THE EFFECT OF SWARD RENOVATION METHOD, FORAGE MIXTURE AND FERTILIZATION ON GRASSLAND YIELD ON SANDY SOIL
Background. Grasslands are considered as valuable for biodiversity maintaining and provides a range of ecosystem services. Optimal growth of renovated grasslands is influenced both by properly selected methods of renovation and subsequent balanced utilisation. The aim of the presented study was to assess the effect of renovation method, forage mixture and mineral fertilization on initial development, species composition and yield of forage grasslands established on sandy soil.
Material and methods. The experiment was conducted at the Agricultural Experimental Station Swojec, which belongs to the Wroclaw University of Environmental and Life Science. Two renovation methods (overdrilling and full cultivation), three types of forage mixtures: pure grass (mixture I), grass with Trifolium repens (mixture II) and grass with T. pratense (mixture III), and four fertilization levels (0, 140 PK (40 P + 100 K), 220 NPK (80 N + 40 P +100 K), 300 NPK (160 N + 40 P + 100 K) were used as experimental factors.
Results. The largest participation in species composition of the first harvest in the period between 2010–2012 was from Lolium perenne and Phleum pratense under both renovation methods. Tall grass species reached an average of 47%, short grasses 24%, and legumes 29% of DM. The overdrilling method significantly increased the plant yield when compared to the full cultivation method. The application of phosphorus and potassium (140 PK) gave the highest yield. The highest yield was obtained in plots where overdrilling of mixtures of forage grasses with T. pratense (mixture III) that were fertilized with only phosphorus and potassium.
Conclusion. The results indicate, that the yield of the grassland is the higher, when overdrilling, as a method of sward renovation, addition of legumes to a grass mixture and the application of phosphorus- -potassium fertilization was applied.