Biochar as an alternate carrier to lignite for the preparation of biofertilizers in India

Carrier based preparations of Azospirillum lipoferum (AZ 204) inoculant, developed using two different sources of biochar (acacia wood and coconut shell) were evaluated in comparison with lignite for their suitability as a best alternate to lignite for biofertilizer production. The survival of the microbial inoculant was estimated over a period of 180 days. Among the different carriers, coconut shell based biochar recorded a maximum population of log 10.79 cfu g-1 of carrier on 180 days after inoculation with a maximum moisture content of 25.22%. It was also found that seedling vigour index of green gram (CO 3) was paramount in response to coconut shell based biochar. In addition, coconut shell based biochar was found to increase the survival of Azospirillum lipoferum upto 180 days (6 months) of storage period at a required population compared to acacia wood based biochar and lignite.