Modeling Climate Change Impacts on Wheat Productivity and Evaluating Adaptive Strategies Using DSSAT-CERES in Nepal’s Central Terai Region of Nepal

Climatic change poses significant challenges to wheat production around the globe. To determine the impact of climate change on wheat production and evaluation possible adaptation strategies, in this study we employed the DSSAT-CERES crop simulation model. This research utilized distinct climatic projections, specifically RCP 4.5 and RCP 8.5. In the research, historical weather data (1990–2022), experimental crop management practices (2018–2022), and future climatic scenarios (NF:2022–2039 and FF:2040–2059) to simulate wheat yields. A randomized complete block design was implemented for varietal crop treatments and understanding the connection between crop yields, irrigation intervals, and fertilizer dose is essential for region-specific farming strategies. Bhrikuti, Gautam, NL 1311 R21 and VIJAYA wheat varieties were taken as treatments, each replicated twice, with three irrigation frequencies (7, 51, and 74 days after sowing) over four consecutive years (2018-19, 2019-20, 2020-21, and 2021-22). The response indicated higher simulated yield for Bhrikuti and VIJAYA, whereas least for Gautam varieties throughout the study period with similar crop management practices. The sensitivity analysis is performed to know the effect of climatic parameters such as Tmax, Tmin, Solar radiation, and CO ₂ concentration in wheat phenology growth stage, i.e., tillering and anthesis stages. The environmental was modifies in such a way that include Near future and Far future scenarios. We found that climatic parameter Tmax had the highest sensitivities, followed by Tmin whereas least for solar radiation among 5 varieties. Also, we got effect of CO ₂ i.e., yields boosted up to 50% and 60% at 500 & 720 ppm. The simulated results highlight the necessity for potential strategies to enhance and sustain wheat yield, optimizing sowing date by shifting from 15 to 30 days from experimental date i.e., November 15. The findings also underscore the critical role of irrigation and fertilizer management, and water availability, for sustainable wheat yields in sub-tropical monsoon climate.