THE NATURE OF AGRICULTURAL SYSTEMS - FOOD SECURITY AND ENVIRONMENTAL BALANCE

Global food security in the future mill depend on growth in production in those areas of the world with favourable soils, adequate water resources, and high yields from wheat and rice cropping. Because the area devoted to rice and wheat cultivation in these favourable conditions has been stagnant or declining since the 1980s, with little prospect for reversing the trend, increases in grain production must come from increases in yield per hectare. To achieve the needed increases in yields of basic food grains, a broad range of constraints facing existing production systems must be removed. Additional inputs for crop production are needed, and new technologies, which have yet to be developed, are essential for managing crop nutrients, pests and diseases. Under normal economic conditions, optimal farm management of high-intensity agriculture produces grain yields that approach 80% of the technical ceiling achieved on experimental plots. As Asian farmers approach this 80% limit, pushing out the technical yield ceiling will be crucial for maintaining growth in cereal yields into the 21st Century. If management practices focus on short-run profitability rather than on long-run sustainability, the challenge to scientists seeking to raise yield potential becomes more complex because of the deteriorating soil environment in which crops are grown. Most of the agricultural land in the developing world has less-favourable endowments of soil and water resources than do the high-productivity farming areas of Asia. These regions are home to the majority of the world's poor. Developments in production ecology suggest that significant improvement is possible in the management of biological processes that govern the efficiency and sustainability of the agricultural systems that dominate in these poorly endowed areas. But a substantial investment in research for crop production will be required.