Adaptation of winter wheat varieties and irrigation patterns under future climate change conditions in Northern China

Climate change poses great challenges for food security and water use. This study aimed to investigate the response of winter wheat in Northern China to climate change and propose corresponding strategies to maintain yield and crop water productivity (WPc). Climate model projections from the fifth phase of the Climate Model Intercomparison Project (CMIP5) were used to drive the process-based soil-water-atmosphere-plant (SWAP) agro-hydrological model. The SWAP parameters were optimized by the Parameter Estimation program (PEST), which extended the crop model to the regional scale. SWAP was used to simulate responses of crop growth, evapotranspiration (ET), and yield to baseline (2006-2012) climate and two representative concentration pathway (RCP) scenarios (RCP4.5 and RCP8.5) for future climate conditions. The results indicated that PEST had high optimization efficiency and calibrated SWAP performed well (average relative error < 20.87 % and normalized root mean square error < 25.83 %). Compared with baseline, the maximum and minimum temperatures increased significantly (P < 0.05) by 6.47 degrees C and 8.59 degrees C, respectively. The cumulative precipitation during the growing season increased by 303.22-316.12 mm. Warming significantly (P < 0.05) reduced the growth period of winter wheat by 25.3-34.7 days, especially in the emergence-heading stage. Path analysis revealed that significant (P < 0.05) change of precipitation was a determining factor in increasing ET. The adverse effect of temperature increase offset the promotion of yield due to radiation, and ultimately led to a yield reduction of 35.57-41.14 %. The optimization scenario indicated that late-maturing varieties and irrigation adjustment could improve yield (up to 38.21 %) and WPc (up to 44.30 %) under future climate conditions. Implementing irrigation at an early growing stage (joining and heading) was beneficial to increase yield and WPc. We recommend combining late-maturing varieties with irrigation adjustments to maintain yield and WPc under future climate conditions.

Automated summary

This study investigated the response of winter wheat in Northern China to climate change, finding that warming temperatures shorten the growth period of winter wheat and precipitation changes affect evapotranspiration rates. Adjusting varieties and irrigation practices can improve wheat yield and water productivity under future climate conditions.