Positive interactions in cereal/legume intercropping may drive high system productivity and ensure the sustainable development of modern agricultural practices. In this study, the effect of nitrogen (N) fertilizer application rates on soil ecoenzymatic stoichiometry, microbial nutrient status and interspecific competition during the cogrowth stages in broomcorn millet (Panicum miliaceum L.)/mung bean (Vigna radiata L.) intercropping were investigated. Two-year field experiments (2018 and 2019) involved the use of the following N treatments: N0, 0 kg N ha⁻¹ (control); N1, 45 and 60 kg N ha⁻¹; N2, 90 and 120 kg N ha⁻¹; and N3, 135 and 180 kg N ha⁻¹ for mung bean and broomcorn millet, respectively. Intercropped broomcorn millet was the dominant species determined by positive competitive ratios and aggressivity values at the early (1.70 and 1.81), middle (2.06 and 1.98), and the later cogrowth stages (3.02 and 2.48), respectively. Nitrogen application increased the competitive ratio and aggressivity by 29.4 % and 24.5 %, respectively, compared with the control. Leaf photosynthesis and aboveground biomass of the two crops were altered by the N treatment, with high N fertilizer inputs significantly reducing the intercropping advantages and land use efficiency. Intercropping and N fertilizer improved interspecific competition and boosted grain yield in 2018 and 2019, and values were 6331.8 kg ha⁻¹ and 6531.3 kg ha⁻¹ for broomcorn millet and 905.0 kg ha⁻¹ and 979.8 kg ha⁻¹ for mung bean, respectively. Moreover, intercropping and N fertilization markedly affected the soil nutrient content, microbial biomass, and enzyme activity involved in carbon (C), nitrogen (N), and phosphorus (P) acquisition in both species. The soil ecoenzymatic C:N:P acquisition ratios were strongly associated with nutrient acquisition by microbes in the rhizosphere, highlighting the importance of microbial metabolic changes driven by nutrient stoichiometry to meet the soil nutrient demands. This study provides an explanation for considering more sustainable agricultural practices of cereal/legume intercropping based on reduced fertilizer application compared with monocropping.

谷物/豆类间作的积极相互作用可能会提高系统生产力并确保现代农业实践的可持续发展。在这项研究中，研究了氮 (N) 肥施用量对高粱黍 ( Panicum miliaceum L.)/绿豆 ( Vigna radiata L.) 间作共生阶段土壤生态酶化学计量学、微生物养分状况和种间竞争的影响. 为期两年的田间试验（2018 年和 2019 年）涉及使用以下氮处理：N0，0 kg N ha ^-1（对照）；N1, 45 和 60 kg N ha ^-1；N2, 90 和 120 kg N ha ^-1；和 N3, 135 和 180 kg N ha ^-1分别用于绿豆和高粱小米。间作高粱黍是优势种，分别由共生早期（1.70 和 1.81）、中期（2.06 和 1.98）和后期（3.02 和 2.48）的正竞争比和侵略性值决定。与对照相比，施氮使竞争率和侵略性分别提高了 29.4% 和 24.5%。N处理改变了两种作物的叶片光合作用和地上生物量，高氮肥投入显着降低了间作优势和土地利用效率。间作和施氮改善了种间竞争，提高了 2018 年和 2019 年的粮食产量，分别为 6331.8 kg ha ^-1和 6531.3 kg ha ^-1高粱小米和绿豆分别为905.0 kg ha ^-1和 979.8 kg ha ^-1。此外，间作和施氮显着影响土壤养分含量、微生物生物量和参与碳（C）、氮（N）和磷（P）获取的酶活性。土壤生态酶 C:N:P 获取率与根际微生物的养分获取密切相关，突出了由养分化学计量驱动的微生物代谢变化以满足土壤养分需求的重要性。本研究解释了基于与单作相比减少施肥的谷物/豆类间作更可持续的农业实践。