In the framework of the Unit’s research project (Project Sol'Hyd'Air - 2012-2015), we study the interactions between the soil’s physical properties (structure, hydraulic properties...) and it’s hydrologic (runoff, infiltration) and biogeochemical functioning (denitrification) under changing climatic and anthropic conditions.

The main research questions addressed in this project are related to:

• The knowledge of soil properties considered in their diversity
• Mechanistic description of processes related to soil functioning
• The study of these processes’ determinism
• The study of Interactions/Feedbacks between processes
• The spatial modeling of soil functioning.

They are declined as follows:

Our work contributes to

• A better soil conservation:
  Water erosion is one of the threats to soils. We develop work to better understand the factors that promote erosion. We are particularly interested:
  • in crusting in connection with the splash. For this purpose we use in particular the rainfall simulation hall;
  • on the effect of the surface roughness on the runoff flow paths. Our preferred tool here is physically based numerical simulation;
  • in the soil’s resistance to erosion (erodibility) using mainly structural stability tests;
  • on the interaction between these phenomena across the small watershed by expert numerical simulation. This approach also allows us to estimate soil sustainability facing global change.

• A better management of the water resource:
  Soils support nutrient and water supply to crops, but also participate in the groundwater recharge.
  • We develop work to characterize the hydrologic functioning of soils at different scales.
  • We analyze the role of changes to the soil structure due to crop rotation on the soil’s Available Water Capacity (RURAC project) and we characterize the variability of soil hydraulic properties at the plot scale to contribute to the proposed agricultural practices that balance agronomic performance and environmental protection (AQUATEAM project).
  • We develop pedotransfer functions for estimating the soil’s Available Water Capacity over large areas, including the contribution of the soils’ stony phase in an original way.
     
• The protection of the air quality:
  Soils are involved in the greenhouse gas N2O cycle. We develop work
  • to quantify (INGOS project) direct and indirect N2O emissions from soils (ESCAPADE and INDIGES projects);
  • to understand the determinism of the functioning of biological processes involved in the cycle of N2O by physical (HYDROGES project) and/or physico-chemical properties of soils (SOLGES project);
  • and to simulate N2O emissions from soils.
  • We create ecological engineering techniques to reduce N2O emissions from soils (SOLGES and PUIGES projects).