Integrating farmers’ knowledge on toxic plants and grassland management: a case study on Colchicum autumnale in Austria

High densities of Colchicum autumnale may endanger grassland management in Austria. As the toxic components persist in hay and silage, the continuation of the management of these grasslands, which are often characterised by a high biodiversity, is uncertain. Farmers possess valuable and context-specific know-how on toxic plants and grassland management. This study aims at assessing the contribution of farmers’ knowledge to nature conservation research on toxic plants in grasslands. In total, we conducted 170 face-to-face interviews with farmers managing grasslands with C. autumnale in four areas of Lower Austria. In addition, the farmers were invited to regional workshops to discuss C. autumnale, control measures and related problems. We also encouraged farmers to carry out on-farm experiments. To provide triangulation of the participatory with academic research results, C. autumnale was mapped in three municipalities, covering in total 686 ha. The majority of all grassland plots were extensively managed meadows. More than half of them were not fertilised and were subject to nature conservation regulations. Farmers reported an increase of C. autumnale on 44% of all grassland plots. Of these, grassland management has been extensified in 64%. About 27% of all farmers regarded C. autumnale as a problem. Among farmers who sold hay, 48% considered it as problematic. The field survey showed that C. autumnale covers up to 73% of grasslands. Farmers’ knowledge is an important contribution to nature conservation research and should be included in the design and implementation of agri-environmental schemes so that long-term extensive grassland management can be assured.