Life cycle assessment of agricultural systems toward circularity

Abstract

Agricultural systems contribute significantly to environmental degradation and health impacts due to conventional practices such as postharvest open burning and the widespread use of chemical fertilizers. This study evaluates the potential for circular agricultural practices to mitigate these impacts in Thailand by repurposing agricultural residues for fertilizer, animal feed, and electricity. Utilizing a Life Cycle Assessment (LCA) methodology, the environmental and economic outcomes of conventional versus circular agricultural practices were quantified, focusing on key Area of Protection (AoP) including disability-adjusted life years (DALY), ecosystem damage (species.yr), and resource depletion (USD₂₀₁₃). The results demonstrate that conventional sugarcane and rice cultivation lead to substantial health impacts (up to 2910 DALY), significant ecosystem damage (up to 4.45 species.yr), and resource depletion costs of up to 14.9 million USD₂₀₁₃. In contrast, cassava cultivation, with its existing circular practices, shows comparatively lower impacts, including 415 DALY, 1.47 species.yr of ecosystem damage, and 10.4 million USD₂₀₁₃ of resource depletion. Circular agricultural scenarios, using crop residues to produce organic fertilizers and animal feed, proved highly effective in reducing these burdens. Circular organic fertilizers reduced total costs by 57 %, while converting residues into animal feed resulted in a net economic benefit of 1.98 billion Thai Baht (THB), representing a 137 % reduction in costs compared to the baseline. The findings highlight the importance of transitioning to circular models, emphasizing the need for policy interventions, improved technology access, and enhanced farmer training to promote circular agricultural practices in Thailand.