Modern analysis of an ancient integrated farming arrangement: life cycle assessment of a mulberry dyke and pond system

摘要: Integrated agriculture and aquaculture (IAA), as typified by the mulberry dike-pond system (DPS) of Pearl River delta southern China, is often cited an example sustainable intensified production due to its characteristic closed loop recycling nutrients. In this study, we tackle two issues that have been hardly addressed in previous analyses production, greenhouse gas emissions (GHGe) from pond role labour. Previous assessments led us revisit sustainability DPS a model for well-studied IAA using life cycle assessment (LCA) methodology. Our study quantifies on-farm CH4 N2O indirect embedded inputs, global warming potential (GWP) metric. To impact high labour requirements system, simple methodology based on metabolizable energy proposed. GHGe suggests fish ponds treat organic waste results higher net than alternative processing options (e.g. composting), even when co-production accounted for. The majority total GWP100 (97 %) can be attributed methane fertilised ponds. Food required meet plays important role, 11 22 % environmental impact. Methane semi-intensive with appears significant source GWP, calling into question systems such DPS. Improving will require better understanding waste-fed ponds, notably respect CH4.