Nitrogen (N) deficiency remains one of the single greatest factors that unnecessarily limits yield in Australian broadacre production.
Over the past two years, we partnered with Farmlink on a Nitrogen Management project ‘Utilising new technologies to better manage within-paddock nitrogen variability and sustainably close the yield gap in Southern NSW ’, funded by the National Landcare Programme.
The results of the project highlighted moderate to high levels of N variability across a selection of paddocks in Southern NSW. The project also investigated the efficiency of a range of methods for defining and managing the variability.
Key outcomes of the project were as follows:
- Measuring the variability in soil N through grid soil sampling or zone-based sampling was essential in the calculation of the N requirements for crop production.
- Grain protein and yield data allowed the plant itself to indicate the adequacy of the N supply. The protein data generally matched the pre-sowing soil N measured, suggesting that protein can be used to guide pre-sowing soil sampling and develop a targeted N strategy. However, canola oil and protein percentage did not show the same potential.
- Mapping of soil textural variability, for example using EM38, was another reliable way of establishing zones for targeted N sampling and management.
Given the immense productivity and environmental benefits of improved site-specific N management, this project has shown the considerable potential for these methods to refine N management strategies on farm.
To understand how you can implement these strategies on your own farm, please contact your nearest Precision Agriculture office.