Attapulgite amendment favors the utilization of high cadmium-contaminated soil for Erigeron breviscapus cultivation

Abstract

A practical measure of soil pollution can effectively control the utilization of contaminated soil during the remediation process. In this study, Erigeron breviscapus was used as the experimental material. Soil polluted with high concentrations of cadmium (Cd) was used to study the effects of different doses of attapulgite (AP) (0, 10, 20, and 40 kg−1 for AP0, AP10, AP20, and AP40, respectively) on the yield and quality of E. breviscapus (as measured by scutellarin), as well as soil remediation. The results showed that the yield and scutellarin content of E. breviscapus decreased by 33.4% and 78.9%, respectively, in soil contaminated with high concentrations of Cd (AP0) compared with the control soil (without Cd added). Moreover, the yield increased by 48.0% and 10.6% in AP20 and AP40, respectively, compared with AP0, and the scutellarin content increased by a factor of 2.35–2.41 in AP10, AP20, and AP40. Compared with AP0, the soil Cd content decreased by 22.5–26.2% in AP10, AP20, and AP40 and the available Cd content and acid-extractable Cd fraction in the soil also decreased. The catalase, peroxidase, superoxide dismutase activities, chlorophyll, and Fe2+ content were increased in AP10, AP20, and AP40, leading to an increased yield and scutellarin content. Overall, AP20 had the best effect on the yield, quality of E. breviscapus, and soil remediation. This study provides a practical measure to consider for concurrent benefits of pollution remediation and utilization of Cd-contaminated soil.