SitS: Electrochemical signals to monitor soil microbiome structure and function

This award was made through the "Signals in the Soil (SitS)" solicitation, a collaborative partnership between the National Science Foundation and the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA). Soil health reflects the ability of soil to support both plant growth and other ecosystems. To date, there is limited knowledge on how soil microbiome compositions and activities are associated with electrochemical signals in the soil environment.

Electrochemical signals produced by organisms in soil can be used to advance non-destructive monitoring of belowground microbiomes and their functional relationships to soil health and plant productivity. The correlations between soil microbiome structure and function and electrochemical signals can be used as a sensor. Such a sensor can be used to predict and control soil health in real-time to improve plant productivity.

This project will train undergraduate and graduate students in the fields of microbial electrochemistry, microbial ecology and -omics, and data science to help generate a much needed workforce with expertise in data- and model-driven soil science and engineering. If successful, this work will develop tools to support future ecosystem research in new ways and help protect the Nation’s food security by enabling more support for sustainable agriculture decisions.

The soil microbiome plays critical roles in plant growth and ecosystem services with relevance to both managed and wild terrestrial habitats. This microbiome is one of the most challenging systems to study due to high biological diversity and spatial heterogeneity. Most work to date focused on dissecting the genomic and metabolic basis of interactions within the microbiome and between the microbiome and plant hosts.

However, there is a lack of measurements that would enable rapid assessment of community structure and function for the purposes of microbiome monitoring, management, and manipulation. In addition, there is limited knowledge on the correlations between electrochemical signals, microbiome structure and function, and soil. Uncovering these relationships will provide foundational knowledge that will enable new ways of monitoring and manipulating plant and soil microbiomes.

One novel approach will take advantage of the fact that much of metabolism conducted by living organisms is redox chemistry. This chemistry is measurable through extracellular electron transfer–electrochemical signals. The project goal is to understand electrochemical signals in plant-soil-microbe systems and develop rules relating electrochemical signals to microbiome function in a model agricultural system.

The project activities include 1) investigation of electron transfer mechanisms in soil to link electrochemical signals, local chemical conditions, and microbial community structure and function; 2) investigation of feedbacks between electrochemical signals, microbiomes and plant phenotypes, and performance; and 3) extraction of rules from high-dimensional data correlating microbiome structure and function to electrochemical signals and plant phenotypes and sensor. This project will build the fundamental knowledge to predict microbiome structure and function from electrochemical signals, paving the way for more in-depth understanding of soil microbiome activity and soil health.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.