Greenhouse Gas and Energy Flux Measurements with Eddy Covariance Technique under Lowland Rice Ecology

In the present climate change scenario, understanding the response of terrestrial ecosystems to environmental changes on temporal scale is a key issue. The changes in weather and climate are closely inter-linked with land surface processes, therefore, interest has been given for establishing global networks for monitoring surface exchanges of matters (trace gases) and energy between ecosystems and atmosphere. Agriculture is responsible for emission of all three major GHGs, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Rice paddy contributes toward the emissions of the most important GHGs responsible for global warming: CO2, CH4 and N2O. Sometimes agriculture has potential role in the global carbon budget of greenhouse gases such as CO2 and CH4 as they sequester the former but release the latter and their relative contribution changes with agricultural management practices. To monitor the GHGs emission, net ecosystem carbon dioxide (NEE), methane exchange (NEME), energy exchange components and net ecosystem carbon balance in lowland tropical rice, the eddy covariance (EC) techniques was employed to linking mass exchange to energy components, linking relationship with soil microbial activities and labile carbon pools with net ecosystem exchange and to quantify carbon budget in lowland rice. Net ecosystem carbon balance was made by computing all the input components and output components. Net ecosystem exchange displayed a distinct daily and seasonal pattern throughout the cropping season and it has shown that the low land rice ecology has the capacity to sequester carbon from the atmosphere in long run. Long-term trails incorporating agricultural practices and the physico-chemical-biological factors in ecosystem are worthwhile research topics to understand the mechanism of C flow in the soil–plant-atmosphere in the lowland rice ecosystem.