METHODS: A new method for assessing the sustainability of land-use systems (I): Identifying the relevant issues

Definitions of sustainability abound. However, they tend to be abstract and thus open to diverging interpretations. Conversely, scientists need concrete guidance to develop quantitative measures of the sustainability of agricultural systems, such as sustainability indicators. Bridging this gap between what policy provides and what scientists need involves strong normative elements. Many publications on sustainable agriculture suggest bridging the gap through participatory stakeholder processes. However, participatory stakeholder involvement is not always practicable, due to the high cost and time required. In addition, the outcome of such processes can lack transparency and validity to outsiders. In this paper (the first of a series of two, [Walter, C. and Stutzel, H., 2009-this issue. A new method for assessing the sustainability of land-use systems (II): Evaluating impact indicators. Ecological Economics]), we introduce an alternative method for concretising sustainability within a given context. It is based on a systematic inventory of potential issues through a structured literature review, and then uses a simple and transparent criterion to decide which of these potential issues is actually relevant within the given context. This approach yields a set of concrete issues against which to test the impact of agricultural production systems. It also makes transparent the normative and descriptive elements of the process, which helps to control value-driven biases. We demonstrate the practical applicability of this approach by testing it for an agricultural area in Northwest Germany.