Long-term activity of social insects responsible for the physical fertility of soils in the tropics.

Ferralsols correspond to the red and yellow soils that are common in the tropics. They are deeply weathered but physical fertility is high because they exhibit a strong microgranular structure whose origin is still actively debated. In the present study, we looked for evidence of the biological origin of the structure resulting from soil fauna activity.

Allochthonous material originating from saprolite as a marker of termite activity in Ferralsols.

Ferralsols, which are estimated to cover 7.5 millions km worldwide, are deeply weathered red or yellow soils found in the humid tropics. They are considered as the end of a geochemical sequence of weathering and are dominated by low-activity clay and sesquioxides.