Brown-headed earthworm helps vignerons and orchardists
Updated
Dig into the first 10 to 15 centimetres of soil in most places in Tasmania and you will find four of the five earthworm varieties imported more than a century ago.
Dig a little deeper and you will come across the fifth, the brown-headed earthworm.
Agronomist and author Graeme Stevenson has been studying these worms and believes the brown-headed earthworm's adaptability and deep digging ability are ideal for locations such as vineyards and orchards.
He said the brown-headed earthworm came to Tasmania in the early days of settlement, brought out by members of the original Van Diemen's Land company.
Mr Stevenson said the worms were now found in many parts of the state and, even though his research into their present locations and numbers is not complete, he suspects they are fairly well distributed.
To check he was examining the same worm, he took samples from five separate and varied locations and had their DNA tested.
Sure enough, they were all found to be brown-headed earthworms, living in a wide variety of environments ranging from a low-intensity chicken run to sandy soil very close to the beach.
He said the worms were not well suited to pasture and cropping land, as regular ploughing and soil movement destroyed their burrows.
"This fellow goes down deep, the only deep digger we've got," he said.
"Deep digging is crucial, it works the subsoil. In fact, they are subsoil creators."
Although they do not breed as prolifically as other earthworms, they have a long lifespan, living for as much as seven years.
In spite of his enthusiasm and belief in the benefits of these worms, Mr Stevenson said it was not so easy to get farmers interested in them.
"One of my challenges is to create awareness in farmers and landholders but worms are a slow story," he said.
"A bit hard to get people excited."
Topics: research, environmental-health, animal-science, rural, hobart-7000
First posted
