L'évaluation environnementale des agrosystèmes: une approche intégrée pour gérer les risques agri-environnementaux

1. L'évaluation environnementale des agrosystèmes:une approche intégrée pour gérer les risques agri-environnementaux

2. 4.0 Bio-fuels in Europe Directive 2003/30 EC 2010 2050 Context - 1 • A growing demand for agricultural produce... (109 tonnes) Tilman et al., Agricultural sustainability and intensive production practices, Nature 418: 671-677, 2002

3. Context - 2 • ...currently met with increased reliance on exogenous inputs... b: total global use of N and P fertilisers, and area of irrigated land c: global pesticide production and imports (Tilman et al., 2002)

4. Context - 3 • ...albeit with decreasing marginal efficiency (Tilman et al., 2002) “Pest control methods with a potential efficiency of 100% raise an issue of durability for agricultural practices [...] similarly to the problem of antibiotics becoming less effective in medicine.” (INRA-Cemagref, Joint expertise report on Pesticides, Agriculture and the Environment, 2005)

5. Context - 4 • Agriculture is being pointed out as a major source of negative environmental impacts IFEN, 6th report on water quality in France (2004)

6. Context - 5 • Potential impacts from agriculture Air pollution Acidification CO2 Global warming Fertilizers (N) Pesticides N2O, NO, NH3, Pesticides Soil organic matter Sol NO3 Pesticides Groundwater Eutrophication Ecotoxicity

7. An unresolvable quandary ? • Humans have made unprecedented change to ecosystems in recent decades to meet growing demands for food, fresh water, fibre and energy. • Various techniques being used increasingly in various parts of the world allow [...] productive use of land while keeping favorable conditions for nature. • The approach taken by the Millenium Ecosystem assessment could provide a useful tool to enable decision-makers to understand far better the full consequences of their action. MILLENIUM ECOSYSTEM ASSESSMENT – UN Living beyond our means: natural assets and human well-being – Statement of the Board

8. Methodology for environmental assessment • Need for integrated assessment, across • Compounds and environmental compartments • Elementary parts of a production chain • Time • A spatial territory relevant to the production or environmental issue at stake • To avoid or manage trade-offs between • Environmental issues • Geographical locations • Generations !

9. Managing a production chain versus a territory ?

10. Outputs: CO2, CH4, NOx NO3-, N20... Pesticides Products et co-products Inputs: Renewable carbon Fertilizers Pesticides Fossile carbon Other fossile resources The 'functional' side: life cycle assessment (LCA) LCA, a conceptual framework to address environmental impacts from the 'cradle to the grave' In agriculture, LCA was applied to waste management, cropping systems analysis, and bio-energy chains.

11. Estimation of fluxes Input X Input X Industry Agriculture Perturbations E = f(soil, climate , managt, X) Indirect emissions E = a X +/-  Direct emissions E within several orders of magnitude! Emissions Outputs Inputs

12. Capturing the spatial variability of field emissions Simulation of N2O fluxes in the Beauce region (fluxes in kg N2O-N/ha/yr) Gabrielle, Laville, et al. (submitted to Global Biogeochem. Cycles)

13. Environmental balance models – example of CERES Atmosphere PLANT PROCESSES • Phenology • Ressource capture • Partitioning • Senescence CO2, N2O, NH3, NO SOIL TRANSFERS • Heat (Fourier) • Water (Tipping bucket) • Nitrate (Convective) mineral N organic N C-N BIOTRANSFORMATIONS Mineralisation - Immobilisation Nitrification - Denitrification Soil Groundwater crop residues absorption drainage, nitrate leaching

14. Challenges wihtin the modelling loop Integration into model; calibration Module selection detailed Extrapolation Process analysis Experiments lighter Model application

15. Challenges wihtin the modelling loop Integration into model; calibration Module selection detailed Extrapolation Process analysis Experiments lighter Model application

16. Integration of nitrous oxide emissions --- Simulated o Observed Haplic calcisol Redoxic luvisol Haplic luvisol Simulation by CERES with two different N2O emission modules Gabrielle, Laville, et al., Nutr. Cycling Agroecosys. (in the press)

17. Challenges wihtin the modelling loop Integration into model; calibration Module selection detailed Extrapolation Process analysis Experiments lighter Model application

18. The 'eco-balance' experiment

19. Challenges wihtin the modelling loop Integration into model; calibration Module selection detailed Extrapolation Process analysis Experiments lighter Model application

20. Extrapolation to new sets of soils and climates

21. Challenges wihtin the modelling loop Integration into model; calibration Module selection detailed Extrapolation Process analysis Experiments lighter Model application

22. Model application: scenario analysis Emissions in g N per tonne of wheat grain produced Oilseed rape / wheat / barley crop rotation, on a rendzina soil (Indre) Data averaged over 30 years Fertiliser N dose (kg N/ha) Mean grain yield (tonnes / ha) Management Scenario N2O NH3 Nitrate Business as usual 210 8.7 10.5 3.7 24.1 “Sound” (Raisonné) 150 8.3 2.9 18.0 7.5 Reduced inputs 7.8 120 15.3 8.5 2.9

23. Is there really room for improvement ? Technological “fixes” at the field-scale Optimising fertiliser N applications (including variable-rate within agricultural field) Selection of crop rotations (eg, legume crops) Introduction of new genotypes (eg, herbicide-tolerant) Displacement of fossile resources (bio-energy, 'green chemistry') Agricultural recycling of urban waste

24. Benefits of herbicide-tolerant crops ? Calculated impacts on various environmental or population targets for rotations with or without herbicide-tolerant, genetically modified crops in Dijon. (Mamy, 2004)

25. Recycling of urban waste Integration into life cycle assessment of waste management Simulation of soil C variations in plots amended with urban waste composts (Gabrielle, Da Silveira, Houot, Michelin, Agric. Ecosys. Environ., 2005) MSW: municipal solid waste BIO: biodegradable waste GWS: green waste + sludge FYM: farmyard manure +N: complemented with fertilizer N

26. Potential benefits on soil quality Compost application may improve the structural stability of soils (Annabi, 2004), and mitigate runoff and erosion risks in loamy soils. How to incorporate such qualitative impacts in life-cycle assessment? Pictures by Y. Le Bissonnais

27. Room for improvement? Maybe make room bigger.... Technological “fixes” at the field-scale Cropping systems approach Identification of 'best management practices' tailored to local conditions At the farm or production basin level Optimal allocation of land use and agricultural inputs Optimisation of nutrients and carbon flows (especially in livestock systems) Rural engineering

28. Territorial approach opens up new horizons • The introduction of new productions entails changes in • Physical and biogeochemical fluxes in local environment • Cropping systems management • Economic revenues and farm management • Organisation of labour, logistics, ... • Perception of agricultural activities by local stakeholders

29. Future research and problematics Integration of environmental assessment with other disciplines (agronomy, economics, social sciences) To internalize determinants of agrosystems management (including land use) Also, internalize environmental impacts in the selection of management strategies Modelling (and experimenting) To generate spatial distributions of input parameters, and validate regional estimates Long-term trends from repeated applications Gaseous emissions (and depositions) Encompassing ecological issues that can hardly be tackled by flux-based methods (eg, soil quality)

30. Linking of bio-physical and economic models Environmental balance model Agronomic scenarios (crop rotations, fertilization, decision rules, ...) N losses, crop yields Micro-economic model 'Typical' farm Profits, social costs Soil types Input costs, market prices, taxation, incentives, etc... Optimal management Environmental performance at territorial level

31. Example: efficiency of agri-environmental measures Profit associated with the optimal combination of nitrogen inputs reduction and soil vegetation cover under nitrate leaching constraint for a typical arable farm of Champagne-Ardennes. (Hardelin, J., Master's dissertation, 2005) PRAITERRE project, coordinated by G. Lemaire (INRA Lusignan), and funded for 2006-2008.

32. Large-scale simulations of N gas emissions: Nitro-Europe Integrated Project coordinated by M. Sutton (CEH Edinburgh), and funded under the 6th EU FP for 2006-2010.

33. Bio-energy, a model frame-work for assessment ? Regional case-studies and chain implementation may be provided by the R&D Cluster on Agro-Resources (in Picardie-Champagne-Ardennes) With support from national and European programmes (BioEnergy Network of excellence) Life cycle assessment may be implemented at supply basin level, Thereby integrating land-use change and territorial impacts (tentative Ph.D. Programme with INRA Laon/Reims/Mons), With links to other sustainability indicators: economic, social, ecological (UT Troyes)

34. Conclusion: challenges ahead From a scientific perspective Develop bio-physical models for environmental assessment Broaden the scope of the assessment and tackle territorial impacts ...and from a personal perspective Foster collaboration with thematically- or geographically-distant groups Entrust work to students (graduates or post'docs) and colleagues

35. Merci à tous !

36. Lecture Outline Context and issues Méthodologie de l 'évaluation intégrée Exemples de résultats Conclusion: vers une approche systémique

37. A range of available methods Methods based on fluxes of matter and energy Temporal variability Agri-environmental indicators Methods based on cropping practices Physical variability (soil, climatic zone) Dynamic Life cycle assessment INDIGO SIRIS ranking; IDEA Static Static Local environment Mean environment

38. Why use biophysical models ? Oilseed rape Sugar Beet Maize GM crop non-GM crop Impacts on “fresh water” target, across soil and crop types (model-based) Dijon Dijon Dijon Toulouse Châlons Châlons Châlons Ph. D. thesis by L. Mamy, 2004 Toulouse Low risk 7 Values of indicator I-Phy for the chemical weeding of GM and non-GM crops Dijon Dijon Dijon Châlons Châlons Châlons Toulouse Toulouse

39. Application to natural systems: a source of controversy LCA of bio-diesel from oilseed rape

40. From field to production system: PRAITERRE Typology and drivers of farms Impact assessment Economic functions Pilot farms Support for innovations Adoption of innovations Impact assessment Economic functions Prior models Selection of suitable innovations Agri- environmental engineering Innovative systems design Posterior models Simulation of future environmental impacts Economic analysis Impact assessment Economic functions Project coordinated by G. Lemaire (INRA Lusignan), and funded for 2006-2008.

41. Using straw for combined heat and power production Global warming impact of one litre of bio-ethanol produced with either pure natural gas or 50% wheat straw. Direct emissions (field) are estimated with a biophysical model, including climate variability.

42. Eat local: common sense or real progress? Life cycle impacts of the production of one litre of milk produced by cows fed with locally-produced oilseed rape cake or imported soymeal. (Lehuger, S., Master's dissertation, 2005)

43. Research issues in a nutshell Modelling (and experimenting) Long-term trends from repeated applications Gaseous emissions (and depositions) Generating spatial distributions of input parameters, and validating regional estimates Encompassing ecological issues that can hardly be tackled by life cycle assessment (eg, soil quality) Expanding physical system to internalize management rules