Long-term Application of Sewage Effluents

Irrigation with sewage water not only meets the water requirement but also fulfill partial nutrient need of the crop. Beside this, under arid and semi arid conditions where irrigation is a prerequisite for successful agriculture, sewage water as a source of irrigation is equally important as the need for its disposal. But the hydraulic and nutrient loadings of raw sewage water are several times above the assimilative capacity of soil-plant system. Long term use of raw sewage waters for irrigating vegetable crops may result in metal accumulation in soils to such an extent that may affect plant growth and may cause clinical problems in animals and human beings too. The manuscript provides introduction to sewage water with respect to the physical and chemical characteristics, its effect on physical and chemical properties of the soils as well as on metallic cations build-up in soil and vegetables grown in these sewage farms. If this work is able to rouse further interest in environmentalist, scientists and students in universities working in various fields associated with pollution, we would consider one of the principal objectives of publishing it fulfilled.