Energy efficiency in an integrated agro-ecosystem within an acidic soil area of the Mekong Delta, Vietnam

Abstract

Background: Both exergy and energy analysis methodologies are used for analysing energy efficiencies in various processes, including agriculture. This study focuses on the connection of three main process components (husbandry-crop-fishpond) in a typical farming household located within an acid soil region of rural Vietnam. The concept of exergy analysis is used to underline the potential for resource efficiency in alternative processes in the agricultural system. For development of an integrated ecological system aiming towards zero emissions, the analytical methods of material cycles and energy flows utilized a set of indicators of resource efficiency in a sustainable agriculture. Results: The design of the ideal integrated farming system "Agro-Industrial Zero Emissions Systems"(AIZES) can increase the system efficiency by making use of indigenous natural materials and waste reuse/recycling. Recycling waste produce energy, fish feed and fertilizer can result in a decreased environmental load of approximately half. Using exergy analysis to calculate an indicator non-renewable yield ratio (NRYR), the systems verified sustainability of agriculture production. Conclusions: The farming household will be able to subsidize their fuel and electricity consumption by utilizing biogas. Surplus biogas will be distributed to proximate households, further creating sustainable goals. Biochar, created by mixing the biomass residues with local plants, will improve soil quality and pig sludge, mixed with biomass residue, will create high-quality fertilizer.