Two decades of tropical soil analyses for a better understanding of soil organic carbon

Soil organic carbon is essential for soil fertility, water retention and nutrient storage. Although crucial for climate regulation and food security, tropical soils remain insufficiently documented. The DATA4C database includes 31,980 soil samples collected in 58 countries in tropical regions between 2002 and 2022. Each sample could be characterised by 41 variables covering the soil's physical and chemical properties, such as texture, pH, carbon and nitrogen content, and cation exchange capacity. These samples were analysed in an ISO 9001-certified laboratory according to standardised protocols. The data has been validated and harmonised over two decades. DATA4C is a valuable resource for modelling tools, agricultural and environmental planning, and the monitoring and assessment of tropical soils. Its aim is to facilitate the reuse of data in various scientific and operational contexts.