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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/ IS6was 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) intI1gene was present in ∼60% of drainage samples in concentrations up to 1,634 intI1ml–1; and (c) evapotranspiration from barley (Hordeum vulgareL., ‘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 intI1gene questions the barrier effect from previous years. 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.

Polyacrylamide (PAM) is used in agriculture to reduce soil erosion and has been reported to reduce turbidity, nutrients, and pollutants in surface runoff water. The objective of this work was to determine the effect of PAM on the concentration of enteric bacteria in surface runoff by comparing four enteric bacteria representing phenotypically different motility and hydrophobicity from three soils. Results demonstrated that bacterial surface runoff was differentially influenced by the PAM treatment. Polyacrylamide treatment increased surface runoff for adhered and planktonic cells from a clay soil; significantly decreased surface runoff of adhered bacteria, while no difference was observed for planktonic bacteria from the sandy loam; and significantly decreased the surface runoff of planktonic cells, while no difference was observed for adhered bacteria from the clay loam. Comparing strains from a final water sample collected after 48 h showed a greater loss of Escherichia coliwhile Salmonella entericaserovar Poona was almost not detected. Thus, (i) the PAM efficiency in reducing the concentration of enteric bacteria in surface runoff was influenced by soil type and (ii) variation in the loss of enteric bacteria highlights the importance of strain‐specific properties that may not be captured with general fecal indicator bacteria.