Pasture species and fire
Native pasture species have evolved under a natural burning regime. At the end of the wet season the perennial native grasses store nutrients and energy in their roots. When they are burnt there is a low loss of these resources. If the soil is still wet when burnt, there may be a small amount of regrowth, known as “green pick”. Some introduced pasture species; particularly the perennial grasses, have the same survival mechanism as the native perennial grasses, storing nutrients and energy in their roots.
For both native and perennial grasses, it is best to only graze lightly after burning to lower the stress on the individual plants and help them survive the dry season.
Introduced legumes such as Leucaena and Shrubby stylo will produce fresh green shoots at ground level following burning. As with the grasses it is best to graze this regrowth lightly. With other introduced legumes such as Amiga, Verano and Wynn cassia the plants are killed by the fire, but they can re-establish from soil seed banks during the next wet season. These legumes can have massive recruitment events following a fire because the heat of the fire breaks down their dormant hard seed.
For more information
Arthur Cameron, Principal Pastures Agronomist. Darwin.
Phone: 08 8999 2214