Transport and Retention of Manure‐Borne Coliforms in Soil

Abstract

the groundwater quality from the watershed would improve with distance from the pollution source as a result Manure is a source of several bacterial pathogens that can potenof dilution, sedimentation, and bacteria die-off. tially contribute to surface and groundwater contamination. Results from most bacterial transport studies in soils are only partially applica-Although soil can mitigate bacterial movement or ble to manure-borne bacteria because microorganisms are released leaching, some bacteria applied onto soil or released along with manure particulates as manure dissolves. The objective of within soil may still be transported through and travel this study was to compare transport of chloride ion, Escherichia coli in the vadose zone to groundwater. Much literature (E. coli) and manure colloids in undisturbed soil columns with a documents bacterial transport from a few meters to well-developed structure. Breakthrough column experiments were 830 m depending on soil or sediment texture and permeconducted with undisturbed, 20-cm long Tyler soil columns from the ability, water saturation degree, and length of time. A horizon. A pulse of 4% filtered bovine manure solution with E. Stoddard et al. (1998) showed that fecal bacteria were coli and KCl was passed through the columns. Escherichia coli contransported to a depth of 90 cm in silt loam soil by the centrations, chloride content, and turbidity were measured in influent first rain after application of dairy manure, when Ͻ2 and in effluent. Columns were cut into 2-cm layers after the experiment to measure: (i) viable bacterial concentrations in pore solution and cm of rain had fallen during a single event. Rainfall or attached to soil; (ii) bulk density; (iii) water content. Companion batch irrigation at intensity of 1 cm h Ϫ1 appeared to be suffiexperiments were performed to measure attachment of E. coli to cient to transport bacteria in poultry manure on the soil in the presence of various amounts of manure. Escherichia coli surface of soil block to a depth of at least 32.5 cm in attachment to soil decreased with increased manure content due to the silt loam soil as result of preferential flow in wellincreased competition for attachment sites. Flow velocity affected structured soil (McMurry et al., 1998). In tilled blocks, E. coli transport and attachment to soil; there was relatively more the fecal coliform concentrations took longer to elute attachment at slower flow velocity than at higher flow velocity. Eschebecause preferential flow paths were disrupted in the richia coli attachment to soil was 18, 5, and 9% at flow velocities of upper 12.5 cm of the soil. Rainfall on well-structured 2.3, 8.4, and 9.3 cm d Ϫ1 , respectively. Spatial variability in soil structure soil caused the preferential movement of fecal bacteria may result in large variations of pore water velocity and consequent differences in transport of manure particulates and bacteria under even in unsaturated flow conditions (McMurry et al., ponded infiltration.

Occurrence of Tylosin-Resistant Enterococci in Swine Manure and Tile Drainage Systems under No-Till Management

“…concentrations and more diverse bacterial species in manure, the more likely that a fraction will be transported through the soil column (Unc and Goss, 2004). Injection of liquid manure into soil can contribute to the rapid movement of bacteria through soil in a short time period after manure application (Guber et al, 2005). Other possible causal factors include bacterial decay; bacterial attachment to soil particles during the process of flow migration in macropores (Beven and Germann, 1982); filtering and retention of microorganisms by the soil during matrix flow; and tillage treatment and soil moisture before manure application.…”

Relação da velocidade de escoamento da solução e do comprimento da coluna de solo com os parâmetros de transporte de potássio em um latossolo e um neossolo

“…Vários estudos de deslocamento de substâncias químicas no solo, como agrotóxicos (Barizon et al, 2006;Montoya et al, 2006;Raymundo et al, 2009) e reguladores de crescimento vegetal (Milfont et al, 2008), são realizados utilizando colunas de lixiviação. O movimento de microrganismos no solo também tem sido estudado em ensaios com colunas (Chu et al, 2003;Guber et al, 2005;Rockhold et al, 2005).…”

Bacteria transport and retention in intact calcareous soil columns under saturated flow conditions

“…Bacteria can only access a smaller range of larger pores due to size exclusion, whereas the chloride can access a wider range of pore sizes. Some other investigators have also observed an earlier breakthrough of bacteria than chloride in intact soils (Guber et al, 2005;Levy et al, 2007;Pang et al, 2008).…”

“…Soil is traditionally considered as an effective bacterial filter (Gilbert et al, 1976;Guber et al, 2005;Kadam et al, 2008;Pachepsky et al, 2006;Stevik et al, 2004). But, soils usually contain some macropores that work as pathways of rapid transport of bacteria.…”

“…Several studies (e.g. Cey et al, 2009;Darnault et al, 2004;Guber et al, 2005;Jiang et al, 2010;Pang et al, 2008;Pivetz et al, 1996;Unc and Goss, 2003;Wang et al, 2013) have revealed that microorganisms and colloids can transport within preferential flow pathways.…”