Abstract:

This study aims to explore the impact of the “VIP+n” comprehensive cadmium control technology system on cadmium-polluted paddy fields in the central and southern parts of Hunan Province. The experiments were conducted in Yaotian town of Leiyang City for two consecutive years, including plot comparative experiments and large-scale demonstration experiments. In the plot comparative experiments, 10 treatments were employed to compare the effects of measures such as low-cadmium-accumulating rice varieties, continuous flooding irrigation, application of quicklime, microbial agents, and foliar inhibitors on cadmium-polluted paddy fields. Based on the results of the plot experiments, three cadmium-reducing technologies with good efficacy and economic feasibility were selected for large-scale demonstration experiments. The results showed that the “VIP+n” cadmium control technology system effectively reduced the cadmium content in rice grains in cadmium-contaminated paddy fields. Compared to the control group, the cadmium reduction rate for early rice using this technology system ranged from 59.66% to 79.45%, while for late rice, it ranged from 46.85% to 48.23%. Among the various cadmium reduction measures, the application of quicklime significantly reduced the cadmium content in rice grains, and the use of low-cadmium varieties alone had a significantly higher cadmium reduction effect than using quicklime alone. In contrast, continuous flooding irrigation, application of microbial agents, and foliar inhibitors did not show significant cadmium reduction effects.

Key words: cadmium contamination in paddy fields, application of quicklime, low-cadmium rice varieties, water management, remediation technique