Short‐term tillage effects on greenhouse gas emissions and global warming potential from soybean in southeast Arkansas

Reduced tillage (RT) is a common conservation agriculture practice, generally regarded to be a valuable greenhouse gas (GHG) mitigation approach through increasing soil carbon (C) stocks. However, direct GHG measurements from RT compared to conventional tillage (CT) treatments can vary greatly depending on site‐specific soil properties and management practices. The objective of this study was to evaluate the short‐term effects of RT on soil‐to‐atmosphere carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) fluxes and emissions, global warming potential (GWP), yield, and emissions intensity (EI) throughout the 2024 soybean ( Glycine max ) growing season in a southeast Arkansas production field. Bulk density was lower ( p < 0.05) in the CT (1.29 g cm −3 ) than in the RT (1.44 g cm −3 ) treatment at the beginning of the growing season, but the greater bulk density in the RT treatment did not result in a change in yield compared to CT. There was no difference in CO 2 fluxes between tillage treatments on any measurement date. Methane fluxes from CT were greater ( p < 0.05) than from RT on four out of seven measurement dates. Nitrous oxide fluxes were greater ( p < 0.05) from CT than RT and greater from RT than CT on four out of eight measurement dates each. Season‐long CO 2 , CH 4 , and N 2 O emissions and EI, as well as GWP, did not differ ( p > 0.05) between RT and CT. Results showed that more continuous RT practices are needed to develop a residue layer capable of affecting GHG emissions.