Differential shifts in microbiome and pathogen populations associated with suppressive soil in long-term continuous corn field compared to rotation corn field

Authors: Adesemoye, Anthony; KODATI, S - University Of Connecticut; Watts, Dexter; MAHARJAN, B - University Of Nebraska

Submitted to: Applied Soil Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2023
Publication Date: 12/1/2023
Citation: Adesemoye, A.O., Kodati, S., Watts, D.B., Maharjan, B. 2023. Differential shifts in microbiome and pathogen populations associated with suppressive soil in long-term continuous corn field compared to rotation corn field. Applied Soil Ecology. 192:105093. https://doi.org/10.1016/j.apsoil.2023.105093.
DOI: https://doi.org/10.1016/j.apsoil.2023.105093

Interpretive Summary: A better understanding of agricultural fields that have low soilborne diseases and high number of beneficial soil microbes could help with the development of eco-friendly alternatives to manage soil-borne diseases. Samples were collected during three times of the year from four locations in Nebraska to determine microbial diversity and activity of specific groups. These samples were collected from long-term continuous corn fields that had a long history of no noticeable disease and corn fields under crop rotation with relatively higher amounts of disease. Comparisons among fields indicated relatively higher populations of potential biocontrol agents such as Bacillus, Paenibacillus, Massilia, Pseudomonas, and Sphingomonas and lower populations of pathogens, Fusarium and Gibberella in the long-term continuous corn field compared to other three fields. This study identified certain beneficial microbes that play important roles in development of soil suppressive properties. Further research is needed to help improve our understanding of this process.

Technical Abstract: Unraveling soil suppressiveness and the microbiome involved could provide the insight needed to advance development of cost-effective and eco-friendly alternatives for managing soilborne diseases. This could enhance crop production and help achieve the increase needed in global food production without large-scale use of pesticides and other chemical inputs, which may cause pollution and negatively affect human health. The goal of this study was to evaluate potential changes in the microbiome and diversity of beneficial microbial communities in the soil suppressive to soilborne pathogens in long-term continuous corn compared to rotation corn field. Samples were collected three times during the year from four locations in Nebraska. Sequencing was conducted on the paired-end Illumina HiSeq platform with three primer sets, including 515F/806R, 1737F/2043R, and 1380F/1510R. Mineralizable nitrogen, carbon (IV) oxide carbon, and biomass carbon evaluated for microbial activity showed a consistent pattern. Comparisons among field locations reflected a relatively higher operational taxonomic units (OTUs) for potential biocontrol agents Bacillus, Paenibacillus, Massilia, Pseudomonas, and Sphingomonas in the long-term continuous corn field compared to other three locations. The taxonomic composition of the fungal communities revealed a high population of Fusarium or the anamorph, Gibberella, in the rotation field compared to the long-term continuous corn field. This study identified certain beneficial microbes that can play important roles in the development of soil suppressive properties. More research is needed to reduce the time required to attain soil suppressiveness.