Drivers of farmers’ willingness to adopt extensive farming practices in a globally important bird area

•Farmers’ reservation prices for agri-environmental scheme design features are estimated using stated preference methods.•The contracts studied concern fertilization, crop diversification, catch crops, peatlands, meadows, and livestock.•Farms’ and farmers’ characteristics are used to explain preference heterogeneity.•Effects of subjective and objective knowledge levels, and experimentally varied information are investigated.