“Our mixed cultures were less dense than pure cultures, which possibly increased the visibility of the flowers.”
We need plenty of agriculture to feed the 8 billion people around the planet, but the cultivation of crops can come at terrible costs to the environment, including continued biodiversity loss. Insects have especially been hard hit with pesticides and insecticides taking their toll on them.
Worse still is that a shortage of flowering plants in agricultural landscapes is leading to a decline in pollinating insects. However, by cultivating a mixture of crops such as faba beans and wheat rather than just one or the other we can help support the population of foraging bees.
This is according to researchers at the University of Göttingen in Germany who realized this after they counted the number of honeybees and wild bees in landscapes containing mixtures of both wheat and faba beans as well as in pure cultures that only contained faba beans.
“We had expected that the mixed crops with fewer flowers would be visited less frequently by bees for foraging than single crops,” says Felix Kirsch, a PhD student at the university’s Functional Agrobiodiversity research group. “To our surprise, this was not the case.”
There could be several reasons for this, the researchers posit.
“Our mixed cultures were less dense than pure cultures, which possibly increased the visibility of the flowers. This might have attracted the similarly large number of bees to the mixed cultures,” says Annika Haß, a postdoctoral researcher in the research group which published their findings in a study .
“In addition, reduced competition between the faba bean plants in mixed cultures could mean that they can invest more resources in the production of nectar and pollen to increase their attractiveness to bees,” adds Prof. Wolfgang Link, head of the group for Breeding Research Faba Bean.
Earlier research has similarly found that having a diversity of flowers in agricultural landscapes benefit bees and bumblebees as well as, potentially, other pollinators.
Besides supporting populations of pollinators like bees, mixed cultivation of wheat and faba beans has other advantages for crop production because yields per bean plant were higher in mixed crops than in pure cultures, the German scientists note.
“Cereal crops can be ecologically enhanced by adding legumes such as beans or lentils. This can make a valuable contribution to increasing the abundance of flowers on the arable land and thus counteracting pollinator decline,” Haß suggests.