In Indonesian tropical forests, land-use change to plantation causes loss of soil organic matter and increased nitrogen inputs by fertilizer or leguminous trees. These changes might risk increasing soil N₂O emission potentials.
We conducted short-term incubation to compare N₂O emission between soils that experienced different land use history (primary dipterocarp forest, Macaranga forest, Imperata grassland, transition from Imperata grassland to Acacia plantation, transition from Imperata grassland to oil palm plantation, and rice paddy) in Indonesia. The N₂O emission rates were measured at three water levels [35%, 60%, and 95% of water filled pore spaces (WFPS)] in the sequential substrate addition: (1) gas sampling after 4 h incubation (control), (2) nitrate addition (N addition treatment), and (3) glucose addition (N & C addition treatment).
N₂O emission rates increase with increasing WFPS. The positive effects of N & C addition treatment were found in the oil palm plantation and the Acacia plantation, while negative effect of N addition treatment was found in the Macaranga forest due probably to N₂O production by fungi. .
Despite similarity of initial soil condition, land use changes of tropical forests cause wide variation in N₂O emission potentials.