Plant Growth-Promoting Rhizobacteria (PGPR) and Compost Materials for AeroHydro Culture

Recently, the development of science and technology for understanding the function and use of microbes in the field of agriculture is increasing rapidly. The ability of microbes to adapt and capture the signals of environmental conditions, followed by genetic changes and the function of cell metabolism can be used as a model in optimizing microbial utilization. The beneficial microbes living in the rhizosphere are usually grouped as plant growth-promoting rhizobacteria (PGPR) and degrading agents microbes of agricultural waste or commonly called decomposers. Both groups of microbes are very important to support plant growth, especially in unfavorable environmental conditions. PGPR are beneficial rhizobacteria that enhance plant growth as well as its productivity with various mechanisms. The interaction of PGPR with host plants is an intricate and interdependent relationship involving not only the two partners but other biotic and abiotic factors of the rhizosphere region. The ability of inoculated bacteria to survive, outcompete with the native microflora, and colonize in the rhizosphere is a critical step for a successful application, especially in extreme conditions. The concept of biological and biochemical processes that is mutually beneficial between bacteria and plants can be used to overcome the environmental problems that are not suitable for plant growth, and finally, plants can grow and produce yield optimally, for example, in the peatland ecosystem. However, it has been difficult to inoculate PGPR and to maintain the root PGPR symbiotic system in field conditions, although sometimes it was a successful process in laboratory conditions. To avoid this inoculation deficit, an “Integrated PGPR Culture System” called AeroHydro Culture has been developed. In this chapter, the stabilization of PGPR function will focus on how to achieve supplying nutrients, oxygen, and beneficial substances based on “Land Surface Management” (AeroHydro Culture). The strategy to develop a liquid organic fertilizer containing selected multi-biocatalyst producing PGPR will also be discussed.