Multi-criteria methods for the evaluation of agricultural production systems

Transcription

1 Multi-criteria methods for the evaluation of agricultural production systems Scientific seminar Environmental assessment of agricultural production systems: application to tropical systems Hayo van der Werf, INRA, Rennes, France March 1, March 2010 Evaluation methods 1

2 Agronomy environmental analysis Netherlands: Agronomy/crop physiology, P. Vereijken INRA Colmar: environmental indicators, Ph. Girardin, Ch. Bockstaller INRA Rennes: farming systems experimentation INRA Rennes: LCA, where s the nitrogen? INRA: LCA, where s the science? Now: one foot in agronomy, one foot in environmental analysis 1 March 2010 Evaluation methods 2

3 Tools for evaluation are needed Rapid and intuitive environmental evaluation 1 March 2010 Evaluation methods 3

4 Environmental impacts of agriculture Classic approach: one site, one pollutant ex. pig farm, nitrates This may lead to pollution transfer One problem (nitrate) is solved, two problems emerge (P, N 2 O) emissions on-farm versus emissions elsewhere Multi-criteria system approach 1 March 2010 Evaluation methods 4

5 Three pig production systems (PhD thesis Claudine Basset-Mens) 1. Good Agricultural Practice (GAP) (conventional) 2. Red Label (RL), (quality label) 3. Organic Agriculture (OA) 1 March 2010 Evaluation methods 5

6 Five multi-criteria methods for environmental evaluation Acronym Name N obj. LCA Life Cycle Assessment 6 EF Ecological Footprint 3 EMA (UK) Environmental Management for Agriculture 12 FarmSmart (UK) National Sustainable Agriculture Indicators 6 Dialecte (F) SOLAGRO agro-environnemental diagnosis 19 1 March 2010 Evaluation methods 6

7 Five methods to evaluate three production systems Méthodes Mode Expression d'expression mode Exploitation Whole dans Farmson ensemble Par Per hectare ha Par Per kg de of porc pig produit ACV LCA EE EF EMA FarmSmart Systems Sce narios DIALECTE Indicateurs Agro- Approche Whole farm approach ferme entière Performance Emissions ecological agroécologiq. indicators BPA GAP RL OA LR AB BPA LR AB BPA LR AB GAP RL OA GAP RL OA 1 March 2010 Evaluation methods 7

8 Methods for environmental evaluation Aim the integration of knowledge, in order to interpret complex systems to support decision making Their aim: characterise actions (systems, scenarios) with respect to their impacts, in order to identify the action that has the least impact identify ways to reduce impacts for each action Such methods can fail in (at least) two ways: they give the wrong answer they are too laborious to use 1 March 2010 Evaluation methods 8

9 The stages of methods for multi-criteria evaluation of farming systems 1. Definition of the system to be evaluated 2. Definition of the overall objective and the dimensions 3. Identification of specific objectives 4. Identification of indicators 5. Calculation and interpretation of results 6. Recommendations to improve the system 1 March 2010 Evaluation methods 9

10 1. Defining the system 1 March 2010 Evaluation methods 10

11 2. Defining the overall objective and the 12 methods : dimensions to be considered Evaluation of environmental impact (6) Evaluation of environmental performance (adherence to Good Farming Practice) (1) Evaluation of sustainability (3: env.+econ., 2: env.+econ.+soc.) In order to: Establish payment amounts (1), Conceive new systems (2), Encourage good practice (1) 1 March 2010 Evaluation methods 11

12 3. Definition of specific objectives for each dimension 12 methods : 26 environmental objectives 2 to 13 objectives per method Few objectives: miss out on a pollution transfer Many objectives: feasibility, interpretation How to choose a set of objectives? Consult stakeholders: emphasis of local and regional problems What role for the researcher? 1 March 2010 Evaluation methods 12

13 3. Definition of specific objectives for each dimension (Environmental dimension: IDEA, LCA) Inputs Emissions System state Non-renewable energy use Greenhouse gases Landscape quality Other resource use CFC (stratospheric ozone) Natural biodiversity Water use Acidifying gases Agricultural biodiversity Land use Eutrophying substances System biomass Erosion Pesticides Air quality Nitrogen fertiliser use Ecotoxic substances Water quality Pesticide use Human toxicity substances Soil quality Waste production Food quality Animal well-being 1 March 2010 Evaluation methods 13

14 4. Identification/construction of indicators for each specific objective Indicators are variables...] that supply information on other variables that are harder to access...] Indicators also facilitate decision making. (Gras et al., 1989). They supply information on a complex system to facilitate its comprehension...] by its users, so that they can take the right decisions to reach objectives (Mitchell et al., 1995). 1 March 2010 Evaluation methods 14

15 The indicator in the causal chain: practices, emissions, impacts Climate, soil Products wheat, milk, Fate Sensitivity of the target Practices Crop rotation, fertilisation, animal density, grazing, type of building Farm Emissions CO 2, CH 4, NH 3, NO 3, PO 4, N 2 O, pesticides Impact Fertilisation Kg N/ha Soil N at harvest NO 3, leached Eutrophisation of costal zone Indicator of practices Indicator of state Emission indicator Impact indicator Environmental relevance Feasibility 1 March 2010 Evaluation methods 15

16 What units for indicators? A global score at farm level Impacts per ha Favours low-input systems Impact per kg of product, Euro of value added Favours high-input systems What is the function of production systems? Occupy land while minimising impacts Produce while minimising impacts 1 March 2010 Evaluation methods 16

17 Four methods for environmental evaluation at farm level EP : Ecopoints (Austria) EMA : Environmental Management for Agriculture (UK) IDEA : Indicators of Farm Sustainability (France) LCA : Life Cycle Assessment (Switserland) 1 March 2010 Evaluation methods 17

18 Indicators used: pesticides Indicator Type EP Number of applications / ha / year Practices MAE Score based on amount of active ingredient, its Impact physical, chemical, toxicological characteristics, the characteristics of the field and of the application technique IDEA Number of applications at prescribed dose / ha / year Practices ACV Scores (soil, water, human toxicity) based on the amount of active ingredient and its toxicological characteristics Impact 1 March 2010 Evaluation methods 18

19 Indicators used: erosion EP MAE IDEA ACV Indicator Score based on the degree of soil cover by crops, the use of under-sowing, of mulch sowing, of a perennial crop Score based on the implementation of non-tillage, absence of crop cover, mulching, grass cover in perennial crops, burning of crop residues A simulation model is used to calculate an amount of eroded soil, taking into account the site, farmer practices and the field s history. Type Practices Practices Impact 1 March 2010 Evaluation methods 19

20 5. Interpretation of results: reference values, weighting, aggregation A reference value facilitates the interpretation of an indicator value: acceptable versus unacceptable What basis: legislation, expertise, stakeholder consensus, science? Weighting of specific objectives What basis: legislation, expertise, stakeholder consensus, science? Aggregation of results facilitates interpretation, decision making, at the cost of loss of information 1 March 2010 Evaluation methods 20

21 Format of output, reference values, weighting and aggregation Format of Reference Weighting Aggregation ouput values EP Scores, variable scale Yes, - : bad, + : good Indirectly, via scale By sum of scores MAE Scores, fixed scale : -100 à 100 Yes, - : bad, + : good Up to the user No IDEA Scores, variable scale No Indirectly, via scale By sum of scores ACV Values No No No 1 March 2010 Evaluation methods 21

22 6. Recommendations to improve the system This stage lacks for most methods A matter of agro-environmental expertise, requiring a dialogue with stakeholders 1 March 2010 Evaluation methods 22

23 A good method for the evaluation of the impacts of farms: Allows the identification of pollution transfers Considers important impacts, including global impacts Considers both direct (on-farm) and indirect impacts (inputs) Uses indicators of impacts rather than indicators of farmer practices Allows several modes of expression ( /ha, /kg, / ) Is easy to interpret (reference values, weighting of impacts, aggregation of results) Is valid and operational 1 March 2010 Evaluation methods 23

24 Conclusions The outcome of a multi-criteria evaluation depends on the characteristics of the options analysed and of the method used It is up to the user to choose the appropriate method according to her/his needs A method can fail in (at least) two ways: It gives the wrong answer It is too laborious to use 1 March 2010 Evaluation methods 24

25 Life Cycle Assessment Conceptual framework: international, inter economic sectors You can t understand a picture when you are inside the frame Peter Boyd 1 March 2010 Evaluation methods 25

26 References Van der Werf, HMG and Petit, J, Evaluation of the environmental impact of agriculture at the farm level: a comparison and analysis of 12 indicatorbased methods. Agriculture, Ecosystems & Environment, 93, Payraudeau, S and van der Werf, HMG, Environmental impact assessment of a farming region: a review of methods. Agriculture, Ecosystems & Environment, 93, Van der Werf HMG, Tzilivakis J, Lewis K, Basset-Mens C, Environmental impacts of farm scenarios according to five assessment methods. Agriculture, Ecosystems and Environment, 118: March 2010 Evaluation methods 26