school energy&environment

Soil degradation

The soil is a dynamic system that has reached a balance with the other surrounding elements. Man can compromise it with his activities and behaviour. The urban development of cities, industrial expansion, the creation of infrastructure like railways, roads, bridges, agriculture, modified the use of soil and sometimes determined its degradation. Soil degradation becomes apparent through some phenomena: desertification, erosion of the superficial layer, an unusual increase of salt content (salinization), acidification and the presence of pollutants. Soil pollution is a particularly serious phenomenon since it has repercussions not only on soil productivity, but also on the composition of the water it gets in contact with (especially drinking water and aquifer water) and on the atmosphere. This is why men have to carry out their activities in such a way as to ensure a high environmental quality of the soil, by eliminating the pollution that has been created in the past (recovery activities) and, above all, avoiding to overexploit the soil. The direct pollution of the soil by inorganic and/or organic pollutants can occur:

• in agricultural lands, when the natural balance is threatened by polluted irrigations, by phytosanitary products, herbicides, fertilizers, etc.;
• in urban, industrial, abandoned areas, also close to mines, as a consequence of the wrong disposal of waste water (water that is used for productive processes or sewage water), and as a consequence of waste containing chemical pollutants.