Humans have degraded the environment to such as extent that we are now starting to see the negative effects, from a massive loss of biodiversity to an increase in the risks of flooding. This has led to an increase in interest of restoring old farmland back to the original ecosystem that it was, yet this is often a long and difficult process, as the soil is often degraded to too poor a quality.
But a new study, published in Nature Plants, has found that heavily degraded environments can actually be restored back to health simply by “inoculating” them with soil taken from healthy ecosystems. This itself is not particularly groundbreaking, but this latest research has found something else. Not only can the health of the environment be restored by the addition of the soil, it can also direct what the restored ecosystem will then become, depending on where the healthy soil has been taken from.
Previous research has shown that the soil is a critical, but often overlooked, factor in having a flourishing ecosystem. The massive trees and plants – and the animals that rely on them – could not exist without the microscopic insects, bacteria, and fungi doing their thing in the soil below. By restoring the health of the soil, researchers have found that they can make the community of plants growing in it much healthier too.
The new research has been looking into how the addition of healthy soil to old farmland, that has been heavily degraded over 60 years and stripped of all nutrients, can restore it to its natural state. They found that by removing the top layer of soil on the farmland and then covering it with just 1 centimeter of healthy soil taken from an already established ecosystem, the researchers could not only begin the restoration of the environment within just six years, but also direct what ecosystem it will become. If they used healthy soil taken from a grassland, for example, they could steer the development of a grassland community, or if they took it from a heathland, it would become heathland, instead.
The idea to rewild large parts of old farmland has been gaining traction over the past few years. It is thought that massive tracts of farmland within the European Union have already been abandoned over the past decade, and it is estimated that by 2030, up to 168,000 square kilometers (65,000 square miles) of farmland will have been abandoned in total. This, argue conservationists, offers a unique opportunity to return the land to how it was pre-agriculture, and encourage wildlife to return.