model applications such as: (1) issues to be addressed must be neither trivial nor obvious; (2) a
modelling approach must reduce complexity rather than proliferate choices in order to aid the
decision-making process; (3) the cropping systems must be sufficiently flexible to allow management
interventions based on insights gained from models. The pro and cons of normative
approaches (e.g. decision support software that can reach a wide audience quickly but are
often poorly contextualized for any individual client) versus model applications within the
context of an individual client’s situation will also be discussed. We suggest that a tandem
approach is necessary whereby the latter is used in the early stages of model application for
confidence building amongst client groups. This paper focuses on five specific regions that
differ fundamentally in terms of environment and socio-economic structure and hence in their
requirements for successful model applications. Specifically, we will give examples from Australia
and South America (high climatic variability, large areas, low input, technologically
advanced); Africa (high climatic variability, small areas, low input, subsistence agriculture);
India (high climatic variability, small areas, medium level inputs, technologically progressing;
and Europe (relatively low climatic variability, small areas, high input, technologically
advanced). The contrast between Australia and Europe will further demonstrate how successful
model applications are strongly influenced by the policy framework within which
producers operate. We suggest that this might eventually lead to better adoption of fully
integrated systems approaches and result in the development of resilient farming systems that
are in tune with current climatic conditions and are adaptable to biophysical and socioeconomic
variability and change. # 2001 Elsevier Science Ltd. All rights reserved.