Why is Soil so Important?
Soil is vital to life on Earth. Without healthy soil, plants cannot grow. The food that we grow to eat and the plants that animals eat all depend on the soil. Organisms that live in the soil depend on it as a habitat. These organisms include bacteria and fungi that help to break down decaying matter so that when a living thing dies, its remains can be ‘recycled’ back into the ecosystem.
In a healthy topsoil rich with nutrients, a single gram could contain as many as 75,000 species of bacteria, 25,000 species of fungi, 1,000 species of protozoa (single celled microscopic organisms), and several hundred species of nematodes (small worms). Plant roots are dependent on these tiny organisms to provide them with the nutrition that they need to grow and to resist diseases.
Soils are also able to absorb and filter water, helping to filter and purify it as it travels through the ground to rivers, or deep underground to water stores known as aquifers. Underground water is some of the purest water available as soil is able to filter out pollutants. By absorbing amounts of rain water, soil can prevent flooding.
Soil also helps protect the planet from climate change. When plants turn the sun’s light into a source of food using photosynthesis, they also absorb carbon dioxide from the air. Dead plants rot down and the carbon inside them becomes ‘sequestered’ (stored) back in the soil. Excess carbon dioxide in the atmosphere can lead to global warming, which causes climate change. By sequestering carbon away, soil helps prevent too much being in the atmosphere. After oceans, soils are the largest ‘carbon sinks’ on the planet, even beating forests in their ability to capture carbon dioxide from the air.