Liberation Deliverable 3.2 : Report on the effectiveness of a range of landscape management practices

Ecological intensification aims to enhance important ecosystem processes that contribute to the delivery of the ecosystem services that underpin agricultural production allowing us to reduce our reliance on synthetic inputs. The potential of ecological intensification will depend on many factors, among the most important of which are off-field management and landscape context. These factors, and importantly the interaction between them, are likely to vary across regions and countries. Identifying off-field management approaches that are successful in enhancing ecosystem services will require assessing a range of strategies. The empirical work carried out in task 3.2 provided original data on the effectiveness of three off-field interventions (hedgerow, set- aside and flower strips) on the delivery of biocontrol and yield in winter cereals across different European countries. For hedgerows we found that the quality of the hedgerow (flower diversity) generally increased biodiversity of several beneficial groups of insects (e.g. butterflies, tachinids, carabids, spiders), while the delivery of ecosystems services such as pollination and pest control tended to respond more to landscape factors (proportion of hedgerows or semi-natural habitats in general in the surrounding). For set-aside we found that this intervention increased locally the biodiversity of several beneficial insect groups (literature) but the spillover to winter wheat fields was small with no apparent benefit on the delivery of aphid biocontrol. Finally, we found that wildflower strips helped to reduce aphid pests in winter wheat fields, which, in turn, enhanced crop yield. However, this potential may only be reached in case strips are properly managed, in a way that optimizes floral diversity, and may only be relevant in agricultural landscapes with a low availability of habitat area for natural enemies. Irrespective of the intensity of the agricultural systems, the two most promising interventions to foster biocontrol and support yield in winter wheats are hedgerows and flower strips, but their effect appeared to be stronger in landscapes with low cover of existing semi-natural habitats.