Increasing profits and reducing risks in crop production using participatory systems simulation approaches

The development of cropping systems simulation capabilities world-wide comb ined with easy access to powerful computing has resulted in a plethora of a gricultural models and consequently, model applications. Nonetheless, the s cientific credibility of such applications and their relevance to farming p ractice is still being questioned. Our objective in this paper is to highli ght some of the model applications from which benefits for farmers were or could be obtained via changed agricultural practice or policy. Changed on-f arm practice due to the direct contribution of modelling, while keenly soug ht after, may in some cases be less achievable than a contribution via agri cultural policies. This paper is intended to give some guidance for future model applications. It is not a comprehensive review of model applications, nor is it intended to discuss modelling in the context of social science o r extension policy. Rather, we take snapshots around the globe to 'take sto ck' and to demonstrate that well-defined financial and environmental benefi ts can be obtained on-farm from the use of models. We highlight the importa nce of 'relevance' and hence the importance of true partnerships between al l stakeholders (farmer, scientists, advisers) for the successful developmen t and adoption of simulation approaches. Specifically, we address some key points that are essential for successful model applications such as: (1) is sues to be addressed must be neither trivial nor obvious; (2) a modelling a pproach must reduce complexity rather than proliferate choices in order to aid the decision-making process (3) the cropping systems must be sufficient ly flexible to allow management interventions based on insights gained from models. The pro and cons of normative approaches (e.g. decision support so ftware that can reach a wide audience quickly but are often poorly contextu alized for any individual client) versus model applications within the cont ext 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 t erms of environment and socio-economic structure and hence in their require ments for successful model applications. Specifically, we will give example s from Australia and South America (high climatic variability, large areas, low input, technologically advanced); Africa (high climatic variability, s mall areas, low input, subsistence agriculture); India (high climatic varia bility, small areas, medium level inputs, technologically progressing; and Europe (relatively low climatic variability, small areas, high input, techn ologically advanced). The contrast between Australia and Europe will furthe r demonstrate how successful model applications are strongly influenced by the policy framework within which producers operate. We suggest that this m ight eventually lead to better adoption of fully integrated systems approac hes 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. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.