Beetles get it dung right

They’re one of God’s gifts to us humans living on this tired, burnt-out continent, says dung beetle expert John Feehan.

The dung beetle is nature’s hardest working insect and could be the future of more sustainable agriculture in Australia.

Many, such as third-generation Crookwell farmer John Lowe, are fertilising their properties, but not out of a bag or an aeroplane. They’re letting the dung beetle do the work.

Top left: third-generation Crookwell farmer John Lowe. Below: Dung beetles bury cow pads into the soil, which improves it. Right: Dung beetle expert John Feehan. Photos: Xanthe Gregory

Top left: third-generation Crookwell farmer John Lowe. Below: Dung beetles bury cow pads into the soil, which improves it. Right: Dung beetle expert John Feehan. Photos: Xanthe Gregory

Mr Lowe introduced three colonies of dung beetles onto his 800-hectare property in 2003 after his daughter met Mr Feehan while on work experience with the CSIRO. 

The beetles naturally fertilise his pastures and have significantly reduced the number of bush flies on his property. “It’s a perfectly natural phenomenon,” Mr Lowe said.

The beetles feed and lay their larvae in the dung, burying the cow pads into the soil. This feeds the nutrients into the ground and removes the waste from covering up productive farming land.

The beetles can drill holes up to 300 millimetres deep, aerating the soil and allowing for greater retention of rainwater, allowing herbicide and pesticide run-off to further penetrate the land instead of being washed into waterways. During winter months, the beetles can also bury sheep dung when it’s soft and able to be manipulated into the soil. 

Australia has 23 CSIRO-introduced species of dung beetle, which can bury pads in as little as one day.

More than 28 million cattle on our continent drop dung about 12 times a day. That’s about half a million tonnes every day of nutrient-rich dung that the beetles can bury in the soil. 

Mr Lowe has 120 head of cattle and, since introducing the colonies, says there have been no disadvantages. “The cow pads disappear. They don’t hang around and get dried out,” he said. 

A reduction in bush and buffalo fly populations is a major benefit from the dung beetles, because flies breed in the cow pads. Where the buffalo fly has no competition, Mr Feehan says, an animal can fail to put on around 30 kilograms in a year, which is a major cost to the farmer. 

Mr Feehan spent 31 years researching the beetles at the CSIRO before funding ran out. Now he harvests beetles from established colonies on farms.  

About “eight to 10 species would suit the southern tablelands,” Mr Feehan said. “All I need is an exact location and I select the species for that climate.

“John Deere’s engineers are very clever, they make incredible machinery, but they could not make a machine that would put dung back underground as the dung beetles do.”

Mr Lowe has witnessed a change in his soils over the 15 years he’s had dung beetles actively working. “They firstly improve soil structure, which then improves pasture fertility,” Mr Lowe said. 

Farmers may be able to support more cattle from the increased growth rate of pasture. “There’s an increase in productivity of around 30 percent and it will continue as time goes on and the soil gets richer,” Mr Feehan said.

He believes dung beetles are key to keeping farms productive for future generations as phosphate reserves decline. “It’s the only way your grandkids are going to survive,” Mr Feehan said.

Cow dung is full of phosphorus and nitrogen, but it goes to waste when it’s not buried into the grass roots.

Eighty percent of the nitrogen from the buried dung will be saved, instead of going off into the atmosphere. “Nothing lives and nothing grows without phosphorus and we live on the most phosphorus-deficient continent on the planet,” Mr Feehan said.

Introducing a colony of dung beetles can cost $400 to $600, which is about the cost of a tonne of phosphate fertiliser.

A dung beetle colony is a self-replacing one-off cost, “which will still be there for your grandkids”.

“A beef producer is infinitely better off getting a new species of dung beetle than he is buying one tonne of phosphate fertiliser or any other type of fertiliser,” Mr Feehan said. “The difference is, you will have to re-do the fertiliser in three to four years time.”

Mr Lowe continues to annually fertilise his property with super phosphate as part of his fertility management plan.

In conjunction with the dung beetles, he also uses agricultural lime to improve the pH levels of soil. 

A farm must have phosphate and other trace elements for the dung beetles to be effective as they will recycle them to perpetuate the health of the paddocks.

“They can’t make something out of nothing,” Mr Feehan said. 

Dung beetles can be found right across Australia and many farmers may find an introduced species burying their cow dung – or one of the 500 native species that feed on native marsupial dung – on their property.

The activity of these beetles may not be year-round and farmers can introduce species that are active during months where others are dormant.

“They may have dung beetle activity from November to March, but they have nothing for the other seven months of the year,” Mr Feehan said.

“They don’t realise that gap in the year, which is much longer than the period they have dung beetle activity, can be filled, particularly down in the southern part of the continent,” he said.

Summer and spring active beetles are working tirelessly in Mr Lowe’s paddocks, but he is looking to introduce a few species that work throughout the winter months to get year-round benefits from the beetle. 

Mr Feehan describes walking on a property with active dung beetle colonies as completely fly-free and the “paddocks as clean and clear as the fairways on a golf course”.

Numerous farmers around the Goulburn district have already introduced dung beetles colonies onto their properties and with their countless advantages, there’s bound to be more hopping on board the dung beetle train.