Good for the garden: With just a flick of a switch, it's toad juice

Fat, warty, toxic, and full of juice. The Aussies will find a use for the loathsome cane toad yet. Picture / David Motte

SYDNEY - Australians are poised to take revenge on the cane toad - by turning the warty pests into liquid fertiliser that will, at last, be good for the garden.

Since their ill-advised introduction to Queensland from South America in the 1930s, the toads have multiplied in their millions and fanned out across the country to the tropical wetlands of the Northern Territory and as far south as New South Wales.

Darwin is under siege, with locals setting traps, "toad-proofing" backyards and organising night-time toad musters to capture and kill dozens of the amphibians by torchlight.

The plan now is to turn the hundreds of thousands of dead toads into liquid fertiliser, or "toad juice". It is said to be particularly good for growing bananas and papayas.

The idea has come from a conservation group, FrogWatch, which has led the fight against the toxic invaders in the Northern Territory and has enough dead toads - 200kg at last count - to start producing around 300 litres of fertiliser.

"We've done preliminary work and the indications are that toads will make very good fertiliser," FrogWatch founder Graham Sawyer said.

"They stink pretty bad when they are rotting down but at the end of the process you are left with a clear blue liquid and a strong smell of ammonia."

The toads' natural poison, which has made them such a deadly menace to native wildlife, disappears once the animals are mulched.

The first batch will be processed at a liquid fertiliser producer in Darwin, where the carcasses will be mixed with molasses to aid decomposition.

FrogWatch hope they will be able to produce enough fertiliser to sell to the public, with the proceeds used to fund a new toad collection service. Locals will be able to dump the pests in bins, from where they will be collected and turned into more fertiliser.

The toads - known as sapo gigante in Spanish for their size - were first introduced into Queensland to prey on a beetle that was devastating sugar cane plantations.

They proved useless against the insects and started to eat other native wildlife instead. At the same time their poisonous skins have killed many Australian predators.

Having hopped their way thousands of kilometres from Queensland to the Northern Territory, the toads are now on the very fringes of Darwin.

A few dozen have been spotted in satellite town Palmerston, just to Darwin's south.

Opinion is divided as to how best to kill a cane toad. Animal welfare groups - and the Northern Territory Government - suggest putting them in a plastic bag and placing them in the freezer.

A local MP, David Tollner, caused controversy last year when he suggested the best way of dispatching the pests was to bash them on the head with a golf club or cricket bat - a blood sport he practised as a child.

"We hit them with cricket bats and golf clubs and the like back then," he told ABC radio.

"Most kids had a slug gun or an air rifle and we'd get stuck into them with that sort of stuff as well. My view is we've got to eradicate them by any means possible."

An even odder suggestion was made by the RSPCA this week - wildlife officials there suggested that people should anaesthetise the toads by smearing them with haemorrhoid cream before freezing them to death.