Direct N₂O emissions following transition from conventional till to no-till in a cover cropped Mediterranean vineyard (Vitis vinifera)

Knowing underlying practices for current greenhouse gas (GHG) emissions is a necessary precursor for developing best management practices aimed at reducing N₂O emissions. The effect of no-till management on nitrous oxide (N₂O), a potent greenhouse gas, remains largely unclear, especially in perennial agroecosystems. The objective of this study was to compare direct N₂O emissions associated with management events in a cover-cropped Mediterranean vineyard under conventional tillage (CT) versus no-till (NT) practices. This study took place in a wine grape vineyard over one full growing season, with a focus on the seven to ten days following vineyard floor management and precipitation events. Cumulative N₂O emissions in the NT system were greater under both the vine and the tractor row compared to CT, with 0.13±0.021kg N₂O–Nha⁻¹growing season⁻¹ emitted from the CT vine compared to 0.19±0.017kg N₂O–Nha⁻¹growing season⁻¹ emitted from the NT vine and 0.07±0.041kg N₂O–Nha⁻¹growing season⁻¹ emitted from the CT row compared to 0.11±0.018kg N₂O–Nha⁻¹growing season⁻¹ from the NT row. Yet these variations were not significant, indicating no differences in seasonal N₂O emissions following conversion from CT to NT compared to long-term CT management. Individual management events such as fertilization and cover cropping, however, had a major impact on seasonal emissions, indicating that management events play a critical role in N₂O emission patterns.