A comprehensive new study of irrigation in Asia warns that, without major reforms and innovations in the way water is used for agriculture, many developing nations face the politically risky prospect of having to import more than a quarter of the rice, wheat and maize they will need by 2050.

This warning, along with related forecasts and possible solutions, appear in a report entitled, "Revitalizing Asia's Irrigation: To Sustainably Meet Tomorrow's Food Needs", which was presented today at 2009 World Water Week in Stockholm by the International Water Management Institute (IWMI). IWMI, FAO and partner researchers obtained the findings using a computer model called WATERSIM, which helps examine difficult tradeoffs between food security and the environment, specifically in relation to water supplies.

The study was carried out by IWMI and the United Nations Food and Agriculture Organization (FAO) along with researchers from partner organizations with funding from the Asian Development Bank (ADB).

It outlines three options for meeting the food needs of Asia's population, which will expand by one and a half billion people over the next 40 years. The first is to import large quantities of cereals from other regions; the second to improve and expand rainfed agriculture; and the third to focus on irrigated farmlands.

To meet expected cereal demand by 2050, IWMI's projections show that, with present trends of yield growth, we would have to increase by 30 percent the amount of irrigated farmland in South Asia, and 47 percent in East Asia. Without water productivity gains South Asia would need 57 percent more water for irrigated agriculture and East Asia 70 percent more. Given the existing scarcity of land and water, and growing water needs of cities, such a scenario is untenable. This clearly points to a need for dramatic increases in water productivity, which can only be achieved with a complete revitalization of irrigation infrastructure, management and policy.

The scenarios presented in the IWMI-FAO report do not factor in climate change, which will likely make rainfall more erratic and increase the strain on already overstretched irrigation systems. As a result, even the study's pessimistic assumptions may prove overly optimistic, according to modeling experts.

http://www.iwmi.cgiar.org/Publications/Other/PDF/Revitalizing%20Asia%27s%20Irrigation.pdf