Soil organic carbon storage and N2O emissions from grassland soils versus cropland soils; Temporary (ley) grasslands; Grassland management options: species choice, fertilization and irrigation; Harvesting strategies: grazing versus mowing and grazing regimes; Integrated crop-livestock systems and silvopastures; Life-cycle assessment of agricultural production systems with grasslands Grasslands have large soil carbon (C) sequestration potential due to permanent vegetation cover and prolific belowground biomass inputs, making their implementation a negative emission technology. However, the extent of carbon sequestration in grassland soils will be dependent on a variety of management approaches and environmental conditions that affect the balance between productivity (i.e. C fixation) and decomposition (i.e. soil respiration). Grasslands are typically used for grazing livestock or to grow hay to feed livestock elsewhere. Both practices may ultimately affect soil microbial activity and influence soil organic carbon (SOC) storage, SOC release and emissions of CO2 and other potent greenhouse gases. While both systems are intended for feeding ruminants, the choice of management will have an impact on a variety of ecosystem services, including SOC sequestration, water quality and above- and belowground biodiversity.