Effect of methane emission, mechanisms and management options in rice field

Abstract

Rice is grown in approximately one third of the world’s irrigated cropland. Rice represents one half of the irrigated cropland in Asia. Rice is often grown in monsoonal climates due to its tolerance to flooding. The global average surface temperature has increased with 0.6 ± 0.2°C over the last century. It is caused by the increased concentration of greenhouse gases (GHGs) in the atmosphere and leads to a phenomenon widely known as ‘greenhouse effect’. Global average surface temperature has increased with 0.6 0 C over the last century and it predicted to increase 1.4-5.8 0 C by the year 2100 Methane is one of the strong greenhouse gas having warming potential of 21 times greater than CO2 and it contributes 20 per cent towards global warming. Now it’s concentration in the atmosphere is 1858 ppb (up to April 2018) compare to 722 ppb during pre-industrial period. Improper management of organic residues, fertilizers, irrigation water, method of rice cultivation etc., are the main reasons for more methane emission from the rice field. So, proper management of these is very important to reduce the methane emission and to ensure higher productivity in rice. Methane contributes 20 per cent towards global warming followed by CFC’s (12%), ozone (7%) and nitrous oxide (4%) but the highest contribution is from the carbon dioxide (62%).