Abstract: Land management is vital for agricultural production and ecosystem service maintenance to mitigate the effects of climate change. This is particularly important in regions with higher proportions of sloping land, where degradation is more prevalent. The mountainous northwest of Vietnam provides a salient example of an area with sloping and highly degraded soils. This article employed data envelopment analysis to investigate the effect of sustainable land management practices on efficiency and yield in the cultivation of oranges. Determinants of production efficiency and the interaction between efficiency and yield were also analyzed. Results indicate that 130 out of the studied 174 groves are not operating at optimal efficiency levels and that most producers would benefit by increasing their scale of production. Furthermore, the adoption of sustainable land management was found to improve production efficiency and yield both positively and significantly. Finally, the production efficiency of orange groves is positively affected by the ethnicity of the head of the farming household, access to extension services, and the degree of sustainable land management adoption. Farming households headed by members with higher levels of education and more farming experience were also found to significantly contribute to scale efficiency.