Reduced tillage and cover crop treatment effects on growing-season greenhouse gas emissions from a soybean-corn rotation on silt-loam soil in southeast Arkansas

Agricultural greenhouse gas (GHG) emissions contribute ~10% to total emissions in the United States, which has resulted in a need for conservation-focused agricultural practices. The objective of this field study was to evaluate the effects of reduced tillage with cover crop (CC) compared to conventional tillage with no CC on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes, season-long emissions, and global warming potential (GWP) over two consecutive growing seasons in a soybean (Glycine max)-corn (Zea mays) rotation in southeast Arkansas. Weekly GHG measurements were made throughout the 2024 (soybean) and 2025 (corn) growing seasons with a chamber and field-portable gas analysers. Season-long GHG emissions, crop yield, and GWP did not differ (P > 0.05) between field treatments in either growing season. Global warming potential from the 2025 corn growing season was 16,176 and 17,025 kg CO2 equivalents ha−1 from the conventional and conservation field treatments, respectively. Despite no large-scale differences (i.e. emissions and GWP), smaller-scale CH4 and N2O flux differences occurred between treatments over time (P < 0.01) during both growing seasons, and for CO2 during the 2025 corn growing season. Results contribute to improving the understanding of practical management for GHG mitigation from upland cropping systems.