POTATOES from within a South Australian research project into developing a more reliable soil phosphorus test are being harvested.
A Department of Agriculture National Landcare Innovation funded project, “Innovative Nutrient Management for the Australian Potato Industry”, is now in its second year.
Managed by Potatoes South Australia Incorporated and delivered by PIRSA’s consultancy business unit, Rural Solutions SA, the project is delving into the Diffuse Gradient in Thin-films (DGT) test.
Correct application rates of phosphorous (P) are regarded as critical for the financial and environmental sustainability of the Australian Potato Industry.
The project aims to deliver 15 replicated trials and nine demonstrations across the state to calibrate the DGT test for potatoes.
Project leader Dr Melissa Fraser said the research team currently have nine replicated trials across the state to assess the DGT test for potatoes.
“This involves applying five different rates of phosphorous to determine the yield response,” Dr Fraser said.
“We measure the amount of phosphorous in the soil using the common soil phosphorous tests, such as Colwell, Olsen and Bray, as well as the DGT test and follow this up with petiole phosphorous testing and then harvest each plot to determine the effect on yield.”
Harvest of the current trials in the South East, Mallee and Kangaroo Island is currently underway with more trials to be established in the coming weeks across the Murraylands, Riverland and Lower lakes.
Potatoes South Australia CEO Robbie Davis was in the area recently to see the trials.
“The level of collaboration and cooperation between producers, service providers and researchers has been outstanding,” Ms Davis said.
“Elders Ltd has come on board to supply fertiliser and support to the project, and APAL Agricultural Laboratory in Adelaide is supporting the project with soil and plant analysis.”
The DGT test has already been calibrated for wheat, barley, canola and peas in southern Australia by University of Adelaide researcher Dr Sean Mason and this project aims to determine the critical threshold P values for potatoes.
The development of an accurate, robust test will enable producers to quickly and easily analyse their soils and apply appropriate rates of Phosphorous fertilisers, improving both their overall economic return and reducing off-site environmental impacts caused by over-fertilisation.
“The critical part of this project is to relay the findings to the industry to enable increased profitability and reduce the likelihood of P loss into the environment,” Ms Davis said.