Soil greenhouse gases emission and nitrogen dynamics under maize straw incorporation and contrasting nitrogen fertilization

Background and aims Straw incorporation was widely accepted in the world for conservation agriculture, whereas the effects on greenhouse gases emissions (GHGs) and nitrogen dynamics under soils formed by long-term contrasting nitrogen (N) fertilizer are still unclear. Methodology An incubation experiment was conducted with or without maize straw using soils collected from fields study after 6-year contrasting N fertilization of 0 (low N), 187 (medium N) and 337 kg N ha ^− 1 (high N). Results Straw amendment significantly stimulated both N ₂ O and CO ₂ fluxes, and increased cumulative emission by 0.82 and 18.98 times than without straw incorporation on average, respectively. Medium N soil observably weakened N ₂ O emission (23.76 µg kg ^− 1 ) than high N soil (162.71 µg kg ^− 1 ) and attenuated CO ₂ emission (1.85 g kg ^− 1 ) than Low N soil (2.30 g kg ^− 1 ) soils with straw amendment. Soil NH ₄ ⁺ -N and NO ₃ ⁻ -N dynamics kept the increasing trend with rising soil N, whereas straw accelerated the decrease of NH ₄ ⁺ -N from 24.72–78.98%, and reversed the tendency of NO ₃ ⁻ -N from enrichment (+ 75.19%) to scarcity (-58.83%) compared to straw removal due to higher soil N fixation capacity. Moreover, partial least squares path modeling and random forest mean predictor importance disentangled straw affected GHGs by altering nitrogen turnover capacity. Conclusion Straw amendment promoted GHGs and enhanced mineral N turnover and diminished the risk of losses. Combing straw with medium N soil could mitigate greenhouse effect and improvement N and C balance in farming system compared to the low and high N soils.