Soil pollution is caused by the contamination of soil from man-made chemicals. This, in turn, is caused by a variety of factors, the most glaring of which includes chemical fertilizers, mining and quarrying, and incorrect disposal of waste.
One of the main causes of soil pollution is farming, because farmers use chemical fertilizers to increase crop yield, as well as pesticides and insecticides to protect those crops. Unfortunately, the chemicals in these products leach into the soil. Nitrogen is a common component in fertilizer that changes the acidity of soil and makes it impossible over the long run to continue growing crops in it. Sulfur dioxide is another chemical that makes soil infertile. Although this chemical is found in many man-made products, it is also a component of volcanic gases.
Mining and quarrying is also a cause of soil pollution because of the runoff and waste that soak into the soil from spoil heaps. Spoil heaps contain toxic substances that permanently harm the surrounding soil. Of course, runoff from factory and household waste is also dangerous to soil. This waste is often buried in landfills, not only ruining the soil, but running into the water supply as well and potentially contaminating it.