Multi-spectral technology such as NDVI and NDRE are effective tools farmers can utilise and are becoming more frequently used as part of aerial imagery for yield mapping. The ability to bridge a clearer understanding of how the data generated by these technologies is interpreted into farming practices could advance the uptake by farmers and the effectiveness of how they are used.
Adam Hancock, Elders
Southern Precision Ag (SPA)
There is a lack of understanding in regard to how multi-spectral technologies can be used in precision agriculture farming methods such as yield mapping and nitrogen applications.
Investigating the accuracy of NDVI and NDRE in detecting canola response to nitrogen to create a variable rate map.
The core objectives of the project were to:
In the field
Several multi-spectral sensors were used over a canola trial site near Frances in the South East to test their ability in generating a variable rate nitrogen map. The trial site used canola seeding rate, nitrogen rate and nitrogen timing as calibration for the sensors before being used by the cooperating grower over a 10ha area of canola.
Images from these sensors were collected at three different stages by Southern Precision Ag (SPA) using a fixed wing drone with mounted sensors.
The variable rate map generated from the data was created for paddock application using NDRE by SPA and built using Pix4D.
Due to above average rainfall experienced in August during testing, trafficability in the paddock was limited and nitrogen applications were delayed. However, a significant amount of data was collected by the sensors prior to these heavy rain events.
Key findings from this project include:
Value for growers
Findings from this project indicate that multi-spectral sensor technology could possibly be used to drive variable rate nitrogen application in canola with further research.
Although there were some issues with variable rate mapping following above average rainfall and waterlogging of the trial site, the sensors indicated significant paddock variation with testing up until this point in the project.
The trial site was open to growers and presented at the MacKillop Farm Management Group’s Frances crop walk, with raw data and the final report made available on the GRDC’s Online Farm Trials website following completion.
A single page fact sheet was to be created for growers in the South East for processes and outcomes of using sensors measure VR nitrogen. However, this was deferred until the project can resume.
The project also received coverage in the Stock Journal.