This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends: providing support services and training, recognizing the variation by location of agricultural circumstances and practices; optimal use of on-farm inputs and the minimal use of external inputs; optimal use of local natural resources and management of renewable energy sources; establishment of networks that deal with exchange of information on alternative forms of agriculture.