LOCATION HALEKULA HI

Established Series
MRK-RTG
08/2012

HALEKULA SERIES

The Halekula series consists of moderately deep, well drained soils. These soils formed in basic volcanic ash in `a`a lava. Slopes range from 2 to 50 percent. The mean annual rainfall is about 890 millimeters (35 inches), and the mean annual air temperature is about 12 degrees C (54 degrees F).

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

TYPICAL PEDON: Halekula very cobbly silt loam, on a north facing, convex, 18 percent slope in pasture at an elevation of 1074 meters (3525 feet). (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures". pH measured with organic dyes. When described on November 15, 1996, the soil was moist throughout.)

A/2C1--0 to 18 centimeters (0 to 7 inches); black (N 2/0) very cobbly medial silt loam, black (10YR 2/1) dry; strong very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and common medium roots; many very fine and fine interstitial and tubular pores; 30 percent angular `a`a gravel and 20 percent angular `a`a cobbles; neutral (pH 6.6); the 2C part of this horizons consists of unconsolidated `a`a lava fragments of variable size; clear smooth boundary. (15 to 20 {6 to 8 inches} thick)

Bw1/2C2--18 to 46 centimeters (7 to 18 inches); black (10YR 2/1) extremely gravelly medial silt loam, very dark brown (10YR 2/2) dry; moderate very fine and fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine interstitial and tubular pores; 40 percent angular `a`a gravel and 20 percent angular `a`a cobbles; the 2C part of this horizons consists of unconsolidated `a`a lava fragments of variable size; slightly alkaline (pH 7.6); abrupt smooth boundary.

2C3/Bw2--46 to 69 centimeters (18 to 27 inches); very dark brown (10YR 2/2) extremely cobbly medial very fine sandy loam, dark brown (7.5YR 3/3) dry; weak very fine and fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine interstitial and tubular pores; 40 percent angular `a`a gravel and 40 percent angular `a`a cobbles; slightly alkaline (pH 7.6); 2C3 material consists of unconsolidated `a`a lava fragments; abrupt irregular boundary. (Combined thickness of the Bw horizon is 38 to 56 centimeters {15 to 22 inches} thick.)

2R--69 centimeters (27 inches); hard, massive `a`a blue rock with class 3 (0.45-1 m) joint fractures.

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; from Puu Waawaa Ranch headquarters drive west 2.1 miles on 4WD road, turn south at corral and drive 0.9 miles; pedon is located about 213 meters (700 feet) west of road. Puu Anahulu Quadrangle; lat. 19 degrees 45 minutes 6.9 seconds N. and long. 155 degrees 52 minutes 19.5 seconds W. (GPS/PLGR)

RANGE IN CHARACTERISTICS:
Depth to bedrock: 50 to 102 centimeters (20 to 40 inches).
Mean annual soil temperature: 11 to 15 degrees C (52 to 59 degrees F).
Rock fragments: 35 to 65 percent by volume of the pedon and range in size from gravel to stones, but are primarily gravel and cobble size lava rocks.

A/2C1 horizon
Hue: 10YR or neutral.
Value: 2 or 3 moist or dry.
Chroma: 0, 1, or 2 moist or dry.
Texture: Very cobbly silt loam or loam.
Soil reaction: Neutral or slightly alkaline (pH 6.6 to 7.8).

Bw1/2C2 and 2C3/Bw2 horizons
Hue: 7.5YR or 10YR.
Value: 2 or 3 moist or dry.
Chroma: 2 or 3 moist or dry.
Texture: Very gravelly or very cobbly silt loam; or extremely cobbly very fine sandy loam.
Soil reaction: Neutral or slightly alkaline (pH 6.6 to 7.8).

COMPETING SERIES: This is the Kealoha series. Kealoha soils are moist in the control section from April through October and have a lithic contact at 102 to 152 centimeters (40 to 60 inches).

GEOGRAPHIC SETTING: Halekula soils are on north slopes on the undissected upland of Hualalai Volcano at elevations from 1067 to 1829 meters (3500 to 6000 feet). These soils are on all hillslope positions of constructional landscapes consisting of undulating to very steep `a`a lava flows that are 3,000 to 10,000 years old. Slope gradients range from 2 to 50 percent. The soils formed in basic volcanic ash over `a`a lava. The mean annual rainfall ranges from 760 to 1020 millimeters (30 to 40 inches), with most of the rainfall occurring from January through July. The mean annual air temperature ranges from 10 to 14 degrees C (50 to 57 degrees). 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 Kamawai, Nawahine, Nenenui, Ohianui, and Puuiki series. Kamawai soils have a lithic contact at 25 to 50 centimeters (10 to 20 inches). Nawahine soils are medial over cindery. Nenenui soils have a lithic contact at 5 to 25 centimeters (2 to 10 inches). Ohianui soils are ashy over cindery and have a lithic contact at 50 to 102 centimeters (20 to 40 inches). Puuiki soils are organic soils over pahoehoe lava.

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

USE AND VEGETATION: Used for grazing and wildlife habitat. The natural vegetation is kikuyugrass (Pennisetum clandestinum).

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. Proposed in 1996.

REMARKS: Soil moisture - usually moist, but 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 0 to 69 centimeters (0 to 27 inches) (A/2C1, Bw/2C2, and 2C3/Bw2 horizons).
Lithic contact - at 69 centimeters (27 inches) (2R horizon).
Andic properties - from 0 to 69 centimeters (0 to 27 inches) (A/2C1, Bw/2C2, and 2C3/Bw2 horizons).

ADDITIONAL DATA: Halekula NSSL sample S97HI-001-004.

National Cooperative Soil Survey
U.S.A.