Variable Rate Application or VRA for short, has been used in precision farming for quite a while! Originally designed for GPS guided tractors, VRA is mainly used for precisely applying fertilizer where it is needed. The adoption of VRA in the agricultural drone world is quickly becoming a popular procedure and for good reason.
A huge advantage with drone application is it’s non destructive! because the product is applied by air. No need for tramlines, zero wheel tracks and bogged vehicles or implements.
So how is it done? well from one end to the other it’s all done by drone! Firstly the crop is mapped with a multispectral drone, and once the images are processed crop health is analysed.
Depending on what stage of the crop cycle (early or later) a specific plant index is used. NDVI is often used for early and NDRE for more mature plants.
Once the Imagery is processed a Prescription map containing specific quantity values is created. This map is uploaded onto our spray drones remote controller and the DJI T40 applies the product.
There are two methodologies when it comes to improving crop yield through VRA, which depends on what is the desired result.
Homogenisation of crop health is to create a more uniform yield, where an attempt to improve the poor performing areas to be similar to healthy areas. This is achived by applying more fertilizer to the poor and stressed parts. This method is the most common and is widely used on broad acre crops
Hetrogenisation is to help boost the healthy areas and minimize dosage on the poorer areas. Hetrogenisation is more used on small higher value crops, where timing is critical.
Once the desired result is decided a specific fertilizer is chosen, which could be in Granulated or liquid form.
The quantity is often up to economic feasability, where it depends on how much the yield is potentially worth compared to the financial input of fertilizer product.
Interested? Contact us to find out more, or for a free Quote.
