Floodplain nutrient and sediment dynamics on the Kent Stour

Floodplain land use is currently of concern. Agri-environmental policy favours grass over arable agriculture, while urban development is deemed unsuitable. The role of meadowland requires evaluation because it exhibits a potential to deliver environmental goods beyond flood detention and habitat creation; it has the potential to take up particular elements and trap sediment. This is particularly important where there is eutrophication of water from agriculture and wastewater and also physical degradation of the channel and floodplain. In this study, carbon (C), nitrogen and phosphorus (P) status and sediment deposition at typical locations on a southern English floodplain were investigated. It is concluded that C sequestration could be significant and there is sediment trapping during times of flood but further P accumulation in the topsoil of grazing land is limited. It is concluded that nutrient loading of the river from sewage effluent and from agriculture is best prevented at source.