LOCATION HIHIMANU HIEstablished Series
TAXONOMIC CLASS: Very-fine, parasesquic, isohyperthermic Oxic Dystrudepts
TYPICAL PEDON: Hihimanu silty clay loam - trees and grass. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
A1--0 to 7 inches; dark brown (7.5YR 3/3) silty clay loam, dark brown (7.5YR 3/2) dry; strong fine and very fine subangular blocky structure; very hard, firm, sticky and plastic; many coarse, medium and fine roots; few weathered pebbles; slight effervescence with hydrogen peroxide; very strongly acid (pH 5.0); clear smooth boundary. (7 to 10 inches thick)
A2--7 to 15 inches; dark brown (7.5YR 3/4) silty clay, same color dry; weak fine and very fine subangular blocky structure; very hard, friable, sticky and plastic; many medium fine and very fine, few coarse roots; many fine pores; few weathered pebbles; upper part mixed with A1 material by worm action; very strongly acid (pH 5.0); gradual smooth boundary. (6 to 10 inches thick)
Bw1--15 to 27 inches; reddish brown (5YR 4/4) silty clay, brown (7.5YR 4/3) dry; moderate fine and very fine subangular blocky structure; very hard, firm, very sticky and plastic; many very fine and fine, common medium and few large roots; many fine pores; few weathered pebbles; very strongly acid (pH 4.8); gradual smooth boundary. (9 to 15 inches thick)
Bw2--27 to 45 inches; reddish brown (5YR 4/4) clay, reddish brown (5YR 4/3) dry; moderate fine and very fine subangular blocky structure; very hard, firm, very sticky and plastic; common very fine and fine and few medium roots; many fine pores; few weathered pebbles; very strongly acid (pH 4.8); gradual smooth boundary. (14 to 20 inches thick)
Bw3--45 to 72 inches; brown (7.5YR 4/4) silty clay, brown (7.5YR 4/3) dry; moderate fine and very fine subangular blocky structure; very hard, firm, sticky and plastic; few very fine and fine roots; many fine pores; many weathered pebbles; intermittent thin bands of dark brown (7.5YR 3/3) and pockets of reddish brown (5YR 4/4); very strongly acid (pH 4.8).
TYPE LOCATION: Island of Kauai, Kauai County, Hawaii; along road to power line tower on Grove Farm Plantation; Koloa Quadrangle; lat. 21 degrees 56 minutes 55.4 seconds N. and long. 159 degrees 27 minutes 28.4 seconds W. (Old Hawaiian Datum)
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to over 60 inches to highly weathered parent material. Stones in the profile vary from none to few. Mean annual soil temperature is about 70 degrees F. The A1 horizon has hue of 7.5YR or 10YR. The B horizon has hue of 5YR or 7.5YR.
COMPETING SERIES: (This needs updating) These are the Hanamaulu, Kolekole, Lolekaa, Makaalae, Pohakupu, and Waikane series. Hanamaulu soils have a mean annual soil temperature of more than 71.6 degrees F. Kolekole soils have a fine-silty control section and have 2.5YR hue in the cambic horizon. Lolekaa soils have an argillic horizon and have 10YR hue throughout the solum. Makaalae soils have very stony subsoil. Pohakupu soils have a fine-silty control section and a mean annual temperature of more than 71.6 degrees F. Waikane soils have an argillic horizon.
GEOGRAPHIC SETTING: Hihimanu soils are on very steeply sloping positions in the uplands of Kauai. Slope is 40 to 70 percent. The soils formed in residuum from basic igneous rock and colluvium at the base of slopes. Elevation ranges from 100 to 2,000 feet. The annual rainfall ranges from 70 to 120 inches. Mean annual temperature is about 69 degrees; average January temperature is 67 degrees F., and average July temperature is 73 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hanalei, Kalapa and Lawai and the competing Hanamaulu soils. Hanalei soils occur on the lowlands and are mottled. Kalapa soils have an argillic horizon. Lawai soils have a very dark grayish brown A horizon and a very fine textured control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are used for watershed, wildlife and grazing. Natural vegetation is koa (Acacia koa), melastoma (Melastoma malabathricum), yellow foxtail (Setaria geniculata), lantana (Lantana camara), false staghorn fern (Gleichenia linearis), lace fern (Sphenomeris chusana), spathoglottis (Spathoglottis sp.), paspalum (Paspalum sp.), puhala (Pandanus odoratissimus), rhodomyrtus (Rhodomyrtus tomentosa), silver oak (Greviliea robusta), guava (Psidium guajava), scrubby ohia lehua (Metrosideros collina).
DISTRIBUTION AND EXTENT: East and southeast mountain footslopes on Kauai. These soils are of small extent comprising about 4,900 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Kauai County, Hawaii, 1971.
REMARKS: This series should be split as elevation range is too broad and some areas are isothermic.
FCC Classification: Chik.
Edit Log: 3/04 SN. Horizon designations updated plus minor changes.
8/02 SN. Classification changed from Fine, oxidic, isothermic Oxic Humitropepts due to changes in Taxonomy.
ADDITIONAL DATA: