Soybean producers facing increasingly erratic rainfall patterns may have a new tool to safeguard yields: strategic seed treatments that shape microbial communities in the root zone.

A new study published in Science of the Total Environment found that Cruiser MAXX seed treatment helped soybeans better withstand flooding stress by altering the diversity and function of the root and rhizosphere microbiome. Flooding reduced soybean yields by up to 746 kilograms per hectare, but treated plants showed enhanced growth, pod count, and reduced flood injury, particularly when flooding occurred three to seven days after planting.

Researchers conducted field trials at the University of Missouri’s Lee Greenley Jr. Memorial Farm, applying flooding at 0, 3, and 7 days after planting. They analyzed plant performance alongside microbial composition using shotgun metagenomic sequencing.

The treatment was found to significantly increase the abundance of beneficial microbes, such as Proteobacteria, and modulate genes related to phytohormone biosynthesis, nitrogen cycling, and carbohydrate metabolism. While flooding decreased overall microbial diversity and functional gene counts, treated plants maintained greater microbial stability and resilience.

The study also identified a redistribution, not a total loss, of microbial function in response to flooding. These shifts suggest that treated plants can recruit and maintain critical microbial support systems even in hypoxic soil conditions.

This research underscores the need for integrated crop management approaches that account for both abiotic stress and microbial ecology, especially as climate change increases the frequency of extreme weather events affecting germination and early root development.

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Source:
Ahmad, W., Coffman, L., Ray, R., Woldesenbet, S., Singh, G., & Khan, A.L. (2025). Flooding episodes and seed treatment influence the microbiome diversity and function in the soybean root and rhizosphere. Science of the Total Environment. https://doi.org/10.1016/j.scitotenv.2025.179554