The challenge of producing sufficient food to feed a growing world population cannot now be met by industrialized and green revolution agriculture as production is currently at or above a sustainable level. Future growth has to occur on resource-poor and marginal lands, where farmers have little or no access to external resources or research and extension support. A precedent for such growth occurred during the agricultural revolution in Britain. Over a period of two centuries crop and livestock production increased 3–4 (...) fold as innovative technologies and techniques developed by farmers were extended to other farmers through tours, farmer groups, open days, and publications, and then adapted to local conditions by rigorous experimentation. These technologies maximized the use of on-farm resources at a time when there was no government ministry of agriculture, no research stations, and no extension institutions. But at the same time as this revolution in on-farm resource use, agriculture also expanded into uncultivated lands, increasing aggregate production but destroying common property resources and so threatening the livelihoods of the poor. (shrink)