Mitigating Cadmium Contamination in Rice: Insights from a Large-Scale Meta-Analysis on Amendments Effects

Abstract

Abstract Background and aims Cadmium (Cd) pollution in rice is a health hazard to humans. The application of amendments decreases Cd bioavailability in soil and Cd accumulation in rice plants. However, a complete and quantitative understanding of the effects of soil amendments on soil properties, Cd availability, rice yield, and Cd accumulation in rice is lacking. Methods This study conducted a meta-analysis using data obtained from 436 peer-reviewed papers to evaluate the impact of amendments on different variables involved in a soil-rice system polluted with Cd. Results Ten amendments significantly reduced the Cd content in rice. Brown rice Cd concentrations decreased by 33.4%, and crop yields increased by 12.1% on average with the application of amendments. Available Cd in soil content decreased by 26.4% because of amendments. Amendments influenced Cd forms in the soil by increasing pH (7.94%), CEC (14.73%), and SOC (11.97%). Various factors considerably influenced the effects of amendments. The selection of amendments principally determined the inhibiting effect of amendments on Cd in brown rice. Various factors influenced the regulation of available soil and rice Cd in a similar manner. For intense precipitation (> 2000 mm), amendments were observed to be more efficient in decreasing the presence of Cd in brown rice. However, their effectiveness was diminished in loamy soils. According to the regression analysis, soil pH was essential in regulating accessible Cd in acidic soils. Conclusion The application of amendments can successfully lower Cd levels in rice grains and enhance soil quality while maintaining rice yield.