Who would have thought that soil – good old dirt as we often think of it – would be worth trillions of dollars?
Soils play a critical role in all of our natural ecological cycles—carbon, nitrogen, oxygen, water and nutrient cycling. In addition to this there are multiple other benefits that the soil ecosystem provides for humans, such as enabling seed germination, plant growth, and decomposition. These ecosystems services are given to us by nature at no cost.
However, how we use them and how our behaviour impacts on them will determine whether they remain sustainable, productive and resilient in the long run.
Today, December 5th, marks the sixth year of World Soil Day – an UN-declared day that seeks to bring awareness to the serious issue and implications of soil loss. Like climate change, the campaign to highlight the threat of soil loss and soil ecosystem health has a much longer history. As long ago as 1984, a National Geographic article asked the question “Do We Treat Our Soil Like Dirt?”. It highlighted the threat to soil health and the soil ecosystem that wind and water erosion, tillage and bad land management practices have on the very top layer of soil, which we depend on for our food production and livelihoods.
Soil erosion is defined as the net long-term balance of all processes that detach soil and move it from its original location. Obviously some soil erosion is a naturally occurring geomorphic process and it isn’t going to stop. But that doesn’t explain it all. And it doesn’t mean that we have a way out of doing the right thing when it comes to caring for our soil.
In the same way as human use of fossil fuels is rapidly changing the rate of CO2 in the atmosphere, human use of soil is causing rates of soil loss that are many, many times greater than the natural rate. Every five seconds, the equivalent of one soccer pitch of soil is eroded, but it takes up to 1000 years for just two to three centimetres of soil to be produced. This means that we could be in serious trouble, for without soil there is no food. In 2018 the UN warned that there are an estimated 60 harvests left before soils are too degraded to feed the planet.
George Monbiot reflects on research that concludes that the intensification of farming over the past century has increased the rate of soil erosion sixtyfold. At the same time, he reports on research that has found that soil in allotments contains a third more organic carbon than agricultural soil and 25% more nitrogen. This is one of the reasons that allotment holders produce between four and 11 times more food per hectare than do farmers. The logical conclusion to draw is that the gentler, more natural methods of food production employed by the allotment holders are in fact more effective than the chemicals used in industrial farming – and far better for our soil.
Find out more about World Soil Day and what you can do to not only help stop soil loss, but actively improve the soil we have. What you do at home, your buying practices at supermarkets and your voice can all demonstrate your commitment to change and encourage better land management practices.
Teachers: There are great resources on Soil Ecosystems for your learners. If you need any assistance in planning and running learning journeys, we are here to help.