The Revised 1996 IPCC Guidelines provide methods for estimating indirect N2O emissions from the following pathways:

• The portion of the atmospheric deposition of NO_x and ammonium (NH₄) associated with nitrogen from synthetic fertilizers and animal manure that have been applied to soils;
• The portion of the nitrogen from applied synthetic fertilizers and animal manure lost as leaching and runoff;
• The portion of the atmospheric deposition of NO_x and ammonium (NH₄) associated with nitrogen volatilization from the discharge of sewage nitrogen into rivers or estuaries;
• Other agriculture sources of NH₃, such as burning of residues and savannas.