Perennial flower strips benefit both pollinators and beneficial insects in farmland

Flower strips are a corridor of land along arable fields sown with flowering plants, often perennial species that provide nectar and pollen over a long period. They serve as habitats and feeding sites for pollinators and predatory insects, helping to increase biodiversity and natural pest control in nearby crops. The idea behind flower strips is to enhance the ecosystem services provided by different organisms, thereby creating a more robust and sustainable farming landscape.

– In our new study, we compared field margins sown with perennial flower mixtures to naturally growing margins at several sites in Skåne, southern Sweden. In total, we investigated ten fields of each type, explains Maria Viketoft.

A holistic view of life in and around the flower strips

The researchers closely monitored both the flower strips and the adjacent crops. They counted insects directly in the field, set up sticky traps to capture flying species, and placed pitfall traps on the ground to track crawling insects. They also measured how many pests were eaten and how quickly organic material decomposed – all to gain a complete picture of how life thrives in and around the strips.

– We clearly saw that the flower strips attract more pollinators such as bumblebees, bees, hoverflies, and butterflies, as well as more species of predatory insects compared with unsown areas. The effects also extended into the nearby crop. This is a concrete example of how we can create more habitats for insects, even in intensive agricultural landscapes, without compromising production. 

Not always a reduction in crop pests

However, flower strips are not a quick fix for all problems. Even though more pollinators and beneficial insects were found in and around the strips, the researchers did not always see a clear reduction in pest numbers within the crops themselves.

– This shows that ecosystems are complex. Building up functioning natural processes takes time, but flower strips can be an important step in that direction.

What makes an optimal flower strip?

So, how should these strips be designed for the best results? How wide should they be, how close to the agricultural fields, and which flower species are most effective in different environments?

– The composition of species is crucial, since different flowers attract different insect groups. A well-balanced mixture should support both pollination and the attraction of predatory insects that can help control pests in the crops.

– A more sustainable agriculture is built not only around production but also around ecological function. The next step is to study long-term effects, economic aspects for farmers, and how flower strips can be adapted to different agricultural environments in Sweden, concludes Maria Viketoft.

Read more

Read the scientific article in Agriculture, Ecosystems & Environment:

Perennial flower strips increase pollinator and natural enemy abundance but have limited effects on pest control in adjacent crops