Managing Nitrogen Inputs

Rural Management Strategies conducted a GRDC  funded project during 2013 and 2014 to demonstrate the use of Yield Prophet, plant available water capacity (PAWC) mapping, plus variable rate application technology to improve Nitrogen decision making in wheat and canola.

Topdressing Nitrogen is a stressful and costly decision.  The aim of the project was to determine whether these tools could aid in the decision making process and improve the economics of topdressing Nitrogen.

During 2013 a decision support framework was developed.  This framework uses Yield Prophet to examine the probability of achieving a grower’s long term median yield with both existing Nitrogen and plant available water, as well as with additional applied Nitrogen. The framework then rates the likelihood of a yield response to additional Nitrogen and provides a suggested action.  An example of the decision making framework is shown below.

The project demonstrated that using these tools can provide the confidence to reduce Nitrogen application rates without having an economic effect on yield.  Such decisions can lead to increased profitability and decreased risk to the business, through reduced costs.