Root exudates mediate microorganisms to improve rhizosphere nutrient availability and crop productivity under straw mulching and slow‐release nitrogen fertilizer

Abstract Root exudates play a key role as signals and nutrients in mediating plant–microbe communication. However, critical knowledge gaps remain regarding how root exudates mediate soil–microbe–plant interactions to regulate crop yield under long‐term straw mulching combined with fertilization. Therefore, we conducted a 3‐year field trial integrating straw management (straw mulch (S) versus removal (S 0 )) with different nitrogen fertilizer types (no fertilizer (W), conventional nitrogen fertilizer (U), and slow‐release nitrogen fertilizer (RU)), employing integrated metabolomic and microbiome analyses to evaluate how root exudates affect microbial communities and may contribute to improved rhizosphere soil nutrients and crop productivity. Using the S 0 W as a control (yield: 357.6 kg ha −1 ) to highlight the effects of management practices, the results showed that both the SU and SRU treatments significantly increased crop yields, reaching 1105.1 and 1631.8 kg ha −1 , respectively. Compared with S 0 W, the SU and SRU treatments also significantly enhanced soil organic carbon content by 43.3% and 54.4%, respectively. The SRU treatment demonstrated the most pronounced improvements in total nitrogen and total phosphorus, with increases of 28.9% and 18.5%, respectively. Furthermore, the SRU treatment significantly increased the relative abundance of microorganisms such as Glomeromycota and Cladosporiaceae , as well as key lipid and organic acid metabolites in root exudates. Weighted correlation network analysis and Mantel tests revealed that putatively annotated metabolites were significantly correlated with both soil nutrient content and the enrichment of key microbial taxa ( Acidobacteriota and Cladosporiaceae ). Subsequent partial least squares path modelling further demonstrated that these interactions were significantly linked to improved soil nutrient status and increased crop yield. In summary, this study provides important insights for ameliorating degraded soils and optimizing extensive management practices. Read the free Plain Language Summary for this article on the Journal blog.