No lesser evil
Controlling methane emissions through acid rain?
adding sulphate to soil in paddy fields is a popular method of controlling methane emission, to the tune of up to 70 per cent. In highly polluted countries such as India and China, acid rain also deposits a substantial amount of sulphate. This leads to more than required sulphate, which can be harmful for paddy. In such cases it becomes imperative to use sulphate sparingly, says a new study published in the August issue of the Journal of Geophysical Research.
Vincent Gauci of the Department of Earth and Environmental Sciences, Open University, Milton Keynes, uk, simulated acid rain conditions and used it to reduce ghg emissions from paddy. He found that the emissions reduced by 24 per cent during grain filling and the ripening stages of rice, which account for half the methane emissions in the cultivation period. When an equal amount of sulphate (deposited by acid rain) was added, it reduced methane emission by 43 per cent.