Row spacing regulates source–sink balance under high-density maize planting in an arid oasis system

The objectives of this study were to explore the interactive effects of planting density and row spacing on maize source–sink traits, quantify dynamic source–sink relationships, and elucidate physiological mechanisms underlying yield formation in arid Northwest China. In a two-year field experiment, grain yield, population biomass, and canopy physiological traits were measured at three row spacings and four planting densities. The traits consistently peaked at 130,000 plants ha –1 . At this density, alternating row spacings of 30 and 80 cm and uniform 55-cm spacing achieved comparable yields, exceeding those from 75-cm row spacing. But the alternating spacing exhibited a more balanced physiological source-sink relationship. We conclude that optimizing canopy architecture via wide-narrow row configurations coordinates active source maintenance with sink-driven translocation, presenting a strategy for high-density maize production.