We evaluate how the share of farmland enrolled in agri-environmental schemes affects the biodiversity friendliness of management practices both on the overall farmland as well as on the enrolled and non-enrolled plots separately. To this end, we prepare a unique dataset for Switzerland that links farm-level accountancy data to plot-level data on management practices and their impact on organismal biodiversity. Our estimates allow us to calculate bounds for potential spillovers on non-enrolled farmland. We find that these are positive but small in magnitude. The effect on the overall farmland is also positive but again rather small.