Variable Rate (VR) technologies support the optimisation of fertiliser applications based on spatial variability in soil parameters and crop nutritional demands. VR combines mapping of spatial variability with GPS/autosteer technologies, and VR input controllers.

VR technologies are used to define management zones or prescription maps based on variation in soil type, pH, moisture, and/or nutrient status. Each zone is assigned an application rate, and the VR controller adjusts inputs accordingly.

VR technology has potential to directly reduce emissions intensity by optimising fertiliser inputs and improving production efficiencies. It also has the potential to reduce the GHG intensity of products (emissions per unit of product) which can be an important criterion for some markets.

Multiple benefits can be achieved through VR fertiliser, including optimised operations and agronomic performance alongside reduced input costs and operator error. Cumulative benefits can lead to improved profit margins and reduced environmental impacts.

The spatial landscape of every enterprise is unique. Designing the right VR approach requires investment in time to establish and optimise prescription maps, to manage and integrate baseline data and to monitor performance for improvement.

In general, benefits are more likely to be achieved in large farms that encompass variable soil types, and where yield variability has significant impact on management decisions and profitability.