Measurement strategies to quantify the effect of diverse management practices on N2O emissions.

Quantifying N2O emissions from agricultural soils and identifying ways to reduce these losses imply that the impact of management practices is adequately determined. Soil properties and climatic conditions are often the most important factors controlling soil N2O emissions and isolating the contribution of practices to total emissions can be difficult. This objective is made even more challenging by the limitations associated with the use of non-steady-state chambers. In my presentation, I will briefly summarize how the main drivers of N2O production and emission in soils are impacted by management practices and how experimental design and methodology can help minimize interference with these soil N2O processes. Application to specific practices such as tillage and nitrogen fertilization (synthetic and organic) will help illustrate how site characteristics (soil properties, relief, heterogeneity), field operations, ancillary variables, and chamber design and deployment strategy can be best selected for reducing biases and uncertainty in quantifying the management-induced N2O emissions, and for reaching experimental objectives.