Tailoring wheat agronomic management to ENSO phases to manage climate variability in Australia at 5-minute resolution

• Published in: Agricultural and forest meteorology 2024-09, Vol.356, p.110168, Article 110168
• Main Authors: Cao, Juan, Zhang, Zhao, Xie, Jun, Luo, Yuchuan, Han, Jichong, Mitchell, Patrick J., Tao, Fulu
• Format: Article
• Language: English
• Subjects: Climate variability; Crop model; Crop yield; ENSO phase; Management practice
• ISSN: 0168-1923
• DOI: 10.1016/j.agrformet.2024.110168

•Applying an advanced gridded CERES-Wheat model for spatial modelling.•Developing optimal agronomic managements for each ENSO phase.•Wheat should be sown earlier in El Niño phase than in other phases.•More nitrogen should be applied in La Niña and neutral than in El Niño phase.•Selecting specific wheat varieties traits for regions and ENSO phase is promising. The El Niño Southern Oscillation (ENSO) significantly influences wheat yield variability in Australia. Tailoring crop agronomic managements to ENSO phases can effectively manage climate variability and reduce crop yield variability. Previous studies have mostly been conducted at a site scale, whose results are hardly extrapolated to a large heterogeneous area. Here, the CERES-Wheat model was calibrated at 5-minute grid scale and applied to simulate wheat yield and adaptation measures under different ENSO phases across wheat cultivation areas in Australia. The results show that the calibrated gridded model can capture wheat phenology and yield variations reasonably. Wheat yields are significantly affected by ENSO-induced changes in precipitation and maximum temperature. During El Niño phase, more dry days, hot days, frost days, water stress, and lower LAI (Leaf Area Index) and ET (Evapotranspiration) lead to an obvious yield decline, especially in southeastern Australia. Wheat sown in the mid-season (Day of Year, DOY of 144) increase yield by 433.5 ± 25.6 kg/ha (27.9 ± 1.6 %) during El Niño, while late-season sowing is more suitable for Neutral (DOY of 153.4) and La Niña phases (DOY of 147.5). A higher nitrogen rate is needed during La Niña (106 kg/ha) and Neutral (106.5 kg/ha) compared to El Niño (94.5 kg/ha) phase. Optimizing varieties is the most effective option and may increase yield by 624±20.9 kg/ha, 562.9 ± 21.5 kg/ha, and 614.3 ± 21 kg/ha for Neutral, El Niño, and La Niña phases, respectively, over traditional farming practices, respectively. The wheat varieties with a larger photoperiod sensitivity and shorter grain-filling duration are favorable during El Niño. Our findings demonstrate a powerful model-based decision support system in tailoring agronomic management practices to ENSO phases and local environments at a high resolution.