Annual flower strips support pollinators and potentially enhance red clover seed yield

1. Ecological intensification provides opportunity to increase agricultural productivity while minimizing negative environmental impacts, by supporting ecosystem services such as crop pollination and biological pest control. For this we need to develop targeted management solutions that provide critical resources to service-providing organisms at the right time and place. 2. We tested whether annual strips of early flowering phacelia Phacelia tanacetifolia support pollinators and natural enemies of seed weevils Protapion spp., by attracting and offering nectar and pollen before the crop flowers. This was expected to increase yield of red clover Trifolium pratense seed. 3. We monitored insect pollinators, pests, natural enemies and seed yields in a total of 50 clover fields along a landscape heterogeneity gradient, over two years and across two regions in southern Sweden. About half of the fields were sown with flower strips of 125 to 2000 m2. 4. The clover fields were pollinated by 60% ...