Simulating wheat response to different climate change scenarios under different nitrogen fertilizer supply in Northern Egypt

Abstract

Background and Objective: Crop models are important tools for simulating crop growth in response to climate change. The objective of the current study was to assess the impact of different climate change scenarios on yield and yield components of a spring wheat in Northern Egypt. Materials and Methods: Two field experiments were carried out in Northern Egypt during winter seasons of 2012/2013 and 2013/2014 to investigate the response of wheat grain yield to different scenarios of climate change under three fertilization treatments (control, 180 and 240 N kg ha-1). Two scenarios were used by generating daily weather data using LARS-WG stochastic weather generator software based on historical weather data from 1997-2012. The scenarios included the increase in minimum and maximum temperatures by 2, 3, 4 and 5°C as well as two concentrations of CO2 (550 and 750 μmole mole-1) according to the Special Report on Emission Scenarios (SRES) A2 and B2. Results: The output of DSSAT 4.6 crop simulation model showed that increasing temperature from current climate to +2, +3, +4 and +5°C resulted in a decrease in grain yield, however, increasing the concentration of CO2 from 550-750 μmole mole-1 resulted in an increase in grain yield meaning that CO2 caused a mitigation of the adverse impact of climate change on wheat grain yield. The reduction in grain yield in response to increasing temperature was mainly due to the reduction in number of spikes per meter square and the reduction in number of grains/spike, however, weight of 1000 grains was not affected by the increase in temperature. Also, the results indicated that the scenarios of climate change shortening the growing season of wheat. Conclusion: Alleviating the adverse impact of climate change on wheat productivity may be achieved by either late sowing or cultivating long season varieties.