Mitigation of methane emission from paddy fields

摘要

Extensive studies have been carried out on methane emission estimation from paddy cultivation, which is one of the major anthropogenic activity releasing methane into the atmosphere. Paddy cultivation is directly connected with the increase in population as the demands of increasing population leads to increasing rice production. This increase has been achieved partly by intensifying cropping (two or three crops per year) and partly by cultivating non-traditional sandy loam to loamy sand soils for paddy cultivation in addition to better cultivars and agronomic practices. How the continuous demand of increase in rice production can be met while keeping methane emission as low as possible is the need of the day. Various parameters like water management, cultivars, nature of fertilizer and soil temperature have been investigated and found to change the emission by a few times to orders of magnitude. Studies of irrigation practices in India have shown that submergence is not necessary for high yields and controlled irrigation can be very effective in mitigation of methane emission without affecting the yield. The use of cultivars having high yields associated with low methane emission and use of appropriate fertilizer can reduce methane emission by more than an order of magnitude. Measurements carried out in this laboratory have also shown an excellent correlation of methane emission with soil temperature and suggest increase in paddy cultivation in the rabi season to be another important parameter to mitigate methane emission. Detailed results would be discussed in this presentation.