Prioritizing the health of ecosystems and water supplies is necessary to improve agricultural sustainability and produce enough food for the world’s growing population, according to a new publication by CGIAR and the United Nations Environment Program, launched on September 4 during World Water Week in Stockholm.
The book, Managing Water and Agroecosystems for Food Security, finds that strengthening ecosystems and natural services like soil retention, pollination and water purification can reverse the degradation agriculture causes to land and water.
“We need to raise food production by some 70 percent by 2050 to feed the 9 billion or more people who will inhabit the plant by then,” said Andrew Noble, program director for the CGIAR Research Program on Water, Land and Ecosystems.
This goal is achievable, but only if the more sustainable and environmentally sensitive “agroecosystem” approach to farming is adopted.
“Food security is currently jeopardized by the unsustainable nature of our agricultural systems, which is limiting our ability to produce food,” Noble said. “Water use is key, as the extraction of water for irrigating crops, coupled with pollution from pesticides and fertilizers, has significant impacts on downstream ecosystems that are fundamental to ensuring the health and functionality of our food production systems.
“The bottom line is, degraded ecosystems are less able to sustain water flows, particularly in light of climate change.”
The book highlights the cyclical nature of the problem. For example, in tropical areas, where pressure on farmland is high, agriculture has expanded to wooded areas. The resulting loss of tree cover and compacted soil reduces infiltration of water and increases water run-off, leading in turn to erosion and salinization. This leaves less water available to support ecosystem services that benefit agricultural processes in the first place, like nurturing vegetation growth and underpinning the yields of edible plants.
But “by considering our agricultural production systems as interlinked agroecosystems, we can manage water and other natural resources to enhance a whole range of ecosystem services beyond the provision of food,” said the book’s lead author and editor Eline Boelee, of Water Health, Netherlands.
“We can develop a mosaic of highly intensive food production, and nature. Forests and wetlands could be connected through, for example, hedgerows with trees and waterways as locally appropriate.”
Decisions on how to manage agroecosystem services will require governments to balance social, economic and environmental considerations, sometimes among different services, the book’s authors said. For example, a program to maximize food production upstream will also need to consider water purification for downstream areas.
“Water should no longer be allocated to ‘food production’ alone, but to ‘agroecosystems,” Boelee explained. “Another option is to get downstream users to pay for environmental services. For instance, a hydropower company might pay upstream farmers to rehabilitate their watersheds to ensure a sustainable supply of water for dams and reservoirs.
“However, if the agroecosystem model is to be widely adopted, institutions need to support action at the local level, integrate natural resources management at river basin and landscape level, and integrate policies at the national level.”
The book urges decision-makers to estimate the costs and benefits of ecosystem services and include these in their calculations.
CGIAR (originally the Consultative Group on International Agricultural Research) is a global partnership that “unites organizations engaged in research for a food secure future,” according to the group’s website. It is sponsored by the UN Food and Agriculture Organization, the International Fund for Agricultural Development, the United Nations Development Program and the World Bank, and its work is carried out by the 15-member CGIAR Consortium of International Agricultural Research Centers.