NEW ZEALAND SOIL CLASSIFICATION

Version 3.0 of the Zealand Soil Classification is the culmination of a period of development from its initiation in 1983 to wide circulation of versions 1.0 and 2.0 (Hewitt 1989) for comment and testing. It represents the best attempt, given the current state of knowledge, to classify New Zealand soils. As the knowledge and understanding of New Zealand soils grows, further revisions will be necessary. Accounts of the methods used in developing the soil classification and the rationale for the classes and differentia used are in preparation. The New Zealand Soil Classification is a national soil classification intended to replace the New Zealand Genetic Soil Classification (Taylor 1948; Taylor and Cox 1956; Taylor and Pohlen 1962). The New Zealand Genetic Soil Classification grew out of the need for reconnaissance mapping of the nation's soil resources. It was successful as a unifying factor in New Zealand soil science, and it played a vital role in the development of pastoral agriculture. However, modern soil surveys and land evaluations required precise definition of classes and keys for their recognition. Furthermore, a new synthesis was needed of the large body of information collected since the 1950s. The present work has grown out of the New Zealand Genetic Soil Classification and, where possible, preserves successful parts of that classification. It has also been influenced by experience in testing the US Soil Taxonomy (Leamy et al. 1983).