Effect of municipal sewage on chemical build-up in soils and vegetables Available to Purchase

A mini-lysimeter study conducted showed that use of lower dilution of sewage water improved the physico-chemical properties and nutrient status of the soils but resulted higher per cent build up of metallic cations in them, particularly Zn, Pb and Ni in sandy clay loam soil and Cu and Cd in sandy loam soil. Indian spinach (Beta vulgaris var. bengalensis) irrigated with lower dilution of sewage water improved OC content of the soils, while cauliflower (Brassica oleracea L.) and carrot (Daucus carota L.) decreased the CaCO₃ content. Metallic cations content in the leaves and roots of the crops increased when irrigated with lower dilution sewage water but the level of metallic cations contamination was quite below the maximum permissible limits suggested. However, contamination of the soils and phyto-toxicity cannot be ruled out if such sewage irrigation is used on long-term basis.