Аңдатпа
Context: Crop acquisition of nutrients from soil is influenced by the interaction between active capture by the plants themselves and passive supply from the external environment. Both the endogenous potential of crops and changes in the external environment can drive shifts in the same microbial communities and functions to enhance nutrient acquisition in the root-soil interface. Objective and Methods: To investigate the mechanisms by which microbial communities and functions influence nutrient transformation and uptake in maize production, we conducted a seven-year continuous field experiment using two maize varieties with distinct productivity responses to nitrogen: Qiangsheng 101 (N-responsive) and Zhengdan 958 (N-efficient). Combined with nitrogen application treatments (0 and 150 kg N ha -1 ), we analyzed changes in different microbial communities within network structures to identify unique communities. By examining the relationships among rhizosphere soil nutrients, root endophytic and rhizosphere soil microbial communities, and their functions, we aimed to construct a mechanistic model of microbial involvement in nutrient transport. Results: The results showed that improved maize productivity was associated with increased ammonium nitrogen and soil organic carbon (SOC) in the rhizosphere soil. Compared to the rhizosphere soil, the root endophytic microbial community actively responded to both endogenous and external environmental drivers. This included an increase in the proportion of network nodes belonging to Bacteroidetes and a decrease in Actinobacteria among bacterial communities, as well as an increase in Glomeromycota and Mortierellomycota network nodes among fungal communities, particularly Glomeromycota. These changes were accompanied by enhanced urease hydrolysis function in both roots and soil, reduced nitrification, and a significant increase in arbuscular mycorrhizal (AM) fungal function. Path modeling indicated that maize variety and nitrogen application induced increased activity of Bacteroidetes in the roots, which enhanced urease hydrolysis function in the rhizosphere. The increased release of nutrients promoted the transport of assimilates to the roots, stimulating Glomeromycota activity and thereby improving AM function. This further enhanced root carbon exudation, increasing soil SOC. When AM fungal function was low, Mortierellomycota contributed to soil SOC accumulation. Bacteroidetes may compete for more organic carbon, inhibiting Actinobacteria activity and thus reducing nitrification. Additionally, the preference of AM fungi for ammonium nitrogen uptake may suppress nitrification and nitrate production. Further investigation is needed to explore the priming effects of soil ammonium ions and aboveground carbon input on AM function. Conclusion: Our study highlights the critical mechanism by which cross-kingdom microbial interactions, driven by urease hydrolysis (bacteria) and AM function (fungi), influence crop productivity through rhizosphere carbon fixation, nitrogen transformation, and uptake.