LOCATION AINAKEA                 HI

Established Series
Rev. CS/SN/HI/MRK
01/2023

AINAKEA SERIES

The Ainakea series consists of moderately deep, well drained soils that formed in basic volcanic ash over material weathered from basalt. Ainakea soils are on uplands and have slopes of 3 to 100 percent. The mean annual rainfall is about 1,905 millimeters (75 inches), and the mean annual temperature is about 22 degrees C. (72 degrees F.)

TAXONOMIC CLASS: Medial, ferrihydritic, isohyperthermic Acrudoxic Hydric Hapludands

TYPICAL PEDON: Ainakea medial silty clay loam, on a north facing, 5 percent slope, in macadamia nut orchard with grass cover, at an elevation of 253 meters (820 feet). (Colors are for moist soil unless otherwise noted. Textures are apparent field textures.)

Ap--0 to 25 centimeters (0 to 10 inches); dark brown (10YR 3/3) medial silty clay loam, dark yellowish brown (10YR 4/4) dry; strong fine and medium granular structure; hard, firm, slightly sticky and slightly plastic; nonsmeary; many very fine and fine roots; many very fine and fine tubular and interstitial pores; 5 percent gravel; extremely acid (pH 4.4); clear wavy boundary. (20 to 31 centimeters {8 to 12 inches} thick)

Bw1--25 to 46 centimeters (10 to 18 inches); dark brown (7.5YR 3/4) medial silty clay loam, dark yellowish brown (10YR 3/4) dry; moderate fine and very fine subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; weakly smeary; common very fine and fine roots; many very fine and fine tubular pores; 5 percent gravel; strongly acid (pH 5.4); clear wavy boundary. (15 to 23 centimeters {6 to 9 inches} thick)

Bw2/2C--46 to 76 centimeters (18 to 30 inches); dark brown (10YR 3/3) very cobbly medial silty clay loam, dark yellowish brown (10YR 4/4) dry; strong very fine and fine subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; weakly smeary; common very fine roots; many very fine and fine irregular pores; 20 percent gravel, 10 percent cobbles, and 10 percent stones; moderately acid (pH 5.6); abrupt wavy boundary. (25 to 38 centimeters {10 to 15 inches} thick)

2Cr--76 to 86 centimeters (30 to 34 inches); 60 percent dark yellowish brown (10YR 3/4) silt loam and 40 percent red (2.5YR 4/8) sandy loam; massive parting to weak fine and medium subangular blocky structure; firm, slightly sticky and nonplastic; nonsmeary; common very fine irregular pores; moderately acid (pH 5.8) abrupt wavy boundary. (5 to 15 centimeters {2 to 6 inches} thick)

2R--86 centimeters (34 inches); hard pahoehoe lava.

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; approximately 1/2 mile east of Kohala Post Office and l.5 miles south of highway in macadamia nut orchard at an elevation of 253 meters (820 feet); Hawi Quadrangle lat. 20 degrees 12 minutes 55 seconds N. and long. 155 degrees 47 minutes 58 seconds W. (Old Hawaiian Datum)

RANGE IN CHARACTERISTICS:
Depth to bedrock: 51 to 102 centimeters (20 to 40 inches).
Mean annual soil temperature: 22 to 24 degrees C. (72 to 75 degrees F.)

The Ap horizon
Hue: 7.5YR or 10YR.
Value: 1 to 3 moist or 2 to 4 dry
Chroma: 2 to 3 moist or 2 to 4 dry
Texture: gravelly or nongravelly, medial, silt loam or silty clay loam
Structure: granular or subangular blocky
Smeariness: nonsmeary or weakly smeary

The Bw horizon
Hue: 7.5YR or 10YR Chroma: 2 to 3 moist or 3 to 4 dry Texture: gravelly or nongravelly medial silty clay loam Structure: moderate or strong Consistence: hard to very hard and slightly compacted.
Smeariness: weakly smeary to moderately smeary

COMPETING SERIES: There are no competing series. Similar soils include the Niulii series. Niulii soils have a mean annual soil temperature of 20 degrees C. (68 degrees F.)

GEOGRAPHIC SETTING: Ainakea soils are on low, windward slopes of Kohala Mountains. The dominant slopes range from 3 to 20 percent. Elevation ranges from sea level to 549 meters (0 to l,800 feet). The soils formed in basic volcanic ash over material weathered from basalt. The mean annual rainfall is 1,524 to 2,286 millimeters (60 to 90 inches) and occurs from October through April. The mean annual temperature is about 22 degrees C. (72 degrees F.), mean January temperature is 19 degrees C. (67 degrees F.), and the mean July temperature is 23 degrees C. (74 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kohala and Niulii soils. Kohala soils have a silty clay texture, an ustic soil moisture regime, and no andic soil properties.

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability.

USE AND VEGETATION: Most of these soils are used for grazing lands, homesites, and some areas are used for orchard crops. Natural vegetation is mainly guava (Psidium guajava), hilograss (Paspalum conjugatum) and christmasberry (Schinus terebinthifolius).

DISTRIBUTION AND EXTENT: This series occurs in the North Kohala District of the Island of Hawaii. This series is of small extent, about 8,000 acres.

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

SERIES ESTABLISHED: Hawaii County, Island of Hawaii, Hawaii, 1971.

REMARKS: Udic soil moisture regime- The soil is not dry in any part of the soil moisture control section for more than 90 cumulative days in most years.
Diagnostic horizons and features recognized in this pedon include:
Umbric epipedon: 0 to 46 centimeters (0 to 18 inches)
Paralithic contact: 76 centimeters (30 inches)
Cambic horizon: 25 to 46 centimeters (10 to 18 inches)
Lithic contact: 86 centimeters (34 inches)
Andic soil properties: 0 to 76 centimeters (0 to 30 inches)

ADDITIONAL DATA: NASIS User Pedon ID 08HI603011. NSSL samples S91HI-001-006.

Edit Log: 12/03 SN. Horizon designations updated, plus minor edits.
8/00 SN. Classification changed from Fine, oxidic, isohyperthermic Andic Ustic Humitropepts due to changes in Taxonomy.
8/09 MRK. Range in characteristics and competing series updated plus minor edits.

---

National Cooperative Soil Survey
U.S.A.