LOCATION WAHIKULI                HI

Established Series
Rev. RCH/HHS/MRK
09/2020

WAHIKULI SERIES

The Wahikuli series consists of moderately deep, well drained soils that formed in residuum weathered from basic igneous rock and volcanic ash. Wahikuli soils are on low elevation, mountain hillslopes and have slopes of 3 to 15 percent. Mean annual rainfall is about 305 to 508 millimeters (12 to 20 inches) and mean annual temperature is about 24 degrees C. (75 degrees F.)

TAXONOMIC CLASS: Fine, parasesquic, isohyperthermic Torroxic Haplustolls

TYPICAL PEDON: Wahikuli silty clay - homesite. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")

Ap1--0 to 20 centimeters (0 to 8 inches); dark reddish brown (2.5YR 3/3) silty clay, dark red (2.5YR 3/6) dry; weak fine and very fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many fine roots; common fine irregular pores; few fine black concretions; strong effervescence with hydrogen peroxide; slightly alkaline (pH 7.4); gradual wavy boundary. (15 to 25 centimeters thick)

Ap2--20 to 38 centimeters (8 to 15 inches); dark reddish brown (2.5YR 3/3) silty clay, dark red (2.5YR 3/6) dry; weak medium and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many fine roots; many fine tubular pores; few fine black concretions and stains; common sand size aggregates that are resistant to crushing; strong effervescence with hydrogen peroxide; slightly alkaline (pH 7.7); clear wavy boundary. (13 to 20 centimeters thick)

Bw1--38 to 69 centimeters (15 to 27 inches); dark reddish brown (2.5YR 3/4) silty clay, dark red (2.5YR 3/6) dry; weak medium and fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common fine roots; many fine and medium tubular pores; few black stains on faces of peds and in pores; patchy pressure faces; 2 percent highly weathered gravel; strong effervescence with hydrogen peroxide; slightly alkaline (pH 7.6); gradual wavy boundary. (25 to 38 centimeters thick)

Bw2--69 to 81 centimeters (27 to 32 inches); dark reddish brown (2.5YR 3/4) gravelly silty clay, red (2.5YR 4/6) dry; weak fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine roots; common fine and medium tubular pores; 35 percent highly weathered to slightly weathered gravel; 2 percent cobbles; strong effervescence with hydrogen peroxide; slightly alkaline (pH 7.6); abrupt wavy boundary. (10 to 18 centimeters thick)

R--81 centimeters; gray porous basalt bedrock with dark reddish brown coatings and very little soil material in voids and cracks; in irrigated areas this material is very difficult to grind out with auger; in dry areas this material is extremely difficult to chip with spade; very slight effervescence with hydrochloric acid on some rock surfaces.

TYPE LOCATION: Island of Maui, Maui County, Hawaii; Lahaina Quadrangle - 20 degrees 55 minutes 09 seconds north latitude and 156 degrees 41 minutes 00 seconds west longitude; 25 feet north of road and 350 feet west of canehauler road about 1.2 mile south of Puukolii Village; in field C-8, Pioneer Mill Company plantation. (WGS84 datum)

RANGE IN CHARACTERISTICS: Depth to bedrock is 51 t0 102 centimeters (20 to 40 inches). Mean annual soil temperature is 22 to 24 degrees C. (72 to 75 degrees F.)

The Ap horizon
Hue of 2.5YR or 5YR.
Chroma of 2 or 3 moist and 3 through 6 dry.
Surface textures are silty clay, stony silty clay, or very silty clay.
Structure is fine to medium subangular blocky.
Rupture resistance, dry is slightly hard to hard.

The Bw horizon
Hue of 2.5YR or 5YR
Value of 3 or 4 dry.
Textures are silty clay, gravelly or very gravelly silty clay, or cobbly silty clay.
Structure is fine to medium subangular blocky.
Rupture resistance, dry is slightly hard to hard.
Patchy lime coatings are present in the lower part of the B horizon in some pedons.

COMPETING SERIES: This is the Makaweli series. Makaweli soils are more than 102 centimeters (40 inches) deep

GEOGRAPHIC SETTING: Wahikuli soils are on low elevation, mountain hillslopes. Slope is 3 to 15 percent. Outcrops of rocks along the rims of drainageways are common. Elevation ranges from 0 to 182 meters (sea level to 600 feet). The soils formed in residuum from basic igneous rock with some influence from volcanic ash from local cinder cones. The annual precipitation ranges from 305 to 508 millimeters (12 to 20 inches). The mean annual temperature is about 24 degrees C. (75 degrees F.); average January temperature is 22 degrees C. (72 degrees F.); average July temperature is 25 degrees C. (78 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lahaina, Molokai, and Wainee soils. Lahaina and Molokai soils have a fine-silty control section and are more than 40 inches thick. Wainee soils have a clayey-skeletal control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff; moderately rapid saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for homesite development with small areas used for urban and recreation. Many areas were used for sugarcane. The natural vegetation is mainly bermudagrass (Cynodon dactylon), feather fingergrass (Chloris virgata), kiawe (Prosopis chilensis) and uhaloa (Waltheria indica).

DISTRIBUTION AND EXTENT: Island of Maui, Maui County, Hawaii. This series is inextensive, with approximately 2,100 acres.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Maui County, Hawaii, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 38 centimeters (Ap horizon)
Cambic horizon - 38 to 81 centimeters (Bw horizon)
Lithic contact - 81 centimeters (R horizon)

OSED scanned by SSQA. Last revised by state on 9/2001.

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National Cooperative Soil Survey
U.S.A.