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With ever increasing population and urbanization, sewage sludge production has increased manifold. One of the potential disposal options of sewage sludge materials is the soil application for enhancing agricultural production. Although there are many benefits due to application of sewage sludge to agricultural lands, but there had also been reports of risks associated with human health. Several human pathogens viz, Salmonella sp., Rotavirus, Giardia lamblia, Ascaris lumbricoides are associated with it. There are occasions to come in contact with infection of these disease causing pathogens viz, during handling of sewage sludge in treatment plants, soil application or wastewater irrigation and through consumption of farm produce. Due to prolonged contact, sewage sludge treatment plant workers and farmers using sewage sludge in field pose the greatest risk of being infected. There are several treatment processes viz, air drying, composting, lime stabilization etc. and post treatment measures viz, drip irrigation, produce washing, disinfection etc. that can cause reduction of pathogens below safe limits, thus paving way for widespread application of sewage sludge in agriculture. Sewage sludge application has significant suppressive effect on various soil borne pathogens, viz., Fusarium, Sclerotium, Pythium, Verticillium etc. This disease suppression phenomenon is mainly due to the biopesticidal effect of several antagonistic microorganisms present in sewage sludge. Application of sewage sludge also alters some of soil properties favoring growth of these antagonistic microbes (Trichoderma, Pseudomonas), resulting in effective disease suppression. It may be concluded that sewage sludge can be applied to agricultural fields as a plant nutrient source and other benefits, such as suppressing of several plant pathogens without any threat to human health, provided it is properly treated with proper pre and post treatment measures.

Key Words: Sewage Sludge, Agriculture, Pathogens, Human Health

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Sewage sludge application in agriculture.pdf