Search

Search Results

• Impact of land use practices on the ecological nitrogen balance indicators of extensive grassland vegetation

  127-143

  Krisztina Varga

  istván Csízi

  Views:

  17

  The effects of different grassland management practices on plant stand structure were investigated in an experiment at the Karcag Research Institute in 2017–2020, which was set up in 2009. The experimental grassland must comply with Natura 2000, the standards for organic grassland certification and the requirements of the horizontal agri-environmental programme. Support schemes that prioritise ecological considerations predispose to different grassland use patterns in a given grassland production area, a fact that justifies the relevance of this research. The specific objective of this research is to clarify the changes in vegetation structure under the most common grassland management practices in the Central Tisza landscape, based on Borhidi’s N balance, an ecological indicator for the meadow Solonetzic soil type typical of the region. In the experimental site with the medium meadow solonetzic soil type, the following grassland utilisation types were investigated in three replications: zero utilisation, i.e. fallow grassland, mulched grassland, where the phytomass was also not removed after stubble mowing, mowing, which meant removing the main crop once a year, and meadow utilisation, where the grass was grazed by sheep after mowing the main crop. In May of each year, a cenological survey was carried out at the time of flowering of the dominant grassland species and the plant species were classified according to Borhidi's ecological nitrogen balance. The highest grouse diversity was found in meadow grassland, 21 plant species, and the lowest in fallow grassland, 6 species. The obtained result may indicate the effect of the open layer of the unutilised phytomass in generating plant species selection in the plants forming the grassland association. It was found that, by the tenth year of the experiment, a change of control plants occurred in treatments representing mulched and meadow utilisation. The change of Festuca pseudovina to a dominant grassland component in the meadow use suggests grazing of the swards at low stubble height. Despite the accumulation of leafy phytomass, the highest coverage of nitrogen-preferring grassland constituents was not in the zero and mulched treatments left unused, but in the mowing treatments. The obtained result may suggest that Alopecurus pratensis, maintaining its position as a leader plant under mowing and being classified as a Borhidi indicator plant for nutrient-rich sites, determined the outcome. In order to clarify the reproducibility of the experimental results, due to the different soil conditions, it may be justified to carry out studies with a similar orientation in other sites and grassland associations.