Wheat, maize and the other grains constitute some 85% of global food production. But these plants are annuals, and they are usually grown in monoculture. The consequences are that harvesting them leaves the earth vulnerable to erosion; extra fertilizers are required for their growth; and they are especially prone to attack by pests and diseases. Could a more natural agricultural system, based on several perennial species, be both productive and avoid some of these problems? The prospects for such systems were discussed at a meeting last month.
