Farmers have been urged to view recent seasonal climate forecasts with caution, as they may change dramatically in the next three months.
Agriculture Victoria seasonal risk agronomist Dale Grey said while current worldwide weather modelling showed low rainfall, some predictions were for an average or neutral outcome, while others ranged between drier and wetter conditions.
"The best way for primary producers to use a seasonal climate forecast at this time of the year is to bear in mind that predictions made now may or may not come off," Mr Grey said.
Plenty of random weather can change things, in the next three months.
- Agriculture Victoria seasonal risk agronomist Dale Grey
Mr Grey, who puts out The Very Fast Break seasonal outlook, said there was a strong consensus for warmer conditions, in the next six months, which may mean a narrowing of irrigation intervals for the autumn startup.
"There are lots of things to think about in autumn, but a seasonal climate forecast isn't one of them," Mr Grey said.
"It's a time of lowest skill and oceans resetting - plenty of random weather can change things in the next three months.
Mr Grey said modelling skill, predicting rainfall three months out, "improves as we move into winter."
But he said there was a strong consensus for an El Nino over the next three months, with uncertainty about it continuing into winter.
But he said autumn forming El Ninos were rare and had tended not to have the classic drying patterns of winter or spring forming ones.
"About a quarter of those years have been very poor, but 75per cent have been wet, average or drier, but okay."
The Bureau of Meteorology reported while southern Australia showed little signal towards wetter or drier conditions, the past two to three decades had seen a decline in autumn rainfall across the region.
Since 1990, 24 of the 29 years had rainfall totals in southeast Australia below the historical (1961-1990) average.
The BoM also reported rainfall across the Murray Darling Basin for the two years from February 2017─19 was the lowest on record for that time-frame, since 1900─1902.
In the six months to December 2018, inflows to the River Murray system were within the lowest 10pc on record.
Planning ahead
Craig Steel, "Woodlea", Finley, NSW, said he was cutting back on fertiliser rates, for winter crops, hoping it would rain, as irrigation allocations were tight.
"If it doesn't rain until the end of May, or into June, what comes up won't grow, and we won't have any winter production."
He said he was running 1200 Merino ewes, which were currently lambing, and had an extensive cropping and pasture program.
"I've actually used shaftal, and ryegrass, barley, faba beans, and I've been looking on social media for multi-species mixes.
"I get more production, its better for the soil so it just helps to have a mix of legumes and grasses.
"We did carry over about 400-500 megalitres of water, from last year, which allowed us to do a spring irrigation on our crops."
He also received 150 megalitres as an efficiency allocation from Murray Irrigation Limited.
It would be used to start pastures in April, but wheat and barley would be sown dry, at the end of the month.
"I've dropped the canola. If it doesn't get going by the end of April, its got no real potential, anyway."
The carryover water was used to finish the spring wheat.
"We only used about a megalitre a hectare, or around that, and we got two and a half to three tonnes per hectare, with one watering."
Watering costs soaked up half the value of the crop.
"Luckily, the sheep price is good," Mr Steel said.
"We will rely on the sheep income; there's not much else if it doesn't rain and we don't et a water allocation.
"You can put sheep on the crop and get something back."
Zero allocation
Southern Riverina Irrigators chairman Chris Brooks said he feared unless it was an exceptionally wet winter, the region would again have zero water allocation.
"That will be the death knock for a lot of these poor farmers, up here," Mr Brooks said.
He said farmers were preparing to sow winter crops and would be expected to start up irrigation.
"But no-one can afford water at $500/ML to do that.
'They are sitting around absolutely terrified and wondering what's going to happen if we don't get enough rain to grow a winter crop."
He said the dry ground compounded high water costs and no allocation.
"You have to get 100mm of rain before you get any runoff.
Paddocks, which required on megalitre to the hectare in pre-watering, would need three.
"The ground is just like blotting paper, so you are spending $1500 a hectare before you even put a crop in."