CH4 and N2O emissions from smallholder agricultural systems on tropical peatlands in Southeast Asia

Jaya, Adi (2023) CH4 and N2O emissions from smallholder agricultural systems on tropical peatlands in Southeast Asia. © John Wiley & Sons Ltd.

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Abstract

There are limited data for greenhouse gas (GHG) emissions from smallholder agricul-tural systems in tropical peatlands, with data for non-CO2 emissions from human-influenced tropical peatlands particularly scarce. The aim of this study was to quantify soil CH4 and N2O fluxes from smallholder agricultural systems on tropical peatlands in Southeast Asia and assess their environmental controls. The study was carried out in four regions in Malaysia and Indonesia. CH4 and N2O fluxes and environmental parameters were measured in cropland, oil palm plantation, tree plantation and for-est. Annual CH4 emissions (in kg CH4 ha−1 year−1) were: 70.7 ± 29.5, 2.1 ± 1.2, 2.1 ± 0.6 and 6.2 ± 1.9 at the forest, tree plantation, oil palm and cropland land-use classes, respectively. Annual N2O emissions (in kg N2O ha−1 year−1) were: 6.5 ± 2.8, 3.2 ± 1.2, 21.9 ± 11.4 and 33.6 ± 7.3 in the same order as above, respectively. Annual CH4 emis -sions were strongly determined by water table depth (WTD) and increased exponen-tially when annual WTD was above −25 cm. In contrast, annual N2O emissions were strongly correlated with mean total dissolved nitrogen (TDN) in soil water, following a sigmoidal relationship, up to an apparent threshold of 10 mg N L−1 beyond which TDN seemingly ceased to be limiting for N2O production. The new emissions data for CH4and N2O presented here should help to develop more robust country level ‘emis-sion factors’ for the quantification of national GHG inventory reporting. The impact of TDN on N2O emissions suggests that soil nutrient status strongly impacts emis-sions, and therefore, policies which reduce N-fertilisation inputs might contribute to emissions mitigation from agricultural peat landscapes. However, the most important policy intervention for reducing emissions is one that reduces the conversion of peat swamp forest to agriculture on peatlands in the first place.

Item Type:	Other
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences
Divisions:	Fakultas Pertanian
Depositing User:	Dr.Ir Adi Jaya
Date Deposited:	27 Jun 2023 08:08
Last Modified:	27 Jun 2023 08:08
URI:	http://repository.upr.ac.id/id/eprint/552

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