Influences of application of sewage sludge compost on N2O production in soils

Abstract Laboratory incubation was conducted to determine the controlling factors affecting the production of N2O in soil taken from short- and long-term experimental sites continuously amended with SS in three types of soil samples. Soil types and sludge application rates significantly affected the production of N2O from soil amended with sludge compost. The yellow soil, with low organic matter content, resulted in higher production of N2O with sewage sludge application probably due to ammonium oxidation in the soil. While andosol soil, with high organic matter content and heavy metal (Zn), resulted in lower N2O production when amended with SS. Uncultivated brown forest soil amended with sewage sludge plus sawdust compost (SSS) at the rate of 20 ton ha−1 showed a peak of N2O production, while no N2O was observed in the same soil at 10 ton ha−1 application rate. These results help us to explain that N2O production from soil amended with SS is greatly affected by soil types, types and application rate of the composts. It should be considered carefully to reduce N2O emission from the recycling of nutrient between soil/agriculture and urban/water treatments in future.