Grassland Restoration in Wind-Eroded Regions Increases Soil Organic Carbon

Grassland restoration in wind-eroded regions significantly increases soil organic carbon (SOC) content compared with cropland, while reducing soil inorganic carbon (SIC). Field measurements in Yanchi County show cropland SOC of about 3.0 g/kg and SIC around 12%.

Grassland restoration raises SOC to about 4.4 g/kg but lowers SIC to about 2.7%, a pattern attributed to greater organic matter inputs and suppression of wind erosion. In contrast, shrubland restoration yields lower SOC (~2.4 g/kg) and SIC (~2.5%), possibly due to slower decomposition of recalcitrant litter and coarse root biomass limiting carbon turnover.

SOC and SIC display depth-dependent distribution, with SOC concentrated mainly in the 0–1 cm layer and SIC more prominent in the 1–5 cm layer. SOC appears primarily controlled by vegetation cover, whereas SIC is strongly influenced by soil pH; both pools are also responsive to wind erosion intensity and soil texture.

The surface 0–5 cm layer emerges as a critical interface mediating interactions among vegetation, erosion, and soil properties, and the study highlights distinct regulatory mechanisms for SOC and SIC under land-use change.