Establishing a Scottish Nitrogen Balance Sheet

Footnotes

1 European Nitrogen Assessment (2011)

2 Scottish Government consultation on the SNBS: analysis report (2021)

3 A nitrogen budget for Scotland (2019) UKCEH report to SEPA

4 OECD (2013) paper: Economy-wide nitrogen balances and indicators – concepts and methodology.

5 EU Nitrogen Expert Panel web pages

6 Published on the Scottish Government website alongside this report.

7 This figure includes wool production (0.8 kt N / yr).

8 Carnell et al. (2021) Atmospheric modelling data for Scottish Nitrogen Balance Sheet. UKCEH Report for the Scottish Government.

9 Carnell et al. (2021) Atmospheric modelling data for Scottish Nitrogen Balance Sheet. UKCEH Report for the Scottish Government

10 National Focal Centre Trends report (2021) Trends in critical load and critical level exceedances in the UK.

11 Bell et al. (2021) Regional freshwater nitrogen budgets for Scotland. UKCEH Report for the Scottish Government

12 Scottish Pollution Release Inventory SEPA online database

13 Scotland’s Aquaculture website

14 Scotland’s Marine Assessment 2020

15 There is further run-off and leaching from other land uses, such as forestry and terrestrial ecosystems, estimated at 18 kt N / yr. This adds up to a total of 122 kt N / yr from run-off and leaching from all land uses, as summarised in Figure 1.

16 UK National Atmospheric Emission Inventory and GHG Inventory: Online database

17 Bell et al. (2021) Regional freshwater nitrogen budgets for Scotland. UKCEH Report for the Scottish Government

18 Materials to land assessment (2020) report to SEPA

19 Scotland’s Aquaculture website

20 Scottish Energy Statistics Hub website

21 Within the national emission inventory structure these losses are recorded as being from the agriculture sector and are hence included (for the purpose of Figure 1) in the 19 kt N / yr of atmospheric emissions from crop and grass production.

22 National Focal Centre Trends report (2021) Trends in critical load and critical level exceedances in the UK.

23 Bell et al. (2021) Regional freshwater nitrogen budgets for Scotland. UKCEH Report for the Scottish Government

24 Lassaletta et al. (2014) 50 year trends in nitrogen use efficiency of world cropping systems: the relationship between yield and nitrogen input to cropland. Environmental Research Letters 9:105011.

25 When compared with Table 1 figures above for crop production (with 58 kt N / yr useful output), the apparently smaller total useful output shown here for whole-agriculture (55 kt N / yr) is related to a substantial proportion of the outputs becoming recycling terms at this scale of NUE calculation. For example, in the whole-agriculture system, crops grown specifically as livestock feed (including human-edible crops such as cereals fed to livestock) are removed from the output side of the NUE equation, in the same way as manures are removed from the input side.

26 The baseline data set out in Table 3 is mainly for 2019, but - as explained in Chapter 2 - this should be understood as reflecting the most up to date information available as of November 2021.

27 The data necessary to quantify the amounts of nitrogen in materials imported and exported do not currently exist in sufficient detail and quality. See Annex A for further information.

28 For the purpose of a whole-economy NUE calculation, fisheries are recorded as both an input to the economy (i.e. fish landed in Scotland) and a useful output (as they will be used as foodstuffs).

29 OECD (2013) paper: Economy-wide nitrogen balances and indicators – concepts and methodology.

30 Securing a green recovery on a path to net zero: the Climate Change Plan 2018–2032 update

31 Cleaner Air for Scotland 2 - Towards a Better Place for Everyone Scotland’s new air quality strategy

32 The UK Forestry Standard (UKFS) The governments’ approach to sustainable forestry

33 UN ECE (2013) Guidance document on national nitrogen budgets

34 UN ECE Task Force on Reactive Nitrogen (TFRN): Expert Panel on Nitrogen Budgets (EPNB) webpages

35 UN ECE (2021) Guidance document on national nitrogen budgets: draft detailed annexes.

36 European Commission EUROSTAT (2013) Methodology and Handbook Eurostat/OECD Nutrient Budgets.

37 Reactive nitrogen flows in Germany 2010 - 2014 (2020) report

38 Also referred to as atomic number – see for example Periodic Table of Elements - PubChem (nih.gov): select “atomic number” as display property

39 Material Flow Accounts for Scotland (2021) Report and data by Zero Waste Scotland

40 Leinonen et al. (2019) Applying a process-based livestock model to predict spatial variation in agricultural nutrient flows in Scotland. Journal of Cleaner Production 209:180-189.

41 Material Flow Accounts for Scotland (2021) Report and data by Zero Waste Scotland

42 Bell et al. (2021) Regional freshwater nitrogen budgets for Scotland. UKCEH Report for the Scottish Government

43 N.B. the data for the sub-basins include areas of England in the Solway and Tweed catchments. These have been adjusted for the SNBS outputs in the main report, where all data refer to Scotland’s territorial boundaries. For example, the Tweed catchment does not flow directly from Scotland into coastal waters, but hydrological flows are exported across the border to England, from where they then flow into England’s coastal waters.