Simulation of soil water balance and crop productivity of long-term continuous maize cropping under high planting density in rainfed agroecosystems

•Both model and experiment were used to explore the effects of density on maize productivity.•High density decreased maize yields in rainfed agroecosystems.•High density did not cause the soil water balance to become negative in dryland farming systems.•Optimal planting density of dryland maize varied among sites and years.