POTENTIAL PRODUCTIVITY OF RED CLOVER VARIETIES IN S.W. SCOTLAND

A reassessment of the potential productivity of 37 varieties of red eiover suggests that DM productivity is equivalent to grass given fertilizer N at 252 kg/ha for the 1st year, 209 kg/ha for 2nd year and 144 kg/ha for 3rd year of production. Corresponding equivalents for CP productivity of the red clover swards were 298, 228 and 206 kg N/ha. Varietal differences in productivity were significant Average yields of total herbage DM in the 1st, 2nd and 3rd harvesting years were 10.9, 8.7 and 8.2 t/ha, containing 6.5, 5.9 and 6.0 t/ha red clover, respectively. For two harvesting years, the most productive varieties were Essi, Kuhn, Hungaropoly, Robina, Tilo Daehnfeldt, Redhead and Corona Otofte. Rea 4N and a few other tetraploid varieties were very productive in the 3rd year. Hungaropoly, although showing a decline in the 3rd year, was the most productive over 3 years, with an average yield of 11.5 t/ha per year total herbage DM containing 10.2 t/ha per year red clover DM. Such high potential DM production warrants further investigation into the persistence of red clover, its conservation and the problems of its utilization by livestock.