Impact of Open Cast Mine Land Use on Soil Physical Properties in Enyigba, Southeastern Nigeraand the Implication for Sustainable Land Use Management

The study examined the extent of soil physical properties deterioration due to mining activities in Enyiba Ebonyi State, Southeastern Nigeria. In the study, two factors were considered: factor A - Soil depths (surface soil: 0-15 cm and subsurface soil: 15-30 cm) and factor B - Distances from mine pits (100 m, 200 m, 300 m, 400 m and 500 m away from mine pit). Four mining sites (Mbaraeke Enyigba, Mkpoda Ugwvu, Nwamgbam Uchakuru and Azu Enyigba) within Enyigba mining vicinity were selected for the study. For standardization, a control was located 1.5 km away from Enyigba mining vicinity. A total of 82 core soil samples and 184 auger soil samples were used for the study. The results showed textural classes at different distances and depths to be predominantly sandy clay loam including those of the control. However, higher values of clay were obtained at lower depths (15 – 30 cm) at both the mine area and control. The bulk density value at the subsurface soil of the mine site (1.67 g/cm3) was significantly (p < 0.05) higher than the surface soil (1.53 g/cm3) and control (1.59 g/cm3). The values of total porosity in all distances and depths were significant (p < 0.05), re- cording a reverse trend compared to bulk density values. Massive deterioration as a result of heavy machinery at the mine area leads to high bulk density mostly at lower depths, low porosity and surface capping compared to the control. The highest bulk density value of 1.79 g/cm3 was recorded at 300 m subsurface soil of the mine area. Limited use of heavy machinery was recommended to reduce soil compaction. Farmers within the study area are encouraged to practice conservation tillage since soil physical properties deterioration affect soil use and productivity