The earthworm, the gardener's ally
The earthworm, a branch of annalid from the Lumbricidae family, is a tireless worker and plays a major role in the biology of your soil.
The tunnels it digs help ventilate and drain the soil. These tunnels favour the installation of the roots of plants and their water supply.
The earthworm mixes the soil by moving from the surface into the ground and vice versa, descending up to 2 metres deep. It brings elements on the surface to the depths of the soil, elements such as dead vegetable matter. It then brings elements from the depths of the soil, trace elements like iron, sulphur, etc., to the surface. It doesn't touch healthy roots or plants.
Carry out the following experiment (this will especially interest your children !) :
In an aquarium, lay down a horizontal layer of compost, then a layer of sand, then a layer of earth, and continue like this until the aquarium is half-full. Cover this with dead leaves and put a dozen earthworms into the aquarium. After a month tyou will find that the soil is riddled with numerous tunnels and that the layers are no longer horizontal ! You will also note that the tunnels are concentrated in the compost layer.
The earthworm's digestive system is full of a bacterial fauna which enriches and compresses the elements of the soil. The squirl it leaves on the surface of the soil is the result of this digestion. It helps neutralize the soil. It moves the equivalent of its weight every day.
Finally, earthworms help spread micro-organisms by swallowing them and ejecting them further away.
These often looked-down-upon little creatures should therefore be preserved as they are of indispenable help to the gardener. Their presence is in fact a good indicator of the quality of your soil.
To avoid chopping up the earthworms, use a fork rather than a spade when turning over your soil.