Mixed crop cultivation offers insect protection without loss of yield

Arthropods play a particularly important role in ecosystems. Until now, there has been a lack of strategic experiments on how arthropods develop in a diverse crop environment and react to the use of chemicals in agriculture. Experiments in arable farming have now shown that greater plant biodiversity has a positive effect on this species-rich group of organisms, which includes insects, millipedes, crustaceans and arachnids.

In the study in question, researchers from the LIB, the University of Münster and the University of Bonn investigated how the diversity and species of crops and the use of agrochemicals - in different combinations and with different factors - affect the biodiversity of arthropods. The growth of weeds and the biomass of crops were also measured.

The results showed that higher crop diversity in mixed cropping had a positive effect on the quantity and diversity of arthropods, regardless of land use intensity. In particular, mixed crops with field beans, linseed or spring rape showed a particularly high arthropod biodiversity. This also showed that lush flowering plants were more attractive to arthropods than legumes or cereals.

"By converting parts of our monocultures to mixed crops, we could increase flower visits from a few thousand to up to 1.5 million insect visits per hectare and thus probably also indirectly promote ecosystem services such as pollination or biological pest control," summarises Christoph Scherber, Deputy Director of the LIB. "Mixed crop cultivation is therefore proving to be a promising strategy against the decline of insects in agricultural landscapes. This would also allow extensive monocultures to be upgraded and preserved as a landscape matrix worth living in. By promoting biodiversity across a wide area, we can also secure the future of biodiversity in intensive agriculture."