LOCATION RAPHO                   UT

Established Series
Rev. JLS/AJE/JBF
12/2010

RAPHO SERIES

The Rapho series consists of very deep, somewhat excessively drained soils that were formed in mixed alluvium from limestone, sandstone and shale. These soils are on alluvial fans, alluvial flats and fan skirts. Slopes range from 2 to 10 percent. Mean annual precipitation is about 250 mm and the mean annual temperature is about 9.5 degrees C.

TAXONOMIC CLASS: Coarse-loamy, carbonatic, mesic Xeric Torrifluvents

TYPICAL PEDON: Rapho gravelly fine sandy loam - abandoned cropland. (Colors are for air dry soil unless otherwise noted.)

Al--0 to 10 cm; pale brown (10YR 6/3) gravelly fine sandy loam, brown (10YR 5/3) moist; weak thin platy structure; structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few fine and very fine pores; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 30 cm thick)

Cl--10 to 28 cm; pink (7.5YR 7/3) gravelly fine sandy loam, light brown (7.5YR 6/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine pores; 25 percent gravel; very violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (15 to 30 cm thick)

C2--28 to 55 cm; pink (7.5YR 7/3) gravelly light loam, brown (7.5YR 5/3) moist; massive; soft, friable, slightly sticky and slightly plastic; few very fine roots; few fine and very fine pores; 30 percent gravel; violently effervescent; moderately alkaline (pH 8.3); clear smooth boundary. (28 to 35 cm thick)

C3--55 to 78 cm; pink (7.5YR 7/3) gravelly very fine sandy loam, brown (7.5YR 5/3) moist; massive; soft, friable, slightly sticky and slightly plastic; few very fine roots; few fine and very fine pores; 25 percent gravel; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (23 to 35 cm thick)

C4--78 to 100 cm; pale brown (10YR 6/3) gravelly very fine sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine roots; few fine and very fine pores; 20 percent gravel; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (0 to 23 cm thick)

C5--100 to 130 cm; pale brown (10YR 6/3) very gravelly sandy loam, yellowish brown (10YR 5/4) moist; single grain; loose, very friable, slightly sticky and slightly plastic; few very fine roots; few fine interstitial pores; 50 percent gravel; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (15 to 33 cm thick)

C6--130 to 152 cm; pale brown (10YR 6/3) very fine sandy loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine pores; 5 percent gravel; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Sanpete County, Utah; 2 1/2 miles west, 1 1/2 miles south of Gunnison; 1,875 feet south and 200 feet west of the NE corner of sec. 27, T.l9S., R.lW; USGS Hayes Canyon 7.5 minute quadrangle; latitude 39 degrees 7 minutes 45 seconds N and longitude 111 degrees 53 minutes 43 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; moist in winter and spring and for brief periods in late summer due to convection storms; aridic bordering on xeric soil moisture regime.
Mean annual soil temperature: 9.0 to 12.0 degrees C.
Organic matter content: Decreases irregularly with depth or remains above .35 percent to a depth of 125 cm.
Calcium carbonate equivalent: More than 40 percent

Particle size control section - Clay content: Less than 18 percent.
Rock fragments: 20 to 35 percent, mainly gravel.

A horizon
Hue: 10YR or 7.5YR.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.

C horizon
Hue: 10YR or 7.5YR.
Value: 6 or 7 dry, 4 through 6 moist.
Chroma: 2 through 4.
Texture: Loam, sandy loam, fine sandy loam or very fine sandy loam.
Modifiers: Gravelly or very gravelly.
Reaction: Moderately through strongly alkaline.

COMPETING SERIES: This is Kapture series. Kapture soils have 0 to 15 percent rock fragments in the particle-size control section and have hues of 2.5YR or 5YR.

GEOGRAPHIC SETTING:
Parent material: alluvium derived from limestone, sandstone and shale
Landform: alluvial fans, alluvial flats and fan skirts
Slopes: 2 to 10 percent
Elevation: 1,372 to 1,920 meters
Mean annual temperature: 8 to 10.5 degrees C
Mean annual precipitation: 200 to 300 mm
Frost-free period: 100 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arapien, Genola, Lisade and Sanpete soils. Arapien and Genola soils do not have coarse fragments. Lisade soils have calcic horizons. Sanpete soils have more than 35 percent coarse fragments in the control section.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium runoff; moderately rapid to rapid permeability; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for livestock grazing and for irrigated alfalfa, and small grain. Many areas are abandoned cultivated land. Principal native vegetation is rabbitbrush, cheatgrass, shadscale, Indian ricegrass and big sagebrush. These soils are correlated to semi-desert ecological sites in Utah.

DISTRIBUTION AND EXTENT: Central Utah; MLRA 28A. The series is inextensive.

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

SERIES ESTABLISHED: Sanpete Soil Survey Area, Utah 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from the surface to 18 cm. (A and part of the C1 horizons)
Particle-size control section: The zone from 25 to 100 cm. (lower C1, C2, C3, C4 horizons)

Taxonomic Version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.

These soils were formerly classified as Alluvial soils.

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National Cooperative Soil Survey
U.S.A.