Résumé : Slurry management is a central topic in the agronomic and environmental analysis of intensive livestock production systems. The objective of this study is to compare the environmental performance of two scenarios of collective slurry management for the disposal of excess nitrogen from animal...Slurry management is a central topic in the agronomic and environmental analysis of intensive livestock production systems. The objective of this study is to compare the environmental performance of two scenarios of collective slurry management for the disposal of excess nitrogen from animal manure. The scenarios are the transfer of slurry and its injection to crop land, and the treatment of slurry in a collective biological treatment station. The study is based on a real case in the West of France, where a group of farmers is developing a collective plan for the disposal of almost 7000 m(3) of excess pig slurry. The evaluation is carried out by Life Cycle Assessment, where emissions and resource consumption are quantified and aggregated into four environmental impact categories: eutrophication, acidification, climate change, and non-renewable energy use. Ammonia emitted is the most important contributor to acidification and eutrophication, while methane contributes most to climate change. Both ammonia and methane are mostly emitted during the storage of slurry and, in the case of the treatment scenario, also during composting the solid fraction of the slurry. The two management strategies are similar with respect to climate change, whereas eutrophication and acidification are twice as large for treatment relative to transfer. Electricity needed for the treatment process is the main contributor to non-renewable energy use for the treatment scenario, while the transfer scenario represents a net energy saving, as energy saved by the reduction of mineral fertiliser use more than compensates for the energy needed for transport and injection of slurry. The overall environmental performance of transfer is better than that of treatment, as it involves less acidification, eutrophication and non-renewable energy use. The method employed and the results obtained in this study can provide elements for a transparent discussion of the advantages and disadvantages of contrasting excess slurry management scenarios as well as the identification of the main aspects determining their environmental performance. (c) 2008 Elsevier Ltd. All rights reserved.
Résumé : In this paper a set of criteria is proposed for the evaluation of the potential contribution of modellingtools to strengthening the multifunctionality of agriculture. The four main areas of evaluation are (1)policy relevance, (2) the temporal resolution and scope, (3) the degree to which spatial...In this paper a set of criteria is proposed for the evaluation of the potential contribution of modellingtools to strengthening the multifunctionality of agriculture. The four main areas of evaluation are (1)policy relevance, (2) the temporal resolution and scope, (3) the degree to which spatial and socioinstitutionalscales and heterogeneity are addressed and (4) the level of integration in the assessment ofscientific dimensions and of the multiple functions of agriculture. The evaluative criteria are applied tothe portfolio of modelling approaches developed and applied in a joint project of the French researchinstitute INRA and the Dutch Wageningen University & Research Centre.The CLUE-S model focuses on prediction of changes in multifunctional land-use at regional scale, givena set of predetermined scenarios or policy variants, e.g. for ex-ante policy assessment and initiation ofdiscussions on regional development. The two other modelling approaches are complementary and aimto address multifunctional farming activities. The Landscape IMAGES framework generates a range ofstatic images of possible but sometimes distant futures for multifunctional farming activities in a smallregion or landscape. It supports the exploration of trade-offs between financial returns from agriculture,landscape quality, nature conservation and restoration, and environmental quality. Co-Viability Analysis generates trajectories of states and farming decisions fulfilling a given set of ecological and productive constraints representing a desired and sustainable future. The three modelling approaches differ in their policy relevance, in the ways that spatial and socioinstitutional scales are addressed and in their degree of explicitation of interaction between the various functions of agriculture, but jointly cover most of the desired capabilities for assessment of multifunctionality. Caveats were particularly identified in the integration of the socio-institutional dimension and the related heterogeneity. Although the model portfolio did not completely satisfy the demands of the set of evaluative criteria, it is concluded that, due to their complementarities, in combination the threemodels could significantly contribute to further development and strengthening of multifunctionality.
ArticleFarmers'involvement in landscape activities: An analysis of the relationship between farm location, farm characteristics and lanscape changes in two study areas in Jutland, DenmarkKristensen, S.P. ; Thenail, Claudine ; Kristensen, L.