Agriculture Reference
In-Depth Information
The general trend of soil and land resource survey programs away from pedological objectives
toward practical land evaluation has also coincided with an improvement in the state of soil
classiÝcation in Australia. This culminated in the publication of the Australian Soil ClassiÝcation
(Isbell, 1996), which ofÝcially replaced the Handbook of Australian Soils (Stace et al., 1968) and
The Factual Key for the Recognition of Australian Soils (Northcote, 1979).
Needs of End-Users
Our focus here is on the provision of practical soil class information for a broad range of
land management issues required by land holders, private enterprises, researchers, and gov-
ernment agencies.
There has been some excellent research leading to the development of numerical methods
for soil classiÝcation (e.g., McBratney, 1994), but these are beyond the scope of the present
paper. Our emphasis here is guided by four questions that are most frequently asked by users
of land resource information:
¤ What soil properties are changing, vertically and laterally, in the landscape and with time?
¤ What are the most suitable approaches to characterize, monitor, predict, and manage the changes in soils?
¤ What soil measurements and user-friendly soil classiÝcations are required to make suitable pre-
dictions about soil and landscape conditions and about sustainable land use?
¤To what extent do soil processes and the management of soils, inÞuence engineering infrastructure
and water quality?
These four questions can be answered by using combinations of pedological data along with
soil physical, chemical, hydrological, and mineralogical data relevant to a particular use. The
combined information assists the understanding of how soils vary in landscapes, so that strategies
can be developed for managing both spatial and temporal changes within them. This may often
involve the development of a user-friendly speciÝc purpose or technical soil classiÝcation systems.
Recently, pedologists in Australia have used existing information from soil maps in combination
with data such as soil physics and mineralogy, to work in nonagricultural contexts. This chapter
presents several case studies illustrating how applied soil science information has been classiÝed
and used to solve a wide range of practical problems for end-users.
APPRAISAL OF SOIL CLASSIFICATION SYSTEMS IN AUSTRALIA
The Early Systems of Soil Classification
The sophistication and effectiveness of classiÝcation can indicate the level of scientiÝc maturity
and understanding of a particular area of study, i.e., the level of knowledge and understanding of
the entity under consideration. A major aim of classiÝcation is to usefully summarize the natural
variability of forms the entity takes, and enhance communication about that entity. The Ýrst soil
classiÝcation of Australian soils was devised by Prescott (1931, 1947) and incorporated concepts
of the Russian system of soil classiÝcation, an approach that was followed broadly by others
(Stephens, 1952; 1956; 1962; Stace et al., 1968). However, the Handbook of Australian Soils (Stace
et al., 1968) also had many features in common with the American Great Group system with its
40 Great Groups, which were familiar to soil scientists throughout Australia (Moore et al., 1983).
Leeper (1943; 1956) criticized these traditional classiÝcation schemes and emphasized ÑproÝle
criteria such as marked texture contrast featuresÒ (Isbell, 1992). Although LeeperÔs classiÝcation
was never used, many of its features were used by Northcote in his Factual Key to develop an
objective system based solely on observed soil proÝle features. This classiÝcation became the basis
for mapping of the continent through the Atlas of Australian Soils (Northcote, et al., 1960 to 1968).
