Synergistic Application of Nanoparticles and Plant Growth-Promoting Rhizobacteria in Sustainable Agriculture

Over time, to enhance agricultural productivity, the use of synthetic chemical pesticides has increased significantly. However, this approach has had detrimental effects on plants, soil, the environment, and human health, requiring immediate attention and prompt action. Among existing approaches, the use of natural microbial-based biofertilizers, i.e., plant growth-promoting rhizobacteria (PGPR), is a promising option to address the unrelenting challenge. PGPR enhances plant productivity through multiple direct and indirect pathways, including the most prominent ones: nitrogen fixation, potassium and phosphate solubilization, synthesis of plant growth-promoting hormones, siderophore production, and inhibition of pathogenic strains. Some strains are also demonstrating advanced traits, such as endophytic potential and nanoparticle production. Several PGPR are now reported to have the potential to produce nanoparticles, particularly silica, selenium, and silver nanoparticles, thereby enabling green synthesis. The trait also addresses the challenges associated with PGPR field application, including restricted diffusion, limited targeted delivery, and low permeability. Nanotechnology-based delivery systems are presently being introduced in agriculture due to their innovative formulation strategies and anticipated environmental and human health benefits. This book chapter discusses the application of nanoparticles used along with PGPR within the framework of sustainable agriculture.