Management effects on botanical composition of species-rich meadows within the Natura 2000 network

Species-rich hay meadows have evolved through traditional management. They are important habitats for plant and animal species and therefore protected by the EU Habitats Directive. The maintenance of these meadows requires regular cutting, but this can only be guaranteed if farmers benefit in some way. Both agricultural productivity and botanical composition are fundamentally affected by management practices. For this reason, a management that balances productivity and conservation goals is necessary. The purpose of this study is to determine the site-specific influence of extensive fertilisation and date of first cut on the botanical composition of species-rich hay meadows. Three fertilisation variants (none, PK and NPK) and four cutting-date variants (based on phenological stage: first cut before, at beginning of, at end of and after flowering of main grasses) were tested on lowland hay meadows at two sites. However, after the 3 years of the trial, the date of first cut had still not significantly influenced botanical composition at the first site. By contrast, annual fertilisation was found to have a significant effect on botanical composition. The conservation status of the species-rich meadows was downgraded (grades given according to assessment parameters) mainly through the application of NPK fertiliser (35 kg P₂O₅, 120 kg K₂O and 35 kg N ha⁻¹) each year. At one site, cutting before flowering led to declining proportions of annuals and biennials. Surprisingly, at the other site, the date of first cut had still not significantly influenced botanical composition by the end of the 3-year trial.