Assessing scenarios on the nitrogen cascade in rural landscapes and territorial modelling – ESCAPADE

The project aims at assessing the impact of agricultural activities and of the landscape mosaic in the nitrogen cascade in the territories. To meet this objective, scenarios of nitrogen management are built at the conventional scales of the plot (shapes, quantities and dates of nitrogen inputs ...), of farming (crop sequences, herd management and waste ...) and also at the original scale of territories (structuring of the landscape, spatial planning ...). Models incorporating the nitrogen cascade process are developed to simulate the flow, balance sheets and nitrogen losses in areas of varying sizes, mostly areas of a few km2 , but also larger areas of hundreds to thousands km2. Three experimental sites, followed by long and complementary in their agro-pedo-climatic conditions, are used to assess the ability of models to simulate the flow of nitrogen.

The expected results are: i) the generation, evaluation and interpretation of scenarios for nitrogen management in the territories, ii) the production of knowledge and reliable tools (models, databases) to quantify stages of the nitrogen cascade in the territories, iii) strengthening interdisciplinary partnerships between research and development on this topic giving an international visibility to this community, iv) the co-construction of innovative solutions to reduce nitrogen losses in the environment or adapt production systems.

Many levers of nitrogen management exist across territories: nitrogen management by the farmer / rancher in consultation with the government, preservation of sensitive areas, landscape schemes such as hedges, ditches ... The produced knowledge and tools at this scale can also be used to assess the cumulative effect of the actions taken in small areas on the flow and nitrogen losses in larger territories.

The project began six months ago. It has not led to scientific productions or patents yet. According to the progress of the project, dissemination of results to farmers will particularly involve technical institutes and cooperative partners of the project.

The agricultural production model is undergoing a major change to reduce nitrogen inputs, while maintaining productivity. This change can not happen without technical and organizational innovations. In particular, the levers must account for the organization of agricultural and livestock activities across territories. In this context, the ESCAPADE project is proposed by teams of complementary research areas (biogeochemistry, atmospheric and hydrological transfers, agronomy, socio-economics, mathematics), including the actors involved in agricultural research and those involved in development. The objective of this project is to find innovative strategies at the territory scale, complementing usual approaches at plot and farm scales. Those strategies aim at optimizing the use of nitrogen at landscape and territory scales, reducing nitrogen losses to the environment, and thus preserving sustainable agro-ecosystems while maintaining the productivity of production systems. With this aim in view, scenarios will be co-constructed in relation to nitrogen management within fields (forms, amounts and application dates of nitrogen inputs...) and farms (crop rotations, livestock and manure management...) as well as landscape management (by modifying the landscape structure). Scenarios will be evaluated by using models developed at different spatial scales, focusing on models that integrate the processes of the nitrogen cascade across landscapes (typical size of 5 to 30 km2). Scenarios will be assessed from environmental, agronomical and socio-economical points of view. Dissemination of results to farmers will be made through technical institutes and cooperative partners involved in the project.