[Effect of Application of Sewage Sludge Composts on Greenhouse Gas Emissions in Soil].

Effect of application of sewage sludge compost on the emission of greenhouse gas from soil was investigated by analyzing the dynamic characteristics and emission factor of CO, CH and NO in soil after spiking two different composts (A:compost with biochar, B:compost without biochar) with varying fertilizing amount into soil. The results indicated that emissions of CO and CH mainly occurred in the plant growth period with low fertilizer amount of biomass charcoal compost reducing CO emissions, and high application content increasing CO emissions. CH emission fluxes showed negative values, indicating that soil could adsorb CH, and the adsorbing amount for control was significantly higher than those for other treatments (<0.01). The absorbing amount in treatment A increased with the fertilizing amount (<0.05). NO emissions mainly occurred at the germination and seedling stages, and emission fluxes increased with the fertilizing amount (<0.01). NO was considered as the main generated greenhouse gas during agricultural process with sludge compost, and its emission factor from sludge compost soil was 1.02%-1.90% (A compost) and 1.28%-2.93% (B compost), respectively. Biochar could significantly reduce the carbon emission, as the total greenhouse gas released from soil with biochar compost was 19.49% to 35.56% less than that in soil without biochar, which was more obvious for NO emission reduction (compared with CH mitigation).