Challenges and opportunities for improving the environmental quality of cadmium-contaminated soil in China

Considering the soil cadmium pollution problem, the Chinese government proposed to estimate the costs and practicality "to completely improve the soil quality by the middle of this century". This study analyzed the challenges in achieving this goal using biophysical data from 10 typical demonstration soil phytoextraction projects. The current annual phytoextraction efficiency was determined as 14.8-490 g ha^-1 a^-1 at 319 RMB g^-1 cadmium. A total of 798 billion RMB and 5 years were required for remediation of cadmium contamination, which was 22 times the investment in soil remediation during 2016-2022. The break-even point of phytoextraction projects was 29 years. The heavy financial burden was considered the primary challenge in improving the environmental quality of such soil. The cost could be reduced by 5.5-35.3 % through optimization measures such as resourcefulness of hyperaccumulator harvests, large-scale breeding, and mechanized management. The break-even point could be shortened to 6-15 years by intercropping/rotating crops, contributing to the goal. Active exploration of phytoextraction efficiency-more efficient accumulators, optimized agronomic measures-is worth practicing.