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

Abstract

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