Multi-species crop mixtures increase insect biodiversity in an intercropping experiment

Recent biodiversity declines require action across sectors such as agriculture. The situation is particularly acute for arthropods, a species-rich taxon providing important ecosystem services. To counteract negative consequences of agricultural intensification, creating a less hostile agricultural “matrix” through growing crop mixtures can reduce harm for arthropods without yield losses. While grassland biodiversity experiments showed positive plant biodiversity effects on arthropods, experiments manipulating crop diversity and management intensity to study arthropods are lacking. Here, we experimentally manipulated crop diversity (1-3 species, fallows), crop species (wheat, faba bean, linseed, oilseed rape) and agrochemical input (high vs. low) and studied responses of arthropod biodiversity. Increasing crop diversity increased arthropod diversity and arthropod numbers. Mass-flowering crops attracted more arthropods than legumes or cereals. Integrating intercropping into agricultural systems could lead to a massive increase in flower visits (up to 15 million visits/ha), indicating benefits of intercropping for insect biodiversity and associated ecosystem services.