Trent Northen studies the chemistry of microbiomes. More specifically, he studies how exogenous metabolites structure a microbial community, and, in turn, how those microbes change the metabolite pool and grow the microbial population. Because his work is primarily funded by the Department of Energy, he's focused on the microbial community in soil and on plant roots. He describes The basic cycle of plant life, metabolites, and the microbial population and how this complex system affects each of its parts; The methods of his lab's research, including studies on hydroponic plant systems that are paired with the work of colleagues in the field; and The applications for these studies, like carbon restoration in poor, less fertile soils. Trent Northen is the Interim Deputy of the EGSB Division and a Chemist Senior Scientist at the Berkeley Lab of Biosciences. He begins the podcast describing the rich and complex cycles of plant, metabolites, and microbes, noting  how plants feed microbes that live in and around their roots and how those microbial populations in turn help the plants with nitrogen-fixing, excluding pathogens, and transporting phosphorous, among other processes. His work mostly focuses on bacteria that live in close proximity to the roots, but he describes how fungi can interact with plant roots over very large distances. For example, biological soil crusts use fungal hyphae in extraordinary ways. He explains this process and ecology in more detail and then he describes his research into the microbial community attached to the roots of the plants—the rhizosphere. He also explains the mechanism of soil depletion in big agriculture, how the compost and organic carbon cycle of decaying plant materials is absent from larger farming systems. Furthermore, he elaborates on ways the work of his lab can and might address such problems as well as studying which plants might grow in low nutrient environments and heal the soil as well as practices for soil carbon restoration and other advances. For more information, see his lab's website, northenlab.org, and eco-fab.org. Available on Apple Podcasts: apple.co/2Os0myK