Robust agriculture: Balancing between vulnerability and stability

The impression that agricultural systems are increasingly vulnerable to unwanted environmental fluctuations has created an urge for robustness in agriculture. However, the meaning of robustness and its relation to sustainable agriculture remain unclear. Considering two related concepts, i.e., vulnerability and stability, this article analyses different conceptualizations of robustness and their applications in agricultural production systems. It is argued that robustness should not be seen as a clear-cut system feature, and that it only exists in the absence of stability and by the grace of disruptions that could possibly harm the system structurally or functionally. The article introduces the term robustness state to refer to an intermediate sphere between vulnerable and stable, in which a system's capacity to cope with both ordinary and occasional disturbances is optimized. We distinguish three robustness states that differ in the degree by which systems are allowed or inclined to follow environmental changes: (1) a state of avoiding exposure, (2) a state of inherent resistance, and (3) a state of response and recovery after being disrupted. In addition to cardinal questions inevitably related to robustness, namely the specification of both system and perturbation, this article discusses the issue in what way a system feature is robust. This issue may help to clarify the actual meaning given to robustness and appears particularly relevant when discussing the desirability of different strategies to cope with aspects of vulnerability. Different rationales behind recent calls to make agricultural systems more robust are discussed with a view to agricultural developments related to sustainability of agricultural practices and the questioned necessity of external control measures.