What are the different sources of soil pollution? Discuss various measures for controlling soil pollution.

(i) Industrial wastes: Industrial wastes like scarp flash and effluents get mixed with soil. These are mostly toxic due to the presence of certain cyanides, chromates, acids, alkalies and metals like nickel, mercury etc. 
(ii) Urban wastes: Urban wastes such as domestic refuse, commercial wastes, rubbish from construction sites, waste paper, rags, fibres, broken glass articles slowly mix up with the soil. They lead to pollution such as foul smell.
(iii) Faulty agricultural practices: Fertilisers, pesticides weedicides etc. are chemical substances and from the soil they pass to ground water and are harmful to aquatic animals.
(iv) Radioactive pollutants: Dumping of the nuclear wastes from the nuclear power plants into the soil has been one of the greatest sources of radio active pollution of the soil. All the radio active wastes from atomic and hydrogen bombs emit radiations which are disastrous for the life on the earth.
Control of soil pollution:
(i) Use of manures: Manure prepared from animal dung and another farm refuse is added to the soil to maintain its fertility.
(ii) Use of biofertilizers: Biofertilizers such as nitrogen fixing bacteria and blue-green algae are inoculated in order to bring about the enrichment of the soil.
(iii) Proper sewage system: This system must be employed and sewerage recycling must be installed in all towns and cities.