Optimizing irrigation management sustained grain yield, crop water productivity, and mitigated greenhouse gas emissions from the winter wheat field in North China Plain

Climate change caused by increasing greenhouse gas (GHG) emissions has led to frequent extreme weather events, which seriously threaten sustainable agricultural production. Therefore, it is essential to optimize proper irrigation management to improve the grain yield, crop water productivity (WPc), economic crop water productivity (EWPc), and lower global warming potential (GWP) and GWP Intensity (GWPI). The effect of irrigation scheduling and irrigation methods on GHG emissions remains largely unknown, even though this knowledge is essential to optimize the irrigation management. To address this knowledge gap, a field experiment was carried out in the North China Plain (NCP) for three winter wheat seasons to measure the influence of different irrigation methods and irrigation scheduling on WPc, EWPc, GWP, and GWPI. Irrigation scheduling including 50%, 60%, and 70% of the field capacity (FC) were kept in the main plots and irrigation methods, including sprinkler, drip, and flood irrigation methods in the sub-plots. The results revealed that relative to sprinkler irrigation at 60% FC, drip irrigation at 60% FC significantly (p < 0.05) improved the yield 4.89-7.52%, WPc 1.0-5.4%, EWPc 1.1-5.49%, lower GWP 7.47-9.34%, and GWPI 10.92-15.23%. Compared with flood irrigation at 60% FC, drip irrigation at 60% FC increased grain yield 5.34-6.81%, WPc 5.65-15.1%, EWPc 5.73-15.12%, lower GWP 10.36-15.16%, and GWPI 16.22-19.40%. Technique for order preference by similarity to an ideal solution (TOPSIS) presented that compared with sprinkler and flood irrigation at 60% FC irrigation scheduling, drip irrigation at 60% FC irrigation scheduling provides the best results for improved the yield, WPc, and EWPc, and optimal balance in GWP and GWPI. Therefore, the irrigation scheduling of 60% FC combined with drip irrigation is suggested for sustained wheat yield, improved WPc and EWPc, and mitigated GWP in the NCP.