Wild pollinators and honeybees respond differently to landscape-scale organic farming and increase sunflower yields

Wild pollinators play a critical role in crop production, yet they are increasingly threatened by agricultural intensification and habitat loss. Hence, identifying effective measures to support pollinators at landscape and field scale is crucial for maintaining pollination services and ensuring sustainable food production. We assessed how landscape composition (area of organic farming, semi-natural habitats and mass-flowering crops) and field management (farming system, weed cover and weed richness) influence wild pollinators and honeybees in sunflower fields. Additionally, we used a pollinator exclusion experiment to assess the effects of landscape composition, field management and pollinators on seed weight, seed number, pollination services and overall yield. Bumblebee abundance increased with organic farming area in the landscape, while solitary bee richness increased with semi-natural habitat area. Both bumblebees and hoverflies declined in abundance with increasing mass-..., Site selection
The study was carried out in 2022 on 14 conventional and 15 organic sunflower fields in agricultural landscapes around Würzburg (Northern Bavaria, Germany, Fig. 1A). The fields were selected in such way that the surrounding landscape composition covered the broadest possible gradients in the area of 1) annual organic farming, 2) semi-natural habitats and 3) sunflower fields, whereby maximizing gradient 1 had highest and gradient 3 had lowest priority (Fig. 1B). Conventional farmers applied mineral fertilizer and herbicides, but no insecticides in the sunflower fields. Organic farmers applied no pesticides or fertilizers, with two exceptions where manure or compost were used. The average number of different crops in the typical rotation was 2.75 ± 0.48 (mean ± SE) for conventional and 4.3 ± 0.33 (mean ± SE) for organic sunflower fields. Minimum distance between study fields was 5.8 ± 0.75 km (mean ± SE). In two cases, distance between fields was less than 2 km (958 and 167..., , # Wild pollinators and honeybees respond differently to landscape-scale organic farming and increase sunflower yields

Dataset DOI: [10.5061/dryad.cfxpnvxh5](10.5061/dryad.cfxpnvxh5)

## Description of the data and file structure

Here, we aimed to disentangle effects on wild pollinators, weeds, and yield components acting at the landscape scale and the local field scale. At the landscape scale, we assessed the effects of landscape composition, quantified as the area of organic farming, semi-natural habitats, and mass-flowering crops, within 500 m and 1 km radiuses around the field center. At the field scale, we assessed effects of field-scale management, based on farming system (conventional vs. organic), weed coverage, weed richness, and sunflower coverage. We surveyed flower visitation of three groups of wild pollinators (bumblebees, solitary bees, and hoverflies) and honeybees in conventional and organic sunflower fields along a gradient of surrounding landscape composition.

We sur...,