Under leadership of CT de Wit a large amount of modeling, building prototypes and also application, was carried out in the 1970s and 1980s. Comprehensive models were built, evaluated and carefully documented in the areas of crop growth production, plant breeding, soil water and nutrients, and in crop protection. Simulation techniques and biophysical theories developed in parallel. Simulation and experimentation always went hand in hand. Much of this work is documented in a long series of PhD theses under supervision of De Wit, in the series of Simulation Monographs (PUDOC), and in numerous other publications. This work has inspired many scientists across the global science community. The CT de Wit Graduate School of Production Ecology (PE) of the Wageningen University builds further on this platform and finds new subjects for research on and with models, and data. The PE platform provides also an excellent opportunity to develop contacts, cooperation and joint software with research groups in related fields and abroad. This book precipitates from such an exploration in new directions. We realize that modem information systems and statistics can offer a substantial contribution to the modelling framework. Good examples can be found here, and these provide a clear direction for the years to come.

In December 1993, ISNAR, in collaboration with International Consortium for Application of Systems Approaches, organized a three-day workshop on systems approaches and -modelling for agricultural development. Sponsored by the Dutch Ministry for Development Cooperation, the workshop was attended by participants from 12 national agricultural research systems (NARS), nine international agricul tural research centers (IARCs), and five advanced research organizations (AROs). Although application of systems approaches in agricultural research and resource management is a rather new field, there is already increasing demand for implemen tation of these approaches. This will require a critical mass of specialists in the NARS and IARCs. Before this critical mass can be obtained, however, the experience that has been gained in this area needs to be evaluated, further possibilities need to be explored, and new objectives and targets need to be set. This book, which contains the papers presented at the workshop, assesses the state of the art of systems approaches in agricultural research, resource management, and rural planning. It also gives an impression of the evolution of this interdisciplinary field and its use in national and international research centers. Another, less tangible, outcome of the workshop was its contribution toward strengthening the network of NARS, IARCs, and AROs. It gave participants and organizers a chance to develop contacts, and provided an opportunity to make the first proposals for collaborative programs. Special thanks are due to Peter Goldsworthy and Luc Boerboom for their crucial role in making the workshop a success in this regard."

In December 1993, ISNAR, in collaboration with International Consortium for Application of Systems Approaches, organized a three-day workshop on systems approaches and -modelling for agricultural development. Sponsored by the Dutch Ministry for Development Cooperation, the workshop was attended by participants from 12 national agricultural research systems (NARS), nine international agricul tural research centers (IARCs), and five advanced research organizations (AROs). Although application of systems approaches in agricultural research and resource management is a rather new field, there is already increasing demand for implemen tation of these approaches. This will require a critical mass of specialists in the NARS and IARCs. Before this critical mass can be obtained, however, the experience that has been gained in this area needs to be evaluated, further possibilities need to be explored, and new objectives and targets need to be set. This book, which contains the papers presented at the workshop, assesses the state of the art of systems approaches in agricultural research, resource management, and rural planning. It also gives an impression of the evolution of this interdisciplinary field and its use in national and international research centers. Another, less tangible, outcome of the workshop was its contribution toward strengthening the network of NARS, IARCs, and AROs. It gave participants and organizers a chance to develop contacts, and provided an opportunity to make the first proposals for collaborative programs. Special thanks are due to Peter Goldsworthy and Luc Boerboom for their crucial role in making the workshop a success in this regard."

Under leadership of CT de Wit a large amount of modeling, building prototypes and also application, was carried out in the 1970s and 1980s. Comprehensive models were built, evaluated and carefully documented in the areas of crop growth production, plant breeding, soil water and nutrients, and in crop protection. Simulation techniques and biophysical theories developed in parallel. Simulation and experimentation always went hand in hand. Much of this work is documented in a long series of PhD theses under supervision of De Wit, in the series of Simulation Monographs (PUDOC), and in numerous other publications. This work has inspired many scientists across the global science community. The CT de Wit Graduate School of Production Ecology (PE) of the Wageningen University builds further on this platform and finds new subjects for research on and with models, and data. The PE platform provides also an excellent opportunity to develop contacts, cooperation and joint software with research groups in related fields and abroad. This book precipitates from such an exploration in new directions. We realize that modem information systems and statistics can offer a substantial contribution to the modelling framework. Good examples can be found here, and these provide a clear direction for the years to come.