Characteristics and differences of crop yield and greenhouse gas emissions under different planting patterns in the Huang-Huai-Hai Region

Climate change has increasingly triggered extreme weather events, leading to significant adverse effects on crop production and posing challenges to the sustainability of agricultural systems. This study investigated the effects of different cropping patterns on crop yields and greenhouse gas (GHG) emissions in the Huang-Huai-Hai Region to provide a scientific basis for constructing climate-resilient, high-yield, and low-carbon cropping systems in the region. The field experiments were conducted between 2015 and 2020 at the Xinxiang Experimental Base of the Institute of Crop Sciences at the Chinese Academy of Agricultural Sciences. Five distinct planting patterns were established: single-cropping winter wheat (W), single-cropping summer maize (M), single-cropping summer soybean (S), a winter wheat-summer soybean double-cropping system (W-S), and a winter wheat-summer maize double cropping system (W-M). This study comprehensively analyzed crop yields under these five cropping systems over six years and calculated the output value and economic benefits associated with each system. Additionally, from 2017 to 2019, we monitored soil GHG emissions, measured crop nitrogen accumulation, and calculated the partial factor productivity of nitrogen. The carbon footprint of each planting pattern was assessed. The results revealed that the W-M double cropping system consistently outperformed the other systems regarding annual maize-equivalent yield, energy output, and economic benefits. This system demonstrated superior productivity, making it a highly effective model for achieving high yields and maximizing economic returns. However, the W-M pattern also exhibited the highest GHG emissions, indicating a potential tradeoff between yield and environmental sustainability. In contrast, the W-S double cropping system reduced cumulative nitrous oxide (N₂O) emissions, direct GHG emissions, and carbon footprint per unit area by 10.7%, 11.1%, and 4.7%, respectively, compared with the W-M system. This reduction highlights the potential of the W-S system to mitigate GHG emissions while maintaining a relatively high yield. Moreover, the study found that single-season soybean cropping resulted in significantly higher nitrogen accumulation than wheat and maize, with increases of 31.1% and 87.8%, respectively. However, despite the lower nitrogen accumulation in maize, it exhibited the highest partial factor productivity of nitrogen. In conclusion, although the W-M double cropping system emerged as the most effective pattern for maximizing crop yields and economic benefits, it also presents environmental challenges owing to its higher GHG emissions. Therefore, further research is essential to develop emission-reduction techniques for the W-M system, with the aim of balancing high yields and low carbon emissions. This study provides critical insights into the tradeoffs and synergies between crop productivity and environmental sustainability under different cropping systems, offering valuable guidance for the development of climate-resilient agricultural practices in the Huang-Huai-Hai Region and similar agroecological regions.