3:00 PM - 3:15 PM
[MIS13-12] Nitrous oxide emission from the drainage and the production processes in oil palm plantation on peatland
Keywords:Nitrous oxide, Oil palm plantation, Nitrogen stable isotope
In this study, we have conducted spatial sampling for dissolved N2O concentration (dN2O) in the oil palm plantation on drained peat soil in July 2018, in Sarawak, Malaysia in order to evaluate the indirect N2O emission from palm oil plantation. We have intensively sampled the water samples from the drainage in the plantation (ca. 120 km2) and the water samples from Raja river, which is adjacent to the plantation. 90% of samples (N = 84) in the drainage water showed over-saturation in dissolved N2O concentration (up to 570%), suggesting that the drainage water in the oil palm plantation acts the source of N2O to the atmosphere. The emission factor for indirect emission (EFr: i.e., dN2O/nitrate concentration) showed relatively higher than the default EFr in IPCC. However, there were no clear linear relationships between the water qualities (including nitrate) and dN2O. We have also analyzed the isotopic composition of dN2O in both drainage and river samples. This analysis suggested the denitrification contributed dN2O in the drainage water.