Life cycle assessment in conventional rice farming system: Estimation of greenhouse gas emissions using cradle-to-gate approach

摘要

Rice farming is one of the highly intensive agricultural activities in Malaysia. Increasing population since the country's independence parallels the increasing demands for rice products. The impact on the environment has been highlighted as one of the criteria for it to be more accessible and acceptable for commercial and consumer consumption as technology progresses. In view of this, Life Cycle Assessment (LCA) provides a platform for the environmental emission from rice to be quantified. This study focused on the conventional approach of rice production, which begins from seed cultivation, land preparation, seeding, field maintenance, and harvesting. It quantified all the inputs involved in the process such as fertilizer, soil conditioner, pesticides and fuel. The results of the LCA's Greenhouse Gas (GHG) impact analysis had identified that net emission for production of un-milled rice grain was 1.39 tonnes CO2 eq per tonne. The analysis further highlighted that major emission contributed mostly from CH4 during field cultivation, measured with percentage CO2 eq contribution of 76.85%. A mitigation potential was therefore proposed for on-field biomass and water management. This included improving the rate of straw degradation and potential of improving water management through alternate wetting and drying (AWD). It may potentially reduce the environmental emission by half if successfully implemented. (C) 2018 Elsevier Ltd. All rights reserved.