Frontiers in irrigation investment and management

A shift in the future allocation of water among competing uses is inevitable. The global trend is to allocate a reduced share of water resources to agricultural uses. The global food system has responded to the doubling of world population by more than doubling food production during the past 50 years, and irrigated agriculture has played a major role. The growth in irrigated area has showed in the past decade and is projected to increase at an annual rate of less than 1% between 1995 and 2020. New investments in irrigation and water supply systems alone will be inadequate for meeting the growing non-agricultural demand for water and for mitigating the impact of water withdrawals from agriculture. Major changes in practices, policies and institutions, along with sustainable irrigation management tools, will be required to ensure that limited water resources are appropriately managed to increase the productivity of water in irrigated agriculture. The key pressure points to improve water productivity in a water system are not necessarily biophysical. They can also be economic, social, environmental or institutional. Changes in these elements need to be assessed in a comprehensive and systematic way to enhance the multifunctional productivity of irrigation systems.