LOCATION OKOE                    HI

Established Series
RTG/MRK
06/2012

OKOE SERIES

The Okoe 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 890 millimeters (35 inches), and the mean annual temperature is about 23 degrees C (73 degrees F).

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

TYPICAL PEDON: Okoe extremely cobbly medial silt loam, on a west facing, slightly convex, 6 percent slope in pasture at an elevation of 341 meters (1,120 feet). (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures." pH measured with organic dyes. When described on July 15, 1997, the soil was dry throughout.) The 2C horizons consist of unconsolidated `a`a lava fragments of variable size.

2C1/A1--0 to 10 centimeters (0 to 4 inches); black (N 2/0) extremely cobbly medial silt loam, black (10YR 2/1) dry; strong very fine and fine granular structure; soft, very friable, nonsticky and nonplastic, nonsmeary; hydrophobic when dry; many very fine and fine, and few medium and coarse roots; many very fine and fine interstitial pores; 35 percent `a`a cobbles, 30 percent `a`a gravel, and 10 percent `a`a stones; neutral (pH 6.8); abrupt wavy boundary. (10 to 15 centimeters (4 to 6 inches) thick)

2C2/A2--10 to 28 centimeters (4 to 11 inches); black (10YR 2/1) extremely cobbly medial silt loam, very dark brown (10YR 2/2) dry; moderate very fine and fine granular structure; loose when dry or moist, nonsticky and nonplastic, nonsmeary; hydrophobic when dry; many very fine and fine, and few medium and coarse roots; many very fine and fine interstitial pores; 40 percent `a`a cobbles and 30 percent `a`a gravel; neutral (pH 7.0); clear wavy boundary. (18 to 28 centimeters (7 to 11 inches) thick)

2C3/Bw--28 to 91 centimeters (11 to 36 inches); dark reddish brown (5YR 2.5/2) extremely 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, and few medium roots; 40 percent `a`a cobbles and 30 percent `a`a gravel; neutral (pH 7.2); abrupt wavy boundary. (0 to 64 centimeters (0 to 25 inches) thick)

2R--91 centimeters (36 inches); hard, massive `a`a blue rock; class 3 (0.45-1 m) joint fractures.

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; from Mac Farms of Hawaii headquarters drive 1.1 miles north on Highway 11, turn left onto orchard road and drive 0.4 miles north; turn left at orchard boundary and drive onto 4WD road 0.8 miles west to gate; pass through locked gate and drive left 0.3 miles to the next gate; drive left 0.8 miles south; pedon is located 37 meters (120 feet) to the west of 4WD road and immediately south of kukui grove. Papa Quadrangle; lat. 19 degrees 8 minutes 39.7 seconds N. and long. 155 degrees 52 minutes 21.4 seconds W. (GPS/PLGR; Old Hawaiian Datum).

RANGE IN CHARACTERISTICS:
Depth to bedrock: 50 to 102 centimeters (20 to 40 inches).
Mean annual soil temperature: 21 to 24 degrees C (70 to 75 degrees F).
Rock fragments: 55 to 75 percent by volume of the pedon and range in size from gravel to stones, but are primarily gravel and cobble-size lava rocks.

2C/A horizon
Hue: Neutral or 10YR.
Chroma: 0, 1 or 2 moist or dry.
Texture: Extremely or very cobbly medial silt loam or sandy loam.
Soil reaction: Slightly acid or neutral (pH 6.1 to 7.3).

2C3/Bw horizon
Hue: 10YR, 7.5YR, or 5YR.
Value: 2 or 2.5 moist, 3 or 4 dry.
Chroma: 2 or 3 moist, 3 or 4 dry.
Texture: Extremely cobbly medial silt loam or sandy loam.
Soil reaction: Neutral (pH 6.6 to 7.3).

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Okoe soils are on low elevation, leeward slopes of Mauna Loa Volcano at elevations from sea level to 366 meters (1,200 feet). These soils are on all hillslope positions of constructional landscapes consisting of undulating to hilly `a`a flows that are 3,000 to 5,000 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 510 to 1270 millimeters (20 to 50 inches), with most of the rainfall occurring from April through October. The mean annual pan evaporation ranges from 1020 to 2030 millimeters (40 to 80 inches). The mean annual temperature ranges from 22 to 26 degrees C (72 to 78 degrees F). The mean summer and mean winter soil temperatures differ by less than 6 degrees C (11 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kaimu, Kainaliu, Kanohina, Punaluu, and Waiaha series. Kaimu soils are organic soils over `a`a lava. Kainaliu soils have a silty clay loam to silt loam textures in the control section. Kanohina soils have a lithic contact at 5 to 25 millimeters (2 to 10 inches) and overlie pahoehoe lava. Punaluu soils are organic soils over pahoehoe lava. Waiaha soils have a lithic contact at 25 to 50 centimeters (10 to 20 inches).

DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to high. 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 koa haole (Leucaena leucophala), guava (Psidium guajava), lantana (Lantana camara), christmasberry (Schinus terebinthifolius), kukui nut (Aleurites moluccana), guineagrass (Urochloa maxima), and piligrass (Heteropogon contortus).

DISTRIBUTION AND EXTENT: South 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 1996.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 91 centimeters (0 to 36 inches) (2C1/A1, 2C2/A2, and 2C3/Bw horizons).
Andic soil properties - from 0 to 91 centimeters (0 to 36 inches) (2C1/A1, 2C2/A2 and 2C3/Bw horizons).
Lithic contact - at 91 centimeters (36 inches) (2R horizon).
Soil moisture - usually moist, but dry in some or all parts for short intermittent periods totaling 90 or more days during the months of October through April in most years (Ustic moisture regime).

ADDITIONAL DATA: NASIS User Pedon ID 01HI601024. NSSL sample S97HI-001-014.

Edit log: 4/09 MRK. Andic textural modifiers added, competing series updated, plus minor edits.

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National Cooperative Soil Survey
U.S.A.