The Elan Valley Meadows Project was initiated in 2004 to help conserve some of the most important examples of species-rich mesotrophic grasslands in Wales. The primary objective of the project was to provide site-specific and ecologically sustainable management advice to help conserve these important and regionally distinct upland-fringe meadows. Specifically, there was a need to determine what levels of nutrient inputs are required to enable reinstatement of traditional hay making practices while still conserving existing high levels of floristic diversity.
Between 2004 and 2013, a long-term replicated field trial was undertaken to determine how a representative group of the Elan Valley meadow sites responded to different inputs of farmyard manure (FYM) and lime in terms of soil chemistry, herbage productivity and species diversity. Small plots (each 35m2) received either light (12t/ha/2yrs) or moderate (12t/ha/yr) applications of FYM, either with or without intermittent liming. Plots were assessed annually and compared with untreated control plots.
Results from untreated control plots showed clear evidence of progressive soil acidification and diminishing hay-yields at all sites studied and particularly highlighted the need to reinstate the traditional practice of periodic liming. Light intermittent applications of FYM were also shown to be an important traditional input for sustaining the desired plant communities together with providing acceptable hay crops. Rates of FYM applied at higher rates were shown to be detrimental by excessively promoting the growth of some undesirable meadow components.
A full report from the study is available via the Natural Resources Wales website here. The outcomes of this research are now influencing conservation decisions on upland fringe habitat elsewhere in Wales.