Challenges and Opportunities for Mitigating N2O Emissions In Fertilized Cropping Systems

English Abstract:

Addition of nitrogen in synthetic or organic form is essential for production of many crops, but also promotes N₂O emissions to the atmosphere. These emissions are also highly sensitive to soil water dynamics and temperature. Thus, interactions of a myriad of agriculture management practices with weather factors and changing climate and their impacts on N₂O emissions are not easily predicted or managed. Using data from our own and other studies, we discuss how traditional N management strategies designed to improve overall N use efficiency (e.g. modification of timing, source, or placement) do not always reduce N₂O emissions, and how the challenges of reducing N₂O emissions are often related to variable and/or extreme weather conditions. For example, use of split applications, specialty fertilizer products, or improved placement do not always reduce, and in comes cases can increase, N₂O emissions. We discuss how new technologies, or the combination of more than one existing technology, as well as better understanding of fundamental process controls over soil N₂O production, can assist in developing mitigation strategies that may be more robust to climate effects.