Nitrogen biogeochemistry of water-agro-food systems: the example of the Seine land-to-sea continuum

As an illustration of the usefulness concept water-agro-food systems, this paper describes mechanisms behind nitrogen cascade from agricultural soils to coastal sea rivers through aquifers, riparian wetlands, and streams estuary, for case study Seine river watershed its receiving sea. It is stressed that structure agro-food system, i.e. way food production trade, as well consumption waste management are organized, main determinant quality ground- surface water aquatic ecosystem functioning.