Biochar, when used as soil amendment, could enhance soil health, plant growth, and farm profitability while offsetting adverse effects of environmental pollution. Yet the adoption rate of biochar among agricultural producers remains extremely low. Message framing has been shown to play an important role in forming positive attitudes and generating desirable outcomes. To understand the effect of message framing in promoting biochar, we conducted a randomized experiment through an online survey of crop producers located in Eastern South Dakota. The results showed that participants who read a message about the benefits of adopting biochar from an economic perspective expressed higher interest in learning about biochar; no such effect was observed among participants who read a message about the benefits of adopting biochar from a stewardship perspective. Compared with the control group, economic and stewardship frames increased farmers’ likelihood of adopting biochar in the next 5 years, by 10.6% and 10.8%, respectively. Our findings illustrate the importance of message framing in encouraging farmers to adopt conservation practices that are rarely used. To promote future adoption of conservation practices such as biochar, it is important to highlight both economic and stewardship benefits when conveying information to farmers.