Nano-biofertilizers: A New Area for Enhancing Plant Nutrition

This chapter deals with new aspects of increasing the efficiency of agricultural fertilizers through applying combination of leading bio- and nanotechnology in the crop fertilization sector. Biofertilizers were discussed in terms of their function as plant growth-promoting and nutrient-solubilizing behaviors. Furthermore, the utilizations of nanoparticles were discussed as carrier and immobilizing agent in biofertilizers formulations. Several evidences that microorganisms associated with metals such as gold and silver nanoparticles resulted in more plant growth promotion compared to bacteria alone, which would provide promising opportunity to explore cost-effective and environmentally friendly nano-formulations for agricultural applications. The biochemical interactions within the rhizosphere that affect nanometal bioavailability including aggregation, anti-aggregation, redox reaction, and transformation to regulate the translocation of nanometals into the plants are discussed. Moreover, some plant nutritional aspect of bio-mediated nonfertilizer was discussed as recent investigations.