Lack of formal security of land tenure is often cited as a constraint for participatory land management programmes which try to motivate African farmers to grow trees and to realize other improvements in their fields in order to control soil erosion. According to this approach, the borrowing of land would represent an insecure form of land tenure hindering sustainable land use. However, on the basis of a case study in Burkina Faso, this article demonstrates that this is not necessarily so: borrowing arrangements may play a part in avoiding local overload of the carrying capacity and in an efficient distribution of village lands among the farming units. Furthermore, borrowing does not hinder some major intensification techniques of land use which are currently being applied in Burkina Faso. Legal interventions which aim to increase security of tenure and to create favourable conditions for sustainable land use may in fact have the opposite effect.