1. Nitrogen pollution mapping at the European level ELPEN meeting, Udine, Italy 21-22 November 2002 Vincent Delaunay

2. Project organisation Produce a European map of sensitivity of ground and surface water to nitrate leaching using abiotic factors (soil, climate…) Produce nitrogen load balances in three European countries: Denmark, France and the Netherlands

3. Tree in ELPEN system NitrogenLeaching sensitvity EuropeBurns NetherlandsMetamodel SurplusOrganic nitrogen load Soil nitrogen balance

4. Tree in ELPEN system NitrogenLeaching sensitvity EuropeBurns Surplus Netherlands Organic nitrogen load Soil nitrogen balance Metamodel I. Nitrate leaching sensitivity map II. Nitrogen load: the Netherlands Not presented

5. I. Nitrate leaching sensitivity map 1. Application of Burns model, 1975 Example: the Netherlands 2. Burns results at the European level 3. Burns model limits II. Nitrogen load: Denmark, France, the Netherlands 1. Organic nitrogen load per hectare UAA 2. Nitrogen balance per hectare UAA Project organisation

6. I. Nitrate leaching sensitivity map 1. Application of Burns model, 1975 Example: the Netherlands 2. Burns results at the European level 3. Burns model limits II. Nitrogen load: Denmark, France, the Netherlands 1. Organic nitrogen load per hectare UAA 2. Nitrogen balance per hectare UAA Project organisation

7. Nitrogen surplus: SoilAtmosphere Water Run-Off Volatilisation (NH 3 ) Leaching Denitrification (N 2, NO 2 ) Nitrogen surplus Mineralisation I. Nitrate leaching sensitivity map

8. Major abiotic factors implicated in the definition of a leaching risk value for one area (available at the European level). Map of vulnerability for nitrogen pollution of ground and surface water Climat Precipitations, Evapotranspiration Soil Texture, Available Water Capacity, Depth, % of C Land cover Effect of different types of land uses (grassland, arable land…) I. Nitrate leaching sensitivity map

9. 1. Application of Burns model, 1975 f = (Ed / (Ed + Vm/100)) X f: leaching nitrogen fraction contained in soil This model permits to evaluate a leaching nitrate fraction on nitrate present in the soil, using soil and climate factor.

10. 1. Application of Burns model, 1975 f = (Ed / (Ed + Vm/100)) X f: leaching nitrogen fraction contained in soil Vm: defined using texture triangle and known Vm values Vm: percentage volumetric field capacity

11. Percentage volumetric field capacity (Vm) – The Netherlands

12. 1. Application of Burns model, 1975 f = (Ed / (Ed + Vm/100)) X f: fraction of nitrate leached X: in cm ; it is a factor that depends on the nitrate repartition considered in the soil. X: If we assume nitrate is initially incorporate uniformly to ploughing depth (w=25 cm) X = h – ½ w h: rooting depth Vm: percentage volumetric field capacity

13. Rooting Depth – The Netherlands

14. 1. Application of Burns model, 1975 f = (Ed / (Ed + Vm/100)) X f: fraction of nitrate leached Ed: Amount of water draining though the soil, calculated from climatic MARS data Ed = P – ETR P: Precipitation ETR: Evapotranspiration ETR = ½ ETP (bare soil in winter: Maxima Map) ETR = ETP (grassland: Minima Map) Soil Available Water for Plants (SWAP) considered empty at the end of August Vm: percentage volumetric field capacity

15. Soil Water Available for Plants – The Netherlands

16. Amount of water draining throuth the soil (Ed) – The Netherlands The soil is satured with water available for the plants (SWAP) Minima Maxima

17. 1. Application of Burns model, 1975 f = (Ed / (Ed + Vm/100)) X f: fraction of nitrate leached Ed: Amount of water draining though the soil, calculated from climatic MARS data Ed = P – ETR X: in cm ; it is a factor that depends on the nitrate repartition considered in the soil. Vm: percentage volumetric field capacity

18. Nitrate leaching sensitivity (Burns fraction) – The Netherlands Minima Maxima Very strong Strong Medium Weak Sensibility

19. 2. Burns results at the european level Nitrate leaching sensitivity (Burns fraction) – Europe Very strong Strong Medium Weak Sensibility Minima

20. 2. Burns results at the european level Very strong Strong Medium Weak Sensibility Maxima Nitrate leaching sensitivity (Burns fraction) – Europe

21. 3. Burns model limits Do not apply Burns model when: there is important denitrification (wet area, weak ground water depth) there are slopes (moutains, hill) there is important mineralisation (soil with high contens of organic matter) (need to be done)

22. Important denitrification (wet area, weak ground water depth) - Europe

23. Slopes (moutains, hill) - Europe

24. Important denitrification and slopes - Europe

25. Distinction of large sensitive areas Extention to the European level Extrapolation limits: Model validity Validation by meseares I. Nitrate leaching sensitivity map

26. Tree in ELPEN system NitrogenLeaching sensitvity EuropeBurns Surplus Netherlands Organic nitrogen load Soil nitrogen balance Metamodel

27. Tree in ELPEN system BurnsInput Rooting depth SWAP Vm Ed (Edmax, Edmin) Result fmax fmin Limitation Burns Slope Denitrification Mineralisation (need to be done) Corrected fmax (not presented) Corrected fmin (not presented) Validation Burns Need to be done

28. I. Nitrate leaching sensitivity map 1. Application of Burns model, 1975 Example: the Netherlands 2. Burns results at the European level 3. Burns model limits II. Nitrogen load: Denmark, France, the Netherlands 1. Organic nitrogen load per hectare UAA 2. Nitrogen balance per hectare UAA Project organisation

29. II. Nitrogen load 1. Organic nitrogen load per hectare UAA Evaluation of the organic presure at national level. Used data: Agricultural census at community level Estimation of spread of nitrogen quantity produced per animal and per year: CoefA

30. 1. Organic nitrogen load per hectare UAA Calculated with national, then French coefficients ONL = OF / UAA ONL: Organic Nitrogen Load OF: Organic fertilisation OF = CoefA x Number of animals

31. Organic nitrogen load per ha - Dutch coefficients Organic nitrogen load per ha - French coefficients

32. Organic nitrogen load per ha - West of France Organic nitrogen load per ha - French coefficients - Danemark

33. 1.Organic nitrogen load per hectare UAA To show large livestock area Livestock density comparison between the different European countries Use estimation of spread nitrogen quantity and national agricultural census Different estimation of spread nitrogen quantity per countries ? Difference in type of area used per countries ? Discussion about the standard: 170 kg organic N par hectare (Nitrate Directive)

34. 2. Nitrogen balance per hectare UAA COMMUNITY Inputs: Organic Fertilisation (OF) Mineral Fertilisation (MF) Outputs: Harvested arable crops (HAC) Crops used for fodder (CF) Balance = ( OF + MF ) – ( HAC + CF ) Global balance taking agricultural nitrogen at the canton « canton » level into account.

35. 2. Nitrogen balance per hectare UAA Balance = (OF + MF) – ( Outputs ) Mineral Fertilisation MF : Mineral Fertilisation  Regional fertilisers purchase desagregation at the community level Organic Fertilisation OF = CoefA x Number of animals

36. 2. Nitrogen balance per hectare UAA Balance = (OF + MF) – (HAC + CF) Harvested arable crops HAC = Coef x Yield x Area Crops used for fodder : Grazing livestock demand estimation Maize yield (and Alfalfa yield evalution)  Assessment of grazing grassland and grass for fodder yield Crops used for fodder

37. 2. Nitrogen balance per hectare UAA Calculated with French coefficients Mineral Fertilisation Organic Fertilisation Balance = (OF + MF) – (HAC + CF) Harvested arable crops Crops used for fodder

38. Nitrogen balance per hectare UAA – French coefficients

39. Nitrogen balance per hectare UAA – West of France Nitrogen balance per hectare UAA – French coefficients - Danemark

40. 2. Nitrogen balance per hectare UAA Nitrogen balance comparable between different countries Weak reliability of certain parameters: Mineral fertilisation Crops used for fodder Results largely depending on parameters choices

41. Tree in ELPEN system NitrogenLeaching sensitvity EuropeBurns Surplus Netherlands Organic nitrogen load Soil nitrogen balance Metamodel

42. Three risk indicators linked to the agricultural nitrogen: Nitrate leaching sensitivity (Burns fraction) Organic nitrogen load per hectare UAA Nitrogen balance per hectare UAA Next work: Indicators validation Indicators relation (to know statiscal link between them) Comparison with real nitrogen pollution (field)data Conclusion

43. Thank you for your attention