Impact of surface‐applied liquid manure on the drainage resistance profile of an agricultural tile‐drained clay till field. Issue 4 (25th May 2022)

• Record Type: Journal Article
• Authors: Bech, Tina B.; Badawi, Nora; Rosenbom, Annette E.
• Is Part Of: Journal of Environmental Quality. Volume 51:Issue 4(2022)
• Page Start: 656
• Page End: 669
• Publication Date: 2022-05-25
• Subjects: Agricultural ecology -- Periodicals; Environmental engineering -- Periodicals; Pollution -- Periodicals; 630
• DOI: 10.1002/jeq2.20354
• Languages: English
• ISSNs: 0047-2425

Abstract

Abstract: Dissemination of antibiotic resistance genes (ARGs) in aquatic environments is a concern due to human and animal health. Application of liquid manure on agricultural land is an important source of ARGs, where pathogens, antibiotic‐resistant bacteria, and selective agents are released. To improve our understanding of ARGs spreading through soils, our main objective was to evaluate the effectiveness of the soil as a barrier protecting water resources. Over the course of a year, profiles and abundances of ARGs and mobile genetic elements in soil and drainage from an agricultural tile‐drained clay till field were investigated upon liquid pig manure application by applying high‐throughput quantitative polymerase chain reaction targeting 143 genes. The findings were as follows: (a) 97 genes were detected, where only the transposon gene tnpA‐03/ IS6 was shared between the genes detected in drainage and those in acidified liquid manure or fertilized soils, indicating that liquid manure application had a limited impact on the drainage resistance profile; (b) intI1 gene was present in ∼60% of drainage samples in concentrations up to 1, 634 intI1 ml –1 ; and (c) evapotranspiration from barley ( Hordeum vulgare L., 'KWS Irina') and a low groundwater table appeared to reduce preferential transport to drainage during the first 3 mo of liquid manure application. Interestingly, the first preferential transport to drainage was observed immediately after the harvest of spring barley. Overall, during the monitoring year we found the soil to be an effective barrier against the spread of fecal ARGs even though the occurrence of the intI1 gene questions the barrier effect from previous years. Core Ideas: Effects of liquid pig manure on soil and drainage were examined at field scale. HT‐qPCR described the antibiotic profile of liquid pig manure, soil and drainage. Soil antibiotic resistance increased and redistributed upon liquid manure application. Soil microbial resistome appeared resilient to previous liquid manure applications. The soil effectively reduced dissemination of antibiotic resistance genes and mobile genetic elements to drainage.