Effects of sewage sludge stabilization on organic-N mineralization in two soils

Abstract

Sewage sludge is a valuable source of organic matter, N, P and certain micronutrients that have beneficial effects on plant growth and biomass production. However, sanitary regulations often require the stabilization of sewage materials prior to applying them to soils as biosolids. Environmental regulations also demand appropriate management of biosolid-N to avoid groundwater contamination. Because stabilization processes usually make sewage sludge less putrescible, we hypothesized that the mineralization rates of organic-N from stabilized biosolids would be affected. Therefore, this study aimed to evaluate the mineralization of five biosolids in two soils - a sandy Spodosol and a clayey Oxi..