 4/6, 5/6; 7.5YR 4/4). This horizon is gravelly sandy clay loam or gravelly heavy sandy loam with 15 to 35 percent fine gravel. Clay ranges from 18 to 30 percent and increase by 3 to 10 percent clay from the A horizon to the Bt horizon. Reaction is mildly alkaline to moderately alkaline. Some pedons have a B3 horizon.

The C horizon is white, or very pale brown (10YR 8/2, 8/3, 7/4). Moist colors are pale brown, light yellowish brown, light gray or very pale brown (1YR 6/3, 6/4, 7/2, 7/3). This horizon is very gravelly loam coarse sand or very gravelly coarse sandy loam with 35 to 60 percent fine gravel that grades into cobbly material as depth increases. In some pedons it is made up of durinodes or silica coatings on coarse fragments.

COMPETING SERIES: These are the Caudle, Cuddeback, Dateland, Harqua, Ligurta, Nyala, Unsel and Vigus series in other families. Caudle, Nyala, Unsel and Vigus soils have mesic soil temperature. Cuddeback soils have a continuous indurated duripan and an SAR less than 10. Dateland, Harqua and Ligurta soils have hyperthermic soil temperature and lack a duripan.

GEOGRAPHIC SETTING: Joshua soils are on old gravelly erosion pavement covered terraces and have gradients of 2 to 15 percent. They formed in mixed alluvium derived from granitic and volcanic rocks. Elevation s are 2,600 to 3,000 feet. A well developed erosion pavement covers from 70 to 90 percent of the surface. The climate is arid with hot, dry summers and cool partly moist winters. The mean annual precipitation is 4 or 5 inches, most of the moisture falls as rain in the winter. Some moisture falls occasionally as snow. The average January temperature is 46 degrees F.; the average July temperature is 84 degrees F.; and the mean annual temperature is 61 to 65 degrees F. The frost free season is 210 to 255 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Cuddeback series and the Mirage and Nebona series. Mirage soils have a sandy clay loam B2t horizon and lack a duripan. Nebona soils have a duripan at a depth of less than 20 inches and lack an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability in the argillic horizon and slow in the Csica horizon.

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

DISTRIBUTION AND EXTENT: Terraces of the Mojave Desert. The soils are inextensive.

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

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

REMARKS: Joshua soils lack the structure required for a natric horizon and do not have a continuous, indurated duripan.

ADDITIONAL DATA: Lincoln, Nebraska, Pedon number S75CA-71-3.

Responsibility for this series was transferred from Davis to Phoenix 9/2015. The last revision to the series was 1/2003. ET

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National Cooperative Soil Survey
U.S.A.