Farm Table says:
What is the problem?
Efficient management of nitrogen (N) is critical to the profitability and sustainability of agricultural systems.
Losses of N can both reduce productivity and in the case of nitrous oxide (N2O) emissions contribute to global warming and ozone depletion.
The limited number of studies from medium rainfall cropping systems have indicated that N2O losses tend to be low to moderate, but that there is the potential to reduce these losses through altered fertiliser management
What did the research involve?
This study investigated
- the magnitude of N2O flux from a medium rainfall cropping system in south eastern Australia
- the potential to mitigate N2O losses through altered timing (at sowing compared with in-season) of N application
- the use of both nitrification and urea as inhibitors.
This study also measured overall N fertiliser losses and crop productivity, as part of a field experiment conducted in the Victorian Wimmera during 2012
What were the key findings?
This study suggests that in a medium rainfall cropping system of western Victoria losses of N as N2O are low compared to the overall N requirements of the wheat crop.
N2O losses also appear to be a minor contributor to overall losses of applied N.
They suggest that successful reduction of N2O loss will result from the development of practices that profitably increase overall N use efficiency; reducing more than just N2O loss.
There needs to be a greater understanding of seasonal forecasts to better predict yield potential and precision placement of fertiliser such as side-banding in season to potentially reduce microbial tie-up and losses.