The Optimal Planting Density of Maize in Western Yunnan Based on AquaCrop Model

Purpose To study the adaptability of the AquaCrop model in western Yunnan and determine the optimal planting density of maize under different rainfall patterns.

Methods Multi-year experimental data on maize planting density from the study region were used to calibrate and validate the AquaCrop model parameters. The model’s accuracy and regional adaptability were assessed. A Pearson Type Ⅲ frequency curve was applied to select representative years of high, normal, and low rainfall from 1980 to 2021, and the maize yields under three different rainfall patterns and six planting densities were simulated using the model.

Results The AquaCrop model effectively simulated maize yields under varying planting densities across different rainfall patterns in western Yunnan. The optimal planting densities identified were 7.885×10⁴ plants/hm² for high-rainfall years, 7.843×10⁴ plants/hm² for normal-rainfall years, and 7.774×10⁴ plants/hm² for low-rainfall years. Simulated yields increased by approximately 38.14%-41.75% compared to traditional planting densities in the region.

Conclusion The optimal planting density of maize is 7.8×10⁴ plants/hm² in western Yunnan, which has significant implications for increasing maize yield, ensuring food security, and improving land use efficiency.