LOCATION SWISSHELM               AZ

Established Series
Rev. SDH/MLR/PDC/CEM/WWJ
08/2012

SWISSHELM SERIES

The Swisshelm series consists of very deep, well drained soils formed in mixed and stratified alluvium from volcanic, granitic and sedimentary rock. Swisshelm soils are on alluvial fans and have slopes of 0 to 3 percent. The mean annual precipitation is about 14 inches and the mean annual air temperature is about 61 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Ustifluventic Haplocambids

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

A1--0 to 5 inches; brown (7.5YR 5/3) sandy loam, brown (7.5YR 4/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many fine irregular pores; noneffervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (3 to 6 inches thick)

A2--5 to 12 inches; brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many fine and very fine irregular and common very fine tubular pores; noneffervescent; moderately alkaline (pH 8.0); clear wavy boundary. (6 to 12 inches thick)

Bk--12 to 22 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine tubular pores; common soft calcium carbonate masses; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (7 to 16 inches thick)

C--22 to 42 inches; light brown (7.5YR 6/4) fine sandy loam, brown (7.5YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (15 to 30 inches thick)

Ck--42 to 60 inches; light brownish gray (10YR 6/2) clay loam, grayish brown (10YR 5/2) moist; massive; hard, friable, sticky and slightly plastic; common very fine roots; common very fine and fine tubular pores; few fine calcium carbonate filaments; strongly effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Cochise County, Arizona; about 3 miles southeast of Elfrida; 900 feet south, 900 feet west of the northeast corner of section 35, T. 20 S., R. 26 E.

RANGE IN CHARACTERISTICS:

Soil moisture: Intermittently moist in some part of the soil moisture control section during July through September and December through February. Driest during May and June. Ustic aridic soil moisture regime.

Rock fragments: less than 15 percent gravel

Depth to carbonates: less than 20 inches

A horizon
Hue: 7.5YR, 10YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 3 or 4, dry or moist
Reaction: neutral to moderately alkaline

B horizon
Hue: 7.5YR, 10YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 3 through 6, dry or moist
Texture: loam, sandy loam, fine sandy loam, very fine sandy loam
Reaction: slightly to strongly alkaline
Calcium carbonate equivalent: less than 5 percent disseminated or as soft segregations

C horizon
Hue: 7.5YR, 10YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 2 through 6, dry or moist
Texture: loam, very fine sandy loam, fine sandy loam, sandy loam, clay loam
Reaction: slightly to strongly alkaline
Calcium carbonate equivalent: less than 5 percent
Stratification: thin strata of contrasting textures are common below 20 inches

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Swisshelm soils are on stream terraces and alluvial fans at elevations of 3,000 to 5,000 feet. Slopes range from 0 to 3 percent. These soils formed in mixed and stratified alluvium from rhyolite, andesite, granite, limestone, tuff and quartzite. The mean annual precipitation is 12 to 16 inches. The mean annual air temperature is 59 to 67 degrees F. The frost-free period is 180 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elfrida, Karro, and Ubik soils. Elfrida and Ubik soils have dark epipedons. Karro soils have a calcic horizon at a depth of less than 20 inches and are fine-loamy.

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.

USE AND VEGETATION: Used for irrigated cropland and livestock grazing. Irrigated crops are cotton, corn, chilies, small grains and alfalfa. Present vegetation is black grama, sideoats grama, blue grama, sand dropseed and cane bluestem.

DISTRIBUTION AND EXTENT: Southeastern and Central Arizona. Swisshelm soils are of small extent. MLRA is 38 and 41.

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

SERIES ESTABLISHED: Yavapai County, Arizona. Soil survey of Black Hills-Sedona Area, Arizona, Parts of Coconino and Yavapai Counties; 1996.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from 0 to 12 inches (A1, A2 horizons)

Cambic horizon - The zone from 12 to 22 inches (Bk horizon)

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

Revised for the correlation of Black Hills-Sedona, AZ, August 2012, CEM

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National Cooperative Soil Survey
U.S.A.