Urea use has proven to be a successful option to boost winter growth, helping farmers to grow more grass, which is vital during the current drought conditions.
Agriculture Victoria livestock industry development officer Nick Linden said after a poor spring and summer and a late autumn break, the need to grow more feed was a top priority.
"Urea is a proven option for increasing pasture growth rates through winter. For those who haven't used urea before, this might be the year to try it.
"In similar conditions to this year, the Weed Managers Producer Demonstration Site (PDS) trialled urea test strips on a fertile annual ryegrass paddock in the Upper Murray. Urea was applied in early July and late August 2024 using two different rates, 75kg urea/ha and 100kg urea/ha," he said.
Pasture growth and accumulation were measured six weeks after each application.
Mr Linden said where there was no urea applied, daily pasture growth rates through July and into August averaged 5 kg DM/ha/day; typical for mid-winter pasture growth.
"Pasture growth rates increased with urea applications and were greatest at the higher urea rate (100 kg Urea/ha), however, the higher rate did not give the best cost/benefit.
"We found that a 75kg/ha urea application lifted pasture growth rates to 17kg DM/ha/day, and the 100kg application lifted growth rates to 23 kg DM/ha/day, compared to 5kg DM/ha/day without urea.
"This increase in pasture growth rate and subsequent availability represented the difference between a pasture that would not maintain weaners or lactating stock, to one that would fully feed either stock class," he said.
Learnings from the urea application trial include:
Select a pasture that has sufficient leaf area, is not lacking in fertility or soil moisture and has a high proportion of desirable species;
Applying urea early, when the pasture is growing, provided increased early growth and higher residual growth rates in late winter/early spring;
An early application of 75kg/ha urea in mid-winter, delivered the best cost/benefit;
Later application delivered little difference in growth between 100kg urea/ha and 75kg urea/ha, especially when growth rates had increased due to higher temperatures and longer days; and,
In all cases, the energy cost from additional feed grown using urea was cheaper than the cost of energy if sourcing grain or hay.