After decades of consistent phosphorus (P) fertiliser application, many Western Australian soils now have adequate P status, presenting an opportunity for farmers to save on input costs.
According to the Crop Nutrition Fact Sheet published recently by the Grains Research and Development Corporation (GRDC), results from more than 100,000 recent soil tests in the south-west of WA showed that most growers are operating at or above the soil P levels required.
Testing subsoil (10 to 30 centimetres) P levels using both the Colwell-P and BSES-P tests across the farm is the key to making an informed decision about fertiliser applications rates.
If those tests show that soil P status is sufficient, there may be an opportunity for growers to save money on P fertiliser by cutting back to a maintenance rate.
The GRDC Crop Nutrition Fact Sheet was included in the November-December western edition of the GRDC magazine Ground Cover, and can be downloaded at www.grdc.com.au/GRDC-FS-PhosphorusManagement
Grain Flashes can be found at www.grdc.com.au/Media-Centre
GRDC Project Code
DAN00165, DAV00095, UA00103, UA00111, DAQ00148, DAN00165, DAN00165, UMU00035
West, North, South