Rebuilding Healthy Microbiomes

Problem

How can soil quality be sustained under intensive, repeated use?

• Although high tunnels can extend the growing season, the quality of the soil under them tends to degrade over time, and crop disease can increase.
• Growers often use chemical fumigation or other soil-sterilizing approaches to kill disease-causing microbes, which can wipe out beneficial microbes essential to plants.

Findings

Researchers looked at how high soil salinity and high soil nitrogen concentrations altered soil microbiome development. They buried small nylon mesh bags containing unsterilized "source" soil in sterilized "recipient" soil and left them to incubate for seven weeks. Recipient soils were amended with salt, nitrogen, both, or neither to determine whether these properties impacted the microbial communities' composition in the recipient soil.

• They found that higher soil salinity and higher soil nitrogen delayed the re-establishment of a diverse soil microbiome.

Impact

The results of this study help to untangle the many factors impacting the recolonization of microbial communities that benefit crop production. The team's findings are laying the groundwork for the development of guidelines that will aid farmers in improving soil fertility, and by extension, crop health and yield.

Research Credit

Team

• Laura Kaminsky, Paul Esker, Terrence Bell

Participating Department

• Plant Pathology and Environmental Microbiology

Competitive Funding

• USDA NIFA (Organic Transitions Program)
• NSF (Graduate Research Fellowship)

Federal and State Appropriations

• USDA NIFA Hatch Projects PEN04651 and PEN04660, Accession #1016233 and #1016474

Emerging Discoveries

Rebuilding soil microbiomes in high-tunnel agricultural systems focus of study

February 08, 2021

The presence of high salt and nitrogen concentrations in high- tunnel soils may make it more challenging to rebuild a healthy soil microbiome following a soil- clearing event, according to microbial ecologists in Penn State’s College of Agricultural Sciences.

Published Research

Abiotic conditions outweigh microbial origin during bacterial assembly in soils.

• Kaminsky, L. M., Esker, P. D., & Bell, T. H. (2021). Abiotic conditions outweigh microbial origin during bacterial assembly in soils. Environmental microbiology, 23(1), 358-371. https://doi.org/10.1111/1462-2920.15322