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Soutenance pour l'habilitation à diriger les recherches Université Pierre et Marie Curie, UFR des Sciences de la Terre Benoît GABRIELLE Chargé de Recherche.

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Presentation on theme: "Soutenance pour l'habilitation à diriger les recherches Université Pierre et Marie Curie, UFR des Sciences de la Terre Benoît GABRIELLE Chargé de Recherche."— Presentation transcript:

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2 Soutenance pour l'habilitation à diriger les recherches Université Pierre et Marie Curie, UFR des Sciences de la Terre Benoît GABRIELLE Chargé de Recherche UMR INRA INA P-G Environnement et Grandes Cultures 20 Janvier 2006 L'évaluation environnementale des agrosystèmes: une approche intégrée pour gérer les risques agri-environnementaux

3 2 Context - 1 A growing demand for agricultural produce... Tilman et al., Agricultural sustainability and intensive production practices, Nature 418: 671-677, 2002 2050 4.0 (10 9 tonnes) 2010 Bio-fuels in Europe Directive 2003/30 EC

4 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)

5 4 Context - 3...albeit with decreasing marginal efficiency 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 ) (Tilman et al., 2002)

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

7 6 Context - 5 Potential impacts from agriculture CO 2 Groundwater NO 3 Fertilizers (N) Pesticides Sol Soil organic matter N 2 O, NO, NH 3, Pesticides Eutrophication Global warming Air pollution Ecotoxicity Pesticides Acidification

8 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

9 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 !

10 9 Managing a production chain versus a territory ?

11 10 The 'functional' side: life cycle assessment (LCA) LCA, a conceptual framework to address environmental impacts from the 'cradle to the grave' Renewable carbon Fertilizers Pesticides Inputs: Outputs: CO 2, CH 4, NO x Fossile carbon Other fossile resources Products et co-products NO 3 -, N 2 0... Pesticides In agriculture, LCA was applied to waste management, cropping systems analysis, and bio-energy chains.

12 11 Estimation of fluxes Outputs Inputs Emissions Input X Indirect emissions E = a X +/- Industry Direct emissions E within several orders of magnitude! Input X Agriculture Perturbations E = f(soil, climate, manag t, X)

13 12 Capturing the spatial variability of field emissions Gabrielle, Laville, et al. (submitted to Global Biogeochem. Cycles) Simulation of N 2 O fluxes in the Beauce region (fluxes in kg N 2 O-N/ha/yr)

14 13 Environmental balance models – example of CERES AtmosphereSoil mineral Norganic N SOIL TRANSFERS Heat (Fourier) Water (Tipping bucket) Nitrate (Convective) absorption C-N BIOTRANSFORMATIONS Mineralisation - Immobilisation Nitrification - Denitrification drainage, nitrate leaching PLANT PROCESSES Phenology Ressource capture Partitioning Senescence crop residues Groundwater CO 2, N 2 O, NH 3, NO

15 14 Challenges wihtin the modelling loop Experiments Integration into model; calibration detailed lighter Process analysis Extrapolation Model application Module selection

16 15 Challenges wihtin the modelling loop Experiments Integration into model; calibration detailed lighter Process analysis Extrapolation Model application Module selection

17 16 Integration of nitrous oxide emissions Simulation by CERES with two different N 2 O emission modules Gabrielle, Laville, et al., Nutr. Cycling Agroecosys. (in the press) Haplic calcisol Redoxic luvisol Haplic luvisol --- Simulated o Observed

18 17 Challenges wihtin the modelling loop Experiments Integration into model; calibration detailed lighter Process analysis Extrapolation Model application Module selection

19 18 The 'eco-balance' experiment

20 19 Challenges wihtin the modelling loop Experiments Integration into model; calibration detailed lighter Process analysis Extrapolation Model application Module selection

21 20 Extrapolation to new sets of soils and climates

22 21 Challenges wihtin the modelling loop Experiments Integration into model; calibration detailed lighter Process analysis Extrapolation Model application Module selection

23 22 Model application: scenario analysis Oilseed rape / wheat / barley crop rotation, on a rendzina soil (Indre) Data averaged over 30 years Management Scenario Reduced inputs Sound (Raisonné) Business as usual Fertiliser N dose (kg N/ha) Mean grain yield (tonnes / ha) Emissions in g N per tonne of wheat grain produced Nitrate N2ON2ONH 3 150 210 120 8.7 7.8 8.3 10.5 7.5 8.52.9 3.7 18.0 24.1 15.3

24 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

25 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)

26 25 Recycling of urban waste 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 Integration into life cycle assessment of waste management

27 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

28 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

29 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

30 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)

31 30 Linking of bio-physical and economic models Soil types 'Typical' farm Environmental balance model Micro-economic model Agronomic scenarios (crop rotations, fertilization, decision rules,...) N losses, crop yields Optimal management Input costs, market prices, taxation, incentives, etc... Profits, social costs Environmental performance at territorial level

32 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.

33 32 Large-scale simulations of N gas emissions: Nitro-Europe Integrated Project coordinated by M. Sutton (CEH Edinburgh), and funded under the 6 th EU FP for 2006-2010.

34 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)

35 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

36 35 Merci à tous !

37 36 Lecture Outline Context and issues Méthodologie de l 'évaluation intégrée Exemples de résultats Conclusion: vers une approche systémique

38 37 A range of available methods Physical variability (soil, climatic zone) Methods based on cropping practices Methods based on fluxes of matter and energy SIRIS ranking; IDEA INDIGO Temporal variability Static Mean environment Local environment Agri- environmental indicators Static Dynamic Life cycle assessment

39 38 Why use biophysical models ? Oilseed rape Sugar Beet Maize Châlons Toulouse Dijon Châlons Toulouse Dijon Châlons Dijon Impacts on fresh water target, across soil and crop types (model-based) Ph. D. thesis by L. Mamy, 2004 GM crop non-GM crop Low risk 7 Châlons Toulouse Dijon Châlons Toulouse Dijon Châlons Dijon Values of indicator I-Phy for the chemical weeding of GM and non-GM crops

40 39 Application to natural systems: a source of controversy LCA of bio-diesel from oilseed rape

41 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 Posterior models Simulation of future environmental impacts Economic analysis Impact assessment Economic functions Prior models Selection of suitable innovations Agri- environmental engineering Innovative systems design Project coordinated by G. Lemaire (INRA Lusignan), and funded for 2006-2008.

42 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.

43 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)

44 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


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