Impact of Organic Fertilisation and Subsequent Grassland Abandonment on Floristic Composition

The aim of this study was to evaluate changes in floristic composition of permanent grasslands after the cessation of their regular utilisation and organic fertilisation. A long-term small plot trial was established in 2004 in locality Rapotín. During 2004-2012, the experiment was fertilised with compost and slurry, both with the range of stocking rates 0.9, 1.4 and 2.0 livestock units (LU)/ha (corresponding to 54, 84, and 120 kg N/ha). The plots were cut 2-4 times per year depending on given dose of fertiliser. During 2013‒2016, the regular management was ceased and the grasslands were completely abandoned. Before the grassland abandonment, the highest total number of species (24 species) was found in the treatments regularly fertilised with compost. The dominance of grasses was influenced by the grassland management, with decreasing intensity of utilisation, the dominance of grasses increased. Four years after the grassland abandonment, the species diversity in almost all treatments decreased and the dominance of grasses increased in all treatments, up to the value 67-80%. Based on the data about the soil chemical parameters from two investigated years, our results suggested not only the effect of grassland management and its subsequent abandonment, but also a residual effect of the both organic fertilisers. These findings indicated the importance of the maintenance of regular grassland management for sustainable conservation of grassland communities.