ICID 2026: INRAE research for more resilient agriculture in the face of water constraints

1. In the face of climate change, how can irrigation and drainage contribute to the agroecological transition? 

Crops are increasingly exposed to water shortages as global warming intensifies. Irrigation can help sustain certain types of production when soil water reserves become insufficient, but adaptation also depends on other approaches, particularly crop selection and agronomic practices.

Research at INRAE explores ways to make agriculture less vulnerable to drought. These include selecting suitable crop species and varieties, as well as practices that influence the capacity of soils to absorb and retain water. Cover crops, crop rotations, reduced tillage and agroforestry do not have the same effects everywhere, but can alter how water moves through and is stored in soils.

These changes are also prompting us to reconsider the role of irrigation itself. The TAI-OCC project in Occitanie is exploring the concept of multi-purpose irrigation. Rather than being supplied solely to support agricultural production directly, water can also be used to establish trees, cover crops or other plants that contribute to agroecosystem functioning.

Further reading 
How can agriculture adapt to increasingly dry summers? (in French). This article explores the issue with specialists Juan David Dominguez Bohorquez, Delphine Leenhardt, Lionel Alletto and Sami Bouarfa.

2. Innovative technology and practices for increasing water use efficiency. Irrigation management and services, remote sensing, irrigation equipment. Where do we stand?

The second ICID question focuses on technologies used in irrigated agriculture. Beyond their technical performance, the congress will examine their capacity to change practices. At INRAE, this research combines modelling, decision support and digital agriculture to adapt irrigation decisions to crop needs and available water.

Remote sensing offers new opportunities to observe water resources on a large scale and better monitor changes over time. It is one of the approaches used by One Water Vision, an international initiative launched in 2024 that brings together more than 20 scientific institutions, with INRAE providing the secretariat for the international research consortium. The initiative draws on the SWOT satellite, launched in 2022, which provides unprecedented observations of surface waters. In time, it will also draw on TRISHNA, a Franco-Indian satellite mission still under development and scheduled for launch in 2027. TRISHNA will offer unprecedented spatial resolution and observation frequency for monitoring vegetation evapotranspiration and water stress. INRAE researchers have contributed to the development of both missions, particularly to estimating river discharge using SWOT data and to methods linking land surface temperature to evapotranspiration for TRISHNA. One Water Vision combines these data with field measurements and modelling to improve water-resource monitoring and provide actionable information for those responsible for managing water.

COSTEA, several events focusing on agricultural water

The Scientific and Technical Committee on Agricultural Water (COSTEA) focuses on farm water and irrigation. Established with support from the Agence Française de Développement (AFD) and implemented by EAT, it brings together researchers, public authorities, professionals and civil-society organisations from different countries. Its work covers, among other topics, agroecology, irrigated systems, treated wastewater reuse and the impacts of climate change.

INRAE is directly involved in its governance. Sami Bouarfa is COSTEA project director in its Permanent Technical Secretariat. He also plays a role in the scientific preparation of ICID 2026, chairing the scientific committee of the French host national committee on Water, Agriculture and Territories.

3. Non-conventional water resources (REUSE, desalination): can we really loosen the grip on water resources, and for what uses?

INRAE has been studying treated wastewater reuse for several years. Several experimental facilities now make it possible to examine the conditions for its use in real-world settings. The questions studied include additional water treatment, crop irrigation and the fate of contaminants.

Reusing treated wastewater for irrigation can avoid withdrawing an equivalent volume of water from a river or aquifer, but this benefit is not automatic. After treatment, this water is often discharged into the natural environment, where it contributes to river flows and may be used further downstream. INRAE research therefore aims to establish the actual water balance of treated wastewater reuse at the scale of a territory. What types of extractions are avoided? How much water is not returned to the environment? And which other uses or ecosystems depend on that water? Reuse can be appropriate, but its benefits depend heavily on local hydrological conditions and on how water already circulates between different uses.

Further reading 
The second life of our wastewater (in French) - an INRAE dossier on wastewater treatment and reuse, coordinated by Nassim Ait Mouheb, Jérôme Harmand, Rémi Lombard-Latune and Jean-Philippe Steyer.