Strategies to reduce Nitrogen (N) losses in Victorian High Rainfall Zone (HRZ) cropping systems are getting clearer.
Recent research in south western Victoria examined rates of N applied, placement of fertilisers and nitrification inhibitors. This work is part of the national agricultural nitrous oxide research program, supported by the GRDC.
Key messages for HRZ growers:
When N is applied in excess of crop requirements large nitrous oxide emissions can occur.
Better matching N applications to crop demand increases N use efficiency.
Split applications of N have lower N losses compared to applying all N at sowing.
Recovery of nitrogen is up to 40% greater when N is applied at 1st node, compared to earlier applications.
Terminate pasture plants as late as practicable when transitioning from pasture to cropping to reduce losses of N.
Avoid long fallow.
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Rob Harris, VIC DEDJTR, Alli Elliot, BCG, Graeme Schwenke, NSW DPI.