Strategies for mitigating winter wheat yield reduction in the Yellow River basin: Simulations and insights from CMIP6 data and the improved DSSAT-CERES-wheat model

Abstract

Winter wheat is a vital staple crop in northern China, and climate change is expected to increase the frequency of droughts, leading to reduced yields. Therefore, it is crucial to study the impact of climate change on winter wheat yield and develop strategies to mitigate these effects. This study used CMIP6 data and an improved DSSAT-CERES-Wheat model to simulate winter wheat's phenological stages, yield, and water stress factors in the Middle and upper reaches of Yellow River basin from 2022 to 2050 and proposed measures to counteract yield reduction. The results revealed that optimal sowing dates and irrigation strategies remained stable under both the Shared Socioeconomic Pathway 2–4.5 (SSP2–4.5) and Shared Socioeconomic Pathway 5–8.5 (SSP5–8.5) scenarios across the middle and upper reaches of the Yellow River Basin. Early sowing combined with targeted irrigation during the jointing and grain-filling stages enhanced winter wheat yields but led to delayed phenological development. Moreover, variations in water productivity (WPc) and yield exhibited consistent spatial patterns across the three subregions of the study area. In region 1, the optimal sowing date is 10 days earlier, with a sowing window of 7–13 days earlier. During normal and dry years, irrigation requirements at the jointing and filling stages are 70 mm and 90 mm, respectively. In regions 2 and 3, the optimal sowing date is 15 days earlier, with a sowing window of 12–18 days earlier. Under the SSP2–4.5 and SSP5–8.5 scenarios, the overall growth rates of winter wheat yield in the Middle and upper reaches of Yellow River basin were 20.62 % and 16.32 %, respectively, with irrigation levels of 60 mm and 80 mm at the jointing and filling stages during normal and dry years. This study provides valuable insights and references for developing strategies to mitigate winter wheat yield reduction in the Middle and upper reaches of Yellow River basin under future climate scenarios.