Mechanism of polyvinyl pyrrolidone‐promoted action of nanosilicon and fulvic acid on heavy metals in rice

Abstract BACKGROUND Reducing cadmium and lead in rice is a priority for achieving food security production. Foliar control technology has become a research focus in mitigating heavy metal contamination in crops. For this, a field experiment was conducted in Liling, Hunan Province, China, to investigate the use of the surfactant polyvinyl pyrrolidone (PVP) to enhance the impact of nanosilicon and fulvic acid on heavy metal accumulation in two rice cultivars: H‐LiangYou 518 (HLY518) and NongXiang 42 (NX42). RESULTS The results showed that the addition of PVP was more effective in reducing Cd compared to the application of nanosilicon and fulvic acid alone. Among them, PVP and nanosilicon addition was more effective. The results showed that foliar spraying of nanosilicon and PVP reduced the Cd content of NX42 and HLY518 rice grains by 45% and 47%, respectively. At the same time, the content of Cd and As in the phloem and xylem was reduced by more than 50% compared to CK. Additionally, contact angle analysis of foliar surface showed that adding PVP decreased the contact angle from 63.1° to 54° for fulvic acid treatment, and from 43.3° to 36.7° for nanosilicon treatment, which increased droplet spreading area, prolonging the duration of action. CONCLUSION Therefore, PVP can further increase the accumulation of Zn and Fe in rice by increasing the residence time of nanosilicon and fulvic acid on the foliar surface of rice, thus reducing the content of Cd and Pb in the rice grains. © 2025 Society of Chemical Industry.