Achieving synergistic improvements in maize yield and nitrogen use sustainability through a novel high-density production system enabled by precision stage-specific regulation

Confronted with the dual imperatives of ensuring food security and reducing environmental pollution in China’s intensive agricultural systems, this study proposes and validates an innovative crop management paradigm: a High-Density Production System enabled by Precision Stage-Specific Regulation (HD-PSR). Based on a three-year field experiment spanning a wide nitrogen (N) application gradient (0–765 kg N ha⁻¹), we assessed the effects of N rate on grain yield, nitrogen partial factor productivity (PFP N ), plant N dynamics (uptake, distribution, and remobilization), soil residual N, and nitrous oxide (N₂O) emissions. The results show that the system achieved a clear yield plateau of 14.7–16.5 t ha⁻¹ at 243.8–306.4 kg N ha⁻¹ , while sustaining efficient internal N uptake and remobilization, providing a strong physiological basis for high yield. Simultaneously, the system markedly reduced the direct N₂O emission factor to a consistently low range of 0.3 %–0.9 %, well below the IPCC default. Notably, both cumulative N₂O emissions and the emission factor exhibited a strictly linear relationship with N application rate, in contrast to the exponential increases widely reported under conventional fertilization. This linearity is attributed to split application, which prevents the accumulation of soil mineral N that typically triggers microbial N₂O emission pulses. A comprehensive benefit index identified approximately 289 kg N ha⁻¹ as the synergistic optimum for high yield and low emissions. Collectively, these findings demonstrate that HD-PSR—through deep integration of high-density planting with whole-season, physiology-oriented precision regulation—can simultaneously enhance grain yield and nitrogen-use sustainability, offering a practical systemic pathway for the sustainable intensification of cereal production. • Maize yield plateaus at 284.8 kg N ha⁻¹ , with N uptake and remobilization saturating at high inputs. • Optimal N rate of 289.1 kg ha⁻¹ achieves 98.7 % maximum maize yield with 59.5 % reduced N₂O emissions under HD-PSR. • Emission factor increases linearly with N rates (0.3 %–0.9 % factors), below IPCC defaults. • Precision management enhances PFP N by optimizing N uptake, remobilization and minimizing soil N residues.