Skip to main content
ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #400897
Research Project: Developing Best Management Practices for Poultry Litter to Improve Agronomic Value and Reduce Air, Soil and Water Pollution

Location: Poultry Production and Product Safety Research

Title: Long-term impacts of conservation agriculture on system-level microbial communities and antibiotic resistance genes

Author
item SEYOUM, MITIKU - University Of Arkansas
item Ashworth, Amanda
item Owens, Phillip
item Moore Jr, Philip
item SAVIN, MARY - University Of Arkansas

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2022
Publication Date: 12/20/2022
Citation: Seyoum, M.M., Ashworth, A.J., Owens, P.R., Moore Jr, P.A., Savin, M. 2022. Long-term impacts of conservation agriculture on system-level microbial communities and antibiotic resistance genes. Abstract. Discovery Farms.

Interpretive Summary:

Technical Abstract: Animal manure improves soil fertility and organic carbon, but long-term deposition may contribute to antibiotic resistance genes (ARGs) entering the soil-water environment. Furthermore, little is known about the long-term impacts of animal manure inputs on the soil-runoff microbiome, which is an important aspect of soil health and the One Health Initiative. The aim of this work was to assess: 1) impacts of long-term conservation practices on the distribution of ARGs and microbial community dynamics in soil, manure (poultry litter and cattle), and runoff; and 2) associations between bacterial taxa, soil health indicators, ARGs, and heavy metals in manure, soils, and surface runoff in a longitudinal study following 15 years of continuous management. This management strategies consists of two conventional (continuously grazed and hayed) and three conservation systems (rotationally grazed, rotationally grazed with a buffer strip, and rotationally grazed with a fenced riparian buffer), all receiving annual poultry litter. Cattle manure, poultry litter, soil, and runoff samples were collected from each watershed in 2018 to 2019 and characterized using 16S rRNA gene sequencing. In addition, four representative ARGs (ermB, sul1, intl1, and blactx-m-32) were quantified from cattle and poultry manure, soil, and runoff using quantitative PCR. Results revealed that continuously grazed systems increased ARGs and microbial communities in soil compared to conservation systems. Further, ARGs were strongly correlated with each other in cattle manure and soil, but not in runoff. Similarly, after 15-years of conservation practices, relationships existed between heavy metals and ARGs. For example, Cu, Fe and Mn were positively linked to intl1, sul1, and ermB in the soil, but trends varied in runoff. These findings were further supported by network analyses that indicated complex co-occurrence patterns between bacteria taxa, ARGs, and physicochemical parameters. Overall, this study provides system-level linkages of microbial communities, ARGs, and physicochemical conditions based on long-term conservation practices at the soil-water-animal nexus.