Fate of Composted and Non-composted Sewage Sludge in Sandy Soil in terms of Nitrogen Mineralization and Recovery of Organic Matter
An incubation study was conducted over a period of eight weeks under controlled conditions (30oC). The study was conducted to assess the dynamics of N mineralization, organic matter decomposition, and pH change in a sandy soil amended with sewage sludge (SS), and co-composted sewage sludge-CSS (SS + green waste-GW). The CSS and SS were obtained from Sharjah municipality and Dubai municipality respectively. Sandy soil was amended with different quantities of CSS and SS (0, 5, 10, and 20 tons/ha). Over the incubation period various observations were recorded to assess the accumulation of mineral N, change in soil organic matter content and pH. At the completion of the study the recovery of organic matter was 56-74% in CSS and 64-72% in SS. Gross nitrogen mineralization rate (N mass released expressed as a percentage of initially added N) ranges between 20-36% and 3-10% from SS and CSS respectively. However, the change in the pH of CSS and SS amended soil as compared to control during incubation period was in significant.