Ecological and economic consequences of using conditioners in grassland mowing

• Applicants: Professor Dr. Klaus Birkhofer; Professor Dr. Frank Wätzold
• Subject Area: Ecology of Land Use ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569035770

Insect populations are declining due to habitat conversion, pollution and climate change, with regional conditions influencing the severity. Research in the Biodiversity Exploratories (BEs) has improved our understanding of the effects of agricultural management. However, despite their widespread use in European grasslands, the effect of mowing conditioners on arthropod mortality remains poorly understood. Conditioners compress the cut grass to accelerate drying, increasing the physical damage to arthropods. With conditioners used on up to 70% of grasslands in some regions, potential biodiversity loss could threaten ecosystem services such as pollination and pest control. A pilot study in Germany found that conditioners may increase arthropod mortality by almost 20%. However, further research is needed to assess regional variations and taxonomic differences in susceptibility. Moreover, it is essential to understand farmers' motivations for using conditioners. Policy recommendations suggest avoiding an outright ban, but instead compensating farmers through agri-environmental schemes (AES) for not using conditioners in biodiversity sensitive areas. However, AES must be cost-effective, i.e. designed to maximise the achievement of biodiversity objectives for a given AES budget. The EcoMow project uses biodiversity and management data from the BEs to investigate the environmental and economic impacts of conditioners. Hypotheses are: H1) Conditioner use increases arthropod damage by 15-25%, with variation explained by land use intensity. H2) Less intensively managed grasslands with arthropod populations that have larger arthropod species will experience greater conditioner-induced damage. H3) Ecological-economic modelling can develop cost-effective AES that combine requirements for biodiversity-enhancing mowing regimes with restrictions on the use of conditioners. H4) Cost-effective AES design differs according to regional productivity, management intensity and farming systems.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1374: Biodiversity Exploratories