Symbiotic nitrogen fixation between legumes and rhizobia is one of the most important and interested subjects in agriculture. To perform this process in a controlled manner, rhizobium inoculants, composed of bacterica and carrier, are used.
Most of manufacturers use peat as the carrier, but this natural compound is not found in Iran. This research directed to prevention of import of soybean rhizobium inoculants and to expansion of high quality nitrogen fixation in domestic legumes. So, the goal of this research is preparation of an appropriate carrier form native organic wastes and minerals and replacement of peat by it.
In this way, 97 simple and mixed compounds were prepared in the form of gamma irradiated and steam sterilized powders and injected with active nitrogen fixing bacteria (microsymbionts of soybean). As the results showed, ideal carrier, a combination of coal, carbonaceous soil, corncob compost, leaf compost, bagasse and perlite, can conserve bacteria in 4oc in a 4 month period with the final concentration of 1×108 to 1×109 bacteria per gram.