These fantastic burrowing creatures are the living, breathing, engineers of the underworld, eating and recycling organic matter to keep our soil healthy.
The intricate network of tunnels earthworms create below the ground is extremely important too, in fact, Charles Darwin said: “It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.” Strong praise indeed!
Worms are hungry little creatures and have the capacity to eat their own body weight in food every day!
Amongst other things, their diet consists of dead plants, fallen leaves, fungi, bacteria and even dead animals. When they eat, worms break down and recycle this organic matter within the soil which helps naturally fertilise the earth and ensure it’s packed with vital nutrients.
The little mounds you sometimes see on top of the soil are called worm castings (essentially, worm poo!) and are the end product of this recycling process. Their casts can contain 5 times more nitrogen, 7 times more phosphorus and 1000 times more beneficial bacteria than the orginial soil that help plants thrive.
Worms loosen, mix and oxygenate the soil as they burrow channels through. They improve its structure, leaving space for water to be drained away from the surface and stored in the soil.
soils without earthworms can be 90% less effective at soaking up water. This means water run-off increases which can lead to erosion and in some cases flooding.
Just as worms can improve soil health, they also don’t like living in very poor-quality soil. To survive, worms need moist soils that contain enough organic matter for them to feed on. So, by digging up a spadeful of soil and counting the number of worms in their sample, farmers can get a pretty good indication of their soil’s health.
As well as keeping soil healthy, worms can help clean up contaminated land by enhancing ‘bioremediation’ – the process by which micro-organisms consume and break down environmental pollutants converting them to non-toxic molecules.
Their wriggling and burrowing movements regulate the distribution of these micro-organisms in the soil. So, while they have a reputation for being dirty – they clean up fairly well!
As important as they are alive for distributing nutrients and organisms and decomposing matter, worms are also very important in the food chain. They provide a crucial protein-rich source of food for other important species like birds, hedgehogs and frogs.
Our underground allies are pretty amazing. Protecting these animals is crucially important to help maintain the health and balance of nutrients in the soil.