Organic substitution regimes (OSR) can improve soil microbial properties in crop production. However, the dynamic responses of soil microbial flora and its driving factors in crop growth periods under OSR are still unclear. Here, a 2-year fertilizer field trial was conducted to explore the response of soil chemistry and microbial properties to OSR in the life cycle of potatoes (Solanum tuberosum L.) in North China. The fertilization treatment included only mineral fertilizer (ConN), substitution of 30% mineral N with organic N (M30), and substitution of 60% mineral N with organic N (M60); soil samples were collected and analyzed in the early flowering period (EP), flowering period (MP), and maturity period (LP) of potatoes. As the potato growth period progressed, M30 and M60 increased soil organic carbon (SOC) compared with ConN. Soil total nitrogen (pH) increased (decreased) under M60, while soil available potassium was similar across three treatments. Compared with ConN, soil bacterial Chao, Shannon, and PD indexes significantly increased under M30 and M60 in MP and LP, and the fungal Shannon index increased in LP. Soil bacterial and fungal community structures under M30 and M60 were only significantly separated from ConN in MP. The bacterial communities of dominant phyla or genera responded more sensitively to the fertilization regimes than the flora of fungi, and the changes in the flora mainly occur in EP and MP. Redundancy analysis revealed that SOC and available phosphorus were highly correlated with soil microbial community compositions. Compared with ConN, soil microbial network complexity and fungal network robustness were higher under M30 and M60, while bacterial network robustness showed the opposite trend. Partial least squares pathway modeling showed that the conversion in the fertilization system or growth period had a direct positive effect on the C/N-cycling function of soil bacteria, but not on the C-degradation function of fungi. Our research has important theoretical implications for the development of microbial fertilizers and fertilization management in different potato growth periods.

有机替代方案（OSR）可以改善作物生产中的土壤微生物特性。然而，OSR下作物生育期土壤微生物区系的动态响应及其驱动因素仍不清楚。本文进行了为期 2 年的肥料田间试验，以探索华北地区马铃薯 ( Solanum tuberosum L.)生命周期中土壤化学和微生物特性对 OSR 的响应。施肥处理包括仅施矿物肥(ConN)、有机氮替代30%矿物氮(M30)、有机氮替代60%矿物氮(M60)；在马铃薯的早花期（EP）、花期（MP）和成熟期（LP）收集并分析土壤样品。随着马铃薯生育期的进展，与ConN相比， M30和M60增加了土壤有机碳（SOC）。M60 下土壤总氮 (pH) 增加（减少），而土壤速效钾在三个处理中相似。与ConN相比，MP和LP中M30和M60处理下土壤细菌Chao、Shannon和PD指数显着升高，LP中真菌Shannon指数显着升高。M30和M60下的土壤细菌和真菌群落结构仅与MP中的ConN显着分离。优势门或属的细菌群落对施肥方式的响应比真菌菌群更敏感，菌群的变化主要发生在EP和MP中。冗余分析表明，SOC和速效磷与土壤微生物群落组成高度相关。与ConN相比，M30和M60下土壤微生物网络复杂性和真菌网络稳健性较高，而细菌网络稳健性则表现出相反的趋势。偏最小二乘路径模型表明，施肥制度或生育期的转换对土壤细菌的C/N循环功能有直接的正向影响，但对真菌的C-降解功能没有直接的正向影响。我们的研究对于微生物肥料的开发以及马铃薯不同生育期的施肥管理具有重要的理论意义。