As major generators of environmental impacts, farms play a crucial role in enhancing the environmental sustainability of food-supply chains. However, appropriately assessing farm environmental performance poses a challenge; a plethora of different indicators have been used for this purpose, sometimes in the absence of conceptual considerations. This paper develops a broadly implementable framework for defining and measuring farm environmental performance which complies with the environmental sustainability concept viewed from an ecological perspective. After providing a critical review of existing indicators in the literature for measuring farm environmental performance and identifying their strengths and above all their weaknesses, it proceeds to develop ideas on how to implement the environmental sustainability concept at farm level. Starting at the macro level, these ideas are based on the central concept of ecosystem carrying capacity (constraints) referring to biophysical threshold thinking. The implementation of this concept at farm level results in the framework that we propose for measuring farm environmental performance. Environmental sustainability requires compliance with the carryingcapacity constraints imposed by the natural ecosystem within which a farm operates.

Abstract:Complying with the carrying capacity of local and global ecosystems is a prerequisite to ensure environmental sustainability. Based on the example of Swiss mountain dairy farms, the goal of our research was firstly to investigate the relationship between farm global and local environmental performance. Secondly, we aimed to analyse the relationship between farm environmental and economic performance. The analysis relied on a sample of 56 Swiss alpine dairy farms. For each farm, the cradle-to-farm-gate life cycle assessment was calculated, and the quantified environmental impacts were decomposed into their on-and off-farm parts. We measured global environmental performance as the digestible energy produced by the farm per unit of global environmental impact generated from cradle-to-farm-gate. We assessed local environmental performance by dividing farm-usable agricultural area by on-farm environmental impact generation. Farm economic performance was measured by work income per family work unit, return on equity and output/input ratio. Spearman's correlation analysis revealed no significant relationship, trade-offs or synergies between global and local environmental performance indicators. Interestingly, trade-offs were observed far more frequently than synergies. Furthermore, we found synergies between global environmental and economic performance and mostly no significant relationship between local environmental and economic performance. The observed trade-offs between global and local environmental performance mean that, for several environmental issues, any improvement in global environmental performance will result in deterioration of local environmental performance and vice versa. This finding calls for systematic consideration of both dimensions when carrying out farm environmental performance assessments.

Improving the sustainability of the dairy food chain requires a simultaneous improvement in global and local environmental performance, as well as in the economic performance of dairy farms. We investigated the effect of different structural, farm management, socio-demographic, technological and natural-environment-related factors on the economic and environmental performance of dairying. Our analysis relied on a case study of 56 Swiss alpine dairy farm observations, for which cradle-to-farm gate life cycle assessments and farm accountancy data were combined. The data refer to the years 2006 to 2008. The effect of the selected factors on farms' economic and environmental performance was analysed by means of non-parametric statistical approaches. The results revealed the existence of some factors presenting synergies and several factors showing trade-offs in the enhancement of farm global environmental, local environmental and economic performance. More generally, the promotion of farm global environmental performance and farm economic performance was shown to be synergetic whereas the enhancement of farm global and local environmental performance turned out to be mostly antinomic. However, some factors, namely organic farming, higher agricultural education, silage-free milk production, and also, to a weaker extent, full-time farming, larger farm size and lower intensity of cattle concentrates use, showed a potential to bring simultaneous improvements in the global and local environmental performance as well as the economic performance of dairy farming. Policy-makers should be aware of the complexity of the joint improvement of farm economic and environmental performance and only promote factors capable of synergistically enhancing the environmental and economic performance of dairy farming.