A field-measured dataset for soil organic carbon stock in South Korean grasslands.

Grasslands, covering about one-quarter of global land use, are crucial for carbon storage, holding approximately 10% of global soil organic carbon (SOC). In South Korea, SOC stock estimates for grasslands currently rely on Tier 1 from the Intergovernmental Panel on Climate Change Guidelines (IPCC GL) for National Greenhouse Gas Inventory, lacking country-specific SOC data. Grassland managements also change SOC stocks, but are not reflected in the current estimation. To advance the accuracy of SOC stock estimation, this study provided a field-measured dataset from 46 grassland sites in South Korea, accounting for variations in soil type (high-activity clay, low-activity clay, sandy, and volcanic soils) and management intensity (improved, nominally managed, and degraded). The dataset, including 208 soil core samples with SOC stock, C/N, and H/C ratios, offers a foundational resource for developing country-specific reference SOC stock values and incorporating management factors to influence SOC stock. This dataset will support improvements to South Korea's national greenhouse gas inventory for grasslands to Tier 2 and Tier 3, aligned with the IPCC GL.