Soil net nitrogen mineralisation (Nt) is crucial for nitrogen availability and ecosystem productivity. However, the patterns and drivers of Nt remain unclear under different management practices. We examined the biotic and abiotic determinants of Nt, using 11 treatments in Northern China fluvo-aquic soil under wheat–maize rotation. Biotic properties, for example, soil microbial community, were determined based on phospholipid fatty acid (PLFA) together with high-throughput sequencing technologies. Abiotic properties were characterised by the content and stoichiometric ratios of soil nutrients. Animal manure applications (HNM, NM, M, FM) significantly increased the Nt (1.80–3.40 mg kg⁻¹) and available phosphorus (Olsen-P) (46.3–199.3 mg kg⁻¹), compared with treatments with plant residues (NG, NS) incorporation. Fallow with animal manure (FM) had the highest Gram-negative bacteria (G-, 29.3 nmol g⁻¹), arbuscular mycorrhizal fungi (AMF, 4.57 nmol g⁻¹) abundance, which was also significantly higher than that of the NG and NS. Structural Equation Modelling revealed that the content of total nutrient, including soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) rather than biotic properties, such as microbial community (λ = −0.26) and enzyme activities (λ = −0.16), had the strongest direct effect on Nt (λ = 0.85). Stoichiometric ratios of C, N, and P controlled Nt indirectly by mediating enzyme activities. Specifically, high Nt was associated with low Dothideomycetes, Tectomicrobia abundance that negatively correlated with SOC, TN, TP, Olsen-P, and BG activity. Random forest model indicated that SOC and Olsen-P contents were top-rated determinants of Nt. Our result indicated that the content and stoichiometric ratios of SOC and N, P directly drive Nt or via microbial ways. Our study highlighted the importance of P to improve Nt: animal manure was thus recommended for nitrogen availability.

中文翻译：

---

净 N 矿化的微生物调控由 C、N、P 含量和化学计量驱动

土壤净氮矿化（Nt）对于氮的有效性和生态系统生产力至关重要。然而，在不同的管理实践下，Nt 的模式和驱动因素仍不清楚。我们在小麦-玉米轮作条件下对华北潮土进行了 11 种处理，研究了 Nt 的生物和非生物决定因素。生物特性，例如土壤微生物群落，是基于磷脂脂肪酸 (PLFA) 和高通量测序技术确定的。非生物特性通过土壤养分的含量和化学计量比来表征。动物粪便应用（HNM、NM、M、FM）显着增加了 Nt（1.80–3.40 mg kg ^-1）和有效磷（Olsen-P）（46.3–199.3 mg kg ^-1），与植物残留物（NG，NS）掺入的处理相比。动物粪便休耕 (FM) 的革兰氏阴性菌 (G-, 29.3 nmol g ^-1 )、丛枝菌根真菌 (AMF, 4.57 nmol g ^-1 ) 丰度最高，也显着高于 NG 和NS。结构方程模型揭示了总养分的含量，包括土壤有机碳 (SOC)、总氮 (TN) 和总磷 (TP)，而不是微生物群落 ( λ  = -0.26) 和酶活性 ( λ  = -0.16)，对 Nt ( λ = 0.85)。C、N 和 P 的化学计量比通过介导酶活性间接控制 Nt。具体来说，高 Nt 与低Dothideomycetes和Tectomicrobia丰度相关，与 SOC、TN、TP、Olsen-P 和 BG 活性呈负相关。随机森林模型表明 SOC 和 Olsen-P 含量是 Nt 的最高决定因素。我们的结果表明 SOC 和 N、P 的含量和化学计量比直接驱动 Nt 或通过微生物方式。我们的研究强调了 P 对改善 Nt 的重要性：因此建议使用动物粪便来提高氮的利用率。