The effect of management system and N-fertilization on the N and P content of leys in the Ioannina Prefecture

The use of leys (cultivated grasslands), play an important role on animal nutrition as well as on the protection of the natural environment from degradation, specifically on mountainous and semimountainous areas comprising, mostly, of abandoned or degraded fields. Important factors that need to be considered in establishing lays are species selection, management systems, and grazing animals. This study presents the results from nitrogen (N) fertilization and lay type on N and phosphorus (P) levels of cultivated and indigenous plant species in a field in the Ioannina prefecture. The three-years experiment comprised of two treatments: 1. Three lay types: Trifolium repens with Lolium perenne, T. pratense with Lolium perenne and Lolium perenne (monoculture), and 2. N-fertilization at the levels 0 kg/ha, 40 kg/ha and 80 kg/ha. Sheep grazed the field. Sampling took place at the end of the third year. The results suggested that fertilization and lay type had no effect on N and P levels of perennial ryegrass. On the contrary, the interaction of lay type and N-fertilization differentiated the N and P levels of plant litter. Additionally, lay type influenced the P-levels of the indigenous species. The results indicate the importance of the appropriate species selection for lay management. The use of nitrogen fixing species may positively influence the diversity as well as N and P content of the indigenous species minimizing the need for further fertilization.