1 Department of Agroecology - Climate and Water, Department of Agroecology, Science and Technology, Aarhus University2 KU-LIFE3 Institute of Food and Ressource Economics, Faculty of Life Science, University of Copenhagen4 Institute of Food and Recource Economics, University of Copenhagen, Denmark5 University of Copenhagen6 Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen7 Department of Agroecology - Climate and Water, Department of Agroecology, Science and Technology, Aarhus University
Agriculture is the main user of limited fresh water resources in the world. Optimisation of agricultural water resources and their use can be obtained by both agronomical and political incentives. Important options are: reduction of the loss of irrigation water in conveyance before it reaches the farm; selection of water-efficient irrigation methods such as drip and micro-irrigation saving 30–40 % water compared to furrow irrigation; improvement of irrigation scheduling using plant and soil sensors and remote sensing-based models; deficit irrigation (DI) raising the water productivity in the range of 10–50 %; use of saline and wastewater for which modelling tools lately have been developed; introduction of drought and salt-tolerant crops eases the use of DI and use of saline water; improvement of cropping systems with development of conservation agriculture. Further options are: use of the ‘virtual water’ principles so that water-rich regions secure food supply to dry regions; reduction in waste of food, feed and biofuel from post-harvest to the end consumer; changing of food composition to less water-consuming products; regulating amount of irrigation water by rationing, subsidies or water pricing to support water-saving measures such as use of drip, irrigation scheduling and DI. The potential for water saving for different measures is discussed and estimated. Reduction in waste of food and loss of irrigation water from conveyance source to farm both has a great potential for water saving compared to other measures. How to choose the measures will depend on the local situation, which is ultimately a political choice.
Journal of Agronomy and Crop Science, 2014, Vol 200, Issue 5, p. 333-343
cropping systems; decifit irrigation; low-quality water; virtual water; waste of food and feed; water pricing and rationing