Perennial, species-rich wildflower strips enhance pest control and crop yield

Abstract

The effectiveness of agri-environment schemes (AES) such as wildflower strips in promoting farmland biodiversity has been relatively well studied. Their effects on biodiversity-mediated ecosystem services, such as natural pest control, in contrast, remain poorly evaluated and their consequences on crop yield largely unexplored. We assessed the effect of sown, species-rich, perennial wildflower strips, promoted through the Swiss AES, on pest control services and their consequences for crop yield in nearby winter wheat. We found strong reductions in cereal leaf beetle Oulema sp. (CLB) density (eggs: 44%, larvae: 66%) and crop damage (40%) caused by CLB in winter wheat besides wildflower strips (N=10) compared with control fields without wildflower strip (N=10). Moreover, average crop yield was increased by 10% in winter wheat next to wildflower strips up to 10m into the fields. Wheat yield was positively associated with broad leaved plant cover, flower density and diversity of nearby flower strips, yet collinearity with wheat density made these effects difficult to disentangle. Our study demonstrates that diverse wildflower strips with known benefits for farmland biodiversity can also promote biological pest control and crop yield. This creates a win-win situation for crop production and biodiversity conservation, through which such AES may contribute to ecological intensification.