How are red wigglers helping combat climate change?

What’s small, kind of slimy, and has a digestive system some claim is a powerful tool in mitigating greenhouse gases?

It’s the composting worm, a 6cm-long waste warrior that is growing in popularity across Australia, and not just among backyard farmers.

Stanwell Power Station near Rockhampton in Queensland this year bought 40,000 composting worms to process some of the 85 tonnes of general waste they produce each year.

At the University of Southern Queensland’s (USQ) Drought Resilience Adoption and Innovation Hub’s Stanthorpe-based Node, researchers are working with farmers and the agriculture industry to trial on-farm worm farms.

The USQ trial will include analysis of soil health, plant health and yields under commercial conditions.

And worm farms are popping up in schools, businesses, commercial farms and rooftop gardens from the outback to the city, owner of Worms Down Under Jen Symmons says.

The environmental scientist turned business owner says worm farming is something anyone can do – on almost any scale from a backyard bathtub to the four-module unit the business recently packed off to a farm in Western Australia.

Worms Down Under has recently been named as a recipient of the Queensland Government Ignite Ideas Fund, with a $92,940 grant to allow mass manufacturing of modular, scalable and flat-packable commercial worm farms.

“This grant will support us to commercialise and distribute our new Worm Mod, a large-scale, modular worm farm system that has the potential to revolutionise the way we convert organic waste into a valuable soil restorer,” Symmons says.

“This is where regenerative agriculture and circular economies come in.

“Our Worm Mod allows farmers, organisations, schools, and businesses to divert organic waste from landfills and convert it into a microbe and nutrient rich organic soil amendment. This not only reduces methane and CO₂ off-gassed in landfills, it also sequesters carbon from the atmosphere and restores it to the soil in a stable form.

“It also restores beneficial microbes and minerals to the farm soils that grow our food, which in turn improves the nutritional value of foods grown in such soil (ultimately eliminating the need for chemical fertilisers, pesticides and herbicides).”

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Worms, Symmons says, will eat just about anything in the right circumstances.

“Not only is it faster than conventional composting and you don’t have to dig, but it also results in the output of beneficial microbes which bring a greater diversity to the soil,” she says. “And in nature, diversity wins.”

Worm farming – also known as vermicomposting or vermiculture – uses a variety of composting worms that differ from ordinary earthworms. Worms Down Under uses a blend of red (red wigglers), tiger, blue, gardener’s friend worms and European night crawlers.

The composting worms eat the waste and excrete castings that are known as “black gold”. The humus is rich in nutrients.

Symmons says in the battle to wrangle carbon from the air and put it back in the soil where it belongs, humus is a hero, rich in carbon.

Professor Rajiv K. Sinha and his daughter Dr Shweta Singh, who live in Queensland, have spent many years studying the benefits of vermicomposting.

“This creator and protector of earth [the worm] can also help the nations to combat global warming and climate change by reducing the emission of greenhouse gases from some sources on earth,” Sinha says.

“The Intergovernmental Panel on Climate Change (2000) recognised that carbon sequestration in soils by addition of composts as one of the possible measures through which the greenhouse gas emissions and global warming can be mitigated.

“Hence earthworms and its vermicompost can play a good role in the strategy of greenhouse gas reduction and mitigation of global warming and climate change, which is inducing natural disasters all over the world.”

Sinha says vermicompost not only prevents emissions by minimising landfill, but puts more carbon back into the soil – a process known as carbon sequestration – in a more stable form. It remains in the soil for longer and improves the condition of the soil.

He says the vermicomposting of all organic wastes would “significantly reduce” the total emissions of greenhouse gases.

Sinha’s studies at Griffith University showed that, on average, vermicomposting emitted significantly less methane than conventional composting.

He is also a supporter of vermifilter technology, initially developed by Professors Jose Toha and Maria Soto at the University of Chile in 1998.

The vermifilter process uses worms as a biofilter to detoxify and disinfect wastewater to produce clean water.

For Jen Symmons, the increasing popularity of vermicomposting in Australia is no surprise.

She says farmers are realising they have been “sold a pup” by chemical companies after generations of degradation of the land.

“Most farmers genuinely want to leave a legacy and be custodians of the land,” she says. “This is something people can do.”