Irrigation ditch in Tanzania: By digging canals, called fanja juu, a farmer can lead run-off water from surrounding areas onto his field, thereby improving the harvest. Photo: R. Kautsky/Azote
Time to mix green and blue water
Centre researchers call for a paradigm shift in water management.
- The world is facing a water crisis, but improved water management in rainfed agriculture can build resilience to cope with future water related risks and uncertainties, say centre researchers Johan Rockström, Louise Karlberg and Jennie Barron.
In a special issue in the journal Agricultural Water Management, the researchers, together with partnering institutions in India, Kenya, Syria and China, present a joint call for a paradigm shift in Integrated Water Resource Management (IWRM).
Better management, please
Growth in the agricultural sector is essential for achieving the Millennium Development Goals (MDGs), but succeeding in doing so requires nothing less than a new green revolution.
If the world is to succeed in curbing malnourishment and hunger, a doubling of food production over the coming 20-30 years is required, particularly in sub-Saharan Africa and parts of South and East Asia. This in turn requires major water investments in agriculture, an economic sector which, including livestock production, is already the most thirsty in its class.
However, it is also a sector that is riddled with drough and dry spells, most notably in tropical agriculture. This is commonly a result of mis-management rather than an absolute lack of water. Better farm-level water management can change that, and it's not necessarily complicated.
- Upgrading rainfed agriculture in the world's water hotspots over the next 50 years will require the same level of concerted water governance and management priorities given to irrigated agriculture during the last 50 years, the researchers say.
Need to shift focus
They argue that in order for IWRM to be efficient, green and blue water resources should be managed together.
- The focus of IWRM remains on planning, allocating and managing blue water resources for irrigation, industry and water supply, while recognizing the need to safeguard environmental water flows for aquatic ecosystem functions in rivers, lakes, wetlands and estuaries. Yet key ecosystems services, such as agricultural production, depend on green water in terrestrial ecosystems. As a consequence of this, the water resource management need to shift its focus from river basins to catchments.
Windows of opportunities
In rainfed agriculture, emphasis must be on securing water to bridge dry spells and to increase agricultural and water productivity through new technological water management options.
- Water management to bridge dry spells can greatly reduce risks. Low yields and low water productivity due to large, non-productive water flows offer windows of opportunity which can be realized by implementing new approaches that encompasses both green and blue water resources from the catchment to basin scale, the researchers conclude.
Source: Rockström, J., Karlberg, L., Wanic, S.P., Barron, J., Hatibud, N., Oweise, T., Bruggemane, A., Farahanie, J., Qiangf, Z. 2010. Managing water in rainfed agriculture—The need for a paradigm shift. In Agricultural Water Management Volume 97, Issue 4, April 2010, Pages 543-550. http://dx.doi.org/10.1016/j.agwat.2009.09.009
Rockström, J., Karlberg, L., Wanic, S.P., Barron, J., Hatibud, N., Oweise, T., Bruggemane, A., Farahanie, J., Qiangf, Z. 2010. Managing water in rainfed agriculture—The need for a paradigm shift. In Agricultural Water Management Volume 97, Issue 4, April 2010, Pages 543-550. http://dx.doi.org/10.1016/j.agwat.2009.09.009
2010-01-30 | Sturle Hauge Simonsen
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