Experts in Queensland are advocating soil testing for P and K at depths of up to 30cm deep, rather than in just the top 10cm layer which is traditionally tested, according to the Queensland and Country Life.
The article says that testing deeper in the soil profile can provide clues to the fertiliser needs in the top 10 centimetres.
Dr Mike Bell, Queensland Alliance for Agriculture and Food Innovation (QAAFI) and David Lester, Department of Employment, Economic Development and Innovation (DEEDI) advocate testing for phosphorus and potassium in the 10-30cm layer as well as the 0-10cm layer.
"This further test can fill in missing information about the background fertility of the soils we are trying to manage," Dr Bell said. "Growers baulk at conducting another costly soil test, but once an initial assessment has been made, the normal 0-10cm monitoring can be resumed.
"Fertility in deeper layers changes more slowly than in the top 10cm, where crop residues and starter fertiliser can make significant impacts from season to season. However, what is in these deeper layers can define the fertiliser strategy needed to maximise productivity and fertiliser use efficiency, and this has been the focus of the current research programme."
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