MANILA, PHILIPPINES - Asia's ageing irrigation systems must be revitalized to produce more crops with less water in the face of the region's surging demand for food (a 70-90% increase to 2030), a rising population, and stressed water resources, say new studies released at a conference here today.
The studies were tabled at the Water: Crisis and Choices - ADB and Partners Conference 2010, organized by the Asian Development Bank. The 5-day event has brought together over 600 water professionals and policy makers from around the world to examine the critical water challenges facing Asia, and the measures needed to overcome them.
Asia accounts for 70% of the world's irrigated land and is home to some of the oldest and largest irrigation schemes. It also draws 80% of its available freshwater resources. But most systems were built before the 1970's, function poorly and often fail to match the needs of farmers.
"Asia's population will reach 5 billion by 2050 and feeding 1.5 billion additional people will require irrigation systems that generate more value per drop of water," says the study Growing More Food With Less Water: How Can Revitalizing Asia's Irrigation Help?.
The study - authored by Aditi Mukherji, David Molden, and Colin Chartres of the International Water Management Institute, and Thierry Facon of the Food and Agriculture Organization - notes that while the total area under irrigation continues to rise in most parts of Asia, systems are irrigating less land than originally intended, water productivity is low, crop output has stagnated and many farmers are exiting formal schemes. With water resources pressured by urbanization, industrialization, pollution, climate change, and competing demands from other sectors, Asia needs to find ways to make its irrigation systems more efficient and productive without tapping more water.
The study suggests that new technologies, such as those that use surface water more efficiently, and improve water storage, need to be looked at closely, while reforms which strengthen the management of irrigation schemes are also crucial. Strategies must incorporate the specific needs of different parts of the region, including Central Asia with its ageing Soviet-era infrastructure, South Asia with its underperforming surface schemes, and Southeast Asia where the rapid expansion of hydropower schemes presents a challenge.
A second paper, Small-Scale irrigation: Is This the Future?, authored by Mr. Facon and Ms. Mukherji, compares options, outcomes, and potential of differently sized irrigation systems, including those where farmers are increasingly 'scavenging' groundwater for use in atomistic irrigation systems. While stressing that there is no 'one size fits all' solution for the region, it highlights the need for improved sector management and closer cooperation and knowledge sharing amongst all stakeholders to improve outcomes.
A third paper, Technologies in Irrigated Agriculture: Costs and Benefits, authored by Chandra Madramootoo and M. Gopalakrishnan, of the International Commission on Irrigation and Drainage, uses case studies from around the region to examine the broad range of tools available for improving the efficiency of systems.
It recommends additional investments in farm technologies such as micro and sprinkler irrigation, which reduce demand for water while increasing crop yields. The study also highlights the need for more effective use of inputs such as fertilizers, energy and labor, improved advisory services for farmers, more private sector participation in technology development, and increased training and capacity building for irrigation staff and agencies.
"Increasing food production with diminishing water supplies and a changing climate calls for innovative measures and new technologies," the authors argue.