CSIRO Australia CSIRO Media Release
Mr Nick Goldie (02) 6276-6478
Mobile (0417) 299-586
Fax (02) 6276-6821

15 October 1998

Ref 98/242


Silicon in the soil can lead to much improved sugarcane yields, and new soil mapping techniques are showing the way to increasing silicon.

According to Suzanne Berthelsen of CSIRO Land and Water, silicon improves the growth of many plants. But sugarcane has a particular capacity to absorb the mineral.

"Sugarcane will take in as much silicon as nitrogen or potassium," says Ms Berthelsen. "We know that cane will grow normally with quite small amounts of silicon, but its surprising ability to absorb very large quantities suggests that silicon may be essential to promote good growth and high yield."

Ms Berthelsen says that fertilizer trials including silicon have until now been 'hit or miss', but that recent soil surveying in the Tully to Innisfail (Qld) district have given researchers an accurate measure of silicon availability.

"Most soils include naturally-occurring silicon compounds, and the available silicon can be quite high," says Ms Berthelsen. "However in the wet tropics there is a process caused by high rainfall and temperature which results in soil acidification. This in turn leads to the loss of compounds such as alumino-silicate clays, so tropical soils have inherently low silicon levels."

The Tully-Innisfail survey shows that nearly half the soils in the district are suitable for sugarcane cultivation, but that 90% of these soils have very low levels of soluble silicon available to plants.

"The surveys have given clear results, which can be used to target further research and fertilizer trials," says Ms Berthelsen. "The silicon availability rating which we have developed from the Tully-Innisfail survey could also be applied with almost no modification to other soils of Australia's wet tropics where sugar is cultivated."

Overseas experiments have demonstrated large yield increases where silicon is added to soils with low levels of available silicon.

"A Queensland trial conducted by the Mossman Cane Protection and Productivity Board, on highly weathered sand with very low levels of available silicon resulted in a 38% increase in sugar yield," says Ms Berthelsen.

More information from: Ms Suzanne Berthelsen 07-4753 8534

Commonwealth Scientific and Industrial Research Organisation
(Australia's largest scientific research organisation)

Updated 15 October 1998 - Jenifer.North@cc.csiro.au
ęCopyright 1998, CSIRO Australia