LOCATION HIKAI AZ
Established Series
Rev. JMH/FF/RKS
02/2025
HIKAI SERIES
The Hikai series consists of deep, somewhat poorly drained soils that formed in residuum from limestone, and dolomite. Hikai soils are on shoulders and summits of structural benches on plateaus. Slopes range from 2 to 40 percent. Mean annual precipitation is about 33 inches, and the mean annual temperature is about 38 degrees F.
TAXONOMIC CLASS: Fine, mixed, semiactive, frigid Oxyaquic Paleudalfs
TYPICAL PEDON: Hikai gravelly sandy loam - subalpine forest. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch (0 to 3 cm); slightly decomposed mixed conifer and aspen litter. (0 to 3 inches thick)
Oe--1 to 2 inches; black (10YR 2/1) moderately decomposed mixed conifer and aspen litter. (0 to 3 inches thick)
A1--2 to 4 inches; pale brown (10YR 6/3) gravelly loam, dark yellowish brown (10YR 4/4) moist; weak medium platy structure parting to weak fine subangular blocky; slightly hard, very friable, nonsticky and slightly plastic; many very fine and common fine roots; few very fine and fine tubular pores; 15 percent gravel; noneffervescent; strongly acid (pH 5.4); abrupt wavy boundary.
A2--4 to 7 inches; pale brown (10YR 6/3) gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; many very fine and common fine and medium roots; few very fine and fine tubular pores; 20 percent gravel, 2 percent cobbles; noneffervescent; strongly acid (pH 5.3); clear wavy boundary. (combined thickness of A horizons is 4 to 17 inches)
AE--7 to 12 inches; light brown (7.5YR 6/3) very gravelly loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine and fine and few medium and coarse roots; few very fine and fine tubular pores; 35 percent gravel, 5 percent cobbles; noneffervescent; moderately acid (pH 5.8); clear wavy boundary. (0 to 6 inches thick)
E--12 to 20 inches; pink (7.5YR 7/3) very gravelly loam, brown (7.5YR 4/3) moist; weak very fine and fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine, and few medium and coarse roots; common very fine and few fine tubular pores; 45 percent gravel, 5 percent cobble; noneffervescent; slightly acid (pH 6.2); abrupt wavy boundary. (2 to 20 inches thick)
Bt1--20 to 39 inches; strong brown (7.5YR 5/6) clay, strong brown (7.5YR 5/6) moist; strong coarse angular blocky structure; very hard, very firm, sticky and very plastic; few very fine roots oriented along faces of peds; few very fine tubular pores; many distinct clay films on faces of peds; 5 percent gravel; noneffervescent; strongly acid (pH 5.4); gradual smooth boundary.
Bt2--39 to 50 inches; yellowish red (5YR 4/6) and red (2.5YR 4/6) gravelly clay, variegated yellowish red (5YR 4/6) and red (2.5YR 4/6) moist; strong coarse angular blocky structure; very hard, very firm, sticky and very plastic; few very fine roots oriented along faces of peds; few very fine tubular pores; many distinct clay films on faces of peds;15 percent gravel, 2 percent cobbles; noneffervescent; very strongly acid (pH 4.8); clear wavy boundary.
R/Cr--50 inches; fractured, very slightly to slightly weathered cherry fine-grained sandstone bedrock with irregular pockets of increasingly weathered cherry sandstone
TYPE LOCATION: Coconino County, Arizona; located about 9.4 kilometers (5.9 miles) north of Bright Angel Point, Arizona; USGS Quadrangle Little Park Lake; Latitude 35.27611, Longitude -112.07804, Datum WGS84.
RANGE IN CHARACTERISTICS:
Soil moisture: Typic udic moisture regime based on precipitation and Thornthwaite calculation. Some moisture is retained in the soil profile throughout most years.
Mean annual soil temperature - 38 to 42 degrees F
Depth to bedrock - 40 to 60 inches
Depth to argillic - 14 to 40 inches
Rock fragments: 5 to 55 percent
A horizons
Hue: 7.5YR, 10YR
Value: 3 to 6 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Fine-earth texture: Sandy loam, fine sandy loam
Reaction: strongly acid to neutral
E horizon
Hue: 7.5YR, 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 3 dry, 3 or 4 moist
Fine-earth texture: sandy loam, fine sandy loam
Rock fragments: 20 to 70 percent
Reaction: strongly acid to neutral
Bt horizons
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 to 6 dry, 3 to 5 moist
Chroma: 4 to 6, dry or moist
Fine-earth texture: clay
Reaction: very strongly acid to slightly acid
Some pedons have Bw, Bt/E or E/Bt horizons
COMPETING SERIES: There are no competing series
GEOGRAPHIC SETTING:
Parent material: residuum from fine-grained sandstone, limestone, and chert
Landform: summits and side slopes of hills and ridges on plateaus
Slopes: 2 to 45 percent
Elevation: 8700 to 9700 feet
Mean annual temperature: 36 to 45 degrees F
Mean annual precipitation: 30 to 35 inches
Precipitation pattern: Wettest months: December through April
Driest months: May, June
Frost-free period: 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Veetee and
Angelbright soils. Angelbright soils are skeletal and do not have an argillic horizon. Veetee soils have an aquic moisture regime and have redoximorphic features in the profile.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained, medium to very high runoff, very slow permeability, saturated with water for 20 consecutive days or 30 or more days cumulative in April and May due to snow melt.
USE AND VEGETATION: These soils are used for recreation, wildlife habitat. Native vegetation includes Subalpine Fir, Engelmann spruce, White fir, Douglas-fir, and Quaking aspen.
DISTRIBUTION AND EXTENT: Kaibab Plateau above 8700 feet in north central Arizona; MLRA 35. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Soil survey of Kaibab National Forest, Arizona, Coconino County, AZ, 2024.
REMARKS:
Diagnostic horizons and features:
Ochric epipedon (1 to 5 inches)
Argillic horizon (24 to 58 inches)
Oxyaquic feature (below 24 inches)
Name is derived from upper elevations of Kaibab Plateau
Lab sample: S2000AZ005004
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National Cooperative Soil Survey
U.S.A.