Vietnam eyes water-saving technology for its rice farms

Fatima Arkin in SciDev.net: Agriculture experts say application of alternate wetting and drying (AWD) technology in Vietnam’s rice farms, one of South-East Asia’s largest rice-producing countries, holds great promise in cutting water use and greenhouse gas emissions from rice cultivation without sacrificing yield output.

Vietnam along with Bangladesh and Colombia recently partnered with the Climate and Clean Air Coalition (CCAC) to introduce the large-scale application of AWD, also known as controlled irrigation in which farmers periodically drain rice paddies rather than keeping them perpetually flooded. The number of non-flooded days can range from 1 to 10 day
s. The technology can reduce water use by 25 per cent and estimated to cut methane from flooded rice field by 50 per cent.

But getting farmers to adopt it will be a struggle, Nguyen Hong Son, vice-president of the Vietnam Academy of Agricultural Sciences, tells SciDev.Net during an interview at the Fourth International Rice Congress in Bangkok, Thailand (27 October to 1 November).

...Aside from economic savings through lower water consumption and pumping costs, there is also evidence that AWD can help crops perform better and improve soil conditions so that machines can operate more efficiently in the fields, says Björn Ole Sander, who is coordinating the effort.

But AWD is not without controversy. Adopting the irrigation method will increase nitrous oxide emissions, which Sander himself acknowledges will be anywhere from 20 to 100 per cent. Still, given that paddy rice does not produce much nitrous oxide to begin with, the decrease in methane, which the crop produces in heaps, will more than offset any increase in nitrous oxide, says Sander. “We still have a huge overall reduction in greenhouse gas emissions,” he adds...

A rice farmer in Vietnam, shot by Wayne77, Wikimedia Commons, under the Creative Commons 3.0 license