Fire management on Trafalgar Station

by Roger Landsberg, Trafalgar Station
From Savanna Burning — Understanding and Using Fire in Northern Australia , Tropical Savannas CRC, Darwin 2001

Trafalgar Station near Charters Towers is a 32,000 hectare property with a carrying capacity of about 3200 adult equivalents.

Pasture management and fire

I aim to "spell" 15–20% of the property each year to allow the grass to strengthen and drop seed; the build-up of pasture gives us an option to burn.

Inspecting the result of an intense prescribed burn at Trafalgar Station. Photo: Jeremy Russell-Smith

If the season is poor, I may keep the grass for drought feed or burn later. However, paddocks that have been locked up after clearing virgin scrub are always burnt and allowed a full growing season before being grazed.

Fire management

The pasture is usually burned in October–November when the weather is hot, slightly humid and the winds are fairly light, preferably from the north. Hot, dry winds tend to push the fire along too quickly, burning the grass but not the weeds or fallen timber.

The conditions must be right before I burn. Having gone to the trouble of planning the burn, spelling the paddock, spending money on fire preparations, getting experienced people in the right numbers and the right equipment for any emergencies, I’m not going to waste the fuel and the benefit by burning in the wrong conditions—an overcast sky, the winds in the wrong quarter or winds too light.

After the fire, stock should be excluded until ground cover is well established, preferably after good rain. Our standard practice at Trafalgar is to sow stylos and grasses into the ash bed 3–4 weeks after the fire and before the first rains.

Fire for woody control

Fire is very effective against some weeds. Currant bush (Carissa ovata) burns well once started, even without much grass fuel. Although the adult plant may not be killed it is controlled so that grass will re-establish.

Dense and light infestations of rubber vine in the paddock are effectively controlled. With a heavy grass fuel load, a light wind and slightly moist ground and atmosphere, fire will kill up to 80% of rubber vine plants, especially if they are small. It can carry a fire without additional fuel if conditions are extremely hot and the sap very active in the plant.

Fire is used to control rubber vine invasion on Trafalgar Station. Photo: Jeremy Russell-Smith

Fire plays a significant part in the control of eucalypt seedlings or suckers in open forest when it is used regularly. But in cleared country after the initial burn, burning in later years is a waste of grass as the suckers tend to regrow within two weeks of the fire.

Cost of burning

Fire is often quoted as a cheap option for pasture and land management. The direct costs of setting up firebreaks, getting the right equipment and personnel, and the actual burning may be quite small on a per hectare basis, but locking up a paddock and burning it is definitely not cheap as production is foregone.

Costs that would arise from not burning include clearing regrowth, controlling weeds or timber, and lost grass growth from competition with woody regrowth.

Good pasture management means stocking conservatively, spelling paddocks and burning for a purpose when it is sensible to do so.