A Teaspoon Of Soil Contains More Living Organisms Than There Are People On Earth.

The soil is an ecosystem in which millions of living creatures live and interact. There can be more creatures in a teaspoonful of good quality soil than there are people in the entire planet earth, i.e. more than 6+ billion - that is amazing! Not only are the numbers of creatures large but there are also many different types of creature. This is partly because the soil is the source of many different types of food for these creatures and is also the source of their nutrition and water. The soil can also offer a range of habitats, for instance the badger's sett, the rabbit warren, the earthworm channel, numerous pores where the small creatures can exist and develop.

Rather little is known about many of these organisms and about their many functions. It is so much easier to learn about creatures that live on the surface of the earth and can be readily seen, for example elephants, blackbirds, bumblebees, butterflies, than it is to learn about the soil creatures many of which live underground all their life. We live in a time when we are using the soil much more intensively than ever before to try and keep food production apace with needs of the fast growing population. We need to develop a much better understanding of the soil ecosystem. The soil ecosystem has been declared by some scientists as the last great biotic frontier.

There is a very huge range of organisms in the soil varying in size from protozoa which require the strongest of microscopes to see them, up to large burrowing animals such as badgers and rabbits which live part of the time in the soil and part of it on the soil surface. Not only is there this large range of size but there is also wide variation in what they use the soil for. Soil organisms can be classified in several different ways: by size, feeding habits, burrowing activities. The most usual way of classifying soil organisms is according to size, in particular, separating them into macrofauna, mesofauna, microfauna and microflora.