Quantifying N2O Emissions Reductions in US Agricultural Crops through N Fertilizer Rate Reduction

ALM

This methodology quantifies emissions reductions of nitrous oxide from US agriculture, brought about by reductions in the rate of nitrogen fertilization to annual cropping systems. Dependant on US state, the methodology utilizes either the generally accepted IPCC Tier 1 default emission factor or an empirically derived, regional emission factor to calculate N2O emission reductions directly associated with a reduction in the nitrogen application rate from inorganic and organic fertilizers, either singly or in combination. This approach is straightforward and transparent and may be considered as a practical, short- to medium-term solution to help reduce N2O pollution from agriculture and as a pre-cursor to more complex Tier 3 modeling approaches under development.

The methodology encourages the application of economically optimum nitrogen rates that do not deleteriously affect yield and specifies the use of verifiable best management practices for nitrogen application, which are specific to the crop, soil, and environmental conditions encountered. The underlying field research used for methodology development is publicly available in the peer-reviewed literature.