Linking land use advantage and temporal stability for row configuration design in maize/soybean intercropping under water-limited dryland conditions in northeastern China

Context In water-limited rainfed regions, recurrent water deficits pose a major challenge to sustaining productivity and temporal stability. Maize/soybean intercropping can enhance resource use efficiency, but its performance is highly dependent on spatial configuration. Existing studies have largely assessed intercropping advantages using land equivalent ratio (LER), while comparatively little attention has been given to the joint optimization of land use advantage and its temporal stability. Objective and Methods In this study, APSIM-strip was further evaluated using two maize/soybean field experiments with different soybean land use proportions and border row ratio (BRR) and was subsequently applied to Fuxin, a representative water-limited rainfed region in northeastern China, across 1961 to 2020. The long-term yield, land equivalent ratio (LER) and their temporal stability under different soybean land use proportion and border row ratio were evaluated. To better design intercropping configurations, a high-stability coefficient metric based on LER (LER-HSC) were developed. Results and Conclusion APSIM-strip performed well in simulating maize and soybean phenological development and yield responses across different maize/soybean intercropping configurations. Decreasing soybean land use proportion increased maize yield and stability but reduced soybean yield, while LER and its temporal stability showed contrasting responses. LER-HSC was highest at a soybean land use proportion of 0.5, indicating the best balance between land use advantage and temporal stability. At this soybean proportion (0.5), LER generally declined as soybean border row ratio decreased, and the highest LER-HSC occurred at a BRR of 0.5, corresponding to the 4 rows of maize intercropped with 4 rows of soybean configuration. Overall, the proposed framework LER-HSC enables intercropping configurations to be evaluated beyond LER alone by jointly considering land use advantage and temporal stability under climatic variability. Our study is helpful for the design of intercropping configurations under changing climate.