In a recent publication, lab Postdoctoral Research Associate Jashanjeet Kaur Dhaliwal shared her research on nitrous oxide (N2O) emissions in a unique, long-term cotton system. The research examined N2O emissions after 42 years of implementing no-till (NT) and legume cover crops under varying nitrogen rates (0 and 67 kg N ha−1) in a continuous cotton system in the Southeastern U.S. To capture detailed emissions, the team conducted intensive manual chamber-based measurements over two growing seasons (2021–2022 and 2022–2023).
The results were insightful: long-term NT did not significantly affect cumulative N2O emissions during the study period. However, hairy vetch (HV) cover crop plots emitted two to three times more N2O than non-cover crop plots in 2021–2022, while the effect was not significant in 2022–2023. When fertilized with 67 kg N ha−1, HV plots had higher cumulative N2O emissions compared to plots without HV in 2021–2022. Despite some interannual variability, the findings suggest that long-term NT may not increase N2O emissions, reinforcing its value for soil health and climate benefits through soil carbon sequestration. At the same time, careful management of legume cover crop residues in nitrogen-fertilized systems is essential to mitigate N2O emissions.
You can find the article, here!
Dhaliwal, J.K., Lussich, F., Sindhu, J., Sean, M.S., & Saha, D. (2024). Long-term tillage and cover cropping differentially influenced soil nitrous oxide emissions from cotton cropping system. Agronomy Journal, https://doi.org/10.1002/agj2.21661