UKCEH report to SEPA. The aim of this study was to quantify key nitrogen flows for Scotland, bringing together the most
recent available data for soils, water, air and human consumption/production (with an emphasis
on agriculture, nutrition and waste). Losses of N to water (132 kt N yr-1), air (80 kt N yr-1) and
terrestrial systems (90 kt N through atmospheric deposition) estimated here are substantial, and
these are mainly due to agricultural activities and, to a smaller extent, waste
recycling/processing. Improved nutrient use efficiency is critical for delivering both
environmental and economic benefits. However, further work is required to complete currently
unquantified and uncertain flows and provide more detail on key activities, to enable the
development of policy options, in conjunction with SEPA’s Sector Plans
