Planting Density Impacts Maize Yield Sensitivity to Vapor Pressure Deficit in Northeast China

This study aimed to investigate the impact of planting density on the yield sensitivity of maize to VPD in northeast China, utilizing both crop model and statistical model approaches. Simulation results indicated a significant increase in VPD during the maize reproductive period in this region in the future. Statistical modeling further confirmed that VPD was the most influential meteorological factor affecting maize yield variability. Our analysis revealed that increasing planting density could enhance maize yield, but it would also intensify the sensitivity of maize yield to VPD. Specifically, under dense cropping conditions from 2070-2099, the yield sensitivity to VPD is projected to increase by approximately 70% compared to low-density cropping. However, increasing planting density could disrupt the balance of soil water supply and demand, leading to a more pronounced decrease in the water stress index with increasing VPD at higher densities.