An innovative technique that can prevent soil erosion.
The University of Aveiro (UA), through the Center for Environmental Studies and the Sea (CESAM) is studying the possibility of introducing an innovative technique, called mulching, that will drastically reduce soil erosion, due to the occurrence of fires. With the growing number of burnt areas in our country, an increase of soil loss in the order of 50 tons is estimated, upon arrival of rains. The erosion problem is even more acute when it affects the normal operation of hydroelectric dams, by the accumulation of thousands of tons of sediment in reservoirs. This leads to the need of dredging and cleaning of the dams. Taking all these factors into consideration, a team of researchers led by UA scientist Sergio Alegre, decided to introduce mulching technique, which consists of covering the burnt land with a layer of crushed forest remains. The technique has had very positive results, showing in 40% of the cases normal runoff of water on burnt land, thus reducing soil erosion by 90%.
There is no shortage of raw materials for shredding to make the mulching in Portugal. There is for example bark, that is not used by pulp mills, which is a very good material for this. It has long fibers that form a cape in the soil retaining water and sediments. There are also the leaves, that once fallen provide a natural protection. In the case of pine, the pine needles themselves are as effective in mulching as crushed forest debris.
