Greenhouse gas budget from a Mediterranean rice paddy field

Rice paddy fields are one of the biggest anthropogenic sources of methane (CH4), the second most important greenhouse gas (GHG) after carbon dioxide. Therefore most studies on the greenhouse gas (GHG) budget in these agricultural systems focus on the evaluation of CH4 production. However, other GHGs such as carbon dioxide (CO2) and nitrous oxide (N2 Combining all GHGs measured, the rice paddy field was a GHG sink of -362 and -770 g COO) are also exchanged with the atmosphere. Since each of the GHG has its own radiative forcing effect, the total GHG budget of rice cultivation and its global warming potential (GWP) must be assessed. For this purpose a field experiment has been carried out in a Mediterranean rice paddy field in the Po Valley (Italy), the largest rice producing region in Europe. 2 eq m-2 year-1 in 2009 and 2010 respectively. It was a CO2 sink and a CH4 source, while the N2 Methods / Approach O contribution to the GWP was small.