Comment: Imagine if your newest farmer worker was on the job 24/7, could help you lift productivity and environmental sustainability, and loves it if the pay is crap writes Federated Farmers communications adviser Simon Edwards.
Entomologist and Dung Beetle Innovations co-founder Dr Shaun Forgie told farmers at two workshops in the Wairarapa in late November that wide dispersal of the six-legged critters on our pastureland would be far more effective and less costly than fencing and riparian planting to achieve water quality gains.
Dung beetles are now active on farms in every state in Australia, where the government has subsidised establishment of colonies for four years and our government is missing-in -action on dung beetle opportunities said the former Landcare Research scientist.
His company estimates that with a $140 million investment over 10 years, we could have established beetle colonies busy breaking down dung, improving soil quality and reducing run-off on 75 per cent of our farms.
That's a lot of money, but Forgie points out it pales in comparison to current costs of waterway fencing, riparian planting and dealing with the pasture fouling and parasites from the 100 million tonnes of dung that cattle, sheep and horses deposit on our farmland every year.
Greater Wellington Regional Council is on board with his message.
In recognition of the environmental benefits, in 2018, GWRC subsidised farmers around Lake Wairarapa to buy colony packages from Dung Beetle Innovations' 3.6ha breeding facility in Whenuapai.
Around 30 farmers in the catchment took up the offer, and 20 others in the wider district.
Last year GWRC offered to pay half the $6,000 + GST cost of four species/four colonies packages in the Mangatarere and Parkvale catchments.
The GWRC partnership saw Dung Beetle Innovations named a finalist in the 'Partnering for Good' section of the 2019 NZI Sustainable Business Network Awards, with DBI also named as a finalist in the "Restoring Nature" section.
Federated Farmers member and DairyNZ climate change ambassador Vern Brasell released two four-season packs of dung beetles last year on the 900-cow farm at Kaiwaiwai where he is a shareholder and "watched them disappear cowpats".
He was back at November's workshop near Carterton to buy more.
Brasell didn't see the cost as significant, given the farm had invested in an $800,000 effluent system and spent $40,000 establishing a wetland. He saw the dung beetles as having plenty of potential.
Smaller scale farmers Kevin and Barbara Thompson, who live "off the grid" and have always regarded environmental protection as key, are attracted to the dung beetle option.
"Farmers are taking hits left and right on all sorts of things" Barbara said.
"I think it's fantastic we can let nature deal with one of our problems".
While there are other dung beetle converts up and down the country, it's more effective when a number of neighbouring farmers in a catchment take it up, said Forgie.
"Dung beetles don't recognise fence lines. They'll fly to nearest fresh dung".
The biggest challenge for sustaining dung beetle colonies – the impact of drenches – is perversely also a farm cost that beetles can bring down.
Some drenches are toxic to dung beetles and their active constituents can persist in dung for several weeks.
The Dung Beetle Innovations website has plenty of advice on how to manage this problem, and as Forgie pointed out, dung beetles can reduce the need for use of expensive drenches in the first place.
The area of forage fouling by deposited dung is four or five times the size of the dung itself.
Animals instinctively don't graze this "repugnant zone" because they would also be eating the larvae of the parasites that can infect their gut.
Forgie said studies have shown established dung beetle colonies dealing with dung can lead to a more than 70 per cent reduction in parasite L3 infection rates.
Farmers can harrow or use strip-grazing management to try and overcome "repugnant zone" grazing loss but Forgie argued we'd be far better off getting beetles to "break down what is a gold mine of organic nutrients, and take them down 45 to 50 centimetres into the soil".
"It's a self-sustaining system that's just common sense".
Find out more
• There are more than 7,000 species of dung beetles around the world, on every land mass except Antarctica.
• The beetles roll up dung into balls or small sausages and use the faeces as food and breeding chambers. A female can lay 80–90 eggs in her lifetime.
• The 11 dung beetle species the EPA has approved for release in New Zealand are tunnellers (rather than ground rollers or dung dwellers). They burrow and take the dung balls 20cm or more below the surface.
• Dung Beetle Innovations imports and breeds species from southern Europe, Africa, Australia and Mexico. Each species has its own behavioural patterns and life cycles. Introducing multiple species means one or more of them is active every season, and they can be tailored to soil types and other geographical conditions.
Dung beetle benefits include:
• Improved aeration and mixing of soils
• Less run-off soil sediment and contaminants from dung
• More available grazing pasture with dung removed and buried
• Cattle urine goes deeper into soil, reducing nitrous oxide
• Plant root biomass in the aerated soil is deeper – a real bonus in areas prone to drought.
- Simon Edwards is communications adviser at Federated Farmers.