[Effects of Different Metal Elements on Cadmium Uptake Under Wheat-rice Rotation Condition].

Abstract

The accumulation of cadmium （Cd） in the food chain poses a serious threat to human health. To explore the possible heavy metal cation inhibitor, a pot experiment was developed to research the addition of Fe, Mn, Zn, and Mg on Cd uptake and accumulation in wheat and rice. Soil Cd content was artificially added to 5 mg·kg^-1 and aged for one month. Fe, Mn, and Zn were added as metal chlorides at a ratio of 100 mg·kg^-1 and Mg for 300 mg·kg^-1. The main results were： ① Zn supplementation significantly enhanced the grain biomass of wheat and rice； ② Zn remarkably reduced the grain Cd content in wheat and rice, with a decrease of 41% and 23% in wheat and rice grain Cd content compared with that in the control, respectively, without yield penalty； and ③ In the wheat-rice rotation mode, the grain Cd content in rice was notably lower than that in wheat, with a reduction to 0.17 mg·kg^-1 for ω （Cd）, which was below the rice Cd limit value （0.2 mg·kg^-1） specified by the national food safety standard （GB 2762-2022）. Collectively, these findings suggest that the application of Zn in a wheat-rice rotation system significantly mitigate Cd accumulation in grains, with rice exhibiting a more pronounced effect. These results hold notable implications for the safe utilization of Cd-contaminated farmland and ensuring food security.