Recruiting bees can lift crop yield and profit

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Improving the management of small, but important, creatures in the cropping landscape can deliver valuable productivity benefits

Photo of ANU scientist Saul Cunningham

ANU scientist Saul Cunningham speaks to growers about how they can protect pollinators in farming systems.

PHOTO: ANU

Bees – native, wild and managed – play an often-overlooked role in broadacre farming, but one that scientist Saul Cunningham is keen to see growers place a higher value.

During his 17 years with CSIRO and in his new role as a scientist at the Australian National University’s Fenner School of Environment and Society, Dr Cunningham’s research has focused on how ecological activities can support healthy farming systems.

He gave growers an insight into crop pollination when he spoke at a GRDC Research Update in Adelaide.

“Farmers have known for centuries that insect pollinators play a role in increasing the yield of many crops, but our knowledge of how to manage pollination for greatest yield benefit has not kept pace with other advances in agronomy,” Dr Cunningham said.

“As a result we usually have an ad hoc approach to pollination, even when growing crops known to benefit from insect pollination.”

However, Dr Cunningham said researchers around the world were showing that, for many crops, the role of pollinators is more important than often realised.Research is busting myths such as the assumption that if a crop self-fertilises then insect pollinators will not be important. Experiments show that even these crops, such as many Brassica species including canola, yield more when insects increase the rate of pollination.

Researchers are also analysing the economic benefits of managed bees in the farming system – a benefit long known in the orchard industry.

Dr Cunningham assessed the impact of managed honeybee hives in South Australian faba bean crops and used yield mapping at harvest to calculate that these pollinators increased yield by 17 per cent close to hives. The yield benefit declined with distance from hives and was low after 700 metres.

The economic study showed that even with the cost of pollinator services, using hives is profitable at typical prices for faba beans. “The message is that pollinators matter more than you might think, so don’t underestimate the yield benefits that could be achieved through better management,” Dr Cunningham said.

Bee maintenance

Photo of managed bees in faba beans on the Yorke Peninsula, SA

Managed bees in faba beans on the Yorke Peninsula, South Australia.

PHOTO: Rebecca Jennings

A renewed interest by researchers in the role of pollinators in agriculture is being driven by fears that bee populations are in decline due to pest and disease outbreaks such as the varroa mite, which attacks honeybees.

Although Australia has not experienced dramatic declines in managed bee numbers and varroa mite has not yet established here, there are concerns that bee diseases could be driven by stresses created by highly agricultural environments, such as chemical use and loss of habitat.

Dr Cunningham says growers can help keep pollinators healthy by:

  • providing flowering resources for wild pollinators in patches of non-cropping land, such as scattered tress, roadsides, fence lines and uncropped paddocks;
  • managing risk of exposure to insecticides by following on-label instructions;
  • having good communication with local beekeepers, so they can move hives away from crops when insecticides are to be applied; and
  • implementing integrated pest management strategies to reduce the need for pesticides.

Protecting pollinator habitat does not just bring an on-farm benefit; it can also protect the farming industry’s reputation with the public. Issues around agricultural chemicals affecting bees have come to a head in Europe in recent years, where public concern about bees ultimately led to the European Union establishing a moratorium on a number of neonicotinoid insecticides.

The Australian Pesticides and Veterinary Medicines Authority reviewed neonicotinoids in Australia in 2014. It concluded that there was no need to follow the European example by further restricting allowable uses, but recommended more research and surveillance and better product stewardship.

Dr Cunningham said protecting pollinators into the future requires research to fill knowledge gaps about field exposure to insecticides and to determine if there are any cumulative effects over multiple foraging trips and even multiple seasons.

More information:

Dr Saul Cunningham,

saul.cunningham@anu.edu.au

Keeping pollinators safe in our cropping systems – GRDC Update paper

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