Integrated Life Cycle Assessment for Sustainable Remediation of Contaminated Agricultural Soil in China

Agricultural land degradation is posing a serious threat to global food security. Restoration of the degraded land has traditionally been viewed as an inherently sustainable practice; however, restoration processes render consequential environmental impacts which could potentially exceed the benefit of restoration itself. In the present study, an integrated life cycle assessment analysis was conducted to evaluate life cycle primary, secondary, and tertiary impacts associated with the restoration of the contaminated agricultural land. The results demonstrated the importance of including spatially differentiated impacts associated with managing the land and growing crops. Comparing four risk management scenarios at a contaminated field in Southern China, it was found that the primary and secondary impacts followed the order of no action > chemical stabilization > phytoextraction > alternative planting. However, when tertiary impacts were taken into account, alternative planting rendered much higher footprint in comparison with phytoextraction and chemical stabilization, which provides evidence against an emerging notion held by some policy makers. Furthermore, assuming that the loss of the rice paddy field in Southern China is compensated by the deforested land in the Amazon rainforest, the total global environmental impact would far exceed that of no action, resulting in 687 ton CO2-e ha(-1) of climate change impact. Overall, the present study provides new research findings to support more holistic policy making and also sheds lights on the future development of various restoration technologies.

Automated summary

Agricultural land degradation poses a serious threat to global food security, and restoring degraded land is considered a sustainable practice, although it may have consequential environmental impacts. Research has shown that different management scenarios for restoring contaminated agricultural land have varying impacts, with phytoextraction and chemical stabilization being more beneficial than alternative planting when considering tertiary impacts.