Importance of biodiversity for farmers larger than expected

In a joint project with seed producer BASF Vegetable Seeds, the researchers looked at leek seed production on 36 commercial production fields in France and Italy. The importance of pollinators for many crops has long been shown. Obviously, a vital plant is also required. The study, which will be published in Ecology Letters, looked into the importance of these two factors in relation to each other.

"Our research shows that wild pollinators are at least as important for crop yield as the vitality of the plants," says lead researcher Thijs Fijen. “This was also a surprising finding for us. It is actually very odd that the agricultural sector has paid so little attention to protecting wild pollinators." In this study, bumblebees and other wild bees were found to be the most important pollinators. According to Professor David Kleijn, co-author of the article and Fijen’s doctoral study supervisor, "The plants were visited by honeybees, but this did not improve pollination, whereas bumblebees clearly did."

Fijen also stresses the importance of bumblebees: "Bumblebees are incredibly important pollinators for many crops, probably because their large, hairy bodies can carry a lot of pollen. Next year, I want to investigate the importance of bumblebees for lupin, a plant whose pods are used in products such as meat substitutes." Fijen has started a crowdfunding campaign for this purpose. "Growing lupin in the Netherlands is a win-win situation: it has a lower ecological footprint than other crops and provides more food for bumblebees." Fijen aims to complete his doctoral research at Wageningen University in the spring of 2019.

Although the findings of the study concern only the improved production of leek seed, the results are probably of much wider relevance. "You may wonder what this means for agriculture in general," says David Kleijn. "For most crops, the contribution of wild pollinators may be somewhat less than shown in our study on leeks, but I still believe that the importance of wild pollinators, and thus biodiversity, is systematically underestimated by the agricultural sector. There is considerable scope for improvement, both for the environment and for agricultural yield."

Text: Wageningen Environmental Research
Photos: Rasbak, Wikimedia Commons CC BY-SA 4.0 (lead photo: buff-tailed bumblebee); Menno Reemer