Systems approaches for agricultural development are needed to determine rational strategies for the role of agriculture in national development. Mathematical models and computer simulation provide objective tools for applying science to determine and evaluate options for resource management at field, farm and regional scales. However, these tools would not be fully utilizable without incorporating social and economic dimensions into their application. The second international symposium, Systems Approaches for Agricultural Development , held in Los Baños, 6-8 December 1995, fostered this link between the bio-physical sciences and the social sciences in the choice of keynote papers and oral presentations, a selection of which is included in this book. The book's contents further reflect how systems approaches have definitely moved beyond the research mode into the application mode. The large number and high quality of interdisciplinary research projects reported from different parts of the globe, to determine land use options that will meet multiple goals and yet sustain natural resource bases, is a key indicator of this `coming of age'. At the farm level, where trade-off decisions between processes and products (commodities) feature strongly, much progress is also evident in the development of systems-based tools for decision making. This book will be of particular interest to all agricultural scientists and planners, as well as students interested in multidisciplinary and holistic approaches for agricultural development.

Zusammenfassung
Proceedings of the Second International Symposium on Systems Approaches for Agricultural Development, held at IRRI, Los Banos, Philippines, 6-8 December 1995

Inhalt
Opportunities for systems approaches at the farm scale.- Systems approaches to farm management in variable environments.- Interdisciplinary tool for optimizing agricultural production and erosion: a conceptual model.- The economics of wheat production in the rice-wheat system in Nepal.- Modelling long-term effects of crop residue management for sustainable farming systems.- The impact of agrarian policies on sustainable land use.- Characterization of rice pest constraints in Asia: an empirical approach.- Systems diagnoses at field, farm and watershed levels in diversifying upland agroecosystems: towards comprehensive solutions to farmers' problems.- Managing dairy-crop production systems for zero-excess phosphorus: a multi-criteria optimization approach.- The role of systems research in grazing management: applications to sustainable cattle production in Latin America.- From decision-making process analysis to modelling and simulation of farm management: application to work organization in two rice-based farming systems.- Modelling socioeconomic influences on agroforestry adoption using a rule-based decision support system.- Systems thinking and practice for alley cropping research.- Economic and financial performance evaluation of a farm in the Brazilian savannas.- Factors influencing animal traction adoption in Kakamega district, Kenya.- Flow modelling with ECOPATH: providing insights on the ecological state of agroecosystems.- On the articulation of simulation and heuristic models of agricultural production systems.- Towards data standards for enterprise and farm-level analysis.- Integrating policy and technical issues for international research on agriculture and the environment using systems approaches.- Rice supply and demand in Asia: a socioeconomic andbiophysical analysis.- The limits of consumption and production of food in China in 2030.- Adjustment of rice supply to the evolution of the consumption pattern in Indonesia (19721993): mid- and long-term perspective and implications.- Increasing Indonesian soybean production: testing policies in a lowland farming system.- Simulation and systems analysis tools for crop yield forecasting.- Towards a conceptual dynamic land-use model.- A systems approach to land-use planning in irrigated areas.- Effects of land-use changes on water and nitrogen flows at the scale of West African inland valleys: a conceptual model.- A model assessing water management strategies for integrated land-use planning in the Mekong Delta of Vietnam.- A quantitative tool for regional land-use analysis.- Computer aided training on the environmental impacts of agricultural development projects: an Egyptian case study.- Preservation of the environment on coral islands and intensification of agriculture: applied study on Maré, Loyalty Islands, New Caledonia.- Watershed management information systems.- The GCTE Crops Networks: a framework for international collaborative research.- Acronyms.