ASSESSMENT OF SOIL QUALITY AND CARBON SEQUESTRATION POTENTIALS OF RE-VEGETATED COAL MINE SPOIL AT MAIGANGA, AKKO LOCAL GOVERNMENT AREA, GOMBE STATE, NIGERIA

Soil quality and carbon sequestration potential are critical components of sustainable agricultural management that are increasingly being considered in policy decisions related to food security, environmental management, and climate change mitigation. This study aimed to evaluate the soil quality and carbon sequestration potential of revegetated coal mine spoil at Maiganga, Akko Local Government Area, Gombe State, Nigeria. Seven dominant tree species (Mangifera indica, Azadirachta indica, Eucalyptus camaldulensis, Acacia Senegal, Jatropha curcas, Syzygium gyneense, and Anacardium occidentale) were identified growing on the reclaimed coal mine spoil. Twelve composite soil samples were collected using an auger under the canopy of each of the seven dominant tree species on the reclaimed coal mine spoil, including reference samples from an unplanted site in the study area, at depths of 0–30 cm and 30–60 cm. A total of 96 composite soil samples were collected and analyzed using standard methods. Results revealed that sand dominated the soil fractions, with soil textural classes ranging from sandy loam to loamy sand. The soil pH ranges from 4.84 to 7.23 and was slightly acidic to neutral in its reactions. Organic carbon (1.86 to 4.79 g/kg) was low with a significantly (p<0.05) higher value (4.79 g/kg) recorded in soils under Eucalyptus camaldulensis, while the total nitrogen value of 1.21 to 3.28 g/kg was medium to high, and the available phosphorus (Ap) value of 0.14 to 9.66 mg/kg was significantly (p<0.05) different, with the highest AP value (9.66 mg/kg) obtained at the Anacardiun occidentale site. The soil quality percentages ranged from 13 to 20% and soil carbon stock values from 10.07 to 27.55 t C/ha. The soils are poor in quality but have higher potential to sequester carbon, contributing to coal mine spoil remediation, climate change mitigation, and food security.