Print this page
Friday, 29 September 2017 10:55

Beetling for healthy soils

Written by  Bala Tikisetty, sustainable agriculture advisor at Waikato Regional Council

Could using exotic dung beetles help address soil health and water quality issues in New Zealand? It’s an option with possibilities.

Dung beetles provide many ecosystem services: decreasing the amount of pasture smothered by faeces (pasture fouling), increasing pasture growth, nutrient cycling, improving soil structure and killing pests and diseases.

Hence, NZ authorities have allowed the importing of dung beetles, now being mass reared here.

I believe that if we can further establish dung beetles in NZ, possibly in the long term millions of these critters will be chewing and burying dung from pastoral animals, with many benefits.

While dung decomposes naturally, intensive farming means large quantities are dropped, and the nutrients and pathogens move into waterways. Pasture production can also be reduced because of fouling.

However, dung beetles search out the faeces of animals which they use for food and reproduction. Most adult dung beetles make tunnels in soil beneath faeces then lay their eggs there.

Other species make balls of the faeces which they roll away and bury deep in the soil before adding an egg.

As the eggs hatch the grubs feed on the dung so they break it down and eventually turn it into a sawdust-like material that adds to the fertility of the soil structure; and the surface dung goes.

The first intentional introduction of a pastoral dung beetle was in 1956 when the Mexican dung beetle took hold at Whangarei; beetles were introduced into South Kaipara in 1994.

But because dung dropping goes on year-round, one species of dung beetle alone is incapable of achieving suitable control.

Widespread use of dung beetles can help improve soil health, reduce runoff, and increase aeration and water penetration into the soil through beetle tunnels; beetles can reduce urine and liquid dung runoff, and reduce microbial contamination, leachate pollution and eutrophication of waterways.

Beetles also help reduce nitrous oxide emissions as 80% of the nitrogen content of dung ‘flashes off’ (is lost by volatilisation) when dung remains on the pasture surface, versus only 10% when beetles bury dung.

Greater pasture productivity is another benefit, as stock will not graze around dung pats, reducing pasture productivity. Burial of nutritious material by dung beetles enhances grass growth, reducing reliance on fertiliser.

Nuisance flies breed in dung but are beaten to resources by fast-burying dung beetles.

Dung beetles could also reduce infection of animals by parasitic worms because dung burial removes the infective stages of the worms; stock drenching could diminish.

Some concerns have been raised that tunnels in the soil created by dung beetles could lead to more leaching of nutrients and E.coli. NZ research shows this is not so because while beetles create tunnels they pack these with their brood balls, sealing them off.

Dung beetles spread only slowly after introduction and research is under way to find better ways to increase their distribution in pasture.

Plenty of information on dung beetles in NZ appears on https://dungbeetle.org.nz/ and describes research done overseas and more recently here.

• Bala Tikisetty is a sustainable agriculture advisor at Waikato Regional Council, phone 0800 800 401.

More like this

Putting excrement to work

What is less than two centimetres long, loves to work during winter, has a hunger for animal poo and could be handy for grape growers?

Beetles provide an answer to nitrogen

While scientists and farm consultants in laboratories try to solve the problem of nitrogen loss on farms, a large force of creatures works underground 24/7 on the issue.

Dung beetles on farmers’ radar

Dairy farmers are taking a strong interest in dung beetles as a potentially important tool for meeting environmental obligations, says Dr Shaun Forgie, of Dung Beetle Innovations.


Longest running ag field days all go

The South Island Agricultural Field Days, held in Kirwee on the outskirts of Christchurch, will celebrate its 70th year in March 2021 with a bigger demonstration area.



Global movers and shakers

Dairy companies around the world are facing a dilemma – whether to expand or divest assets, says Rabobank’s Mary Ledman.

Live cattle exports in limbo

The fate of 28,000 cows in quarantine in New Zealand and supposedly destined for China in the coming weeks hangs…

Machinery & Products

Mowers get a makeover

Well known throughout New Zealand over the past 18 years, Pottinger has redesigned its rear-mounted Novadisc mowers to incorporate a…

Hardy spotlight

High quality, reliable lighting is essential for anyone involved in agriculture or the great outdoors.

Simmm twin water blasters

Italian made Simmm Power Cleaner 100/11 and Power Gun 100/11 single-phase (230 volt) electric water blasters are proving popular in…

OPD argument raging on

A stoush is brewing with the Federal Chamber of Automotive Industries (FCAI) heavily criticising Farmsafe Australia’s recent Safer Farm Report.