Directions in tropical agroforestry research: past, present, and future

Reflections on the past two decades of organized research in tropical agroforestry raise several issues. Research efforts started with an inductive and experiential approach but have subsequently followed a deductive and experimental approach that includes hypothesis testing and the development of predictive capability; agroforestry research is thus being transformed into a rigorous scientific activity. The research agenda, so far, has given high priority to soil fertility and other biophysical interactions, less priority to anthropological and sociological aspects, and little priority to evaluating costs and returns, pests and diseases, and the so-called non-timber forest (tree) products. Moreover, larger-spatial-scale issues, such as carbon sequestration, water quality, and biodiversity conservation, have been neglected because of the emphasis on field- and farm-scale studies.