Is there a Role for Microbial Management in Organic Agriculture?
Project Director
Terrence H. Bell
Year Funded
2019
Award Number
2019-51106-30196
Funded Institution
Pennsylvania State University
Grant Program
ORG (Organic Transitions)
USDA NIFA Report (alternate)
Project Overview
Many organic farmers seek to optimize soil biological function through organic soil amendments and commercial microbial inoculants designed to enhance soil health or perform specific functions. The complexity of soil microbial ecosystems and management variables makes efficacy of these inputs highly variable and difficult to predict.
This project endeavored to elucidate the leading factors modulating soil microbial processes and the potential benefits of applied inoculants, and to develop guidance on when and how to use them.
Farmer Takeaways
(1) Soil salinity and high levels of soluble N – conditions that often occur in high tunnel soils – can slow microbial colonization and limit diversity.
(2) Soil disturbances such as fumigation, solarization, or anaerobic soil disinfestation reduce microbial diversity and can interfere with functions such as N cycling.
(3) Reinoculation with diverse soil microbial guilds (not just one or a few species) can restore these soil functions.
(4) Commercial microbial inoculants vary widely in quality, and some may not even contain the active organisms listed on their label.
Project Outputs
Understanding and Managing Soil Microbes | Penn State Extension Article
Soil Microbes in Organic Cropping Systems 101 | eOrganic Webinar
Management of Soil Microbes on Organic Farms | eOrganic Webinar
King, William L., Sarah C. Richards, Laura M. Kaminsky, Brosi A. Bradley, Jason P. Kaye, and Terrence H. Bell. 2023. “Leveraging Microbiome Rediversification for the Ecological Rescue of Soil Function.” Environmental Microbiome 18 (1): 7.
King, William L., Laura M. Kaminsky, Maria Gannett, Grant L. Thompson, Jenny Kao-Kniffin, and Terrence H. Bell. 2022. “Soil Salinization Accelerates Microbiome Stabilization in Iterative Selections for Plant Performance.” New Phytologist 234 (6): 2101–10.
King, William L., and Terrence H. Bell. 2022. “Can Dispersal Be Leveraged to Improve Microbial Inoculant Success?” Trends in Biotechnology 40 (1): 12–21.