New study : Two decades of organic amendments increase subsoil carbon at the QualiAgro long-term experiment

A new study published in Geoderma highlights the contribution of the QualiAgro long-term field experiment, part of the SOERE-PRO network and integrated into the AnaEE-France research infrastructure.

After 24 years of applying organic amendments such as composts and manure, researchers observed a significant increase in soil organic carbon (SOC) stocks not only in surface layers but also in the subsoil (down to 90 cm). The study shows that while belowground carbon inputs from crops play an important role, they cannot fully explain the observed carbon accumulation, suggesting that other mechanisms contribute to long-term carbon storage at depth.

These findings underline the importance of considering subsoil processes when assessing the impact of organic amendments on soil carbon sequestration and climate change mitigation.

DOI : https://doi-org.inee.bib.cnrs.fr/10.1016/j.geoderma.2025.117546