LOCATION WAHIKULI HIEstablished Series
TAXONOMIC CLASS: Fine, parasesquic, isohyperthermic Torroxic Haplustolls
TYPICAL PEDON: Wahikuli silty clay - sugarcane. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
Ap1--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, sticky and plastic; many roots; common fine pores; few fine black concretions; strong effervescence with hydrogen peroxide; mildly alkaline (pH 7.4); gradual wavy boundary. (6 to 10 inches thick)
Ap2--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, sticky and plastic; many roots; many fine pores; few fine black concretions and stains; common sand size aggregates that are resistant to crushing; strong effervescence with hydrogen peroxide; mildly alkaline (pH 7.7); clear wavy boundary. (5 to 8 inches thick)
B2--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, sticky and plastic; common roots; many fine and medium pores; few black stains on faces of peds and in pores; patchy pressure faces; few highly weathered pebbles; strong effervescence with hydrogen peroxide; mildly alkaline (pH 7.6); gradual wavy boundary. (10 to 15 inches thick)
B3--27 to 32 inches; dark reddish brown (2.5YR 3/4) silty clay, red (2.5YR 4/6) dry; weak fine subangular blocky structure; hard, friable, sticky and plastic; few roots; common fine and medium pores; 30 to 40 percent highly weathered to slightly weathered gravel; few cobbles; strong effervescence with hydrogen peroxide; mildly alkaline (pH 7.6); abrupt wavy boundary. (4 to 7 inches thick)
R--32 inches; gray porous basalt 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' 09" north latitude and 156 degrees 41' 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.
RANGE IN CHARACTERISTICS: Depth to bedrock is 20 to 40 inches. Mean annual soil temperature is 75 degrees F.
The Ap horizon has hue of 2.5YR or 5YR, and chroma of 2 or 3 moist and 3 through 6 dry.
The B horizon has hue of 2.5YR or 5YR, and value of 3 or 4 dry. Patchy lime coatings are present in the lower part of the B horizon in some pedons.
COMPETING SERIES: These are the Ewa, Keahua, Waiakoa, and Waikapu series. Ewa soils are more than 40 inches deep over coral. Keahua and Waiakoa soils have a fine-silty control section. Waikapu soils have a fine-silty control section and have slickensides in the B horizon.
GEOGRAPHIC SETTING: Wahikuli soils are on uplands. Slope is 3 to 7 percent. Outcrops of rocks along the rims of drainageways are common. Elevation ranges from 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 12 to 20 inches. The mean annual temperature is about 75 degrees F.; average January temperature is 72 degrees F.; average July temperature is 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 PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for sugarcane with small areas used for urban and recreation. 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.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Maui County, Hawaii, 1971.
OSED scanned by SSQA. Last revised by state on 3/78.