Why soil is one of the most amazing things on Earth
Why soil is one of the most amazing things on Earth
Soil… it’s one the most underrated, and little-understood, wonders on our fragile planet. Here’s why… SOIL… THE WONDER STUFF BENEATH YOUR FEET. BRIDGET EMMETT, SOIL SCIENTIST UK CENTRE FOR ECOLOGY & HYDROLOGY Far from being lifeless dirt, it’s estimated that in a single gram of soil, there could be as many as 50,000 species of microscopic organisms, or microorganisms. And in one teaspoon of soil, there are more microorganisms than there are people on the Earth. But much of what lies beneath, in this hidden and deep universe, is still alien to us. Despite being literally under our feet, humans have so far only identified a tiny fraction of the extraordinary life teeming underground. But these animals and microorganisms perform an invaluable role. Millions of years of evolutionary competition have led the microorganisms to produce antibiotic compounds to fight their neighbours. And these compounds form the basis of many of the antibiotics used by us humans. We literally make medicine from our soil. No-one knows how many new treatments could be lying under our feet, waiting to be discovered. One of the most special creatures living in soil is the earthworm. Darwin was fascinated by them and said: "It may be doubted if there are any other animals which have played such an important part in the history of the world," due to their importance in making and sustaining soil. Earthworms journey down and around, creating breathing holes, like lungs in the soil. This creates space for plant roots to grow and keeps soil alive. Under the soil, there are also vast and intricate webs of fungal threads. Plants and fungi need each other to thrive, and so they do a deal… Fungi can’t capture carbon dioxide to grow like plants can, but they’re better than plants at mining the soil for nutrients, so they trade. Plants give fungi carbon to grow, and fungi give plants nutrients like nitrogen and phosphorus. It’s a mutually beneficial relationship. And just one example of the interconnected ecosystem we’re all part of. Plant matter decays and provides food for microbes. They provide food for worms. Worms are food for birds and so on… Soil provides us humans with almost everything we eat. But it’s not just about what soils can do for us. It’s important we value, appreciate - and crucially protect – soil for a whole load of other reasons too. Think about this for a moment. It takes more than 100 years to build just 5 millimetres - half a centimetre - of soil. But just moments to destroy, through chemical contamination, urbanisation, landslides, erosion and more. Some soil is really ancient - dating back millions and millions of years. The oldest soil on Earth is thought to be in South Africa and dates back three billion years. In the UK, our soil is around 15,000 years old, and it formed after the last ice age. Soil is also a really valuable carbon store - capturing carbon and locking it away in stable forms deep underground. It stores three times as much carbon as all the plants on Earth combined, including trees. But because it grows so slowly, we need to protect what we have. We are not succeeding. We know many of the problems. Intensive farming is one of them. It releases carbon from our soils. And we’re losing soil 50 to 100 times faster than it’s able to re-build. In Europe, 60-70% of soils are thought to be unhealthy. And in croplands in the UK, in less than 30 years - from the end of the 1970s - we lost more than 10% of the carbon the soil had stored for us. And since then? Well, we just don’t know, because in many countries there’s little data on soil. It’s poorly protected and regulated. We grow on it, build on it, build from it. It filters and cleans our waters, reduces flooding, and regulates our atmosphere. It’s one of the most biodiverse habitats on Earth, and a vital part of the nitrogen and carbon cycle on our planet. But the sad truth is, right now, soil hasn’t enough champions fighting for it. We literally treat it like dirt. And yet there is so much untapped potential, so much wonder, and so many secrets, just waiting to be discovered… in the ground beneath our feet.