LOCATION NANUKU                  HI

Established Series
RTG-MRK
06/2012

NANUKU SERIES

The Nanuku series consists of moderately deep, somewhat excessively drained soils that formed in sandy material from `a`a lava and basic volcanic ash. Slopes range from 2 to 20 percent. The mean annual rainfall is about 360 millimeters (14 inches), and the mean annual air temperature is about 28 degrees C (82 degrees F).

TAXONOMIC CLASS: Sandy-skeletal, isotic, isohyperthermic Typic Torriorthents

TYPICAL PEDON: Nanuku extremely cobbly silt loam, on a west facing, slightly convex, 3 percent slope under grasses at an elevation of 213 meters (700 feet). (Colors are for dry soils unless otherwise noted. All textures are "apparent field textures". pH measured with electrode in 1:1 water.)

2C1/A--0 to 8 centimeters (0 to 3 inches); yellowish brown (10YR 5/4) extremely cobbly silt loam, dark brown (7.5YR 3/3) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; nonsmeary; common very fine roots; common very fine interstitial pores; 85 percent `a`a lava (50 percent cobbles, 30 percent gravel, and 5 percent stones); soil surface covered by 90 percent cobbles, and 10 percent stones and boulders; slightly acid (pH 6.2); the 2C part of this horizon consists of unconsolidated `a`a lava fragments of variable size; abrupt wavy boundary. (5 to 18 centimeters {2 to 7} inches thick)

2C2--8 to 76 centimeters (3 to 30 inches); lithochromic dark gray (5YR 4/1) and dark reddish gray(5YR 4/2) extremely cobbly sand, dark reddish brown (5YR 3/3) moist; massive; loose when dry or moist, nonsticky and nonplastic; nonsmeary; few very fine roots; 75 percent `a`a lava (45 percent cobbles, 25 percent gravel and 5 percent stones); slightly alkaline (pH 7.6); abrupt irregular boundary; (50 to 76 centimeters {20 to 30 inches} thick)

2R--76 centimeters (30 inches); hard `a`a blue rock.

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; along Waikaloa Road, about 46 meters (150 feet) south of mile marker 2; the pedon is located on the mauka (upslope) side of the road about 20 meters (65 feet) from red and white posts on northeast end of curve, and about 46 meters (150 feet) east beyond `a`a lava flow. Puu Hinai quadrangle; lat. 19 degrees 54 minutes 59 seconds N. and long. 155 degrees 50 minutes 07 seconds W. (Old Hawaiian Datum)

RANGE IN CHARACTERISTICS:
Depth to bedrock: 50 to 102 centimeters (20 to 40 inches).
Mean annual soil temperature: 24 to 31 degrees C (76 to 87 degrees F.)
Rock fragments: 60 to 85 percent by volume of the pedon and range in size from gravel to stones, but are primarily gravel and cobbles.

2C1/A horizon
Hue: 5YR to 10YR.
Value: 3 or 4 moist, 3 to 5 dry.
Chroma: 2 to 4 moist or dry.
Texture: Extremely or very cobbly silt loam or sandy loam.
Dry consistence: Loose or soft.
Moist consistence: Loose, friable or very friable.
Soil reaction: Slightly acid or neutral (pH 6.1 to 7.3).

2C2 horizon
Hue: 5YR to 10YR.
Value: 2 to 4 moist, 3 to 5 dry.
Chroma: 1 to 4 moist or dry.
Texture: Extremely or very cobbly sand.
Structure: Single grain or massive.
Moist consistence: Loose or friable.
Soil reaction: Neutral or slightly alkaline (pH 6.6 to 7.8).

COMPETING SERIES: There are no competing series. Similar soils include the Kaniku series. Kaniku soils have a mean annual soil temperature that ranges from 17 to 21 degrees C (63 to 70 degrees F).

GEOGRAPHIC SETTING: Nanuku soils are on west slopes on the undissected low elevation, leeward slopes of Mauna Loa Volcano at elevations from sea level to 457 meters (1,500 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 sandy material from `a`a lava and basic volcanic ash. The mean annual rainfall ranges from 180 to 510 millimeters (7 to 20 inches), with most of the rainfall occurring from October through April. The mean annual pan evaporation ranges from 2030 to 2540 millimeters (80 to 100 inches). The mean annual air temperature ranges from 24 to 30 degrees C (76 to 86 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 Auwaiakeakua and Kiholo series. Auwaiakeakua soils are clayey-skeletal. Kiholo soils are clayey and less than 10 inches deep over pahoehoe lava.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Runoff is negligible in depressions on gentle slopes and very low on steeper slopes. Permeability is very rapid in the soil and very slow in the underlying bedrock.

USE AND VEGETATION: Used for wildlife habitat. Vegetation is fountaingrass (Pennisetum setaceum) and kiawe (Prosopis pallida).

DISTRIBUTION AND EXTENT: South Kohala District, Island of Hawaii; MLRA 157. The soils are of small extent.

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

SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii 2012. Proposed 1997.

REMARKS: Soil moisture - usually dry, but moist in some or all parts for less than 90 days in most years (Aridic moisture regime).

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 8 centimeters (0 to 3 inches) (2C1/A horizon.)
Lithic contact - 76 centimeters (30 inches)

ADDITIONAL DATA: NASIS User Pedon ID 01HI601019. NSSL pedon S94HI-001-007.

Edit log: 2/08 Minor edits made. MRK

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National Cooperative Soil Survey
U.S.A.