Combining mercapto‐functionalized palygorskite with zinc affect cadmium phytoavailability and soil microbial activity in rhizosphere soil

Abstract

AbstractCadmium (Cd) pollution in soil poses a grave threat to human health. Combining various approaches to reduce Cd accumulation in crops is an active area of research to remediate farmlands with medium‐high levels of Cd contamination. The Mercapto‐functionalized palygorskite (PGS‐SH) and zinc (Zn) application alone or in combination were investigated to explore the reduction of Cd uptake by B. chinensis L and transformation of Cd in soil. The sole application of Zn or PGS‐SH increased the biomass of B. chinensis L. and decreased the concentration of Cd in plants, but more improvements were observed from the combined application of Zn and PGS‐SH. Low concentration of exogenous Zn (50 mg·kg‐1) significantly increased the soil respiration rate (SRR) and the soil dehydrogenase activity (sDHA), while promoted B. chinensis L. growth while inhibiting Cd uptake. However, excessive exogenous Zn (≥ 200 mg·kg‐1) significantly inhibited B. chinensis L. growth and soil microbial activity. The combined application of PGS‐SH and Zn had the highest sDHA (145.59%) and lowest transport factor (TF) (27.59%) compared with the CK. The combination of PGS‐SH and Zn fertilizer is a safe and effective means to reduce the accumulation of Cd in plants and restore microbial activity.