Development of an inexpensive legume-Rhizobium inoculation technology which may be used in aerial seeding

Abstract

Encapsulation of seeds with alginate entrapped rhizobia (AER) bead has been developed as a new seed-applied inoculum technique for utilizing legume-Rhizobium symbiosis for the management and protection of natural ecosystems. Alginate beads trapped water and immobilized rhizobia which ensured germination of seeds and nodulation of seedlings. Incorporation of a synthetic polymer, Jalshakti, in alginate beads did not enhance symbiotic nitrogen fixation but sufficient number of rhizobia remain viable in them even after 30 weeks of storage reflecting suitability of these materials as carriers for rhizobia. Plant cultures raised from these beads were similar to or even better than the inoculated controls in symbiotic parameters indicating the effectiveness of seed-applied inoculum technique. Pelleting of seeds with these polymers after coating with gum arabic lead to substantial reduction in symbiotic association and viability of rhizobia. Experiments involving two legume-Rhizobium associations indicated that the encapsulation of seed with AER bead is a cheap, inexpensive and effective inoculation technique which may be used in aerial seeding.