Improving rice grain yield and reducing lodging risk simultaneously: A meta-analysis

Smart agronomic management practices (e.g., employing lodging-resistant cultivars, appropriate fertilization, and applying plant growth regulators (PGRs)) can reduce crop lodging risk. However, their integrated effects on grain yield and lodging risk in rice paddies remain poorly defined. Here, we conducted a meta-analysis to examine the effects of agronomic practices on rice yield and lodging risk, synthesizing data from 68 published studies with 475 observations. Our results showed that compared with inbred varieties, hybrid rice increased grain yield by an average of 8.9%, and enhanced lodging index (LI) (increasing lodging risk with a higher LI) at the 1st (+23%) and 3rd (+17%) internodes with no significant effect at the 2nd internode. Inorganic nitrogen (N) fertilization increased both rice yield (+42%) and LI at the 2nd (+31%) and 3rd (+23%) internodes, but did not significantly affect LI at the 1st internode. The application of silicon (Si) and potassium (K) fertilizers increased rice yield by 7.2% and 18%, respectively, while simultaneously reducing LI by 14% and 19% at the 1st internode, by 15% and 21% at the 2nd internode, and by 4.5% and 18% at the 3rd internode. Prohexadione calcium and uniconazole increased rice yield by 6.7% and 8.3%, respectively, while paclobutrazol had no significant effect on rice yield. Prohexadione calcium and uniconazole reduced LI by 14% and 21% at the 1st internode, by 26% and 31% at the 2nd internode, and by 16% and 54% at the 3rd internode, respectively, whereas paclobutrazol only reduced LI at the 3rd internode by 12%. In conclusion, the application of Si, K, prohexadione calcium, and uniconazole is a promising strategy for improving rice yield and reducing lodging risk. In addition, we suggest that high-yielding practices (e.g., hybrid rice and inorganic N fertilization) and lodging-resistant practices (e.g., the application of Si, K, and PGRs) should be combined to increase grain yield and simultaneously reduce lodging risk in rice paddies.