1. ORGANISATION DE COOPÉRATION ET DE DEVELOPMENT ÉCONOMIQUES
OECD
OCDE
ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT
THE OECD EXPERIENCE OF CALCULATING AGRICULTURAL NUTRIENT BALANCES (Nitrogen and Phosphorus)
Kevin Parris, OECD
Trade and Agriculture Directorate
Joint Eurostat, OECD, EEA and JRC Workshop on Calculating Regional Gross Nutrient Balances
10-11 September 2007, Luxembourg 1
Directorate for Food, Agriculture, and Fisheries 1

3. Why is OECD developing a set of agri-environmental indicators (AEIs)?
Describing the current state and trends of environmental conditions in agriculture
Highlighting where ‘hot spots’ are emerging
Providing a tool to better explain the causes and effects of changes in environment
Comparing trends in performance across countries and in relation to environmental targets
Using indicators in policy analysis: monitoring, evaluation and projection scenarios

4. State of the Environment
What is coverage of indicators in Volume 4 (to be published January 2008, see handout)
Policies
Driving Forces
State of the Environment
30 OECD country reviews:
1. Policy context 2. Environmental trends (e.g. soils, nutrients, water, air, biodiversity) 3. Overall evaluation
Farm systems: organic
Soils: erosion
Water: quality and use
Farm practices: nutrients, pest, soil, water, biodiversity
Air: ammonia, ozone, GHGs
Farm input use, nutrients (N & P), pesticides, energy, water
Biodiversity: genetic, species, ecosystems

6. Policy Relevant – across OECD countries
Why calculate nutrient balances? (based on OECD indicator selection criteria)
Policy Relevant – across OECD countries
Water pollution (surface water, groundwater, marine water) high priority environmental issue with substantial economic cost to society, e.g. UK agri-water pollution 2003/4 €725M
Analytically Sound – science based
Methodology to calculate balance based on ‘sound’ science of nitrogen and phosphorus cycles, compared to fertiliser/ha
Measurable – data availability
Most primary data available annually, from farm to national level, to calculate balances across all 30 OECD countries
Easy to Interpret – unambiguous
An increase/decrease in balance surpluses indicates the potential for increasing/decreasing environmental pressure

7. Why has OECD/Eurostat chosen the gross nutrient balance methodology?
Based on initial discussions between OECD experts in mid/late 1990s, and proposal from Belgium
At this time a number of EU countries were already regularly calculating soil surface balances
Review of research literature reinforced choice of soil surface balance
After initial round of OECD balance estimates in Volume 3 (2001), expert peer review suggested OECD move from ‘net’ (soil and water loss) to ‘gross’ (soil, water and air loss) balance calculation

8. Main elements in the OECD gross nutrient balance calculation (nitrogen and phosphorous)
1. Applies to the nitrogen balance only.
2. Nutrients surplus to crop/pasture requirements are transported into the environment, potentially polluting soils, water and air, but a deficit of nutrients in soils can also occur to the detriment of soil fertility and crop productivity.

9. How are the nutrient balances estimated?: 1. Balance data collection
Annual data collected for all 30 OECD countries from 1990 to 2004
Data sources include:
Primary data, from national statistical agencies, but in a few cases where certain data series are absent, Eurostat and/or FAO sources are used
Nutrient conversion coefficients, for most countries national coefficient estimates are used, but for a few countries where an individual or no coefficients are available, OECD has estimated coefficients based on a similar country or group of countries (e.g. Greece)

10. How are the nutrient balances estimated. : 2
How are the nutrient balances estimated?: 2. Annual balance calculation
Each national balance (N & P) is compiled from 4 data sets:
Primary data:
Nutrient inputs --
Inorganic and organic (e.g. sewage sludge) fertilisers (tonnes)
Livestock numbers (head of live animals)
Quantities of seeds and planting materials (tonnes)
Area of legume crops (only N balance)
Nutrient outputs --
Harvested crops and forage production (tonnes of production)
Nutrient conversion coefficients for inputs and outputs
Primary data (1) multiplied by nutrient coefficients (2)
Calculation of balance: Inputs minus outputs (tonnes)

11. How are the nutrient balances estimated?:
3. Balance verification (up to present)
Peer review across OECD Member countries, both methodology and also data discrepancies
OECD Secretariat (with Eurostat/EEA), checking for:
consistency in use of methodology (e.g. inclusion of volatilisation in livestock manure coefficients);
primary data gaps and inconsistencies across data series 1990 to 2004;
inconsistencies of nutrient coefficients compared to other countries (i.e. higher/lower than OECD average) and correlation of dairy cow N manure coefficient with milk yield (not for P as correlation not applicable).

13. What are the key OECD results from the balance calculations: 1990 to 2004?
Overall reduction of OECD nutrient surpluses (tonnes) -4%N, -18%P, but greater decrease for EU15, -23%N and -39%P, but Portugal increased, also Hungary (N), Ireland (N), and Spain (P)
Most countries showing greatest surplus reduction also have above average intensity of use (kg N or P per ha), e.g. Belgium, Denmark, Lux., Netherlands
Nutrient use efficiency (ratio of outputs/inputs) has improved in most cases together with increasing adoption of nutrient management practices

15. Index 1990-92 = 100 Canada Hungary Ireland New Zealand Australia EU15
-50 50
100
150
200
250
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Index = 100
Canada
Hungary
Ireland
New Zealand 60 70 80 90
110
120
130
Australia
EU15
Japan
United States 20 40
140
Finland
Greece
Netherlands
Slovak Republic

16. Spatial distribution of the Polish nitrogen balance 2004

18. How can the nutrient balances be improved?: 1. Methodology
Extending national gross balance methodology to regional and river basin scale
Examining consistency in methods of nutrient coefficient calculations and improving coordination with other efforts, e.g. HELCOM (Baltic), OSPAR (North Sea), Gothenburg (ammonia), UNFCCC
Providing uncertainty estimates with balances
Including denitrification in balance
Examining how to reveal difference between dissolved and particulate P in soils in P balance

19. How can the nutrient balances be improved?: 2. Primary data
Ensuring data cover only agriculture (e.g. inorganic fertilisers)
Verifying that pig and poultry numbers reflect correctly annual production cycles
Checking for inconsistencies in agricultural land area data (e.g. total, arable and pasture areas) between different national and international sources

20. How can the nutrient balances be improved. : 3
How can the nutrient balances be improved?: 3. Nutrient coefficients and balance results
Variation in coefficients across countries and annual coefficients (livestock) used rarely (e.g. Netherlands)
Volatilisation accuracy and double counting
Uncertainty of nutrient uptake by harvested/grazed fodder crop and grass, e.g. DM, yields, consumption
Improve biological nitrogen fixation in pasture
Cross check trends in balance results with trends in other indicators, e.g. over for Italy, Norway, Spain the N balance declined but ammonia increased (can this be correct?)

21. Countries reporting (max. 30) Variable in Nitrogen Balance
Variation in selected national coefficients used in the OECD nitrogen balance
Countries reporting (max. 30)
Variable in Nitrogen Balance
Unit
Range of Coefficients 24
Fattening pigs >50kg
kgNmanure/head/year
7.0 – 18.6 23
Sheep (above 1 year)
7.0 – 22.0 27
Layers (poultry)
0.5 – 1.2 29
Barley (grain)
kgN/tonnes (DM)
14.8 – 28.0
Maize silage
2.6 – 15.6
Permanent pasture
4.6 – 40.0
Biological N Fixation: Pulses
kgN/hectare
40.0 – 176.0 26
Atmospheric deposition: on Pasture
2.7 – 46.5

22. How can the nutrient balances be improved. : 4
How can the nutrient balances be improved?: 4. Use in policy monitoring, evaluation, and projections
Integrating balance results into models linking agric. and env. policies to nutrient balances and environmental outcomes (i.e. water and air pollution)
Establishing policy baselines, threshold levels and targets from which to monitor progress
Converting physical balances into monetary values, for national accounting and economic analysis
Examining potential for balance projections

23. Linking data and tools/models for evaluation of environmental and economic outcomes
Current
PSE
Agri-environ. Policy Inventory
Agri-environ. Indicators
FAO data
Statistical
Methods
Simulation
(1)
SAPIM
(2)
PEM
(3)
AGLINK
(4)
GTAP
Economic
efficiency
Evaluation
Environmental
effectiveness
Tools/methods

24. What are the future plans for OECD work on nutrient balances, other agri-environmental indicators, and their use for policy analysis?
Seeking to regularly update core set of AEIs (including balances) from 2008 as part of annual OECD/Eurostat environmental data questionnaire
Making greater use of balances in agri-environmental modelling work
Working with member and non-member countries to establish/ improve balances (e.g. Romania, Spain)
Developing networks and coordination with other international org., e.g. Eurostat, EEA, JRC, FAO

26. THANK YOU
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