Nitrogen use efficiency (NUE) and tools for farmer engagement: a good reason for being imprecise

Ashley Evans1, Donna Lucas2, Dr Doris Blaesing2

1 RM Consulting Group, PO Box 396, Penguin, Tasmania, 7310,,

2 RM Consulting Group, PO Box 396, Penguin, Tasmania, 7310


A nitrogen use efficiency (NUE%) calculator was developed to engage with cropping farmers and advisors on reducing nitrogen (N) losses from crop production.

The calculator utilises the ‘partial nitrogen balance’ (or ‘output-input ratio’) method to calculate NUE% for an individual crop, a rotation or a whole farm. It also enables estimating the monetary value of potentially unused mineral and organic nitrogen fertiliser.

Experience has demonstrated that both, farmers and advisors, are keen to engage with the tool due to its ease of use and the value of the results in supporting decisions on farm and monitoring NUE% over time. Farmers and advisors have used the calculator for a variety of reasons, including for verification of current best management practices, a means to assess whether or not fertiliser application is efficient and as a way to benchmark groups of producers in a region or groups growing a specific crop.

Calculating NUE% is a successful way to engage with cropping farmers and advisors. The review of nitrogen inputs, removal and costs, based on easily available data, proved an effective starting point for moving to more in-depth discussions about overall nitrogen, soil and crop management. This supported good planning and decision-making for farmers. In our experience, attempting a review of management practices with complex information and using assumptions where actual farm data is not available can disengage people.