Abstract：
Carbon:nitrogen:phosphorus (C:N:P) stoichiometry plays a vital role in regulating P transformation in agriculture ecosystems. However, the impact of balanced C:N:P stoichiometry in paddy soil, particularly regarding relative soil P transformation, remains unknown. This study explores the response of C:N:P stoichiometry to manure substitution and its regulatory role in soil P transformation, along with the associated release risk to the environment. Based on a 5-year field study, our findings reveal that replacing 30 % of chemical P fertilizer with pig manure (equal total NPK amounts with chemical P fertilizer treatment, named CFM) increased soil total C without altering soil total P, resulting in an elevated soil C:P ratio, despite the homeostasis of crop stoichiometry. This increase promoted microbial diversity and the accumulation of organic P in the soil. The Proteobacteria and Actinobacteria produced lower C:PEEA metabolism together, and enhanced in vivo turnover of P. Additionally, by integrating high-resolution dialysis (HR-Peeper), diffusive gradients in thin films (DGT), DGT-induced fluxes in the soil (DIFS), and sediment P release risk index (SPRRI) models, we observed that, in addition to organic P, CFM simultaneously increased soil Al-P, thereby weakening the diffusion and resupply capacity of P from soil solids to the solution. Consequently, this decrease in P release risk to the environment was demonstrated. Overall, this study establishes a connection between crop-soil-enzyme C:N:P stoichiometry, soil microorganisms, and soil P biogeochemical processes. The study further evaluates the P release risk to the environment, providing a novel perspective on both the direct and indirect effects of manure substitution on soil P cycling.
摘要：
碳：氮：磷（C：N：P）化学计量在调节农业生态系统中磷的转化中起着至关重要的作用。然而,平衡C:N:P化学计量对水稻土的影响，特别是关于相对土壤磷转化，仍然未知。本研究探讨了C：N：P化学计量对粪肥替代的响应及其在土壤磷转化中的调节作用，以及对环境的相关释放风险。根据一项为期5年的实地研究，我们的发现表明，用猪粪代替30%的化学磷肥(与化学磷肥处理相同的NPK总量，命名为CFM)增加了土壤总碳，而不改变土壤总磷，导致土壤C:P比升高，尽管作物化学计量的稳态。这种增加促进了土壤中微生物的多样性和有机磷的积累。变形菌和放线菌一起产生较低的C：PEEA代谢，并提高了P的体内周转率。此外，通过整合高分辨率透析（HR-Peeper），薄膜中的扩散梯度(DGT)，DGT诱导的土壤通量（DIFS），和沉积物磷释放风险指数(SPRRI)模型，我们观察到，除了有机P，CFM同时增加土壤AlP，从而削弱了P从土壤固体向溶液的扩散和再供应能力。因此,P对环境的释放风险有所降低.总的来说,这项研究建立了作物-土壤-酶C:N:P化学计量之间的联系，土壤微生物,和土壤磷的生物地球化学过程。该研究进一步评估了P释放对环境的风险，为粪肥替代对土壤磷循环的直接和间接影响提供了新的视角。
