Soil Organic Carbon and Total Nitrogen Stocks under Different Land Uses in a Semi-Deciduous Forest Ecoregion of Ghana

Understanding soil organic carbon (SOC) and total nitrogen (TN) stocks is crucial for soil health, land use management, and climate change mitigation. However, knowledge on this topic is very limited in the Abuakwa North Municipality of Ghana. To address this, we assessed the status of SOC and TN stocks, and other soil properties under forestlands, cocoa plantations, and croplands. Soil samples were collected at depths of 0–15 and 15–30 cm in 2018 and 2023 for laboratory analysis using standard methods. The study showed that soil pH under cropland was significantly lower than the other land uses, although depth differences were insignificant. Forestland exhibited significantly lower bulk density and higher total porosity compared to the other land uses. The SOC and TN concentrations and stocks were significantly higher in the surface layer than in the subsurface layer for all land uses. In 2018, forestland had significantly higher SOC and TN stocks than cropland, but not different from cocoa plantation at 0–15 cm depth. By 2023, forestland’s SOC and TN stocks in the surface depth were significantly higher than cocoa plantation and cropland. In the subsurface depth, forestland consistently had higher SOC and TN stocks for both years. The study concluded that land use types significantly influenced SOC and TN stocks, with forestlands showing the highest potential for carbon sequestration and nitrogen accumulation, followed by cocoa plantations, while croplands showed the least potential.