The objectives of this project are to:

• Increase the awareness, knowledge and understanding of soils and soil nutrition to land managers throughout SA;
• Increase farmers skills to enable farmers to suitably sample, analyse, monitor and interpret soils within zones to improve their decisions to improve soil health and improve the resilience and sustainability of crops and pastures;
• Testing and adoption of technologies (NDVI, pH and EC mapping, grid mapping) that will assist growers to drive innovation and prepare for drought, build on farm resilience to drought and manage farm operations leading into and during dry years / drought.

Project description: 

A one-year project ‘Soil zone mapping and variable rate application (VRA) for drought resilience and preparedness’ managed by the Agricultural Bureau of SA was carried out with the Mallala, Petersville and Sth Kilkerran Agricultural Bureau Groups. The project was delivered in 2024 by SARDI, Peninsula Precision Ag, Northern and Yorke Landscape Board and supported by the SA Drought Hub, through funding from the Australian Government’s Future Drought Fund.

The aim of the project was to identify and sample different zones within paddocks and look at the variation of soil pH and nutrients across paddocks. The data provided growers with information to make more informed decisions to optimise fertiliser and/or soil amendments within zones, leading to the use of variable rate application.

Fourteen focus paddocks were selected and from this a total of 30 zones were identified (2-3 zones per paddock depending on soil type and variability). The zones were created using satellite imagery using Normalised Difference Vegetation Index (NDVI) in August/September compared over a number of years and also compared to yield maps.

Learn more about the project through the Agricultural Bureau of South Australia case study.

Key achievements and results: 

The project has shown how to use new technology such as NDVI, zone mapping, pH mapping and grid mapping to identify the variations across paddocks and to assist farmers to use variable rate application. Using variable rate application across paddocks allows more inputs in some areas and less inputs in other areas leading to a greater resilience to drought/dry seasons. In addition, there is an improvement in soil health and an increase in production and profitability.

Key achievements, results and a full project report can be found in the Soil zone mapping and variable rate application (VRA) for drought resilience and preparedness technical report, prepared by Andrew Harding of PIRSA- SARDI.