National-scale field delineation in Mozambique refines our understanding of cropland distribution, field size, and deforestation actors

Abstract The design of science-based policies to improve the sustainability of smallholder agriculture is challenged by a limited understanding of fundamental system properties, such as the spatial distribution of active cropland and field size. We integrate 1.5 m resolution satellite imagery, satellite embeddings, and deep learning to map individual fields in complex smallholder systems at policy-relevant scale. We identify 17 million fields across Mozambique for the target year 2023, reflecting the cropland distribution but also pointing to previously uncaptured agricultural regions located in agricultural frontier regions which host 5%–9% of the Mozambican population. Field size in Mozambique is low overall, with half of the fields being smaller than 0.2 ha, and 78% smaller than 0.5 ha. Field size varies with accessibility, population density, and forest cover change, suggesting the presence of diverse actors, including semi-subsistence smallholder farms, medium-scale commercial farms, and large-scale farming operations. Our results suggest that field size is a key indicator relating to the socio-economic and environmental outcomes of agriculture and their trade-offs.