| Nitrous oxide (N2O) is one of the greenhouse gases playing a role in climate change. Agricultural soils are major sources of nitrous oxide. Mitigation strategies for the reduction of N2O emissions are therefore currently being investigated. In this study, N2O fluxes from two management systems applied to a corn-soybean-wheat rotation in Southern Ontario, Canada, were measured from January 2000 to April 2002, using a micrometeorological method. One system, termed the conventional system, employed a conventional till strategy and fertilising as recommended for each crop. The other system, named the best management system, employed a no-till strategy, N fertilization based on soil test level and using a cover crop when possible. Various approaches to calculate the zero displacement values were compared. It was found that using different approaches to calculate the zero plane displacement values caused the eddy diffusivity value to vary. This can be an important source of error when quantifying the exact amount of N2O emitted from soils. Results indicated that cumulative N 2O loss from the 2-year study was 5.37 kg N ha−1 and 3.94 kg N ha−1 for the conventional and best management systems respectively. It was therefore concluded that the best management system holds promise as a means for reducing N2O emissions. |
