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

Climate change has increasingly triggered extreme weather events, leading to significant adverse impacts on crop production and posing challenges to the sustainability of agricultural systems. This study investigates the effects of different cropping patterns on crop yields and greenhouse gas (GHG) emissions in the Huang-Huai-Hai Region, aiming to provide a scientific basis for constructing climate-resilient, high-yield, and low-carbon cropping systems in the region. Field experiments were conducted from 2015 to 2020 at the Xinxiang Experimental Base of the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences. Five distinct planting patterns were established, including single-cropping winter wheat (W), single-cropping summer maize (M), single-cropping summer soybean (S), winter wheat-summer soybean double cropping system (W-S), and winter wheat-summer maize double cropping system (W-M). The study thoroughly analyzed crop yields under these five cropping systems over six years, calculating the output value and economic benefits associated with each system. Additionally, from 2017 to 2019, the study monitored soil GHG emissions, measured crop nitrogen accumulation, and calculated the partial factor productivity of nitrogen. Furthermore, the carbon footprint of each planting pattern was also assessed. Results revealed that the W-M double cropping system consistently outperformed other patterns in terms of 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 trade-off between yield and environmental sustainability. In contrast, the W-S double cropping system showed a reduction in cumulative nitrous oxide (N₂O) emissions, direct GHG emissions, and carbon footprint per unit area by 10.7%, 11.1%, and 4.7%, respectively, compared to the W-M system. This reduction highlights the W-S system's potential for mitigating GHG emissions while still maintaining a relatively high yield. Moreover, the study found that single-season soybean cropping resulted in significantly higher nitrogen accumulation compared to 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, while the W-M double cropping system emerges as the most effective pattern for maximizing crop yields and economic benefits, it also presents environmental challenges due to its higher GHG emissions. Therefore, further research is essential to develop emission reduction techniques for the W-M system, aiming to achieve a balance between high yield and low carbon emissions. This study provides critical insights into the trade-offs 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 agro-ecological regions.