Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2015
Publication Date: 3/31/2015
Citation: Brooks, J.P., McLaughlin, M.R., Adeli, A., Read, J.J. 2015. The effect of broiler litter, swine effluent, and municipal biosolids land application on small plot pathogen, antibiotic resistance, and nutrient levels (abstract). Waste 2 Worth Conference Proceedings. March 30-April 3, 2015, Seattle, WA.
Technical Abstract: Land applying agricultural and municipal wastes carries an inherent risk associated with nutrient and pathogen runoff and contamination, but with that risk comes a potentially sustainable process to reclaim otherwise residual waste material. Few studies compare the two residuals. The purpose of this study was to compare concentrated animal feeding operation (CAFO) manure to municipal biosolids. A 5x4 randomized block design comprised of broiler litter, swine effluent, and municipal biosolids treatments were land applied on a cooperator farm established with forage plots over a three-year period. Soil core samples were collected weekly followed by monthly, and were processed for heterotrophic plate count bacteria, thermotolerant coliforms, enterococci, staphylococci, gram-negative bacteria, Clostridium perfringens, Salmonella spp., Campylobacter spp., Listeria monocytogenes, antibiotic resistant bacteria and genes, and 16S rRNA. Immediately following land application, most pathogens and indicator bacteria were inactivated; however, Salmonella persisted through the first few months, particularly in waste with high organic content. Pathogen levels were dependent on waste type, with Clostridium perfringens typically found in swine effluent applied plots. Campylobacter spp. was not detected at any time point, and E. coli was fleetingly detected. Differences in phenotypic antibiotic resistance weren’t detected, while genotypic were different. Overall, the influence of waste didn’t alter 16S rRNA levels. Time significantly influenced the presence of 16S rRNA and pathogens, while indicator bacteria persisted, albeit at lower levels per time point. Microbial ecology, only briefly investigated via terminal restriction fragment length polymorphisms, yielded slight differences between plot treatments. Overall, differences between waste treatments were noted and influenced antibiotic resistance and pathogen/indicator persistence, which have short- and long-term public health risk implications.