AS FEROCIOUS as this month's bushfires were, it appears that most pastures on well grazed farms will recover.
The recovery rate will depend on the fuel load, and therefore the heat of the fire, and what species were growing.
Agronomist with the University of Melbourne's Mackinnon Project, Lisa Warn, said drought conditions had reduced fuel loads in most grazed pastures to low levels.
"Even though the weather on the Saturday (of the fires) was ferocious, in most cases the low fuel loads meant that the burn was probably cool to moderate," Lisa said.
"The fuel load in most cases would have been lucky to be 1000kg/ha of dry matter, which is not much.
"The reality is that most farmers had their paddocks grazed down pretty well, so most of those pastures will recover."
Pasture species affected by a cool-to-moderate burn would recover the best, Lisa said.
"The main ones that won't recover are the annual grasses such as silver grass, barley grass and annual ryegrass, which had already taken a hit from the drought. They don't have a protective hard seed and the seed is close to the surface," Lisa said.
Native pastures were designed to come back after fire.
"They come back with a vengeance as we saw after the King Valley fires (in 2006)."
Lisa said established phalaris, fescue, cocksfoot and perennial ryegrass should all recover from a cool-to-moderate burn.
Sub clover would recover too, because its seeds were protected under the soil, although the rate of recovery would depend on the timing of the autumn break.
However, in areas where there was more fuel, the hotter burn may have affected sown species such as perennial ryegrass.
And in areas of bush grazing or pasture land along the edge of bush, it could be two years or more before anything came back.
Lisa said it was unlikely the soil would have been sterilised on most farms that had been well grazed.
"It would be more likely where there were haystacks or round bales stockpiled," she said.
Lisa said the message was to wait until the autumn break and then monitor pasture recovery,
"Don't rush into any issues with pasture," she said.
"Most areas that have been well grazed will recover over the next 12 months, but the carrying capacity will be down because the loss of annual component."
Lisa said fire recovery was similar to drought recovery.
"It has a similar impact on stock, pastures and other issues such as water supply and erosion," she said.
"The strategies are to keep the stock off affected pastures until the break using containment and then try to wait four to six weeks after the break before resuming controlled grazing, preferably rotational grazing.
"If you are keeping stock you are looking at containment and feeding for another four months.
"In most cases, I wouldn't be thinking of resowing - maybe just fertilising and managing the grazing so the species have every chance of recovering."
For more details phone the Mackinnon Project on (03) 9731 2225.
