Impact of Marble Mining on Soil Properties in a Part of Guinea Savanna Zone of Southwestern Nigeria

Abstract

The effects of marble mining activities on the properties of soils of Igbeti marble area, Oke-Ogun, Southwestern Nigeria were investigated. Sample plots of 10 x 10 m2 were established at 150 m intervals from the factory site up to a distance of 600 m and with a sample plot at 10 km to serve ascontrol in four cardinal directions. A total of 84 composite soil samples from 21 established plots were taken for soil physico-chemical properties. No plot falls under agricultural crops. The results show that there is drastic deterioration in the quality of soil as a result of mining activities. There was increase in total porosity and decrease in bulk density of the soil as you move away from the mining site. The soil pH changed greatly from 5.90 in the control site to 8.20 in highly polluted soils. Soil organic matter,
total nitrogen and available phosphorus decreased with increase in dust particulate from the mining sites. Except for Ca²⁺ and Mg²⁺ that decreased with distance from the mining site, Na⁺ and K⁺ increased slightly. The availability of the extractable micronutrients (Fe²⁺, Mn²⁺, Cu²⁺ and Zn²⁺) increased as the soil acidity increased, though Cu²⁺ availability dropped slightly at control site. It is concluded that there is the need for close monitoring of marble mining activities in Nigeria as deposit of marble particulates may result to soil nutrients’ imbalance and hence poor soil health especially in areas polluted with marble particulates.

Key words: Mine waste, pollution monitoring, soil deterioration, soil pollution, soil nutrients’ imbalance.