Deep fertilization combined with straw incorporation improved rice lodging resistance and soil properties of paddy fields

Deep nitrogen fertilization (DNF) coupled with straw incorporation has the potential to improve the grain yield and nitrogen use efficiency of mechanically transplanted rice. However, the effects of different fertilization approaches combined with straw incorporation on lodging resistance ability, and soil properties are still uncertain. Therefore, a two-year field experiment was comprised of broadcast fertilizer treatments (broadcast fertilizer without straw (BFS0) or with straw (BFS)), deep fertilizer treatments (DNF without straw (DFS0) or with straw (DFS)). Results depicted that deep fertilizer treatments significantly improved the pushing resistance force by 63.81–129.58 % and decreased the lodging index by 22.01–80.82 % of rice compared with broadcast fertilizer treatments. Deep fertilizer treatments optimized the length of the first four internodes and increased the internodes diameter and culms wall thickness in the third and fourth internode, and higher silicon and lignin content in the fourth internode, compared to broadcast fertilizer treatments. Furthermore, the straw incorporation treatments also improved soil total nitrogen, soil available potassium, and soil organic matter by 5.60–11.48 %, 17.75–22.56 %, and 7.17–18.26 %, respectively, regardless of fertilizer application method. Hence, this study suggests that deep nitrogen fertilization can be adopted as an agronomically effective tactic to improve lodging resistance in rice whilst the combination of straw incorporation and deep fertilization can be considered to further improve the soil properties.