The Multifaceted Role of Silicon and Silicon-Solubilizing Bacteria in Sustainable Agriculture

Silicate-solubilizing bacteria (SSB) play a crucial role in weathering and converting insoluble Si minerals into plant-absorbable forms, thereby improving Si nutrition and plant performance. This chapter provides an overview of the multifaceted role of Si and SSB in sustainable agriculture. It begins by discussing the cycling of Si in soils, highlighting the key drivers and dynamics that control its availability. The chapter then delves into the mechanisms by which Si alleviates both abiotic and biotic stresses in plants. Particular emphasis is placed on the benefits of Si in enhancing the legume-rhizobia symbiosis and improving nitrogen fixation. The chapter further explores the diverse strategies employed by SSB to dissolve insoluble Si minerals. The taxonomic distribution of SSB is discussed, along with techniques for their isolation and identification. Finally, the chapter highlights the beneficial effects of SSB application in soils, as well as emerging strategies, such as the use of silicon nanoparticles and the combined application of SSB with low-cost Si sources, to further advance sustainable agriculture and food security.