Grazing canola system possible

Jo FulwoodThe West Australian

Consultants say results from canola crop-grazing trials in the eastern Wheatbelt are encouraging in regard to the value of grazing early sown crops in lower-rainfall zones.

Results from the canola trials, run on the Crook family property near Merredin in collaboration with ConsultAg, show a yield loss of only 5 per cent in the early grazed treatment.

In contrast, the plots grazed twice or grazed late, had a significant yield loss of 12 per cent.

ConsultAg agronomist Brad Joyce said if moisture was available early, it appeared canola was resilient enough to withstand the pressure from early grazing.

The trials, partly funded by GRDC, were sown on April 2 and April 20, with six different grazing and non-grazing treatments over both the early and later-sown crops, including early grazing on both times of sowing, twice-grazed and late grazing on some early sown plots.

Mr Joyce said he was yet to determine if the economics of the 3 to 4 per cent of weight gain in the sheep, which were grazed at 4.2 dry sheep equivalent, would outweigh the yield loss.

But Mr Joyce said if the analysed results showed little statistical difference between the plots, farmers should have the confidence to graze on early sown canola.

"In the dry July period, and after grazing, the plants were turning purple and blue and wilting, but we were amazed at how quickly they recovered after that next rain," he said.

"Canola is an incredibly resilient plant."

Mr Joyce said for every day each plot was grazed, it delayed the flowering window by half a day.

But despite this, frost and heat-stressed grain was still visible in the grazed plots.

He said the plots were grazed for 24 days in April and May, then some plots were grazed a second time for 21 days in June and July.

Mr Joyce said the early sown crops had significantly more biomass than the later sown crops at the normal break of the season when feed would normally be short, allowing for good grazing opportunities. "We'll just have to wait for the full analysed results to know whether or not the economics stack up," he said.

According to Jayden Crook, 45 to 50mm of subsoil moisture was available to the early sown crops after the property received 69mm over just two days in late March.

Mr Crook said his property received 100mm of rain in March and April, which had set the crops up for a good early establishment.

He said the canola trial had been opportunistic as a result of the March and April rains, and he would consider early sowing and early grazing again if the moisture was available.

"The subsoil moisture gave us the confidence to have a crack at canola early, and now that we have harvested a reasonable amount of the crop sown in that early window, we will definitely sow early again if that early rain occurs," Mr Crook said.

"This canola trial was an opportunity to see if we could graze these canola crops and still achieve good yield results.

"It was also a chance to see if we could delay the flowering window through grazing to avoid the frost window."

But Mr Crook said the dry July period had been cause for concern after the crops had been grazed.

"We were definitely concerned about some of the more heavily grazed plots, how hard they were down, and how much the season disappeared on us," he said.

By contrast, Mr Crook said an early sown ungrazed paddock of 75ha out-yielded the total canola farm average by more than 400kg.

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