Productivity potential and seasonality of five grass species under varying Nitrogen levels at three latitudes in Ireland

摘要

This multi‐site project was initiated in Ireland to address the expected implications of the recent European Union CAP reform (26 June 2003), which established management directives that curtail soil fertility and animal stocking rates to threshold levels on farms.As this is expected to increase extensification of grassland use, the existing ryegrass based high fertility production systems (DAF 2007, Gilliland, 2007) need to be re‐evaluated for their ability to meet grazing animal needs in comparison with alternative minor grass species.Comparative studies of grass species have been conducted in the past ( Frame, 1989 and 1991) but varietal improvements have since been achieved in most species.Furthermore, the interactions between climate, fertility levels and stock grazing strategies for seasonal production have not been adequately determined.Therefore, the primary objectives for the current study were to assess the relative productivity potential of a range of grass species under different fertility and defoliation regimes at widely different climatic locations.