Soil Organic Carbon in Mainland Southeast Asia: Threats, Strategies, and Research Priorities for Sustainable Land Management

This paper investigates the critical role of soil organic carbon (SOC) in sustaining agricultural and environmental systems across Southeast Asia, with a focus on Vietnam, Lao PDR, Cambodia, and Thailand. SOC is fundamental to soil fertility, agricultural productivity, and climate change mitigation, yet its stocks are increasingly threatened by deforestation, unsustainable land-use practices, soil erosion, and the intensifying impacts of climate change. Through a literature-based review, we assess both the direct and indirect pressures on SOC and evaluate the different national strategies aimed at soil protection and the enhancement of carbon sequestration. By systematically comparing global and national soil carbon datasets, we reveal significant discrepancies and data gaps between global SOC maps provided by FAO platform with national datasets, underscoring the necessity for improved regional coordination. Our review also demonstrates a need for strengthened collaboration in monitoring, reporting, validation, and data sharing to better understand the spatial and temporal variability of soil carbon stocks. Finally, a targeted survey among scientists was conducted in the region, and allowed identifying key research priorities and barriers to effective SOC management. Based on these findings, we propose a collaborative framework designed to foster knowledge exchange and joint action to promote sustainable land management and climate resilience in the region.