Effects of Passivators on Artemisia selengensis Yield and Cd Stabilization in a Contaminated Soil

Cadmium (Cd) contamination in agricultural soils has caused serious environmental risks and public health concern; possible eco-friendly immobilization technologies are required to reduce Cd accumulation. A set of pot experiments was carried out with two genotypes of Artemisia selengensis grown in a Cd-contaminated soil, which was amended with hydrated lime (L), diatomite (D) and biochar (B), either alone or in combination, to investigate the impacts of these passivators on bioavailability and mobility of Cd in soil and crops. The results demonstrated that hydrated lime and diatomite significantly promoted the immobilization of soil Cd and decreased the accumulation of Cd in Artemisia selengensis, and biochar significantly increased Artemisia selengensis yield. The residual fraction of Cd was increased 1.35 similar to 1.51 times for Fuqiu Artemisia selengensis and 0.97 similar to 1.05 times for Dayeqing Artemisia selengensis, respectively, under the hydrated lime (L) and hydrated lime+diatomite+biochar (LDB) treatments. Correspondingly, Artemisia selengensis yields were increased by 44.45%similar to 52.50% and 37.91%similar to 43.36%, respectively, in the treatments of biochar (B) and combination amendment (LDB). The results indicate that combination passivators (LDB) are recommended in practical applications, given their high efficiency for soil remediation and potential benefits. Fuqiu Artemisia selengensis, rather than Dayeqing Artemisia selengensis, are suggested to be employed for plants in mildly Cd-contaminated soil to ensure vegetable safety. These findings provide stronger evidence and theoretical support for in situ remediation of Cd-contaminated soil.