The cause of soil degradation and how it affects us
Soil is not an inert medium but a living ecosystem that is essential to life. It takes hundreds and thousands of years to form an inch of topsoil, and many more centuries before it is fertile.
While soil degradation is a natural process, it can also be caused by human activity. In the last few decades, soil degradation has been sped up by intensive farming practices like deforestation, overgrazing, intensive cultivation, forest fires and construction work.
These actions disturb soil and leave it vulnerable to wind and water erosion, which damages the complex systems underneath.
Silvia says, ‘Several practices associated with intensive agriculture, especially tilling, disrupt soil structure. They accelerate surface runoff and soil erosion, loss of organic matter and fertility and disruption in cycles of water, organic carbon and plant nutrients. These practices also have a major negative impact on soil biodiversity.
‘When soil degrades, the processes that take place within it are damaged. This causes a decline in soil health, biodiversity and productivity, leading to issues at all levels of many ecosystems, and resulting in large environmental consequences such as floods and mass migration.’
When natural land such as a forest is converted into farmland, it removes important nutrients and prevents the recycling and replenishing of organic material.
It also reduces the amount of carbon the soil can store by 50-75%. With global warming being one of the biggest environmental crises of our time, this would be a giant step backwards.
Soil compaction occurs when there is a combination of wet soil and a heavy weight, for example unwieldy machinery in farming. Networks of tunnels and pores created by various organisms collapse beneath the pressure and air is squeezed out, threatening underground habitats and the availability of nutrients. Tilling soil also has similar results.
Salination – salty water – is a result of excessive irrigation or extraction of groundwater in coastal areas. This can make some bacterial species inactive and can kill many other microorganisms.
Without underground life, land would become barren. In a worst-case scenario, it can lead to desertification, where the soil is damaged beyond repair and nothing grows except a handful of plants that can handle very harsh conditions.
But it’s not just agriculture that is to blame: increasing urbanisation also has a negative impact. The widespread use of tarmac and concrete prevents water from being absorbed into the ground. This results in the death of millions of microorganisms and can lead to water runoff in other areas where it may cause flooding and erosion.
Soil degradation can have disastrous effects around the world such as landslides and floods, an increase in pollution, desertification and a decline in global food production. One of the biggest threats to our future food security is land degradation and the…