Unlocking climate resilience by exploring the mitigation potential of improved rotation with cover cropping

Agroecosystem services of conservation agriculture practices, such as crop rotation with cover crops (CCs), can effectively contribute to climate change mitigation through reduced greenhouse gas (GHG) emissions and enhanced soil organic carbon (SOC) sequestration. However, the long-term impact of CCs on possible SOC saturation must be considered, along with potential trade-offs between SOC sequestration and N₂O emissions. This study aimed to (i) determine the impact of including legume and non-legume CCs in improved crop rotations on crop productivity, SOC sequestration, GHG emissions, water use efficiency (WUE), and direct on-farm C footprint (DCFP) compared with no-CC and business-as-usual (BAU) rotations, and (ii) evaluate the spatial variability and long-term effects of these management practices under projected climate conditions in the Texas High Plains (THP) using the DSSAT model. The results demonstrated that CC-inclusive rotations led to significant agronomic and environmental benefits. Compared to BAU, CCs increased grain units (GU) stability, enhanced SOC sequestration, and reduced net GHG emissions and DCFP. Notably, rotations incorporating CCs decreased DCFP by 60% (0.091 vs. 0.250 kg CO₂-eq kg^-1 GU) compared with BAU and 30% (0.091 vs. 0.132 kg CO₂-eq kg^-1 GU) compared with no-CC, reinforcing their potential role in climate-smart agriculture. SOC sequestration increased by 13.4% (74.0 vs. 65.9 Mg ha^-1) compared with BAU and by 6.9% (74.0 vs. 69.2 Mg ha^-1) compared with improved rotations without CCs, highlighting the potential role of CCs in long-term C storage. Additionally, WUE improved with CC integration, particularly in the northern and eastern regions of the study area. While no-CC had a WUE ranging from 8.5 to 9.5 kg ha^-1 mm^-1 under historical conditions, CC-based rotations achieved >10.5 kg ha^-1 mm^-1, emphasizing their contribution to water resource efficiency. These findings emphasize the critical role of CCs in climate-smart agricultural strategies, highlighting the need to optimize rotations and nutrient management practices to sustainably intensify agriculture in semi-arid regions.