Tenure arrangements were studied in central Benin, with special attention to factors diminishing or enhancing mutual trust between landowners and migrant farmers. Two contrasting tenure arrangement systems occur. The first is found in Ouoghi village, where landowners and villagers are organized around the Association de Développement Economique et Social du Village de Ouoghi (ADESVO). The second is found in the Boubouhou area, where land tenure is managed by landowner lineages. In both systems migrants are not allowed to grow trees, for fear that this will strengthen migrants' ownership rights. Originally, migrant farmers were incorporated through a land-for-labour transaction. Nowadays, this practice has irretrievably changed due to the increasing importance of monetary transactions in agriculture and the presence of economic opportunities outside agriculture, which constrain labour availability. The problem to be overcome is how to change mutual perceptions of tree planting as a covert claim to land ownership, since agroforestry is a potential key to soil fertility maintenance. We facilitated alternative formal written-down land use rules, including adoption of agroforestry and improved soil management practices. Negotiation proved to be more complicated with landowners in Boubouhou because they did not want the existing bilateral relationships with migrants to be changed. But in Ouoghi migrants and owners had already created an institution for collective management of land, which allowed for better interaction and communication among the stakeholders. Here, it was easier to integrate technology components into formal tenurial arrangements. An attempt was made to build soil quality monitoring by scientists into the negotiation process.