THE EFFECTS OF AUTUMN MANAGEMENT ON GRASS GROWTH IN WINTER AND SPRING

The effects of date of autumn closure and nitrogen application on grass growth in winter and spring were examined. The experiments were carried out at Lusignan, West Central France and at Johnstown Castle, South East Ireland. In France, autumn nitrogen and early closing increased tiller numbers during winter and produced earlier growth. The latter was due to the number of tillers present, rather than the size of the individual tillers. In Ireland and in France, early autumn closed plots had greater tiller numbers than the late autumn closed plots and this resulted in earlier spring grass. Autumn nitrogen had no influence on either tiller numbers or growth in spring under the conditions that pertained in the experiments in Ireland. Nitrogen concentration in the leaves in autumn and winter was lower under French than under Irish conditions. These results suggest that under Irish conditions autumn nitrogen is not needed for the promotion of early grass, assuming that N levels in herbage in autumn are generally in the region of 3.5-4.0 g kg-1 dry matter.