This study is a contribution to the discussion of the principles and methods of sustainable agricultural development in the tropics. It contains a definition of ecofarming, and an outline of the major ecofarming techniques, as well as the major results of a survey of ecofarming development activities and a commentary on the current research on ecofarming. Further chapters take a closer look at indigenous agricultural knowledge, and explore the possibilities of collaboration between farmers and scientists in developing ecofarming techniques. Consequences for technical co-operation are discussed. In the annex a list of contact addresses for ecofarming activities is given.