Indicators for sustainable agriculture - a theoretical framework for classifying and assessing indicators

Indicators can be used for identifying, simplifying and quantifying agri-environmental aspects of sustainability. They offer us a way to proceed from the theoretical definition of sustainability to more practically oriented approaches. This study examines agricultural systems with a view to identifying the points and levels at which the sustainability of these systems can be assessed. The agri-environmental indicators are presented within the Pressure‐State‐Response (PSR) framework. Although suitable for ecological indicators, this framework is not highly relevant for economic and social indicators, which were thus studied from a more general theoretical perspective. As the concept of sustainability includes a number of different value-laden definitions, the setting of indicators should be seen as an ongoing re-evaluation rather than a technical process of measuring certain parameters. The need to refine the assessment methods was recognised in several subthemes of agricultural sustainability. A major shortcoming was found to be the lack of tools for evaluating qualitative phenomena such as landscapes and animal welfare. Likewise, in economics and the social sciences, much needs to be done to promote understanding of the interactions between these disciplines and environmental processes. Moreover, the basic framework of the assessments requires further examination, for instance, when interpreting the indicator results, when dealing with uncertainty and when seeking to identify cause-effect chains, even though these questions are no longer purely matters of indicator methodology.