Impacts of manure application timing and tillage practices on antibiotic resistant bacteria and genes in drainage water from manured fields

dc.contributor.advisor Michelle L. Soupir
dc.contributor.advisor Adina Howe
dc.contributor.author Guyer, Hannah
dc.contributor.department Department of Agricultural and Biosystems Engineering (ENG)
dc.date 2019-11-04T21:48:52.000
dc.date.accessioned 2020-06-30T03:18:34Z
dc.date.available 2020-06-30T03:18:34Z
dc.date.copyright Thu Aug 01 00:00:00 UTC 2019
dc.date.embargo 2020-07-23
dc.date.issued 2019-01-01
dc.description.abstract <p>Agriculture is an economic cornerstone in Iowa and the surrounding states, as well as arguably the entire United States as a whole. However, there is growing concern about the use of antibiotics in the animal agriculture sector and its contribution to antibiotic resistance (Levy & Marshall, 2004). Yet it is still unclear how antibiotic resistance is affected by the environment at the field scale and what mechanisms can be employed to minimize the transport. This three-year study monitors both phenotypic and genotypic antibiotic resistance markers in subsurface drainage from research plots with varying manure application times and tillage practices. Enterococcus and tylosin and tetracycline-resistant Enterococcus were monitored as well as three antibiotic resistant genes (ermB, ermF, tetM) to 1) quantify antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in subsurface drainage 2) evaluate the impact of field management practices, manure application timing and tillage both the antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs), and 3) assess relationships between phenotypic and genotypic indicators of antibiotic resistance. Results of the study show overall low levels of both ARB and ARGs leading to further research questions with the targeted improvement of new methods. Although recommendations on specific field management practices best suited to minimize ARB and ARG transport cannot be drawn from the results of this study, it was shown that manure application in the spring had the strongest potential for future research.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/17458/
dc.identifier.articleid 8465
dc.identifier.contextkey 15681450
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/17458
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/31641
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/17458/Guyer_iastate_0097M_18335.pdf|||Fri Jan 14 21:23:32 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Bioresource and Agricultural Engineering
dc.subject.keywords Agriculture
dc.subject.keywords Antibiotic Resistance
dc.subject.keywords Drainage
dc.subject.keywords Manure
dc.subject.keywords Water Quality
dc.title Impacts of manure application timing and tillage practices on antibiotic resistant bacteria and genes in drainage water from manured fields
dc.type thesis en_US
dc.type.genre thesis en_US
dspace.entity.type Publication
relation.isOrgUnitOfPublication 8eb24241-0d92-4baf-ae75-08f716d30801
thesis.degree.discipline Agricultural and Biosystems Engineering
thesis.degree.level thesis
thesis.degree.name Master of Science
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