Parched ricefields emit less methane
it’s hard to picture paddy fields without water puddles. But by draining flooded rice fields for two days before the flowering stage, methane emissions can be reduced by as much as 56 per cent. Significantly, draining deprives me thane-producing micro organisms of the oxygen-starved conditions they thrive in. This is what results of a study conducted by the environmental science division of the National Botanical Research Institute (nbri), Lucknow, suggest.
Research done by the Institute for the Study of Earth, Oceans and Space, University of New Hampshire (unh), usa, bears out nbri’s findings. It goes a step further and points out that changes in water management in China during 1980-2000 have not only reduced methane emissions, but also led to an increase in rice yield.
Methane is a heat-trapping gas that causes global warming. Worldwide, flooded rice fields are responsible for around eight per cent of the annual emissions of the gas. Forty-two million hectares of rice fields in India release about 3.61 million tonnes of methane each year.
Besides water draining, the nbri scientists evaluated effects of organic manures, biofertilisers and chemical fertilisers. Emissions of four common varieties of paddy