AMMONIUM-based fertilisers can revert to ammonia when applied in the paddock, a gas which vents into the atmosphere and results in the loss of that percentage of the fertiliser.
This process, volatilisation, is affected by moisture, temperature and soil pH, with acidic soils being more prone to loss, but urease inhibitors have been developed to reduce this effect, with two products being tested at the Cunderdin site.
James Easton, CSBP, noted that up to 30 per cent of the fertiliser can be lost through volatilisation, with the use of the inhibitors being able to reduce this loss by up to 50pc.
He pointed out that cost is the key to these products, for it may be more economical to apply a higher rate of fertiliser than to spend money on reducing volatilisation, even by 50pc.
The products tested showed mixed results to date, with the cost of the inhibitor being largely unknown for commercial application, with indications being that the treatment to coat the fertiliser could cost around $5/ha.
The coating on the fertiliser lasts for seven to 10 days, but that is adequate as most volatilisation occurs within one week.
