Effects of nitrogen fertilizer and red clover (Trifolium pratense L.) component on productivity of grass-legume mixed swards

The effects of two levels of red clover (low and high) and three levels of N fertilizer (0, 28, 56 N kg ha-1) on herbage accumulation and quality of grass-legume mixed swards were studied. Total herbage accumulation of the mixtures with high legume percentage was significantly higher than those with low legume percentage and this was most pronounced at second harvest. Swards high in legumes also had higher crude protein concentrations and lower weed percentages than those low in legumes. Although the effect of N on herbage accumulation was not significant, an increase was observed for crude protein concentration of the grass fraction at the higher N levels. A reduction in legume percentage was observed with increasing levels of N. It was concluded that presence of 25 to 35% red clover in the sward increases total herbage accumulation.