Intercropping Sedum alfredii and Pseudostellaria heterophylla to mitigate heavy metal stress in contaminated soil

Heavy metals (HMs) contamination in agricultural soil interferes with vital plant physiological processes, significantly constraining the growth of medicinal plant Pseudostellaria heterophylla (P. heterophylla). To mitigate HMs stress, Sedum alfredii (S. alfredii) has been applied as an efficient hyperaccumulator for phytoremediation. However, intercropping S. alfredii with P. heterophylla and the associated soil hydrochemical properties responses remain largely unknown. This study aims to mitigate the stress of HMs, i.e., Lead, Cadmium and Copper, in the contaminated soil by intercropping S. alfredii and P. heterophylla. The growth of P. heterophylla will be evaluated with leaf and root development, and HMs removal efficiency will be analysed with the concentrations of HMs in plant tissues and residual soil. Additionally, soil hydrochemical properties will be measured. This study will elucidate how intercropping S.alfredii and P. heterophylla influences soil HMs bioavailability by affecting soil hydrochemical properties. A clear and detailed description of the experiment and measurements will be provided, and the results will be carefully analysed to identify key findings, explain underlying mechanisms, and highlight new insights.

The authors would like to acknowledge the financial support provided by the State Key Laboratory of Climate Resilience for Coastal Cities (ITC-SKLCRCC26EG01) and the Research Grants Council of HKSAR (C5033-23G).