Use of Sewage as a Source of Plant Nutrient Potentials and Problems

摘要

Sewage is a potential source of irrigation water and plant nutrients, Irrigation with sewage at 7.5 cm/ha would provide 36,5, and kg/ha V,P, and K, respectively and considerable amounts of secondary and micronutrients. Application of sewage increases yield of crops compared to irrigation with fresh water. It also increases total N, P, K, and organic carbon contents of soil, reduces the bulk density with concomitant increase in hydraulic conductivity, pore space, and increased bacterial and fungal populations in soil resulting in higher microbial activity. However, potential hazards due to heavy metal pollution, eutrophication, groundwater contamination by nitrate, and health risks from pathogens are of concern. To combat such problems several techniques have been developed for sewage treatment. In a country like India encountering the problems of water scarcity and high cost of fertiliser, sewage can be successfully used as a source of plant nutrient and irrigation.