Photosynthetic performance and yield of intercropped maize and soybean are directly opposite under different intercropping ratios and maize planting densities interactions.

Background: Maize-soybean intercropping, a sustainable intensification practice, has been extensively studied. However, systematic research on how maize planting density and crop allocation patterns influence yield-related photosynthetic mechanisms in intercropping systems is scarce. This study conducted a two-year field trial during the 2022 and 2023 planting seasons to evaluate the effects of intercropping ratios (M4S4: four rows maize to four rows soybean; M2S2: two rows maize to two rows soybean) and maize planting densities (D1: 45 000 plants ha, D2: 52 500 plants ha, D3: 60 000 plants ha) on photosynthetic performance and yield of maize and soybean, with monoculture as controls.