Intercropping wheat and rapeseed in Cd-polluted weakly alkaline soil: Crop productivity, Cd enrichment capacity, and rhizosphere soil characteristics

Phytoremediation is the use of plants to remove or neutralise environmental contaminants, and it provides a promising approach in addressing heavy metal-contaminated soils. However, single-species phytoremediation can be challenged by both its limited metal ion extraction efficiency and crop yield. In this study, we investigated the beneficial effects of intercropping rapeseed ( Brassica napus ) and wheat (Triticum spp.) varieties (Jimai and Zhengyu) with different Cd accumulation potentials on several agronomic traits. The results revealed that intercropping with Jimai and Zhengyu wheat markedly increased the dry and kernel weights of Zhongshuang rapeseed by 10.89–28.57 % and 18.95–27.76 %, respectively. Additionally, intercropping reduced the transfer of active Cd to plants, as indicated by the observed increase of 37.25–154.91 % inbound Cd states, and the available Cd content in the root soil was reduced by up to 35.74 %. This approach also enhanced crop yield, soil health and microbial diversity, thereby highlighting its potential utility in effective soil remediation and sustainable agricultural practices. • Intercropping rapeseed and wheat significantly boosts phytoremediation efficiency. • The wheat varieties Jimai and Zhengyu enhance the growth and yield of rapeseed. • Cadmium transfer to plants is significantly reduced in intercropped systems. • Intercropping improves soil health and increases microbial diversity. • A sustainable strategy for managing heavy metal contamination is proposed.