LOCATION AKAHIPUU                HI

Established Series
rev. MRK-RTG
08/2012

AKAHIPUU SERIES

The Akahipuu series consists of moderately deep, well drained soils that formed in basic volcanic ash in `a`a lava. Slopes range from 2 to 20 percent. The mean annual rainfall is about 560 millimeters (22 inches), and the mean annual air temperature is about 20 degrees C (65 degrees F).

TAXONOMIC CLASS: Medial-skeletal, amorphic, isothermic Pachic Haplustands

TYPICAL PEDON: Akahipuu very cobbly medial silt loam, on a west facing, convex, 16 percent slope in pasture at an elevation of 451 meters (1480 feet). (Colors are for moist soils unless otherwise noted. All textures are "apparent field textures". pH measured with organic dyes. When described on August 8, 1996 the soil was moist in the surface layer and dry below.).

A/2C1--0 to 8 centimeters (0 to 3 inches); black (10YR 2/1) very cobbly medial silt loam, very dark brown (10YR 2/2) dry; strong very fine and fine granular structure; slightly hard, friable, nonsticky and nonplastic; nonsmeary; many very fine and fine roots; many very fine and fine interstitial and few vesicular pores; 40 percent angular `a`a cobbles and 15 percent angular `a`a gravel; moderately acid (pH 6.0); the 2C part of this horizon consists of unconsolidated `a`a lava fragments of variable size; clear wavy boundary. (5 to 10 centimeters {2 to 4 inches} thick)

Bw1/2C2--8 to 18 centimeters (3 to 7 inches); dark brown (7.5YR 3/3) very cobbly medial silt loam, dark yellowish brown (10YR 3/4) dry; single grain; loose when dry or moist, nonsticky and nonplastic; nonsmeary; common very fine and fine roots; common very fine and fine interstitial pores; 40 percent angular `a`a cobbles and 15 percent angular `a`a gravel; ); slightly acid (pH 6.2); the 2C part of this horizon consists of unconsolidated `a`a lava fragments of variable size; diffuse wavy boundary.

Bw2/2C3--18 to 64 centimeters (7 to 25 inches); dark reddish brown (5YR 3/3) extremely cobbly medial silt loam, dark brown (7.5YR 3/4) dry; single grain; loose when dry or moist, nonsticky and nonplastic; nonsmeary; common very fine and fine roots; common very fine and fine interstitial pores; 40 percent angular `a`a cobbles and 20 percent angular `a`a gravel; neutral (pH 7.2); ); the 2C part of this horizon consists of unconsolidated `a`a lava fragments of variable size;clear wavy boundary. (Combined thickness of the Bw horizon is 46 to 66 centimeters {18 to 26 inches} thick.)

2C4--64 to 97 centimeters (25 to 38 inches); dark reddish brown (5YR 3/3) extremely cobbly loamy sand, dark brown (7.5YR 3/4) dry; single grain; loose when dry or moist, nonsticky and nonplastic; nonsmeary; few very fine and fine roots; common very fine and fine interstitial pores; 40 percent angular `a`a cobbles and 35 percent angular `a`a gravel; slightly alkaline (pH 7.6); abrupt wavy boundary. (13 to 38 centimeters {5 to 15 inches} thick.)

2R--97 centimeters (38 inches); hard, massive `a`a blue rock with class 2 (0.45-1 meter) joint fractures.

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; from Palani Junction (Kailua Quadrangle), drive north on Highway 190 for 3.8 miles; turn left and drive northwest on road for 1 mile; pedon is located 6 meters (20 feet) east of road at an elevation of 451 meters (1480 feet); Kiholo Quadrangle; lat. 19 degrees 45 minutes 37.3 seconds N. and long. 155 degrees 58 minutes 55.3 seconds W.(Old Hawaiian Datum)

RANGE IN CHARACTERISTICS:
Depth to bedrock: 50 to 102 centimeters (20 to 40 inches).
Mean annual soil temperature: 18 to 22 degrees C (65 to 72 degrees F).
Rock fragments: 35 to 85 percent by volume of the pedon and range in size from gravel to stones, but are primarily gravel and cobble size `a`a lava rocks.

A/2C1 horizon
Hue: 10YR or neutral.
Value: 2 moist or dry.
Chroma: 0, 1, or 2 moist or dry.
Texture: Extremely or very cobbly medial silt loam.
Soil reaction: Moderately acid to slightly acid (pH 5.6 to 6.5).

Bw/2C horizon:
Hue: 5YR, 7.5YR, or 10YR.
Value: 2 or 3 moist or dry.
Chroma: 3 or 4 moist or dry.
Texture: Extremely or very cobbly medial silt loam or very cobbly medial sandy loam.
Soil reaction: Slightly acid or neutral (pH 6.1 to 7.3).

2C4 horizon
Hue: 5YR, 7.5YR, or 10YR.
Value: 3 or 4 moist or dry.
Chroma: 3 or 4 moist or dry.
Texture: Extremely or cobbly sandy loam, very or extremely cobbly loamy sand, or extremely gravelly sand.
Soil reaction: Neutral to slightly alkaline (pH 6.6 to 7.8).

COMPETING SERIES: This is the Kemole series. Kemole soils are 102 to 152 centimeters (40 to 60 inches) deep to bedrock.

GEOGRAPHIC SETTING: Akahipuu soils are on mid elevation, leeward slopes of Hualalai Volcano at elevations from 305 to 1067 meters (1000 to 3500 feet). These soils are on all hillslope positions of undulating to hilly `a`a lava flows that are 3,000 to 10,000 years old. Slope gradients range from 2 to 20 percent. The soils formed in basic volcanic ash over `a`a lava. The mean annual rainfall ranges from 380 to 760 millimeters (15 to 30 inches), with most of the rainfall occurring from January through July. The mean annual pan evaporation ranges from 1520 to 1780 millimeters (60 to 70 inches). The mean annual air temperature ranges from 17 to 21 degrees C (63 to 70 degrees F). The mean summer soil temperature and the mean winter soil temperature differ by less than 6 degrees C (11 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are Kahaumanu, Napuu, Puuikaaka, and the similar Waawaa series. Kahaumanu and Napuu soils have lithic contact at 25 to 50 centimeters (10 to 20 inches). Puuikaaka soils have a lithic contact at 5 to 25 centimeters (2 to 10 inches) and are over pahoehoe lava. Waawaa soils are medial and are more than 152 centimeters (60 inches) deep.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is very low to low on gentle slopes and low on steeper slopes. Permeability is rapid in the soil and very slow in the underlying bedrock.

USE AND VEGETATION: Used for grazing and wildlife habitat. Vegetation is fountaingrass (Pennisetum setaceum), lantana (Lantana camara), cactus (Opuntia), and ohia lehua (Metrosideros polymorpha).

DISTRIBUTION AND EXTENT: North Kona District, Island of Hawaii; MLRA 161B. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii 2012.

REMARKS: Soil moisture - dry in some or all parts for short intermittent periods totaling 90 or more days during the months of July through January in most years (Ustic moisture regime).
Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon - from a depth of 0 to 64 centimeters (0 to 25 inches) (A/2C1, Bw1/2C2 and Bw2/2C3 horizons).
Lithic contact - at a depth of 97 centimeters (38 inches) (2R horizon).
Andic soil properties - from a depth of 0 to 64 centimeters (0 to 25 inches) (A/2C1, Bw1/2C2, and Bw2/2C3 horizons).
Textural modifiers based on correlations with known lab samples to field observations of smeariness, and consistence.

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National Cooperative Soil Survey
U.S.A.