New Project to Improve Soil Health and Drought Resilience

Media Release

August 2024

A new Agricultural Bureau of SA project is now underway in the Lower North and Yorke Peninsula to improve soil nutrition, increase productivity and profitability and for drought resilience.

The Department of Primary Industries and Regions SA (PIRSA) – SARDI in partnership with Peninsula Precision Agriculture (Arthurton) and the Northern and Yorke Landscape Board are delivering the one-year project, funded with the Australian Government’s Future Drought Fund through the South Australian Drought Resilience Adoption and Innovation Hub. Participating Bureau branches include Mallala, Sth Kilkerran, Petersville and Arthurton.

Senior consultant at SARDI, Andrew Harding said “the project is using a zone-based approach to target fertilisers and soil amendments to meet yield potential”. He explains, “in some zones nutrients and soil amendments may be able to be reduced while in other areas nutrients and soil amendments may need to be increased”.

The zones for each of the 13 focus paddocks were created using satellite spatial imagery using Normalised Difference Vegetation Index (NDVI) in August / September compared over a number of years and then compared to yield maps.

Each paddock has 2 or 3 zones, and each zone has been sampled for a complete soil analysis including nitrogen and carbon to 60 cm in depth. Soil sampling has helped to identify soil issues and constraints including salinity, acidity, alkalinity, boron and/or shallow soils.

Where acidic soils have been identified, paddocks have been mapped with the Veris® pH machine. This shows where lime needs to be targeted and applied at a variable rate.   

Mr Harding said that “a major issue is the high soil pH on calcareous soils particularly on the Yorke Peninsula that locks up phosphorus. Grid mapping has been conducted by Peninsula Precision Agriculture to investigate the variation of Colwell phosphorus, phosphorus buffering index (PBI) and DGT-phosphorus across the paddock”.

“From this phosphorus can then be applied as a variable rate across the paddock. More phosphorus may be needed in the high PBI areas and phosphorus may be able to be reduced in the lower PBI areas”.

From the soil test results fertiliser strips have been applied to determine the most effective and economic rate of fertilisers. 

Janette Ridgway, Chair of the Agricultural Bureau of SA said “this project will involve field days and case studies and will provide landholders with a better understanding of soil test results and improve soils knowledge, leading to greater confidence in making fertiliser decisions and managing for drought and dry conditions. Information from the project will be available on the Agricultural Bureau SA website.”               

The project will continue until December 2024. For further information on the project contact Andrew Harding, Senior Consultant (Soil and Land Management) on 0417 886 835.