The anticipated benefits of soil carbon restoration practices may be undermined by enhanced soil biological activity leading to increased nitrous oxide emissions; however, the limited understanding of soil N cycling constrains our ability to fully assess their net mitigation potential. The objective of our study was to evaluate the impact of different land management practices on greenhouse gas emissions (GHG), identifying the factors involved in the process and the potential mitigation capacity of agronomic practices that favor SOC sequestration. A field study was conducted on a petrocalcic Paleustoll in the Argentinean semi-arid pampa. Four land management practices were studied: natural grassland (NG) which was the reference land use, crop-pasture rotation (RO), soybean with subsequent cover crop (S-CC) and soybean monoculture (S-S). Gas sampling was conducted at different moments coinciding with soybean pre- and post-sowing, and soybean pre- and post-harvest for two years (2019-2020 and 2020-2021). During GHG measuring periods several driving factors were measured including C/N ratio of surface and root residues, soil microbial biomass C and N, soluble C and N, nitrate N content, soil water content, and soil temperature at 0-0.1 m depth. Results showed that although nitrous oxide emissions in RO and S-CC were 58 and 33 %, respectively, higher than in the S-S treatment, these were offset by the increase in SOC storage rates, registering a net gain of C of 1.4 and 0.6 Mg CO2-eq ha(-1) y(-1). In contrast, S-S showed a net C loss of 0.5 Mg CO2-eq ha(-1) y(-1)). Key driving factors of GHG were soluble N, plant residue C/N ratio, and water-filled pore space. High soluble N and WFPS above 40 % promoted denitrification, increasing N2O emissions, while plant residues C/N ratios < 20 enhanced N mineralization, nitrate availability and soil respiration, leading to elevated CO2 emissions. Conversely, C/N ratio > 40 limit microbial respiration and gas emissions. Diversified cropping systems that integrate pastures (NG and RO) and cover crops (S-CC) showed enhanced SOC storage and contributed at the same time to sustainable GHG mitigation.