Role of Photosynthetic Diazotrophs in Reducing Methane Flux from Rice Soil Ecosystem

Abstract

This Technical brief is a short summary of the results obtained from the field trials conducted at Anbil Dharmalingam Agricultural College and Research Institute, Trichy, India during Rabi (2010-2011) to evaluate the role of photosynthetic diazotrophs in reducing methane flux from rice soil ecosystem as a part of climarice project. Global warming induced by increasing concentration of greenhouse gases (GHGs) in the atmosphere is a matter of great environmental concern. Methane, carbon dioxide, nitrous oxide and chlorofluorocarbon are the GHGs which have strong infrared absorption bands and trap part of the thermal radiation from the earth surface. Rice fields have to be considered as a significant source of greenhouse gases and rice field eco systems account for about 60 Tg methane per year or about 12 per cent of the global annual methane emission. The purpose of this study is to explore the potential of blue green algae and azolla in minimizing methane flux at source in paddy field ecosystem. In the present study, combined application of organics and blue green algae not only recorded higher yield, but also found to emit less methane in paddy cultivation than the application of organics alone.