Effects of Selenium–Zinc Interactions on the Bioavailability of Selenium/Zinc in Soil and Its Mechanism
Abstract Purpose Biofortification is a core strategy in solving the malnutrition of selenium (Se) and zinc (Zn) for global human being. However, whether Se and Zn co-biofortification can manipulate soil Se/Zn bioavailability and its mechanism still remains unclear. Methods The pot experiment was conducted to investigate the co-amendment of selenate and Zn sulfate on the growth of pak choi, especially on the uptake of Se and Zn, and to elucidate the effect of soil pH and soil enzyme activity on the bioavailability of Se/Zn in soil and its mechanism. Results Results showed that plant growth inhibition caused by the application of high Se rate was significantly alleviated with Zn supplements, and the biomass in the shoots and roots of pak choi in Se2.5Zn20 and Se2.5Zn50 treatments significantly increased (67.0%–112.8%) compared with the Se2.5Zn0 treatment. Additionally, Se and Zn co-amended application significantly enhanced soil available Se/Zn content compared with correspond single Se/Zn treatments. The increase of soil available Zn content could be attributed to the significant decrease in the soil pH, while the increase of soil available Se was from the biochemical conversion caused by the activity of catalase, urease, and alkaline phosphatase. Conclusion Se–Zn co-amendment can ameliorate bioavailability of Se/Zn in soil by regulate the pH and enzyme activity of soil.
