Classification of the Soils of Hawaii
H. Ikawa, Raymond S. Uchida, and Gordon Y. Tsuji
The purpose of this web page is to allow the land use planners, extension agents, researchers, farmers, and others to make use of the common soil series names and their corresponding classification for soil management and for transfer of agrotechnology amongst and between similar soils.
There are at least 190 different soil series in Hawaii. Soil series usually have local names and they are classified so that they can be identified systematically. Through updated soil survey of an area, other soil series may be created. The latest soil survey reports of Hawaii are located in the Hamilton Library of the University of Hawaii at Manoa, in most of the public libraries in Hawaii, as well as in many of the offices of government agencies. (USDA, Soil Conservation Service in cooperation with the University of Hawaii Agricultural Experiment Station, 1972 and 1973).
Soil Taxonomy is the name of the classification system of the U.S. It is used not only in the U. S. but also in many countries worldwide. The guiding document is Soil Taxonomy, A Basic System of Soil Classification for Making and Interpreting Soil Surveys, Second Edition (1999). Published by the USDA, Natural Resources Conservation Services (NRCS), it may be purchased from the Superintendent of Documents, U.S. Government Printing Office, P.O. Box 371954, Pittsburgh, PA 15250-7954.
Briefly, Soil Taxonomy is like the plant or animal classification system. It is an hierarchical system with several categories. The six categories are (1) Soil Order, (2) Suborder, (3) Great Group, (4) Subgroup, (5) Soil Family, and (6) Soil Series. Closely related or similar soils are grouped in each of the categories.
General information is associated with the highest category, the soil order. The most detailed and specific information is the lowest category, the soil series. These categories are described in the next section, "The Categories of Soil Taxonomy."
Numerous agricultural studies and research findings from Hawaii have been reported nationally and internationally. Many of them are identified with a specific soil or a group of soils. Some are studies from the early 1900s, while others are more recent. Although the classification names of these soils may have changed over time, the names of the soil series and their properties have remained the same. This web page provides not only the taxonomic names associated with Soil Taxonomy but also the earlier Great Soil Group Classification System names developed in the 1930s.
For the use of the soil family in agrotechnology transfer, see the publication by Silva (1985).
Soils are classified in Soil Taxonomy by using the Keys to Soil Taxonomy (USDA, Soil Survey Staff, 2006). The morphological, physical, chemical, and mineralogical properties of soils are used with the keys to obtain the taxonomic classification.
This web page, however, will not discuss how soils are classified, but it will provide the listing of the soil series as well as the taxonomic classification. Subsequent web pages will discuss how soil interpretation and suitability rating for specific uses can be made from the taxonomic classification.