highly significantP < 0.01
The treatment-year interaction significantly affected maize yield and WUE ( P < 0.05), and had a highly significant effect on those of soybean ( P < 0.01). 2C4S significantly boosted maize yield (2022: 4.04%-33.53%; 2023: 2.58%-26.98%) and exhibited the least soybean yield reduction under intercropping compared to SJSJ.