• Whether all nitrogen input sources have been estimated;
• Whether default or country-specific (Parties are encouraged to use country-specific information) activity data, emission factors, and partition fractions for each of the categories of nitrogen added to soils (i.e., synthetic fertilizer, animal manure, sewage sludge, nitrogen fixing crops, histosol cultivation, crop residue incorporation) have been used;
• Whether annual statistics on the use of nitrogen synthetic fertilizers, production of nitrogen fixing crops (e.g., area of pulses and area of forage crops), residue producing crops and histosols have been collected;
• Whether emissions estimates from synthetic fertilizers, manure application as fertilizer, and sewage sludge application as fertilizer have been corrected for ammonia volatilization;
• Whether the updated emission factors (EF₂) for the cultivation of organic soils (i.e., histosols) that are provided in the IPCC Good Practice Guidance have been used.

Reference:
IPCC Good Practice Guidance, Section 4.7