Rhizobial inoculation of Trifolium repens L. in Sri Lanka

The objective of this study was to develop an  environmental friendly, low cost technology for cultivation  of livestock forage legumes so as to minimise the use of  nitrogen fertiliser (N-fertiliser) that pollute the pristine  highland watersheds. Inoculants were prepared by screening  several rhizobial isolates obtained from farm cultivated clover  plants and selecting the most efficient strain. In field tests at  three separate sites, the average amount of biomass produced  by inoculated Trifolium plants was higher compared with the  plants fertilised with urea. Root nodulation and other plant  parameters were assessed on several randomly harvested plants  60 days after planting. The results indicate that root nodulation  and plant growth increased significantly in inoculated plants.  Average results obtained from nine crop cuts taken during a  period of 15 months showed that regeneration and biomass  production after crop cutting were better under inoculation  than under N-fertiliser application. It is inferred that rhizobial  inoculation has the potential to replace N-fertiliser applications  to Trifolium repens L. in the Sri Lankan highland farming  systems.