title: Redistribution and persistence of microorganisms and steroid hormones after soil-injection of swine slurry.
abstract: The redistribution and fate of contaminants in pig slurry after direct injection were investigated at two field sites, Silstrup (sandy clay loam) and Estrup (sandy loam), in Denmark. Intact soil samples were collected for up to seven weeks after slurry injection and concentrations of Salmonella Typhimurium Bacteriophage 28B (phage 28B), Escherichia coli, steroid hormones and other slurry components (water, volatile solids, chloride and mineral N) determined in and around the injection slit. The two experiments at Silstrup and Estrup differed with respect to slurry solid content (6.3 vs. 0.8%), as well as soil clay content (27 vs. 15%) and differed considerably with respect to the initial redistribution of slurry-borne contaminants in soil. The transport of microorganisms from the slurry injection slit to the surrounding soil was much lower than that of mineral N and chloride due to attachment and entrapment. The redistribution of E. coli was more affected by site-specific conditions compared to phage 28B, possibly due to the larger cell size of E. coli. The overall recovery of phage 28B was 0.8-4%, and of E. coli 0.0-1.3% in different samples, by the end of the study. Nine different steroid hormones were detected in the slurry slit, and a slow redistribution to the surrounding soil was observed. Overall recovery of estrogens was 0.0 to 6.6% in different samples. The study showed that the combination of soil and slurry properties determined the initial spreading of contaminants, and hence the potential for subsequent leaching.
authors.affiliation: Department of Agroecology, Aarhus University, Blichers Alle 20, DK-8830 Tjele, Denmark. Electronic address: aminmgmbau@yahoo.com.
authors.forename: M G Mostofa
authors.initials: MG
authors.lastname: Amin
authors.forename: Tina B
authors.initials: TB
authors.lastname: Bech
authors.forename: Anita
authors.initials: A
authors.lastname: Forslund
authors.forename: Martin
authors.initials: M
authors.lastname: Hansen
authors.forename: Søren O
authors.initials: SO
authors.lastname: Petersen
authors.forename: Mette
authors.initials: M
authors.lastname: Lægdsmand
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial / Q000662:veterinary; D003718:Denmark; D004926:Escherichia coli / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry; D012739:Gonadal Steroid Hormones / Q000032:analysis; D008372:Manure / Q000032:analysis* / Q000382:microbiology* / Q000821:virology; D009584:Nitrogen / Q000032:analysis; D012483:Salmonella Phages / Q000302:isolation & purification; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*; D034421:Sus scrofa; D053719:Tandem Mass Spectrometry
chemical_list: D012739:Gonadal Steroid Hormones; D008372:Manure; D012989:Soil Pollutants; D009584:Nitrogen
keywords: Animal slurry; Environmental fate; Microorganism; Steroid hormone