Land application of pulp and paper mill sludge may reduce greenhouse gas emissions compared to landfilling

Abstract Land application of pulp and paper mill sludge (PPMS) may replace landfilling in certain jurisdictions. However, the consequences of this change in management on greenhouse gas (GHG) emissions from PPMS are unknown. Land application may also entail temporary storage by landfilling due to a timing mismatch between PPMS production and application. We quantified direct GHG emissions from landfilled PPMS (pilot scale; N-rich and N-poor types) over two snow-free seasons, and after application of previously landfilled PPMS (LPPMS;