Link to home

Crop-specific microbiome responses to four-year rotational sequences

Maria Soledad Benitez Ponce: The Ohio State University

<div>Crop rotations beyond two years provide multiple benefits to agroecosystems, which result from interactions between plants, soils and microorganisms. Two consecutive years of sampling in the corn and soybean phase of diverse 4-year rotation sequences and a 2-year corn-soybean rotation was performed at a field site in South Dakota. Rotation sequences studied included small grains, legumes and/or oil-seed crops. Plants were sampled at seedling and flowering to evaluate plant vigor and rhizosphere-associated microbiome through amplicon sequencing of bacterial and fungal ribosomal markers. Both years soybean performed best in rotations containing winter wheat, and performance was not different between the 2-year and the 4-year rotations including spring wheat. Soybean rhizosphere mycobiome mirrored this pattern and was driven by differences in abundance of Glomeromycetes and Sordariomycetes across rotation sequences. Soybean rhizosphere-associated bacteria responded to plant stage with higher abundance observed at flowering for taxa across different phyla. For corn, greatest plant vigor was consistently observed in a rotation including spring wheat, particularly when pea preceded corn. Corn rhizosphere-associated fungi and bacteria preferentially responded to plant stage. Further analysis will focus on interactions between rotation sequence, crop species and crop developmental stage to provide insight on microbiome benefits stemming from diversified cropping systems.</div>