Farmers could boost bee species and improve crop yields with new wildflower seed mixes more diverse than existing ones, a study has shown.
The research, recently published in the Journal of Insect Conservation, highlights that variety is the key for helping threatened pollinator species.
It comes as farm groups urge the government to improve the options available to them as policy begins to shift toward a 'payment by results' approach.
As stated in the new Agriculture Bill, farmers will be rewarded with public money for “public goods” – such as better air and water quality, higher welfare standards or measures to improve habitats.
Looking at improved ways for farmers to boost pollinators, University of Sussex PhD student Rachel Nichols and her team partnered up with Emorsgate Seeds to identity which wildflowers attracted certain bee species in the plots where the wildflower seed is produced.
This provided the bees with an abundance of flowers and was a rigorous test of their preferences.
The findings of the study also suggest that the current mixes recommended by Defra might not be as effective as they could be.
In fact, the existing nectar flower mix and the flower-rich margin mixes suggested contain only one each of the 18 species found to be most attractive in the study.
As wild bees are often better pollinators than honeybees, the research focused on how best to attract species likely to transfer more pollen per visit.
A more diverse mix of pollinator species has also been shown to improve crop yields, encouraging those running the project to find a combination that was attractive to as many different species as possible.
Professor John Holland, who is one of the supervisors in the study, said: “This work is the first of its kind, but shows how important it is to monitor how effective current measures are.
“Those mixes used in current agri-environment schemes are having a positive impact, but we must remain open to how we can improve.”
Across the five-month study, Rachel Nichols and her team monitored 44 different wildflower species, spotting 40 different wild bee species.
They were able to identify a combination of 14 wildflowers that supported all but three of these.
Some bees were shown to be heavily dependent on certain wildflowers, with almost all of the small garden bumblebee visits observed on kidney vetch.
In contrast, more common wild bees such as the red-tailed and buff-tailed bumblebee visited a wide range of flowers, demonstrating a preference for wild knapweed.
Ms Nichols said this illustrates the importance of wildflower diversity in any future seed mixes.
The team are now trialling two new mixes in order to understand how practical it may be to use, both in terms of handling and seed establishment.
