Optimal production, with the help of soil testing and phosphorous application, is the focus for grower Tim Harrington on his property in the south west corner of Western Australia.
Tim farms 2700 hectares of canola and malt barley varieties and is currently experimenting with some long season wheat varieties just 30 kilometres south of Darkan, WA.
Test results were showing varying phosphorous levels across his property on soil typically described as forest gravel soil, depending on the testing procedure used.
Moving to a Diffusive Gradients in Thin-films test (DGT test), which research indicates is a more accurate predictor of plant available phosphorous, has given results reflecting the visual assessments.
In the last three years, plot trials on low phosphorous sites testing varying rates of applied phosphate have been used to find the rate for optimal production.
Research centred on the Diffusive Gradients in Thin-films test (DGT test) and its use in the acid soil landscape in Western Australia is currently being put to the test with the help of producers such as Tim Harrington and a network of agronomists from around the country.
Research Agronomist and Director of Agronomy Solutions Dr Sean Mason has worked with Tim Harrington, in collaboration with WA agronomist Wayne Pluske, Equii, to begin using the DGT test in WA. He offers further insight into the underlying science of phosphorus management in this case study.