AN international import is helping SA farmers improve their soil health and crop productivity.
Rural Solutions SA sustainable agriculture senior consultant Andrew Harding said more than two million hectares of agricultural land in the state was prone to soil acidification. He said many had a pH less than 5 in the first 10 centimetres, with soil acidity in the sub-surface layer also becoming a significant problem.
“Unfortunately soil pH can vary greatly across paddocks,” he said.
When soil pH falls below 5, the productivity of crops and pastures begin to decline, as does microbial activity while nutrients become less available to plants.
Lime is the preferred method to treat this and was traditionally applied uniformly across the paddock, based on a single soil test.
As the cost of acquiring lime and freight have increased, there has been a search for alternative management strategies.
Last year PIRSA invested in a Veris soil pH on-the-go mapping machine, imported from the United States. It is one of only three in the state.
The Veris system is attached to a tractor or four-wheel-drive and driven across a paddock.
It collects soil samples at a rate of 10-12 points/ha, and brings these up to an electrode to measure the pH. Mr Harding said it would be almost impossible to measure with that frequency by hand.
The measurement and the GPS coordinates are logged in the ute simultaneously, generating a map of the paddock.
Mr Harding said the variation of pH within paddocks could mean wasted application while, once mapped, a farmer could reduce applications to where it was required.
“They can tailor it to where it’s needed, saving money and helping improve the productivity and profitability of the paddock,” he said.
Rural Solutions SA have been collaborating with other agencies, the ag bureau and farmers to trial this new technology.
In that time about 15,000ha across the state has been mapped.
Mr Harding said the trials showed targeted lime application had an average saving of 30 per cent for most farms, with one farmer saving about 50pc in lime, freight and spreading costs.
The Veris mapper is being offered to farmers on a cost-recovery basis.
Rural Solutions SA executive Daniel Casement said the new machine was a great example of agricultural innovation to support the state’s industry.
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