Influence of Cropping Practices on the Persistence and Vertical Migration of Escherichia coli from Wastewater in Hydromorph Soil in Wet Tropical Zone

Little attention is paid to the influence of cultivation practices on the persistence and vertical migration of undesirable bacteria in hydromorphic soils as they have increased the risk of crop recontamination. Therefore the objective of this study was to determine the implication of some cultural practices on the persistence and vertical migration of E. coli in the soil. In this study, raw sewage (single application) and stream water (multiple application) were applied on lettuce, carrot and aubergine plots. The results revealed that overall, E. coli persisted longer on plots with crops and were more persisted in the rainy season on all cultivated plots that had received wastewater from the sewage treatment plant until harvest. While in the dry season, it was only detected at harvest on lettuce plots. The E. coli rate increased gradually overtime on the plots that had received water from the watercourse. Aubergine was the only plant that significantly facilitates the vertical migration of E. coli to the water table. On the whole, crops favored the persistence of E. coli on the soil surface and therefore increase the health risk related to the use of wastewater in agriculture.