Plantain dominated in mown mixed swards, but produced less than the original ryegrass-dominant sward

This trial determined the effect of compost on mixed species pasture. Existing (five year old) perennial ryegrass provided the control. A mixture of perennial ryegrass, white clover and plantain was sown into sprayed-out treatment plots, giving five replicates of six treatments. One treatment was direct drilled another was cultivated and drilled. The remaining three were spread with compost (50, 100 or 150 t/ha wet weight) and cultivated. Plots were mown at 35 d intervals for two years with clippings returned to the sward. Although grass established well at 500 plants/m2 plantain quickly came to dominate in all renewed plots, at 55-61% of DM in year 1 and 57-79% of DM in year 2. Grass contributed 29-35% of DM in year 1 and 10-30% in year 2, with clover 5-8% in year 1 and 10-14% in year 2. Grass dominated control plots (73 and 82% DM, respectively), while clover contributed more DM in absence of plantain (22% and 17%). Compost did not affect production. Cultivation gave a slight advantage over direct drilling, but new swards produced <50% the total DM of the control (P<0.05). Substantial investment was involved, so rewards need to be considerable to recoup costs.