By Helena Foster, Community Gardener at Wodonga Middle Years College
Worms are without doubt man’s greatest ally, if only we had the wisdom to see it. They are our little unseen and unsung ecological heroes, quietly burrowing just under the surface of our Earth. Their entire life’s purpose is keeping our soils fertile and bountiful.
Over 2,000 species of worms in existence worldwide can be divided roughly into two categories: earth worms and compost worms.
Earthworms burrow into the soil feeding on it as they go. Some species have been found as deep as eight metres down, but most of earthworm activity happens in the first 2metres. They move large amounts of mineral rich soil from the lower strata to the surface and also carry organic matter from the surface down into deeper soil thus increasing the depth of our fertile topsoil. Their burrows create drainage channels and aerate the soil, improving its water holding capacity, whilst their castings distribute plant nutrients and microorganisms throughout the soil structure.
Compost worms work closer to the surface, breaking down the organic litter and mixing it into the first 20-50 cm of the earth’s crust.
Both ingest decaying organic matter then expel it in a form of globules of nutrient- rich worm castings which, when diluted in water, make perfectly balanced and readily accessible fertiliser.
As if all of the above was not miraculous enough, here are 3 more mind- boggling worm facts:
1. in soils rich in organic content one single worm can produce in excess of 4.5 kg (10 lb) of castings per worm per year;
2. the content of organic material, microorganisms and available nitrogen, phosphate, potassium, calcium and magnesium in fresh worm castings is up to 10 times higher than in the soil they ingest;
3. complex digestive processes of worm’s gut are able to break down and transmute high concentrations of heavy metals and other pollutants in soils, thus rendering hazardous disused industrial sites, landfill, etc., healthy and fertile in a relatively short time.
With food security being a bit of a pressing modern issue, we are now witnessing a revival of backyard food growing.
It makes sense that gardeners encourage worms to populate their gardens – the fertilizer they produce is of best quality, it doesn’t come wrapped in plastic and it’s free.
Next week I will explain how to set up a simple worm farm system in our backyard.