Long Term Grassland Rehabilitation and Agroforestation Transform Soil Health Parameters in Grazing Areas in Semi-Arid Conditions

Land use change is one of the major drivers of global environmental change, as it affects biodiversity, soil quality, and consequently the functioning of ecosystems. In semi-arid regions of the Middle East, intensive grazing has historically led to soil degradation and loss of vegetation cover. Restoration approaches such as agroforestation with drought-tolerant tree species and grazing exclusion have been widely promoted to counteract these effects. This study aimed to evaluate the effects of different land use practices: agroforestation with almond trees (AT), restored grasslands (RG), and heavy grazing (HG) on key soil properties including soil organic carbon (SOC), total nitrogen (TN), nitrogen (N), phosphorus (P), and potassium (K). The goal was to assess how these land uses influence soil fertility and carbon sequestration over time under similar ecological conditions. A total of 150 soil samples were collected from a depth of 0–10 cm across a 2.0-hectare area for each land use type at the Bolbanabad Research Station in Kurdistan, W Iran. Sampling was conducted in both September 1997, before land use transformation, when all areas were grassland used for grazing and September 2023, allowing for a 26-year comparative analysis. The findings revealed significant impacts of land use change on SOC and TN. Both SOC and TN increased substantially in the AT and RG areas, with the highest SOC (8.44 mg/g) and TN (1.46 mg/g) values observed in the AT land. In contrast, the HG area has the lowest SOC (2.02 mg/g) and TN (0.49 mg/g) values. Similarly, N, P, K levels and the C/N ratio mirrored these results, being highest in the AT and lowest in the HG areas. Under similar ecological conditions, agroforestation with suitable commercial tree species and grassland restoration appear to be effective strategies for enhancing soil fertility, increasing carbon sequestration, and promoting ecosystem resilience. However, additional research is necessary to establish sustainable grazing practices that support both livestock productivity and long-term soil health.