Agriculture Reference
In-Depth Information
14
CHAPTER
New Zealand Soil
Classification—Purposes and Principles
A.E. Hewitt
CONTENTS
Introduction ....................................................................................................................................179
Purposes for Soil ClassiÝcation in the Context of Numerical Analysis.......................................179
Outline of the Principles ................................................................................................................180
ClassiÝcation Structure and IdentiÝcation of the Soil Individual.................................................181
Hierarchical Position of the Hydromorphic Soils .........................................................................182
Field Assignment to Soil Classes ..................................................................................................183
Nomenclature .................................................................................................................................183
Priority of Classes over Key ..........................................................................................................184
Distinctive Character of New Zealand Soils .................................................................................184
Conclusion......................................................................................................................................185
References ......................................................................................................................................185
INTRODUCTION
The New Zealand Soil ClassiÝcation was published in 1993 (Hewitt, 1993a) and replaced the
New Zealand genetic soil classiÝcation (Taylor, 1948; Taylor and Pohlen, 1968) as the national
system of soil classiÝcation in New Zealand. A comprehensive description of the New Zealand
Soil ClassiÝcation is not given in this account. Instead the reader is referred to publications in the
References list. The aim here is to discuss some features of the classiÝcation (some of which are
distinctive) that guided its development and application.
PURPOSES FOR SOIL CLASSIFICATION IN THE CONTEXT
OF NUMERICAL ANALYSIS
The New Zealand Soil ClassiÝcation was developed at a time when computing power was
beginning to show its potential for rapid and convenient numerical analysis. The classiÝcation was
