LOCATION RIZNO UT+AZ NM COEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, calcareous, mesic Lithic Ustic Torriorthents
TYPICAL PEDON: Rizno fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; light red (2.5YR 6/6) fine sandy loam, reddish brown (2.5YR 4/4) moist; weak medium platy structure; soft, very friable; few medium and coarse roots; many medium interstitial pores; strongly effervescent; carbonates are disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (0 to 4 inches thick)
C--2 to 8 inches; red (2.5YR 5/6) gravelly fine sandy loam, reddish brown (2.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, very friable; many very fine, fine, and medium, and few coarse roots; many very fine, fine and medium tubular pores; 25 percent gravel; strongly effervescent; carbonates are disseminated; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 18 inches thick)
R--8 inches; calcareous sandstone.
TYPE LOCATION: Grand County, Utah; about 10 miles northwest of Dead Horse Point State Park; located about 500 feet east and 500 feet north of the southwest corner of sec. 22, T. 25 S., R. 19 E.
RANGE IN CHARACTERISTICS:
Soil moisture regime: Ustic aridic soil moisture regime.
Soil temperature regime: mesic
Mean annual soil temperature: 47 to 58 degrees F.
Particle-size control section: 5 to 18 percent clay
Depth to lithic contact: 4 to 20 inches to calcareous sandstone and limestone.
A horizon
Hue: 2.5YR, 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 to 6, dry or moist
Texture: fine sandy loam, loam, very fine sandy loam
Rock fragments: 0 to 35 percent
Reaction: slightly to moderately alkaline
C horizon
Hue: 2.5YR, 5YR
Value: 4 to 7 dry, 3 to 6 moist
Chroma: 3 to 6, dry or moist
Texture: very fine sandy loam, fine sandy loam, sandy loam, loam
Rock fragments: 0 to 35 percent as gravel, channers, cobbles
Reaction: slightly to strongly alkaline
COMPETING SERIES: These are the competing Bigmon (T)(CO), Hideout (UT), Kenzo (I)(UT), Lazear (CO), Redspear (WY), Rizozo (NM), Skyvillage (NM), Travessilla (NM), Travson (WY), and Zukan (UT)series. Bigmon, Hideout, Skyvillage, Travessilla, and Travson soils have hues of 7.5YR or yellower. Redspear and Zukan soils have Bw and Bk horizons. Rizozo soils have less than 25 percent sand coarser than very fine sand. Lazear soils have a hue of 7.5YR or yellower and more than 18 percent clay in the particle-size control section. Kenzo soils are inactive.
GEOGRAPHIC SETTING: Rizno soils are on structural benches on cuestas, mesas, and ridges. Elevations range from 4,000 to 8,000 feet with slopes ranging from 2 to 60 percent. These soils formed in residuum, colluvium, and eolian material derived from sandstone, siltstone or limestone. The mean annual air temperature is 45 to 56 degrees F. The mean annual precipitation is 8 to 13 inches. The wettest months are July, August, and September and the driest months are April, May, and June. The frost-free period is 100 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anasazi, Arches, Begay and Mido soils. Anasazi soils have bedrock at 20 to 40 inches. Arches soils have a sandy particle-size control section. Begay soils are more than 60 inches deep. Mido soils are more than 60 inches deep and have a sandy particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; very low to medium runoff; moderate and moderately rapid permeability.
USE AND VEGETATION: Used mainly for livestock grazing. Vegetation is blackbrush, Mormon-tea, Utah juniper and pinyon.
DISTRIBUTION AND EXTENT: Southeast Utah, northern Arizona, southwestern Colorado, and northwest New Mexico. LRR D, MLRAs 35 and 39. Discontinue use in MLRA 34 in northwest Colorado. This series is of large extent.
MLRA OFFICE RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Henry Mountains Area, Wayne County, Utah, 1985.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 2 inches (A horizon)
Lithic feature - bedrock at 8 inches (R horizon)
Particle size control section: The zone from 0 to 8 inches. (A and C horizons)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Responsibility was transferred from Region 6 (Lakewood) to Region 8 (Phoenix) in September 2009 as a result of the correlation of Canyonlands National Park (UT688), WWJ
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