Beyond expansion: Bottom-line thinking for sustainable farmland in global drylands

Across the world’s drylands, farmland expansion has long been promoted as a pathway to food security. Yet in regions characterized by shallow soils, water scarcity, and fragile ecosystems, expansion often intensifies systemic vulnerability. This paper develops a bottom-line governance framework that translates ecological, resource, and socio-economic limits into decision boundaries for dryland agriculture. It highlights the asymmetry between expansion driven by policy and market incentives and contraction shaped by climatic stress, demographic change, and declining ecological viability. A three-tier bottom-line model is proposed, distinguishing ecological integrity, sustainable resource use, and livelihood stability as analytically distinct yet interdependent constraints. The analysis further clarifies how trade-offs among these bottom lines should be sequenced under climate pressure and identifies differentiated institutional pathways for operationalizing bottom-line governance across contrasting governance contexts. Sustainable land management in drylands therefore depends not on expanding cultivated area, but on recognizing limits and internalizing them ex ante within land-use decision-making.