Abstract: To explore the input threshold of a one-time application of N fertilizer that considers maize yield and environmental effects in the black soil region of Northeast China, this study established a 8-year field experiment in the black thin-layer soil region of Jilin Province (Liufangzi Village, Gongzhuling City) from 2016 to 2023. This study revealed the responses of maize yield, N uptake and utilization, soil NO₃⁻-N content, and soil N apparent balance to different N fertilizer application rates under the condition of a one-time application of N fertilizer (common urea plus controlled-release N fertilizer at a N ratio of 4∶6). Six N fertilizer application treatments were established: 0, 70, 140, 210, 280, and 350 kg∙hm⁻², labeled as N0, N70, N140, N210, N280, and N350, respectively. The results showed that the 8-year average maize yield increased by 63.8%–188.8% under N fertilizer application treatments compared with no N fertilizer, and significant differences were observed (P<0.05). The advantages of maize yield under N fertilizer application treatments were mainly attributed to the increased grains per ear and 100-kernel weight of maize. The maize yield showed an upward trend with increased N fertilizer application rates, reaching the yield platform under 210 kg∙hm⁻² of N fertilizer application rate. With this N fertilizer application rate, the average maize yield over eight years was 11 668 kg∙hm⁻². N apparent recovery efficiency (REN), N agronomic efficiency (AEN), and N partial factor productivity (PFPN) decreased with increasing N fertilizer application rates. The NO₃⁻-N contents in the 0–100 cm soil layerincreased with increasing N application rates. The NO₃⁻-N content under N210 treatment was similar to the initial value of the experiment after the maize was harvested in 2023. In the 8 year experiment, the N apparent balance results showed that inorganic N residual and N apparent loss increased with increasing N fertilizer application rates. Inorganic N residual under N210 treatment was similar to the initial values in the experiment. When it reached the yield platform at 208.8 kg∙hm⁻² of N fertilizer application rate, maize yield, N apparent recovery efficiency, inorganic N residual, and N apparent loss were 11 835 kg∙hm⁻², 48.2%, 172.3 kg∙hm⁻², and 53.9 kg∙hm⁻² respectively. The calculated theoretical results for maize yield, N apparent recovery efficiency, and N apparent loss matched well with the observed values under the maximum maize yield under N210 treatment. Within the 95% confidence interval of the N fertilizer application rate under the theoretical maximum maize yield, the optimum N fertilizer application rate was calculated at 198−219 kg∙hm⁻². In conclusion, the range of N fertilizer application at 198−219 kg∙hm⁻² obtained higher maize yield and N use efficiency, maintained the basic stability of soil N pools before and after maize harvest, and maintained N apparent loss to a lower level. Therefore, it can be used as an input threshold for the one-time application of N fertilizer that considers maize yield and environmental effects. These results provide a theoretical basis for the one-time application of N fertilizer to maize in the black, thin-layered soil region of Northeast China.