Diversified Farming (DF) practices are strategies to support biodiversity in agricultural landscapes. Despite the potential ecological benefits of DF practices, their acceptance among farmers remains limited. Therefore, understanding farmer's perceptions is essential for effective policy decision-making and applicable agri-environmental policies. We conducted structured face-to-face interviews with 145 farmers in Lower Saxony to estimate the ecological-economic performance of DF practices based on farmers' perceived changes in yield, variable costs, and gross margin of cereal production. Farmers expected diversified crop rotation to increase gross margin (20%), while reduced tillage, direct seeding and flower strips would decrease it (58%, 61% and 13%). Cover crops were expected to provide ecological benefits with only slightly reduced profit (1%). Farm soil fertility was positively related to the perceived gross margin, while farmers' risk attitude and the number of DF practices applied showed no significant influence. Farmers working on mixed farms, i.e., integrating livestock and crops, expected lower variable costs than farmers working on arable farms. Our findings highlight that DF practices can be valued differently, with the greatest benefits seen in improved crop rotation. The acceptance of DF practices that farmers perceive as negative, such as reduced tillage and direct seeding, would require adapted agri-environmental incentives.