Over the last few years high level gatherings of the Worlds leaders and their advisors have repeatedly agreed that addressing the multiple needs for water for two billions or more people - the forecast population increase by 2020 - is of high priority. The challenge is to achieve a balance between using water for food while also meeting expanding domestic and industrial needs for water. Opinions differ among the experts regarding some of the issues. However, the consensus reached was that the contribution of irrigation to incremental food production should be substantial.
Different scenarios (options) have been examined to explore a number of issues, such as the expansion of irrigated agriculture, the increase in food production from rainfed areas and the public acceptance of genetically modified crops. On the one hand there is the business-as-usual scenario - a continuation of current trends in production and policy leading to regional water shortages and possibly a global water crisis; and on the other hand there is a policy of major investment - rapidly increasing agricultural research and development of irrigation and drainage.
At the World Food Summit in 1996, the Food and Agriculture Organization (FAO) estimated that 60 percent of the extra food required must in future come from irrigated agriculture. The International Commission on Irrigation and Drainage (ICID) estimated that current food production would have to double within the next 25 years. The ICID strategy for implementing the Vision for Water for Food refers to the same FAO estimate regarding the role of irrigated agriculture in sustaining future world food supplies. The new slogan more crop per drop crystallizes the objective to be achieved by ICID member countries, particularly those that have nearly reached full development of their scarce water resources.
Some analysts believe that what is needed is a new and greener revolution to once again increase productivity and boost production. However, the challenges are far more complex than simply producing more food because global conditions are different from what they were at the time of the Green Revolution. Meeting the present challenges is even more difficult because so few opinion leaders appear to be aware that the world may face urgent food and agriculture problems. The abundance of grain produced in the world, and the fact that 840 million hungry people apparently remain invisible, also obscures the challenges (Shah and Strong, 2000).
Severe droughts and sharply rising food prices spurred national governments and international agencies to address the food crisis of the 1960s and 1970s. The Green Revolution, consisting of crop variety improvements, increased use of fertilizers and expansion of irrigation, averted the projected shortages in food production. According to some experts, another food crisis predicted by advocates of a new boom in investment for irrigation is not yet in view. Food grain prices have remained stable for the last 15 years. There is hunger in the world, but that is because the hungry cannot translate their needs into demand or civil disorders disrupt food flows. However, according to the authoritative Consultative Group on International Agricultural Research (CGIAR), the world is entering the 21st century on the brink of a new world food crisis that is as dangerous, but far more complicated than the threats it faced in the 1960s (Shah and Strong, 2000).
Much could be said on the role of demographic and economic factors, such as world trade, price commodities and agricultural subsidies to farmers in meeting the challenge. However, the purpose of this paper is not to contribute more to the debate between experts on food security. It is to examine the probable consequences of the business-as-usual scenario that has been the prevailing model for the development of irrigated agriculture, particularly of the large-scale irrigation systems, in many countries. It also projects the likely benefits of increased investment in irrigation and advocates a new approach to design and management of irrigation systems in association with institutional and policy reforms.
According to the International Water Management Institute (IWMI) reliable and timely delivery is the exception, not the rule, in most developing country irrigation systems. Typically farmers in the more favoured parts of irrigation systems receive an adequate supply, while those at the tail end can face ruin. Poor management directly aggravates existing inequities within the farming community. Many farmers, frustrated by unreliable water deliveries, have opted to install tubewells. Consequently, groundwater use is exploding in many surface systems to compensate for the unreliable service from canal systems. Perhaps it will require a shock such as occurred in the 1960s and 1970s to awaken policy makers and the public at large to take the necessary actions to improve the management of these canal systems.
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 This comment by the International Water Management Institute may be an overstatement influenced by the selection of projects in which it is involved. However it reflects the less-than-satisfactory water distribution and allocation in some countries. Undoubtedly some countries have reached a higher level of performance, for example in Latin America where water is distributed on a pre-arranged basis, and in Southern China where farmers draw water from millions of farm reservoirs.