Cultivation of beans in various agricultural land

image: A bumblebee steals nectar from a faba bean
to see After

Credit: Nicole Beyer

Insect pollination is essential to the production of many food crops. The presence of pollinators, such as bees, depends on the availability of nesting sites and sufficient food. If these conditions are lacking, pollinators do not appear either and the yield of flowering arable crops, such as broad beans or rapeseed, also suffers. A team from the University of Göttingen and the Julius Kühn Institute (JKI) in Braunschweig studied how the composition of flowering crops and semi-natural habitats in the landscape affects the density of bees, their behavior when collecting nectar and faba bean (Vicia Faba) given. The results of the study have been published in the journal Fundamental and applied ecology.

The researchers show that in landscapes with a high proportion of semi-natural habitats and in landscapes with a high proportion of faba beans, more bumblebees were found in bean fields. Also, bean yields were higher here. Scientists recorded and observed the foraging behavior of honey bees and wild bees in bean fields in agricultural landscapes with different landscape compositions. They also worked out the yield parameters for an individual plant. “Insect pollination has a positive effect on bean yields. Our surveys showed about 34% more beans per pod in insect-pollinated plants compared to insect-inaccessible plants,” says Dr Doreen Gabriel from JKI.

“The pollination success of broad beans depends not only on the density of bees in the fields, but also on the particular species of bee collecting the nectar. Species of bumblebees that have short proboscis often steal nectar from beans by biting holes in the calyxes (the outer sepals that protect the flower bud).In contrast, bumblebee species that have longer proboscis regularly collect nectar from the front of the flower, resulting in increased cross-pollination rate.However, there are hardly any studies that have investigated whether the behavior of nectar-gathering bees is also influenced by the availability and distribution of other resources in the landscape, i.e. say the composition of the landscape,” says first author Dr. Nicole Beyer, who did her doctorate at the University of Göttingen and now works at the Thünen Institute in Braunschweig. The study shows that bumblebees short-tongued stole broad bean nectar more frequently when there was a high proportion of broad beans in the landscape.

“Our study illustrates the importance of landscape composition for crop yield, as shown in the example of faba bean. The availability of flower-rich habitats can improve the density of bees in the fields, their foraging behavior and their pollination services,” concludes Professor Catrin Westphal, Head of Functional Agrobiodiversity at the University of Göttingen.

Original release: Beyer, N., Gabriel, D. & Westphal, C. (2022). Landscape composition alters pollinator densities, foraging behavior, and faba bean yield formation. Fundamental and Applied Ecology, doi: https://doi.org/10.1016/j.baae.2022.03.002

Contact:

Nicole Beyer

University of Goettingen

Faculty of Agricultural Sciences – Functional Agrobiodiversity

Grisebachstrasse 6, 37077 Goettingen, Germany

Tel: +49 (0)551 39-22312

Email: [email protected]

www.uni-goettingen.de/en/601681.html

Doctor Doreen Gabriel

Institute of Crop and Soil Sciences

Julius Kühn Institute – Federal Center for Cultivated Plant Research

Bundesallee 58, 38116 Braunschweig, Germany

Tel: +49 (0) 531 5962340

Email: [email protected]

Professor Catrin Westphal

University of Goettingen

Faculty of Agricultural Sciences – Functional Agrobiodiversity

Grisebachstrasse 6, 37077 Goettingen, Germany

Tel: +49 (0) 551 3922257

Email: [email protected]


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Amalia H. Mercado