Short-term integration of perennial peanut into bahiagrass system influence on soil microbial-mediated nitrogen cycling activities and microbial co-occurrence networks

Project Type: Graduate Student
Funds awarded in 2022: $16,454.00
Projected End Date: 08/31/2024
Grant Recipient: University of Florida
Region: Southern
State: Florida
Graduate Student:
Major Professor:
Dr. Hui-Ling Liao
University of Florida
Integration of perennial peanuts into warm-season grasslands offers a potential solution to reduce nitrogen (N) fertilizer input and enhance N cycling through soil microbial activities. There is limited information on the changes in soil microbial diversity and communities following the short-term integration of rhizoma perennial peanut (RPP; Arachis glabrata Benth.) into warm-season perennial bahiagrass (Paspalum notatum Flügg´e) as well as its impact on N cycling processes. This study investigated changes in N cycling populations and soil microbial communities in bahiagrass-RPP mixtures compared to their monocultures at <2 years after RPP establishment in Spring (March) and Fall (October) seasons. Real-time qPCR was used to quantity N functional groups in the soil involved in nitrification, denitrification, and N2 fixation. DNA amplicon sequencing was employed to examine co-occurrence networks of soil microbes, while activities of soil enzymes [N-Acetyl-β-d-glucosaminidase (NAG) and leucine aminopeptidase (LAP)] involved in N mineralization were also measured. Bahiagrass-RPP mixtures had no effect on N cycling genes. Ammonia oxidizing archaea were the major ammonia oxidizing prokaryotes compared to ammonia oxidizing bacteria in bahiagrass-RPP systems. We found that bahiagrass-RPP mixtures exhibited greater prokaryotic alpha diversity and NAG activities than RPP monoculture. Meanwhile, RPP influenced soil fungal community composition (beta diversity) and enhanced the relative abundance of dominant
soil fungal genera (Fusarium, Gibberella, and Humicola). The presence of RPP in bahiagrass systems led to increased negative microbial interactions in microbial occurrence networks. Greater complexities in microbial networks were linked to forage growth season, which was related to enrichment of the relative abundance of Basidiomycota. Our findings showed that RPP has the potential to influence N cycling process in bahiagrass system by altering the abundance of certain N cycling microbes, especially fungal taxa, within 2 years of RPP establishment.
Peer-reviewed Journal Article
Adesuwa Erhunmwunse, University of Florida
Cheryl Mackowiak, University of Florida
Ann Blount, University of Florida
Jos´e Dubeux, University of Florida
Andrew Ogram, University of Florida
Hui-Ling Liao, University of Florida
Target audiences:
Farmers/Ranchers; Educators; Researchers; Consumers
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.