Impacts of Irrigation with Sewage Effluent on Physical and Chemical Parameters of Egyptian Soil آثار الری بمیاه الصرف الصحی على المعاییر الفیزیائیة والکیمیائیة للتربة المصریة

Abstract

Egypt may soon suffer from water problems due to many factors, including the intransigence of upstream countries in addition to climate change and various pollution factors. Under these circumstances, many farmers are forced to use sewage water for irrigation, which may eventually lead to deterioration of soil and environmental quality. Therefore, the present investigation aims to study the influences of sewage water application for varied extended periods on some physical and chemical parameters of Abu-Rawash soil and to compare between the general properties of sewage effluent water and Nile water. In sewage effluent, Na+ was the dominant cation and EC, SAR, pH, and NH4+ values below the Permissible Maximum Level while nitrate content exceeds the safe level. The total N content in sewaged water was more than 13 folds that of Nile water. In sewage effluent irrigated soils, there are appreciable increases in clay fraction by 8.02 and 12.0 folds compared with the virgin soil. CaCO3 content of soil continuously irrigated with sewage water reduced as increasing period of application while there are an increasing in soil pH and EC. Only remarkably increase in ESP was occurred in the top soil layers of sewage irrigated soils. Bulk density and Hydraulic conductivity of sewaged soil decreases with increasing period of application and total porosity and available water capacity increased. The results reflect deficiency of nutritional status of uncultivated sandy soils in an arid zone, especially in N content.