Modelling suggests some hope for rotational grazing in the future
By Robyn Cowley and Dionne Walsh, NT Department of Primary Industry and Resources
Short-term studies are always limited by the seasons experienced and brief time frame. Pasture can take a very long time to recover from long term heavy grazing. For example in the VRD, recovery on degraded areas in the Ord River Regeneration Project and on Kidman Springs took around 30 years.
We used a pasture growth model to look gaze into the future to see if rotational grazing combined with wet season spelling at Beetaloo might promote vegetation recovery, and how long that might take.
The model predicted:
- crash grazing during the wet or growing season led to land condition decline
- wet season spelling followed by crash grazing during the dry season usually improved land condition
- land condition also improved if wet season spelled then continuously grazed
- the time for land condition recovery with wet season spelling combined with cell or continuous grazing was around 15 years, but depended on stocking rates
- the lower the stocking rate, the faster the recovery
- the rate of pasture recovery was slightly faster if rotationally grazed rather than continuously grazed after a wet season spell.
In summary: Be very careful about crash grazing during the growing/wet season. It could cause further pasture damage.
Wet season spelling combined with rotational or continuous grazing in the dry season may lead to land condition improvement.
But land condition change takes time. Don’t assume that rotational grazing will lead to rapid recovery. And getting your stocking rates right is still important!
How to get the most from your wet season spell – lessons from Pigeon Hole
A full wet season spell gives the best results for palatable perennial grasses.
Spell until perennial grasses are dormant if you want to increase them.
In the dry season aim to graze 20% of the total pasture weight, or 30% of the pasture height. Because animals don’t graze all plants equally, eating 20% of all the pasture usually results in 50% utilisation of the preferred plants.
Last updated: 20 September 2019