Fire crews are expected to remain on site at a Kerang hay supplier until at least tomorrow, after a $1 million blaze destroyed at least 5600 bales, a truck and sheds.
Loddon CFA commander Brian Suckling said seven of the site's 20 sheds had been destroyed.
He said 25 crews and dozens of firefighters, including strike teams from Mallee and Campaspe, were involved in extinguishing the blaze.
"Nearly every single truck in Gannawarra shire was involved, with some from around Swan Hill and others from much further afield," Mr Suckling said.
"We are working frantically with the owners to try and move hay around, to try and prevent the fire spreading any further.
"We are confident, over the next couple of days, we will have favourable weather conditions and should be able to bring the fire under control."
The fire, believed to have been caused by spontaneous combustion, broke out around noon on Tuesday.
"The damage could well be more than $1 million, there is a truck that's burned as well as sheds," Mr Suckling said.
"There was nothing suspicious about it, just nature at work."
He said firefighters expected to be on site until at least late into the night, and possibly for another 48 hours.
"We will be there as long as we need to be," he said.
It was one several blazes in rural Victoria, on Cup Day.
Kerang Fire Brigade captain Ramon Steel said crews arrived on scene to find just one hay shed engulfed in fire, before an unexpected wind change initiated an uncontrollable firestorm.
Several hours later they were hit by an ember attack, spreading the fire to another six sheds.
Crews then worked through the night, to contain the fire.
"Nothing could be done to stop the shower of sparks that headed straight for the sheds in line of fire due to the direction and strength of the wind," Mr Steel said.
He aid it was one of the worst fires he had witnessed in his 39 years as a firefighter.
CFA Chief Officer Jason Heffernan said if hay was baled with high moisture content and was green, it could heat up like compost, which could lead to spontaneous combustion weeks or months later.
"Farmers who have decided to carry on with hay production need to be extra vigilant this year to make sure conditions are right for making hay and for the future storage and transport as well," Mr Heffernan said.
"Hay fires are a real threat to properties and stock in primary production areas.
"Whether you're a seasoned hay grower or switching to hay this year, it's imperative to take care of your hay and crops this fire season."
Haystack fires could also start easily from lightning strikes or sparks from equipment.
"You should regularly monitor your haystacks by using a temperature probe or a crowbar to detect heating hay," Mr Heffernan said.
"Signs of heating hay can include steam rising from the stack or unusual odours like burning, must, pipe tobacco smell or a caramel smell.
"By being vigilant, you're protecting yourself from the financial impact of losing valuable fodder and protecting your property and family from the potential danger of hay fires."
Andrew Miller
I'm a general reporter with Stock & Land, with a special interest in irrigation issues. I completed my cadetship, with the Age, in 1980. Over my career, I've worked for ABC radio news (Mt Isa, Qld) and at provincial and suburban newspapers.
I'm a general reporter with Stock & Land, with a special interest in irrigation issues. I completed my cadetship, with the Age, in 1980. Over my career, I've worked for ABC radio news (Mt Isa, Qld) and at provincial and suburban newspapers.
