to survive – today, we undoubtedly use a lot more resources, in a much more inefficient and almost wasteful way with little thought of the impacts. This is how it has come to be that over the last 40 years, we have lost about a third of the Earth’s arable land due to erosion or pollution setting us in a very dangerous trajectory in terms of our capacity to produce food in adequate quantities in the future1.
But on a more positive note, we now seem to be increasingly acknowledging that we need to put an end to activities that are depleting our planet’s natural wealth. Instead, we should be looking at how to restore it and live within our planet’s environmental limits.
The even better news is that a lot of the land that we have damaged, polluted or depleted, we can still salvage. This can be achieved through the process of land restoration or land rehabilitation which aims to bring the land to its original state or very close to that.
Practical solutions to restore destroyed land
There are two key reasons that land needs to be restored or rehabilitated, namely due to desertification and mining activities or other industrial activities. These causes require quite different solutions.
Once the soil is stabilised, its nutrient content needs to be improved. This can be done by planting nitrogen-fixating plants such as clover, yellow mustard and beans or crops such as wheat, barley, olives as well as certain herbs. To help this process along, the crops planted in the soil need to be harvested or ploughed into the soil every year whereas a system of crop rotation needs to be established to prevent the depletion of soil nutrients2.
A number of innovative technologies have emerged to help sustain ecosystems where desertification is happening. One such technology involves harnessing solar power to desalinate sea water so that it can be used to grow plants3.
Seeking to restore mined land to a state similar to what it used to be is most certainly challenging not only due to the physical changes in the landscape but also the fact that the mining area is left with a lot of waste and often polluted grounds. Over the years, countries have legislated on how mining areas can be restored and often placed responsibilities with the companies extracting the minerals.
Modern day practices require that a number of things must take place once mining activities have ceased. In particular, waste and polluted material is fenced off and rendered inaccessible.
For example, waste dumps created during the mining process are contoured to flatten them out and stabilise them against erosion whereas landfills are covered with soil and vegetation which is planted to consolidate it. If the extracted ore contained sulphides it is covered with a layer of clay to ensure that contact with the rain and air does not oxidise it and result in sulfuric acid.
Successful restoration project in Switzerland
Companies can always go the extra mile, however, as the case of Swiss cement company Holcim showcases. Before its merger with French cement manufacturer Lafarge, Holcim had redeveloped a number of its sites.
For example, in Switzerland, Holcim converted ones of its quarries into a biodiversity hub for an endangered species of dry meadows which had lost most of its habitat since the 1950s.
As the location of the Holcim quarry was once a spot where the dry meadows grew, the company undertook a considerable restoration of the local natural environment which now provides habitats for rare species and has now become one of the best spots in the region for dry meadows, which are nationally important 4.