Synergistic Phytoremediation of Cadmium-Contaminated Soil: Intercropping Rapeseed and Kenaf for Enhanced Biomass, Metal Uptake, and Soil Health

Abstract

Aims and Background The growing human population and scarcity of new arable land necessitate exploring contaminated lands for agriculture production. Intercropping, a strategic method involving different plant species to enhance plant biomass, soil health and phytoremediation, thus promoting sustainable agricultural practices on contaminated lands. Therefore, the selection of suitable intercropping systems is of great interest for sustainable agriculture. Methods This research focused on the phytoremediation potential of rapeseed and kenaf in cadmium-contaminated soil, evaluating their performance in both intercropping and monoculture system. Additionally, it examined the growth, morphological, and physicochemical responses of the plants. Results The results revealed that intercropping of these two species significantly enhanced their biomass production, chlorophyll content, and photosynthetic efficiency compared to monocultures. Antioxidant enzyme activities in both plants were elevated under intercropping, reducing oxidative stress markers such as malondialdehyde (MDA) and superoxide anion (O₂⁻). Intercropping increased Cd accumulation in both shoots and roots of kenaf and rapeseed, correlating with a decrease in soil pH and an increase in available Cd content in the soil. Both species showed potential for metal phytostabilization, with BCF > 1 and TF < 1 in intercropping. It is also found that intercropping enhanced the activity of soil enzymes, urease and catalase while reducing sucrase activity, indicating improved soil health and microbial activity. Conclusion These findings suggest that intercropping kenaf and rapeseed not only improves plant growth and Cd uptake but also promotes better soil health and resilience under Cd stress, offering a sustainable approach for phytoremediation in contaminated soils.