Typically, microenvironments (MEs) are ecologically specialized compared with their surroundings; concentrate soil, water and nutrients; are protected; and are physically, biologically and managerially complex and diverse. In third world agriculture, MEs often contribute to livelihoods and their sustainability by diversifying households' portfolio of sources of food and income, by intensifying, increasing and stabilizing production and decreasing risk, by storing and supplying reserves for bad times and contingencies, by reducing the need to migrate, and by providing sites for innovation and experiment.
In knowledge, and in R&D to develop the considerable potentials of MEs in third world agriculture, farmers have several comparative advantages but scientists can help as consultants. As a precondition for long-term investment in MEs, farm families need clear and secure rights and tenure. Non-farming professionals can contribute through better observation and heightened awareness of MEs, and through reversals of location, learning, and role. A shift in extension from packages of practices to baskets of choices should enable farming systems and livelihoods to be more sustainable by becoming more complex and diverse. A challenge to non-farming agricultural professionals in the 1990s is whether they can make the quiet personal revolutions needed to support these changes.