Integrated Life Cycle Assessment of Small-Scale Sugarcane Harvesting Machines to Improve Sustainability

Sugarcane is a vital crop for Thailand’s bio-economy, yet the traditional practice of pre-harvest burning to facilitate manual harvesting creates significant environmental, social, and economic challenges. This study utilized an Integrated Life Cycle Sustainability Assessment (LCSA) to evaluate the potential of innovative, small-scale harvesting technologies—specifically sugarcane detrashers and tractor-mounted harvesters—to improve the sustainability of the sector across four scenarios: Conventional Pre-harvest Burning (CPB), Owner-operated Small-scale Harvesting (OSSH), Contracted Small-scale Harvesting (SSH), and Conventional Large-scale Harvesting (CLH). Environmental findings revealed that the CPB scenario contributes the most greenhouse gas emissions (25.9 kg CO 2 eq/t sugarcane), primarily driven by methane and nitrous oxide emissions from burning, whereas the CLH and small-scale options (OSSH/SSH) achieved lower carbon footprints by avoiding field burning and leveraging technical efficiency. Economically, while the CLH scenario yielded the highest net income and lowest total costs, the OSSH scenario demonstrated comparable performance and remained robustly viable even under maximum machinery price assumptions, as confirmed by Monte Carlo simulations. Socially, the OSSH and SSH scenarios exhibited the best performance with fewer "social hotspots" (subcategories falling below standard norms) compared to the CLH and CPB scenarios. Ultimately, the OSSH scenario achieved the highest overall sustainability score, effectively balancing technical productivity with social well-being. These results suggest that for farmers who can afford higher capital investments, the OSSH model is highly recommended, while SSH remains a superior alternative for those without their own machinery. policymakers should support these small-scale transitions to solve labor shortages, eliminate seasonal haze, and fulfill national Bio-Circular-Green (BCG) economy goals.