April 29, 2013
Blue-green' revolution could boost food security in Bangladesh
by Tom Lawson
29 April 2013
A new method of farming has the potential to turn Bangladesh into a food-secure, poverty-free country within a decade
A new method of farming is helping farmers in Bangladesh produce more food in less space, and could improve the country's economy and food security in the face of climate change, a new report says.
According to the report, published in the journal Ocean & Coastal Management, a process combining rice and fish farming produces more food on the same area of land, without negative environmental impacts.
The process sees Bangladesh's coastal farmers add fish such as shrimp and prawns to wet paddy fields in order to grow rice and seafood side by side.
Bangladesh's main crop of rice cannot provide an adequate food supply alone, the report claims, and improving food security is a high priority for a country where 27% of the population is undernourished.
The problem is worsened by limited land availability. Bangladesh is one of the most densely populated nations in the world and annual flooding affects 18% of the country. This is expected to increase as sea levels rise which, according to the Global Climate Risk Index 2013, makes Bangladesh the fourth most vulnerable country to climate change in the world.
However, the report argues that rice-fish farming could provide a 'blue-green revolution' for coastal agriculture. The method can be used in areas flooded with salt water and has the potential to significantly increase crop yields and nutritional variety per hectare. Adding fish to paddy fields has been found to increase rice yields by 8-15%, according to another report by the same researchers published in 2011.
Fish waste discharge has been found to increase the availability of nitrogen and phosphorous in the soil, making it more fertile. The fish also act as a pest management system by eating insects that harm crops, in turn reducing the need for pesticides.
Another benefit is the aeration of water by fish, which reduces methane emissions by 30% compared with rice monoculture. Methane is a greenhouse gas around 20 times more potent than carbon dioxide and rice is one of the largest agricultural emitters.
These improvements in yield could significantly improve the agricultural economy of Bangladesh. The aquaculture sector already contributes significantly to GDP through exports: in 2008-2009 the country exported $404m worth of prawns and shrimp. However, if all of the 2.83m hectares of land suitable for rice-fish combination farming were used, an additional $9.4m could be made annually from aquaculture.
But despite the benefits, the method is yet to be adopted widely. Nesar Ahmed, co-author of the report and researcher in fisheries management at Bangladesh Agricultural University, says: 'The method has been demonstrated successfully and a considerable number of farmers have been trained through various projects, but rice-fish farming remains marginal in Bangladesh because of socioeconomic, environmental, technological and institutional constraints.'
However, Ahmed is optimistic that rice-fish farming could transform the country: 'Bangladesh could become a food-secure and poverty-free country within a decade if we can accelerate economic growth and food production through a blue-green revolution.'