Farmers attended an uPtake Trials Field Day in September to see firsthand two fertiliser trials underway in the Geographe Bay Catchment. As the sun was shining, the project partners shone a light on some of the outcomes of the trials so far.
Local farmer Brett Sue said that he is interested in how this research could benefit his farm business.
“The split application of phosphorus has been intriguing,” said Brett.
“I’ve also learned more about the benefits to plant growth, use of phosphorus and reduction of leaching into the environment.”
By engaging farmers on site at the trial locations, and partnering with local catchment group GeoCatch, the project aims to keep farmers engaged in the research process.
The results so far
The Jindong uPtake trial site, now in its third year, is comparing seven different treatments of phosphorus (P). The Jindong site has a mid-range PBI (Phosphorus Buffering Index) soil type and all the trial plots at this site started with a soil P level that was almost double what is required to produce 95% of the pasture yield the soil is capable of producing.
So far there has been no statistically significant difference in pasture production in applying more than 5kg of P per hectare. There has however, been a notable increase in dry matter production at this site with the addition of Nitrogen, Potassium and Sulphur.
The site continues to highlight the importance of soil testing to identify nutrients that may limit pasture production and to fertilise accordingly.
A second trial site located at Treeton near Cowaramup is investigating whether splitting P applications on low PBI soils reduces the risk of leaching.
The results at this point in the growing season show no statistical difference in dry matter production, however analysis of leachate indicates that more than 50% of the P applied in an application of 20 units in the autumn has already leached through the soil profile and is no longer available for pasture production. Results from this site will be updated at the end of the growing season.
uPtake is a partnership project designed to improve nutrient use efficiency on grazing farms by increasing farmer and industry knowledge, confidence and uptake of the science supporting fertiliser recommendations.
This project is jointly funded through the State Government’s Healthy Estuaries WA and the Australian Governments’ National Landcare Program with more than $5.5 million funding to improve the health of waterways and estuaries and help increase farm productivity and profitability.