Emergy-based sustainability assessment of the rice cropping system under scaled-down intensification: Insights from a case study on South Korea (2003-2021)

초록

Rice cropping systems (RCS) have evolved into resource-intensive systems as they prioritized yield maximization to meet growing food demand. In particular, many Asian countries have recently faced increasing pressure to use more intensive RCS due to reductions in paddy area driven by socioeconomic transitions. However, the impact of this shift on the ecological sustainability of RCS remains poorly understood. This study investigated how the emergy input structure and sustainability of RCS changed in response to a rapid reduction in system scale. To this end, an emergy-based multi-step analysis was conducted for South Korea's RCS over the period 2003 to 2021, selected as a representative case. The results revealed that the RCS underwent a two-phase transformation. During Phase I (2003-2013), the emergy required to produce 1 g of rice decreased by 39.4 %, while the emergy sustainability index (ESI) increased by 76.3 %. In contrast, Phase II(2013-2021) was characterized by a 10.4 % decline in the ESI, along with a strong decoupling between total emergy input and value added. This pattern indicated a shift in RCS priorities from improving emergy efficiency and sustainability to emphasizing economic productivity. These findings suggest that although a reduction in the scale of RCS may present opportunities to enhance sustainability, strategic interventions are essential to maintain long-term progress. The insights from this study contribute to a clearer understanding of sustainability trajectories in RCS under socioeconomic transitions and offer guidance for developing proactive strategies in other rice-producing countries likely to face future contractions in RCS scale.

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