The worldwide population is expected to rise to 9.6 billion by 2050. In order to feed this growing population agricultural production will need to keep pace and increased by 60 percent (and nearly by 100 percent in developing countries) over the 2005-2007 base. Another Green Revolution is therefore called for. However, this time around the green revolution would have to be integrated and more inclusive in terms of optimal use of resources, both land and water; reducing the risks of climate variability and change by provision of equitable and reliable irrigation services thereby enhancing agriculture productivity and preserving the ecosystem. It is estimated that 85 percent of projected food demand in 2050 could be met by bridging the gap between the actual and potential yield of both rain-fed as well as irrigated agriculture.
Under these challenging requirements, irrigated agriculture faces a number of challenges. Low efficiency of irrigation systems, rapid growth of demand for water from other sectors such as urban, industrial and energy sectors are just a couple of major concerns. Efforts to ensure sustainable agriculture water management would require improving performance of irrigation systems through modernisation and revitalisation; adoption of modern technology and improved irrigation techniques leading to water saving to satisfy needs of other competing sectors or expansion of irrigation; conservation, recycle and reuse of water and so on. While doing so the consumption of energy, which is one of the crucial inputs, has to be factored in order to ensure more income per drop of water to the farmers.
Theme of 23rd Congress “Modernizing Irrigation and Drainage for a new Green Revolution” is expected to address these issues in the form of two questions.
Energy drives the processes involved in food production - to pump water from groundwater or surface water sources, to power tractors and irrigation machinery, and to process and transport agricultural goods. Increasing food production by 60 percent will require an increase in energy consumption in agriculture by 84 percent. Policies in energy and water sector influence each other and food production. Energy subsidies play a significant role in low irrigation inefficiencies. The advent of liquid biofuels as a source of fuel for transport added a new and complex dimension to the water–energy–land and therefore food nexus. Thus, water, energy and food are inextricably linked. The subsidized treatment for the growth of biofuels to gain greater security for energy for transport is at the cost of water for food. The critical link of bio-fuels with water security is ultimately whether growing crops for fuel competes for limited water and land with growing food for human consumption.
Water productivity which in simplistic terms is referred to as ‘crop production’ per unit ‘amount of water used’ focuses on ‘producing more food with the same amount of water resources’ or ‘producing the same amount of food with less water resources’. Water productivity gains in agriculture can secure water resources for other uses including for ecosystem services. Integrated land and water management at the watershed scale is key to improving the water productivity and enabling sustainable water resource management. Targeted policy actions are needed to support this. Since water-energy-food nexus affects agriculture water productivity, there is need to revisit the concept of water productivity in its entirety.
While modernising large irrigation systems, lining of canal forms a major component with the objective to save water that is lost between the source and the field. However, it is often argued that such an approach does not actually save water as the water that seeps through the canal finds its way to the groundwater and is ultimately available for use further downstream. The argument needs to be passed through the energy lens to present a more comprehensive picture.
Various water saving measures such as improved water management, effective real-time operation of water released, soil conservation and aquifer recharge, conjunctive use of surface and groundwater and recycling of used water have repercussions on the energy consumption and the economic viability of the measure. Therefore, in order to improve irrigation services through modernization of irrigation and drainage systems there is need to revisit the water productivity, water saving and water security concepts through the prism of water-food-energy interlinkages and identify associated challenges explore opportunities.
60.1 Emerging issues and challenges of water saving, including impact of transferring water out of agriculture
60.2 Understanding water productivity, water and energy use efficiency and water footprint of crops
60.3 Water security for growth and development
Irrigation systems are often designed to maximize efficiencies and minimize labour and capital requirements. While investing in modernization of irrigation system questions that will address the issue of increased productivity revolve around when to irrigate, how much to apply, and can the efficiency be improved. The degree of automation considered, depends on various technical, social and economic factors which need to be considered. Options for design of irrigation systems undergoing modernization are influenced by the extent of information that one can have at his disposal, its interpretation and reaching out at the optimal solutions.
Technology plays an important role in all types of water applications that are in use at present such as flood and furrow irrigation, micro irrigation system (drip and sprinkler) both pressurised and non-pressurised presenting a number of option. Precision irrigation presents a great potential as only the water that is required for evapotranspiration and used by the plant for gainful purposes, at a time and in quantity that is optimal for its growth can be applied. It is based on monitoring the health parameters of the plant and the field soil moisture condition and its topographical variations.
It is essential to adopt a cost effective and efficient irrigation application technique suited to a particular situation through the use of technology. However, while deciding the use of technologies, factors like type of crops, topography, agro-climatic zones; and the socio-economic aspects and cost effectiveness etc have to be taken into account. While selecting appropriate technologies based on the prevalent socio-economic conditions, considerations must be given on its affordability and adaptability.
61.1 Adopting precision irrigation and improving surface irrigation to combat water scarcity
61.2 Using ICT, remote sensing, control systems and modelling for improved performance of irrigation systems
61.3 Adaptability and affordability of new technologies under different socio-economic scenarios
Irrigation techniques for reuse of wastewater in agriculture and its impact on health and environment
Global Review of institutional reforms in irrigation sector for sustainable agriculture water management, including water users associations.
Water Use in food value chains