by Lee Menhenett - Technical Agronomist
Graziers in southern Australia traditionally apply their fertiliser from late February to early April, when the autumn rains arrive.
This is to make sure the phosphorus applied as SuPerfect is readily available for the germinating sub-clover, giving it every opportunity to grow to its full potential in autumn and winter.
When phosphorus isn’t already on the ground when the autumn rains arrive, for whatever reason, potential pasture growth through autumn and into winter starts to be compromised.
The pressure is then on to get a fertiliser spreading contractor onto the paddocks ASAP.
By then, there’s often a long list of graziers and a short list of spreader contractors, the ground might be too wet and you end up facing delays and disappointment.
Rather than missing the optimal window for topdressing pastures, consider the benefits of fertilising pastures in summer.
From an operational perspective, it couldn’t be better. You can get the job out of the way, take advantage of freight and spreader availability and avoid the rush later on.
From an agronomic perspective, there are no disadvantages with early SuPerfect application.
Research by Agriculture Victoria has shown that there are no pasture yield differences whether phosphorus fertiliser is applied in summer or autumn.1
It has also shown that applying phosphorus fertiliser earlier than the traditional autumn application does not increase the likelihood of phosphorus losses through run-off.
SuPerfect does not require rain to move the phosphorus into the soil. A light dew, or minimal moisture from the soil or atmosphere is all that is required for the phosphorus to be released.
The phosphorus will then be available when the autumn break comes and you can sit back and watch your pastures grow.
The only potential for phosphorus losses from SuPerfect application are from run-off.
However, these can be avoided by looking at the weather forecast and avoiding spreading at a time when heavy rain or storms are forecast within four days.
You should also make sure that there is at least 70% ground cover, with minimal bare patches in the pasture.
Talk to your local fertiliser adviser today to develop a fertiliser plan for this summer, based on soil and plant tissue testing and beat the rush.
Lee Menhenett
Agronomist – grazing systems
Incitec Pivot Fertilisers