Presentation from the WCCA 2011 conference in Brisbane, Australia.

1. Combining different modelling
approaches for a participative
assessment of alternative agricultural
systems at different scales
.
Delmotte S 1*, Lopez-Ridaura S1, Goulevant G1, Mouret JC1, Le Page C2, Chauvelon P3, Sandoz A3,
Barbier JM1, Wery J4
1INRA, UMR Innovation, 2 place Pierre Viala 34070 Montpellier Cedex 2.
Corresponding address :* delmotte@supagro.inra.fr
2CIRAD, UPR Green, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France
3Fondation Sansouire, Station Biologique de la Tour du Valat, Le Sambuc, F-13200 Arles, France
4SupAgro, UMR System, 2 place Pierre Viala, 34060 Montpellier Cedex 2, France

2. Introduction Participative Integrated Assessment of
Agricultural Systems
Multifunctionality of agriculture, importance of
social, economic and environmental aspects.
Evaluate alternatives systems and trade-offs
Need for tools that allow PIMPAAS:
Prospective (alternative systems and changing
environment)
Multiscale (different processes at different levels)
 Farm-regional (territory) scale
Multicriteria assesment (different objectives)
Participative (local knowledge, support for
individual and collective decisions, negotiations)

3. Introduction La Camargue
 Small and well delimited region (160 000 ha)
 Several well identified actors
(farmers, syndicate, cooperatives, natural parcs)
 Several constrasting objectives (agricultural
production, wildlife conservation…)
 Concrete options for agricultural production (e.g. organic)
 Participative Integrated Assessment (PIA) of scenarios of
future farming systems

4. 1. Engagement of the local stakeholders (1/2)
 More than 20 individual meetings at the begining of the project
 Identification of actors, scales of analysis and objectives
Application
Scenarios:
 CAP reform: i.e. suppression of a rice coupled subsidy (2012)
and decrease of direct payment.
 Pesticides reduction and OF development (national plan).

5. 1. Engagement of the local stakeholders (2/2)
Scales Indicators
Farm Costs of production (€)
Gross margin (€)
Gross margin including subsidies (€)
Application
Total working time per year (h)
Area organically managed (ha)
Farm, sub region, region Amount of subsidies (€)
Treatment Frequency Index (TFI)
Area of each crop on organic and conventional (ha)
Production of each crop on organic and conventional (t)
Proportion of area organically managed
Sub region, region Area of each crop
Total value of agricultural productions (€)
Proportion of irrigated area
3
Water used for irrigation (m )
Employment generating by agricultural activities (man year)

6. 2. Data acquisition
 Definition of activities (1600)
 Quantification of activities

7. 2. A farm typology

8. 3. Application of three approaches for
scenario building and assesment
 Development of a retrospective Land Use Change
approach, discussion with local stakeholders
 Development of an agent-based model (IMPASIAS -
Integrated and Multiscale Participative Assessment of
3 approaches
Scenarios and their Impacts on Agricultural Systems-) to
formalize and evaluate scenarios with farmers during
interactive simulation sessions, and discuss them with
local stakeholders.
 Scenario definition with the local stakeholders and co-
construction of a bio-economic model

9. 3.1 LUC methodology

10. 3.1 LUC results
Main messages:
 Different strategies to adapt to economic changes
 Identifying farm types more probable to convert to OF: livestock
breeder and diversified cereal farmers
 Quantifying variations and trends of land use at field/farm scale
 Discussed with the stakeholders to make hypothesis on farm
evolutions and think of farm adaptability

11. 3.2 The IMPASIAS model
Agent-based model for interactive
simulation. Based on the dynamic
choice by individual farmer of land
use at farm scale.
Interactive sessions in two steps:
 Decisions of land use (selection of
the agricultural activities)
 Individual analysis of results at
farm and regional scales
3 sessions, 14 farmers of 8 types

12. 3.2 Results of scenario related to CAP reform
At farm level:
 Diversified farms wont suffer much by CAP reform and could easily
convert to OF.
 Farming systems based on rice production would suffer a decrease of
gross margin. Need to diversify, but none of the strategy tested gave
satisfactory result from the farmers’ point of view.
At regional level:
 The suppression of specific payments could reduce the rice area
nearly by half  issues related to processing industries and irrigation
water infrastructure maintenance.

13. 3.3 Co-construction of a Bio-Economic model

14. 3.3 Bio-Economic model results
At farm level:
 Adapting to the CAP reform means diversifying production
unless a specific payment at 150€.ha-1 is maintained.
 Diversifying with sorghum appeared to be a good alternative for
either gross margin maintenance and pesticide reduction
At territorial level:
 The pesticide used would
decrease by 30%
(ABM), however, with the
same decrease in rice
production, greater could
reduction could be attained
(BEM) with limited loss in
regional value of agriculture
Setting a new agri-
environmental measure?

15. 4. Combining the different approaches
for PIMPAAS ?
Projection using LUC allowed:
 Improving knowledge on farming system functioning
 Identifying probable spots for change
Interactive simulation (ABM) with farmers allowed:
 Verifying and validating used data
 Mutual learning and reflection about adaptive strategies,
 Understanding land use decision making/constraints for farmers
 Upscaling and enhancing discussion with local stakeholders
Simulations with local stakeholders and the BEM allowed:
 Formalizing stakeholders objectives
 Identifying conflicts and trade-offs.
Discussion
 Improving knowledge on local policy impacts and ex-ante
assessment of technical alternatives and policies

16. 4. The need for a participative approach?
For PIMPAAS, we need to :
 Follow an adaptive process (from engagement to
collaboration)
 Engage stakeholders to get and legimate data
 Identify sharing/conflicting objectives
 Assume a neutral position
 Improve our common understanding of issues related to
agriculture
Discussion
 Listen to stakeholders claims to collective discussions

17. Thanks for your attention!