The Effect of -sterilization of biofertilizer's carrier on bacterial inoculants survival

Tejima, Kohei; Yokoyama, Tadashi*; Sato, Katsuya; Takeda, Kiyoko; Narumi, Issei

Biofertilizer is a substance that holds beneficial microorganism for plant growth (e.g. Rhizobia) in the carrier such as peat, perlite, charcoal and soil. To use biofertilizer more efficiently, it is necessary to keep the amount of viable inoculants in the biofertilizer for a definite period of time. The inoculants survival in the biofertilizer could be affected by the physical and chemical properties of carrier materials and by the competition with native microorganisms in the carrier. -irradiation is expected to sterilize the carrier materials without changes in physical and chemical properties. In an effort to demonstrate the advantage of -sterilization, the survivals of inoculants were monitored to assess the shelf life of biofertilizer.