APPROACHES TO A GREATER USE OF BIOLOGICAL NITROGEN-FIXATION IN LEGUME-GRASS SWARDS

Rhizobium strains which early promote the nitrogenase activity and boost yields in alfalfa or red clover may also increase dry matter and crude protein yields in alfalfa-grass or red clover-grass swards, provided the legumes make up at least 70 % of the dry matter. When preparing the seed mixtures, the site-specific competitive power of the grasses must be taken into consideration. Inoculated legume-grass swards give higher dry matter and lower crude protein yields, compared with legumes grown alone.