Occurrence of couch grass [Elytrigia repens (L.) Desv. ex Nevski] under different grassland management

The objective of this research was to investigate occurrence of common couch grass (Elytrigia repens (L.) Desv. ex Nevski) under different grassland management by means of a small-plot trial. The trial was managed during 2003–2011 with four levels of utilisation: intensive (4 cuts per year, 1st cut on 15 May), medium intensive (3 cuts per year, 1st cut on 30 May), low intensive (2 cuts per year, 1st cut on 15 June), and extensive (2 cuts per year, 1st cut on 30 June). Four rates of fertilisation were applied for each utilisation treatment: nil-fertilisation, P30K60, N90P30K60, and N180P30K60 (pure nutrients). The intensively utilised treatments without N fertilisation showed the lowest mean percentage cover of couch (3.0 %, and 2.8 %, respectively). Further, we found a significant increase in couch grass cover (up to about 30 %) as a response to nitrogen fertilisation and it was most significant in grasslands utilised with two cuts per year. It can be concluded that grassland utilisation in three cuts per year and the dose 90 kg.ha−1 of nitrogen led to the maintenance of the occurrence of couch at the reasonable level up to 10–15 %.