The Environmental Impact of Fertilisers on Freshwater

Fertilisers drive the productive potential of land, but inefficient use can cause issues such as the impairment of freshwater quality. This chapter outlines our current understanding of nitrogen (N) and phosphorus (P) use efficiency by crops, factors involved in the loss of N and P from land and the likely impact on freshwaters (surface and ground). This understanding is then combined with knowledge on the range and cost-effectiveness of strategies to mitigate losses and the associated implementation pathways (e.g. voluntary or regulatory instruments) to meet a water quality target. We end with some thoughts on where additional research is best focused to reduce the environmental impact of fertilisers on freshwater.