Modeling effects of climate change on crop phenology and yield of wheat-maize cropping system and exploring sustainable solutions.

Abstract

Background: Wheat-maize cropping systems in semi-arid regions are expected to be affected by climate change in the future, which is alarming for global food security, environmental sustainability and socioeconomic development. Therefore, management practices like optimized plant geometry and fertilization need to be explored to counter these expected threats. To do this, the APSIM model was calibrated using 5-year data (from 2017/2018 to 2022) regarding yield, biomass, plant height, emergence, anthesis and crop maturity of wheat and maize from farmer fields.

Results: The performance of a model run was assessed using root mean square error, normalized root mean square error, coefficient of residual mass, coefficient of determination (R²) and Nash-Sutcliffe efficiency, whose average was 1.59, 0.13, 0.001, 0.84 and 0.78, respectively, for calibration while 2.75, 0.20, -0.009, 0.80 and 0.75, respectively, for validation. Regarding crop phenology, it was modelled that the emergence, anthesis and maturity were earlier by 7-9 days, 8-10 days and 2-6 days, respectively, for wheat; 6-10 days, 13-20 days and 16-24 days, respectively, for spring maize; 3-5 days, 5-11 days and 8-19 days, respectively, for autumn maize under different climate change scenarios in near to far future. Simulations revealed the average reduction in the yield of wheat, spring maize and autumn maize by 11.5%, 11.8% and 11.0%, respectively, in near future (2025-2065) while 17.5%, 20.5% and 17.0%, respectively, in far future (2066-2100). Further, simulations discovered the potential of higher levels of fertilization (nitrogen = 60-100 kg ha^-1 and phosphorus = 40-75 kg ha^-1 for wheat while nitrogen = 75-120 kg ha^-1 and phosphorus = 40-80 kg ha^-1 for maize) and plant density (100 to 150 plants m^-2 for wheat and 8 to 13 plants m^-2 for maize) to enhance the yield of wheat, spring maize and autumn maize by 31-36%, 22-38% and 26-43%, respectively, in near future while 33-38%, 21-55% and 19-31%, respectively, in far future.

Conclusions: The findings underscore the effects of climate change on wheat-maize cropping systems and the importance of implementing optimized fertilization and adjusting plant density to mitigate the adverse effects of climate change, thereby safeguarding food security and sustaining agricultural productivity. © 2025 Society of Chemical Industry.