| 要旨トップ | 目次 | 日本生態学会第59回全国大会 (2012年3月,大津) 講演要旨
ESJ59/EAFES5 Abstract


一般講演(ポスター発表) P2-361A (Poster presentation)

Phosphorus application accelerated N2O emissions from soils of an Acacia mangium plantation when acacia roots were excluded, but reduced when there were acacia roots

*Mori, T.(Kyoto Univ.), Ohta, S.(Kyoto Univ.), Ishizuka, S.(FFPRI), Konda, R.(Sumitoto Forestry), Wicaksono, A(MHP), Heriyanto, J.(MHP), and Hardjono, A.(MHP)

Rapidly spreading leguminous plantations in tropics recently have been suggested to be new important nitrous oxide (N2O) sources due to their high nitrogen (N)-fixing ability and rapid spread. We examined effects of phosphorus (P) fertilization on the N2O emissions from an Acacia mangium plantation in Indonesia by separating root-excluded plots and root-existing plots using trench method to understand roles of microbial and plant root activities in the effects separately. In root-excluded plots, P application tended to enhance N2O emissions. Higher inorganic N content in P-applied plots indicated that P application accelerated the N-cycling and stimulated nitrification and/or denitrification, thereby enhanced N2O emissions. In contrast, P application significantly reduced N2O emissions in root-existing plots, attributed to accelerated root N uptake. Inorganic N content was lower in P-applied plots. Our study suggests that P fertilizer is helpful to suppress the N2O emissions from Acacia mangium plantations but yet P fertilizer have to be used carefully, because when there is no vegetation as harvesting times P application could stimulate the N2O emissions.


日本生態学会