S29

Sustainable water management in agricultural areas
Convener: Jérôme Molénat | Co-Conveners: Delphine Leenhardt, Rim Zitouna Chebbi, Fernando Nardi, Christophe Cudennec

Agriculture in the 21st century has been challenging the need of increasing production to supply food of a growing world population, in a context of climate change and increased pressure on resources, particularly water resources. Within a territory, the agricultural and hydrological systems are in strong interaction and co-evolve. On the one hand, agricultural production is dependent on water availability. On the other hand, agricultural activities can exert significant pressure on water resources through withdrawals, particularly for irrigation. The use of agricultural inputs (pesticides, fertilizers) or unconventional water (treated wastewater, brackish water, etc.) also poses health and environmental risks to aquatic ecosystems. Finally, the agricultural use of water comes into conflict with ecological, industrial or domestic uses in certain territories.
In this context, agroecology is promoted worldwide to contribute to food production and security, and also to preserve or restore natural resources, such as water, and ecosystems, including aquatic ecosystems. Agroecology takes advantage inter alia of diversities, plant or crop diversities and diversities of knowledge for example. It is based on a detailed knowledge of each context, and in particular of the hydrological processes and fluxes of catchment.
Along with agroecology, the emergence of the water-food-energy (WEF) nexus over the last ten years recognizes the strong interactions of these three components and the need to develop integrated approaches involving the agricultural, water management and energy sectors. The territory is then considered as a level of biophysical, social and economic organization to operate management strategy. The nexus is particularly used to reformulate and even rethink problems and solutions for the management of irrigated agriculture, which increases yields, withdrawals large volumes of water and consumes electrical energy to power the pumping and water distribution systems
In this session, we invite contributions on the following topics:
• understanding, evaluating and increasing water use efficiency at the catchment scale in a context of climate change. In this regard, the interest and the role of agroecological solutions, such as the reasoning of the choice of crops, the spatial organization of cropping systems, or water conservation practices (tillage, bench) have to be considered, along with the added value of climate services;
• understanding the interactions between biogeochemical cycles, agriculture and water resources in order to identify agroecological solutions maintaining agricultural production and preserving water resource and aquatic environment;
• identifying and evaluating, particularly in relation to the wef nexus and climate, the interest of alternative water resources (treated wastewater, brackish water, etc.) or in terms of water storage or supply infrastructure (water reservoirs, small channels, etc.);
• how to accompany the agro-ecological transition, particularly in terms of decisions and changes impacting water resources (choice and spatial organization of cropping systems, choice of infrastructure and type of water for irrigation, landscaping, etc.)?
• studying the conflicts of uses, between agricultural water uses and other uses, within the territories and investigating the knowledge and cultural gaps that avoid the transitioning to fair and sustainable allocation of water resources among competing sectors following a WEF nexus approach. What are the origins of these conflicts? How can they be arbitrated? Which are the major barriers (technological, social, cultural, economic, etc.) that avoid the embracing of the multiple benefits of WEF nexus strategies;
• investigating the role of citizen and stakeholder engagement in support of agroecological sustainability and in promoting mutual trust among the multiple actors that govern water and natural resource management strategies in agricultural areas. Which are the value and trade-offs characterizing the implementation of participatory approaches and citizen science for sustainable water management in agricultural areas?