Subject terms
SECONDARY
Since the 1960s, the increased availability of modern seed varieties in developing countries has had large positive effects on households’ well-being. However, the effect of related land use changes on deforestation and biodiversity is ambiguous. This study examines this question through a randomized control trial in a remote area in the Congo Basin rainforest with weak input and output markets. Using plot-level data on land conversion combined with remote sensing data, we find that promotion of modern seed varieties did not lead to an increase in overall deforestation by small farmers. However, farmers cleared more primary forest and less secondary forest. We attribute this to the increased demand for nitrogen required by the use of some modern seed varieties, and to the lack of alternative sources of soil nutrients, which induced farmers to shift towards cultivation of land cleared in primary forest. Unless combined with interventions to maintain soil fertility, policies to promote modern seed varieties may come at the cost of important losses in biodiversity.Availability of modern seed varieties in developing countries has had positive effects on households’ well-being. Here, the authors show that without support to maintain soil fertility, access to modern seed varieties increases primary forest clearance in DR Congo.