Soil acidification

Soil acidification is a natural process, recently aggravated by human activities through the emission of sulphur and nitrogen compounds from the combustion of fossil fuels and from industrial processes.

Fertilisers and soil drainage may also cause acidification. In Western and Central Europe acidic deposition is the main cause of soil acidification.

The main impact of acidification on the environment is the leaching of acidifying compounds from the soil to the surface and ground water. Acidification, combined with cations of iron, aluminium, calcium, magnesium and some heavy metals, decreases the soil's buffering capacity.

Sand soils have lower buffer capacities and thus only a small change in pH may be sufficient to change the soil from a buffering to a polluting agent. There is a risk of heavy metals being released when pH is very low.

Soil acidification and its effects on forests and crops can be counteracted by fertilisation and liming (liming will increase soil pH, but will also have an impact on soil biota that is not necessarily desirable). However, this treatment cannot restore the soil's buffering capacity, making soil acidification one of the most severe environmental threats in Europe, the full effects of which cannot be reversed.

Learn more about acidification