Sustainable water management in agriculture

摘要

There is general agreement that population increase, coupled with economic growth and mounting awareness of the need for nature preservation, are now subjecting existing freshwater resources to considerable pressures. Looking at current and future trends of agricultural production worldwide, it is clear that irrigation is essential to meet current food demand and that irrigation will have to increase in the future. The use of large amounts of water by crops is dictated by the evaporative demand of the environment and is tightly associated with biomass production and yield. Increases in potential biomass production per unit water transpired during the next 10-20 years will be small despite promises from biotechnology. Breeding for yield potential will also provide a small contribution in the near future, so the real opportunity to increase the productivity of water resides in closing the current large gap between actual and potential yields. To increase the effectiveness of irrigation in a sustained fashion, without detrimental impacts on the environment, a number of measures need to be considered, particularly: improving water management at farm and district levels and reforming institutions to allow for user participation.