Friday, July 15, 2011
Charles Darwin wrote, “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 organized creatures”.
It is the earthworm which continually renews and maintains the valuable top soil. All the waste products of life: the dead vegetation, the manure and the dead animal residues are the chief source of food for earthworms.
The actual numbers of earthworms per acre will vary considerably, according to the quantity of organic matter, humus, that is found in the soil. Darwin found concentrations of from 25,000 to 53,000 per acre. It has been suggested that there could be eight million earthworms in a single acre, and that some of their burrows could penetrate to a depth of six feet. One can therefore imagine what a tremendous aeration function these creatures would have under these circumstances. The extensive systems of tubes which they develop through the soil, helps the water penetrate to great depths, as well as giving passage to plant roots and air.
Sir Albert Howard described the earthworm as the gardener’s manure factory. In the passage down the earthworm’s alimentary canal, the organic matter and the soil is neutralized by constant additions of carbonate of lime secreting from three pair of calciferous glands, near the earthworm’s gizzard. It is here that the matter is ground prior to digestion. The casts thrown up by worms contain everything that the plant needs in abundance.
Quoting Charles Darwin again, he wrote, “The whole of the superficial mould over any expanse, has passed and will pass again every few years, through the bodies of worms.”
Lawn makers and gardeners should therefore encourage worms, because they speed the breakdown of organic matter; they burrow and materially aid soil drainage, allowing air and water to penetrate more deeply. They also turn over the soil and enrich it with their castings. Earthworms have a profound effect on the ecology of the soil.Back