There are often very few flowering plants in agricultural landscapes, which is one reason for the decline of insect pollinators. Researchers at the University of Göttingen have now investigated how a combination of bean (bean) and wheat crops affects the number of pollinating insects. They found that areas of mixed crops compared to areas of single crops are visited more often by foraging bees. Their results have been published in the journal Agriculture, ecosystems and the environment.
The researchers observed and counted the foraging of honey bees and wild bees in mixtures of wheat and beans, and in pure cultures containing only beans. “We would have expected bees to visit mixed crops that have fewer flowers much more than single crops,” says PhD student Felix Kirsch from the Functional Biodiversity Research Group at the University of Göttingen. “To our surprise, that was not the case.”
This may be due to several reasons. “Our mixed cultures were less dense than pure cultures, which may increase the visibility of flowers. This may have attracted a similarly high number of bees to the mixed cultures,” suggests Dr. Anika Haas, a postdoctoral researcher in the Functional Biodiversity Research Group. “In addition, reduced competition between bean plants in mixed cultures may mean that they can invest more resources in nectar and pollen production to increase their attractiveness to bees,” adds Professor Wolfgang Linke, Head of the Breeding Research Group FABA. beans.
“The mixed cultivation of wheat and beans also has other advantages for crop production,” says Professor Catherine Westphal, Head of Functional Agricultural Diversity. For example, yields per bean plant were higher in mixed crops than in pure cultures. Hasse concludes, “Cereal crops can be ecologically improved by adding legumes such as beans or lentils. This can make a valuable contribution to increasing the abundance of flowers on arable land and thus counteracting the pollinator decline.”