LOCATION WAIAKOA HIEstablished Series
TAXONOMIC CLASS: Fine, kaolinitic, isohyperthermic Torroxic Haplustolls
TYPICAL PEDON: Waiakoa very stony silty clay loam - pasture. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
Ap--0 to 2 inches; dark reddish brown (5YR 3/3) very stony silty clay loam, reddish brown (5YR 3/4) dry; moderate medium and thick platy structure; hard, friable, sticky and plastic; many roots; many fine pores; roots tend to follow plates; 1 to 3 percent stones on surface; strong effervescence with hydrogen peroxide; neutral (pH 6.7); abrupt smooth boundary. (1 to 3 inches thick)
B21--2 to 8 inches; dark reddish brown (5YR 3/2) silty clay loam, dark reddish brown (5YR 3/4) dry; weak coarse prismatic structure; hard, friable, sticky and plastic; many roots; many fine and very fine pores; compact in place except a few pockets of loose material; 5 percent gravel-size rock fragments; strong delayed effervescence with hydrogen peroxide; neutral (pH 6.7); gradual wavy boundary. (4 to 8 inches thick)
B22--8 to 16 inches; dark reddish brown (5YR 3/3) silty clay loam, dark reddish brown (5YR 3/4) dry; weak coarse prismatic structure; hard, friable, sticky and plastic; many roots; many fine pores; common sand-size aggregates that are resistant to crushing; 5 percent gravel-size rock fragments; strong delayed effervescence with hydrogen peroxide; slightly acid (pH 6.4); clear wavy boundary. (6 to 9 inches thick)
IIB23--16 to 25 inches; very dark grayish brown (10YR 3/2) gravelly silty clay loam, dark grayish brown (10YR 4/2) dry; weak coarse prismatic structure in place and weak medium subangular blocky structure when disturbed; hard, friable, sticky, plastic and weakly smeary; common roots; many fine and very fine pores; 20 to 30 percent gravel-size rock fragments that are highly weathered; neutral (pH 6.7); gradual wavy boundary. (7 to 12 inches thick)
IIC--25 to 33 inches; very dark brown (10YR 2/2) stony silty clay loam, very dark grayish brown (10YR 3/2) dry; massive; hard, friable, sticky and plastic; common roots in patches; very porous; common hard earthy lumps; 10 to 20 percent soil material in cracks; 70 to 80 percent grayish brown (2.5YR 5/2) highly weathered basic igneous rock; 10 percent hard rock fragments; common black stains on rocks that effervesce violently with hydrogen peroxide; neutral (pH 7.0).
IIR--33 inches; hard bedrock.
TYPE LOCATION: Island of Maui, Maui County, Hawaii. Puu O Kali Quadrangle - 20 degrees 47' 20" north latitude and 156 degrees 24' 30" west longitude, 50 feet east of Waiakoa Road and about 1 mile south of gate in Makai pasture of the Old Grove Ranch.
RANGE IN CHARACTERISTICS: Depth to bedrock is 20 to 40 inches. Surface stoniness ranges from nonstony to extremely stony. Mean annual soil temperature is 75 degrees F.
The A horizon has hue of 5YR or 2.5YR, value of 2 or 3 moist or dry and chroma of 2 or 3 moist and 3 or 4 dry.
The upper part of the B2 horizon has hue of 5YR or 2.5YR, value of 2 or 3 dry and chroma of 2 or 3 moist and 3 or 4 dry. Calcium carbonate occurs as coatings on the bedrock in some pedons.
COMPETING SERIES: These are the Ewa, Hawi, Iao, Keahua, Koele, Mahukona, Molokai, Paia, Wahikuli, Waikapu and Wainee series. Ewa, Iao, Keahua, Mahukona, Molokai and Paia soils are deeper than 40 inches to bedrock. Hawi, Iao, Paia, Wahiluli and Waikapu soils are fine textured in the particle size control section. Koele soils lack prismatic structure in the B horizon, have 7.5YR or yellower hue throughout the solum and have a mean annual soil temperature of 70 degrees F. Wainee soils have a clayey-skeletal particle size control section.
GEOGRAPHIC SETTING: The Waiakoa soils occur on uplands. Slope is 3 to 25 percent. Rock outcrops are common along the drainageways. Elevation ranges from 100 to 1,000 feet. The soils formed in residuum from basic igneous rock with some volcanic ash in the upper part. The annual precipitation ranges from 12 to 20 inches. Mean annual temperature is about 74 degrees F.; average January temperature is 72 degrees F.; average July temperature is 76 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alae, Keahua, Keawakapu and Pulehu soils. Alae soils have an ashy control section. Keahua soils are more than 40 inches deep. Keawakapu soils have a fine over fragmental control section. Pulehu soils have a fine-loamy control section and are more than 40 inches deep .
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for pasture and irrigated sugarcane. The natural vegetation is mainly buffelgrass (Pennisetum cilliare), Spanish needle (Bidens pilosa), uhaloa (Waltheria indica) and zinnia (Zinnia pauciflora).
DISTRIBUTION AND EXTENT: Island of Maui, Hawaii. This series is moderately extensive, with a total of approximately 21,000 acres.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Island of Maui, Maui County, Hawaii, 1971.
ADDITIONAL DATA: The described pedon was sampled for soil characterization. Sample number S65Ha-4-20-(1-5).
OSED scanned by SSQA. Last revised by state on 3/78.