The supply of environmental services from the multi-functionality of agriculture requires some forms of non-market valuation. The objective of the study is to estimate farmers’ willingness to accept to supply biodiversity conservation and carbon sequestration through agro-forestry and afforestation, based on a survey of 200 farmers in Barombi Mbo. The results indicate that almost all farmers perceive the importance of forest for climate regulation, flood control, erosion control, wildlife habitat, and as a spiritual site. A total of 85.5% of farmers express a positive willingness to accept (WTA) for afforestation programme, while some are willing to adopt agro-forestry. From the Tobit model results, variables age, origin, environmental sensitivity, awareness to payment for environmental services scheme and knowledge of bio-fertilizers significantly influence the WTA. The mean WTA for environmental services provision is up to 4,488 FCFA /year with a total cost of afforestation programme of 1,370,491 FCFA /year. With appropriate policy incentives, farmers could adopt these practices and contribute to the improvement of the environment.