Farmers in the Geographe catchment are set to benefit from local fertiliser trial results which are showing that costs can be saved by not applying phosphorus fertiliser on paddocks that have adequate P levels.
The results have come from the first year of the state government’s uPtake trial program where 14 of 19 sites showed no productivity response to phosphorus applications.
Twelve trials showed a productivity response to the addition of basal nutrients (nitrogen, sulphur, potassium and micronutrients) demonstrating the importance of addressing the limiting nutrient in the soil to maximise productivity and improve water quality.
Department of Water and Environmental Regulation (DWER) Manager of Aquatic Science Malcolm Robb said the result was consistent with national soil testing of more than 22000 paddocks over the last 10 years showing 16700 paddocks had sufficient or excess phosphorus in the soil to meet pasture needs.
“Having confidence in the science behind the soil testing program is critical for farmers to change their fertiliser practices and improving the health of our waterways,” Mr Robb said
uPtake has been running since last year to help refine fertiliser applications so we can reduce nutrients being washed off grazing farms across the South West and into waterways, threatening the health of our waterways and the bottom line of farmers.
“Optimising fertiliser use; dairy effluent management; and identifying and evaluating new whole-of-farm best practice to reduce nutrient losses to waterways is a win for both farmers and the environment,” Mr Robb said.
Farmers are currently encouraged to soil test their paddocks and calculate their fertiliser rates based on data collected under the national project. The trials expand on data from the national project, to ensure fertiliser calculations are relevant to Western Australia and the Swan Coastal Plain’s sandy soils.
A technical reference group has been established to develop the design of the trials, with scientists from the Department of Primary Industries and Regional Development (DPIRD) and Department of Water and Environmental Regulation (DWER) and the agriculture sector involved.
In 2020, the Geographe catchment will be hosting two trial sites. Field days and opportunities to farmers to see the results will occur throughout the year.
The project is funded with $3.26 million from the State Government’s Healthy Estuaries WA program (formerly Regional Estuaries Initiative); and $2.35 million through the Australian Government’s National Landcare Program with in-kind support from fertiliser, dairy and beef industry groups.