Agricultural Soil Legacies and Their Implications for Sustainable Afforestation: A Chronosequence Study

Afforestation of former agricultural land is widely promoted as a strategy to mitigate climate change and support sustainable land management. However, soils subjected to long-term cultivation often retain chemical legacies that may persist for decades after land-use change, influencing soil functioning and ecosystem development. This study investigates the persistence of selected agricultural soil chemical properties following afforestation using a chronosequence approach. Post-agricultural soils afforested for 15, 40, and 80 years were examined on Dystric Brunic Arenosols developed from sandy parent material. Composite samples were collected from forest-floor horizons (Ol and Ofh) and upper mineral horizons (A and B). The analyzed parameters included organic carbon (Corg), total nitrogen (Nt), sulfur (S), soil pH, hydrolytic acidity (Ha), exchangeable base cations (EBC), and cation exchange capacity (CEC). The results show that agricultural soil legacies persist for several decades after afforestation. Soils under the 15-year-old stand were characterized by higher exchangeable calcium, higher base saturation, and lower hydrolytic acidity, reflecting the persistence of historical liming. With increasing stand age, soil acidity increased, and base-cation concentrations declined, while organic carbon accumulated mainly in forest-floor horizons. These findings highlight the importance of considering agricultural soil legacies when evaluating the sustainability of afforestation and its role in long-term ecosystem services.