Movement and persistence of fecal bacteria in agricultural soils and subsurface drainage water: A review

Jamieson, R.C. , Gordon, R.J., Sharples, K.E. , Stratton, G.W. and Madani, A. 2002. Movement and persistence of fecal bacteria in agricultural soils and subsurface drainage water: A review. Canadian Biosystems Engineering/Le genie des biosystemes au Canada 44:1.1-1.9. The presence of pathogenic bacteria in public and private water systems has emerged in the past year as a priority water quality issue. Livestock agriculture is considered one of the primary causes of bacterial contamination of surface and ground waters. The application of animal manures to tile drained land, and the subsequent transport of pathogens with subsurface drainage water to surface water systems, has been identified as a major pathogen transport pathway. The objective of this review is to summarize the information that has been produced with respect to the survival of fecal bacteria in soil waste systems and their transport to tile drainage water. Factors influencing fecal bacteria survival include moisture, soil type, temperature, pH, manure application rate, nutrient availability, and competition. Cool, moist environments are considered optimal for bacterial survival. Field scale transport studies have shown significant transport of bacteria to tile drains under common manure management practices. Results from column and field studies suggest that the transport of bacteria through undisturbed soils is primarily controlled by macropore flow phenomena. Manure management strategies intended to reduce bacterial transport to tile drains, such as deep tillage, may conflict with other environmental management concerns. Further research is required to: (i) assess the effects of alternate cultivation practices on bacterial transport, (ii) verify that enteric pathogens behave similar to indicator organisms, and (iii) evaluate the effects of manure pre-application treatment methods, such as long-term storage and composting, on bacterial survival. La presence de bacteries pathogenes dans les systemes d’aqueducs prives ou publics est devenue une priorite du debat actuel sur la qualite de l’eau. On considere que la production animale est une des principales causes de contamination bacteriologique des eaux de surface et souterraines. On a observe que les pathogenes migraient vers les eaux de surface principalement apres l’application de dejection animales sur des sols draines. L’objectif de cette revue de litterature est de presenter un resume de l’information qui existe sur la survie des bacteries fecales dans les sols et leur migration vers les drains. Les facteurs qui influencent la survie des bacteries fecales incluent l’humidite, le type de sol, la temperature, le pH, le taux d’application du fumier, la disponibilite des elements nutritifs et la competition. Dans des conditions fraiches et humides, la survie des bacteries est optimales. Lors d’etudes a l’echelle du champ ou des pratiques d’epandage conventionnelles etaient utilisees, on a observe une migration significative des bacteries vers les drains. Les resultats d’etudes dans des colonnes de sol et au champ suggerent que dans les sols qui n’ont pas ete travailles, la migration des bacteries est principalement controlee par le mouvement de l’eau dans les macropores. Certaines strategies de gestion des fumiers comme le labour profond, dont l’objectif est de reduire la migration des bacteries vers les drains, peuvent entrer en conflit avec d’autres preoccupations environnementales. Les besoins de recherche identifies sont: (i) de determiner les impacts de pratiques culturales alternatives sur la migration des bacteries; (ii) de verifier que les pathogenes enteriques se comportent de la meme facon que les organismes indicateurs; (iii) d’evaluer les impacts de pre-traitements du fumier, comme l’entreposage a long terme ou le compostage, sur la survie des bacteries.